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Table of Content

25 October 2014, Volume 35 Issue 20
Processing Technology
Enzymatic Hydrolysis of Dark Muscle from Yellowfin Tuna (Thunnus albacares) and Nutritional Evaluation of Hydrolysates
LIU Jian-hua1, WANG Bin1, KUAI Peng2, CAI Yan-ping1, DING Yu-ting1,*
2014, 35(20):  1-5.  doi:10.7506/spkx1002-6630-201420001
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This study investigated the preparation of protein hydrolysates from dark muscle from yellowfin tuna as an edible
fish by-product with trypsin. By using orthogonal array design, the optimal enzymatic hydrolysis conditions were determined
as 2 400 U/g, 8.0, 55 ℃, and 6 h for enzyme dosage, initial pH, temperature, and hydrolysis time, respectively, resulting in a
degree of hydrolysis (DH) of (19.89±0.10)% and a nitrogen recovery of (64.88±0.72)%. The molecular weight distribution
of the hydrolysate as determined by high performance liquid chromatography (HPLC) suggested that significant degradation
of macromolecular proteins produced the hydrolysate mostly consisting of oligopeptides below 3 kD with molecules less
than 1 kD accounting for the majority (79.23%) of the total oligopeptides. The hydrolysate contained all the common amino
acids and was rich in eight essential amino acids (accounting for 42.38% of the total amino acids), and thus could be used as
a nutritional supplement.

Optimization of Insoluble Dietary Fiber Extraction from Apricot Kernel Skin and Its Physicochemical Characteristics
SHEN Hui1, FAN Xue-hui1, ZHANG Qing-an1,2,*, LI Yu-mei1
2014, 35(20):  6-10.  doi:10.7506/spkx1002-6630-201420002
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The extraction conditions of insoluble dietary fiber (IDF) from apricot kernel skins were optimized using
response surface methodology by modeling extraction yield with respect to three variables including alkali concentration,
ultrasonication time and extraction temperature. Furthermore, factors affecting the water-holding capacity and swelling
capacity of IDF were also studied. The results showed that the optimal extraction conditions were as follows: sodium
hydroxide concentration, 0.70 mol/L; ultrasound-assisted extraction time, 51 min; and extraction temperature, 86 ℃. The
extraction yield of IDF was 49.73% under these conditions. In addition, this study found that the water-holding capacity and
swelling capacity of the IDF were affected less by glucose concentration, but significantly by pH and temperature within the
investigated ranges.

Optimization of Physical Force-Assisted Alkaline Extraction of Rice Bran Protein
XU Feng1, WANG Chang-yuan1,2,*
2014, 35(20):  11-16.  doi:10.7506/spkx1002-6630-201420003
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This study comparatively evaluated the efficiencies of alkaline extraction, colloid milling-assisted alkaline
extraction, ultrasonic-assisted alkaline extraction, and colloid milling, ultrasonic-assisted extraction for the extraction of
rice bran protein (RBP) with respect to RBP yield and purity. It was shown that a significantly increased extraction yield
and a RBP purity of 74.27% were obtained by the colloid milling, ultrasonic-assisted extraction method. In this method,
the extraction parameters ultrasonic power, solid-to-solvent ratio, temperature and extraction time were optimized by
response surface methodology using the Design Expert 8.0.6. The optimum extraction conditions for maximizing RBP
yield were determined as 40 mesh, 9, 69 W, 4 s, 2 s, 20:1 (mL/g), 40 min and 46 ℃ for rice bran granularity, pH, ultrasonic
power, working time, intermittent time, solid-to-solvent ratio, ultrasonication time and extraction temperature, respectively.
The predicted extraction yield of RBP was 92.14%, agreeing with the experimental value (90.84%). The colloid milling,
ultrasonic-assisted extraction method could significantly increase the extraction yield of RBP and shorten the extraction time
and thus could provide a foundation for for further study of rice bran protein.

Optimization of Removal of Hexavalent Chromium from Aqueous Solution by Adsorption onto Squid Ink Melanin Using Response Surface Methodology
WEI Rong-bian1, LU Ting-ting2, WANG Yang-guang2, SONG Ru2,*
2014, 35(20):  17-21.  doi:10.7506/spkx1002-6630-201420004
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In the present study, squid (Ommastrephes bartrami) melanin was employed to adsorb Cr(Ⅵ) in aqueous
solutions. Three adsorption conditions (temperature, time and pH) for Cr(Ⅵ) onto squid melanin powder with a granularity of
90 mesh at a concentration of 15 mg/mL were optimized by response surface methodology based on a Box-Behnken model.
The observed removal rate of total chromium ions was 64.86% under the optimal adsorption conditions: 35 ℃, 90 min
and pH 5.2. Scanning electron microscopy (SEM) demonstrated massive aggregation of the spherical granules of squid
melanin upon adsorption of Cr(Ⅵ). Fourier transform infrared (FT-IR) spectroscopy revealed that hydroxyl, amino and
amide groups were the potential binding sites for chromium ions.

Extraction and Characterization of Walnut (Juglans regia) Kernel Lectin
JI Ai-qing1, HAN Hong-yan1, YANG Hong-yan2, WU Guo-liang3
2014, 35(20):  22-25.  doi:10.7506/spkx1002-6630-201420005
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The aim of this study was to investigate the extraction conditions and some characteristics of lectin from walnut(Juglans regia) kernel. The results indicated that the agglutinating activity (Aa) could accurately reflect blood agglutinationefficiency. Crude lectin with strong hemagglutination activity was obtained from walnut kernel by extraction with phosphate buffer solution (PBS) at pH 7.4 for 24 h followed by fractional precipitation with 70% (NH4)2SO4. The lectin could agglutinate A, B, O and AB types of red blood cells without blood type specificity. The hemagglutination activity could be inhibited by saccharide derivatives, but not by monose or oligose. The lectin from walnut kernel was temperature-insensitive,and showed a broad reaction pH range (5.0–8.0). Thehemagglutination activity of walnut kernel lectin from Baokexiang cultivar was the strongest among five tested walnut cultivars, which showed an Aa of 0.478.

Preparation of Peanut Protein Isolate from Low-Temperature Peanut Meal, a Byproduct from Cold-Pressed Peanut Oil Production and Its Stability in Beverage
WANG Ying1,2, WANG Ying-yao2,*, LIU Jian-xue1, FANG Bing2, LI Ju-fang2
2014, 35(20):  26-30.  doi:10.7506/spkx1002-6630-201420006
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Alkaline extraction and subsequent acid precipitation were employed to produce peanut protein isolate from lowtemperature
peanut meal as a byproduct from the production of cold-pressed peanut oil, and the preparation process was
investigated. The results showed that when the extraction process was carried out at 55 ℃ for 2.5 h at an alkali pH of 9.5
with a solid-to-solvent ratio of 1:11 (g/mL), the maximum extraction yield of 90.25% was obtained. SDS-PAGE analysis
indicated that electrophoretic bands of the peanut protein isolate were consistent with the typical bands of peanut proteins.
Then, some functional properties including nitrogen solubility index (NSI), emulsifying activity and emulsion stability of
this protein isolate were analyzed. Particle size analysis showed that the average particle size D[4,3] was 4.31 μm, and the
slope for dynamic particle change, as checked by a stability analyzer, was 26.66%/h. The beverage prepared from the peanut
protein isolate had a significant stability. This study may provide a new direction for the value-added utilization of peanut
meal protein.

Response Surface Methodology to Optimize the Extraction Process of Mung Bean Lectin
HUANG Ze-hua1, WANG Qian-wen1, ZHANG He1, LI Yu-nan1, LI Qing-bo1, CAO Long-kui1,2,*
2014, 35(20):  31-36.  doi:10.7506/spkx1002-6630-201420007
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The experiment was designed to use erythrocytes for assaying the agglutinating activity of mung bean lectin,
and to improve the processing conditions for glutaraldehyde- and trypsin-treated rabbit red blood cells. Rabbit red blood
cells (RBC) were fixed with 0.15% (V/V) glutaraldehyde at 25 ℃ for 20 min, and the RBC were treated with trypsin
(25 U/mL) at 25 ℃ for 15 min to increase the assay activity and extend their preservation time. In the investigation, we
found that the most suitable extraction solvent for mung bean lectin was phosphate buffer solution. Based on the results of
single-factor experiments, a Box-Behnken design (BBD) of three variables at three levels each was carried out to obtain
maximum activity of mung bean lectin by response surface analysis. The maximum activity of mung bean lectin was
predicted to be 134.91 U/mg and observed to be 139.02 U/mg under the optimum extraction conditions: solid-to-liquid ratio,
1:9.09 (g/mL); NaCl concentration, 0.3 mol/L; and extraction time, 4.16 h.

Optimization of Complex Biopreservatives to Improve Quality Preservation of Pomfret Fillet by Response Surface Methodology
SHI Jian-bing, XIE Jing*, GAO Zhi-li, SU Hui, WU Yan, ZHANG Fu-yu
2014, 35(20):  37-42.  doi:10.7506/spkx1002-6630-201420008
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The purpose of this study was to optimize complex preservatives consisting of tea polyphenols, lysozyme and
chitosan using response surface methodology based on Box-Behnken experimental design to improve quality preservation
of pomfret fillets and prolong their shelf life. A quadratic polynomial regression model was established with total volatile
basic nitrogen (TVB-N) as the response value. The results indicated that the best formulation of complex preservative was
composed of 1.35% tea polyphenols, 0.054% lysozyme and 1.38% (m/m) chitosan by analysis of variance and regression
fitting. Tea polyphenols and chitosan, as well as lysozyme and chitosan had a significant interactive effect on the quality
of pomfret fillets during storage (P < 0.05). TVB-N, aerobic plate count (APC), thiobarbituric acid (TBA), trimethylamine
(TMA), pH and K value of pomfret fillets treated with the optimized complex preservative were determined and their sensory
scores were evaluated during storage at 4 ℃. The results showed that the optimal complex preservative could significantly
reduce the contents of TVB-N, TBA and TMA, and inhabit the growth of microorganisms (P < 0.05). Hence the complex
preservative could effectively delay the deterioration of pomfret fillets, prolonging the shelf life to 12 days compared to 5–6
days for the control group.

Optimization of Purification of Diacylglycerol by Molecular Distillation and Characterization of Purified Product
ZHU Zhen-lei1, CAO Li-li1,2, JIANG Shao-tong1,2, PAN Li-jun1,2,*
2014, 35(20):  43-47.  doi:10.7506/spkx1002-6630-201420009
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This study aimed to obtain a diacylgcerol (DAG) product with high purity. Molecular distillation was used
in deacidification and purification of DAG prepared by enzymatic synthesis. The effects of dripping speed, distillation
temperature and rotation speed on the molecular distillation were investigated. Based on single factor experiments,
the molecular distillation conditions were optimized by orthogonal array design as follows: dripping speed, 2 mL/min;
distillation temperature, 170 ℃; and rotation speed, 300 r/min. Under these optimal conditions, the purity of DAG was
72.51%. After a two-step molecular distillation under the same conditions, the purity of DAG was 92.31% with an acid value
of 0.97 mg KOH/g. Compared with soybean salad oil, the purified DAG had some advantages including higher stearic acid
content, higher stability, and lower iodine value, saponification value and peroxide value.

Preparation and of Gelatin Microspheres and Their Adsorption Capacity for Polyphenols
LIU Xiao-xiao1, LIU Bin1,2, KAI Tuo1, ZHANG Guang-feng1, YANG Xiao1, CHEN Xiang-gui1,*
2014, 35(20):  48-51.  doi:10.7506/spkx1002-6630-201420010
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Gelatin microspheres were prepared by an emulsification technique and characterized with microscope and
scanning electron microscope. The adsorption and desorption of various polyphenols by gelatin microspheres was
investigated, and the reusability of the microspheres was also evaluated. The results showed that when the adsorption was
carried out at 35 ℃ and pH 3.5 for 120 min, gelatin microspheres exhibited good adsorption efficiency for epigallocatechin
gallate (EGCG), punicalagins and proanthocyanidins, but demonstrated a weak adsorption for chlorogenic acid. After being
treated by distilled water at 80 ℃ for 120 min, the adsorbed polyphenols could be released effectively. When the mass
ratio of polyphenols to microspheres was 5:1, the adsorption rates of the other polyphenols except chlorogenic acid were
54%–78% with the amount of polyphenols adsorbed by per unit mass of the microspheres being 107–156 μg/mg, and the
desorption rates of the adsorbed polyphenols were 60%–75%. Moreover, the adsorption and desorption rates for EGCG
remained at over 55% after fifth repeated reuse of the microspheres, but sharply declined after eighth reuse. This study
reveals that the gelatin microspheres can be potentially applied to remove and recover polyphenols in foods.

Effect of Steeping Conditions on β-Glucan Content and in vitro Protein Digestibility of Germinating Oats
MIN Wei, JIAO Ying-shen, LIU Fan, LI Ju-xiu*
2014, 35(20):  52-56.  doi:10.7506/spkx1002-6630-201420011
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In this work, we used single factor and orthogonal array designs to investigate the effects of steeping conditions
including temperature, depth and time on β-glucan content and in vitro protein digestibility (IVPD) of germinating naked
oats. It was demonstrated that both steeping depth and time had no significant impact on β-glucan content of geminating
oats, but a more obvious decrease in β-glucan content was observed with an increase of steeping temperature. IVPD value
decreased with increasing steeping depth, but increased with increasing steeping time. The results of orthogonal array design
suggested that the optimum steeping conditions were established as follows: steeping (11 ℃ for 16 h in total) for 4 h and airrest
for 8 h with a steeping depth of 15 mm, under which IVPD value was increased by 58.02%, and β-glucan content was
decreased by 8.60%.

Optimization of the Preparation of Tea-Flower Daqu, a Starter Culture for Chinese Liquor
BAI Rui1, JIANG Jun1,2,*, XIANG Fei1, YANG Huan1, LI Wei1, LI Da-xiang1,*
2014, 35(20):  57-61.  doi:10.7506/spkx1002-6630-201420012
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A novel starter culture (daqu in Chinese) for Chinese liquor was made by the traditional procedure from wheat
added with tea flower and mother daqu. The manufacturing process was optimized by orthogonal array design. The surface
of tea-flower daqu made by culturing wheat with 2.0 g/100 g tea flower, 3.0 g/100 g mother daqu and 45 mL/100 g water
added for 25 d was covered with uniform white mycelia without splits and with a sharp cross-section. It also had obvious
burning circles and a strong daqu fragrance without off-odor. The tea-flower daqu had a moisture content of 12.5% and
an acidity of 0.9. The power of saccharification, liquefaction and fermentation were 816.5 mg/(g·h), 1.1 g/(g·h), and
57 g CO2/(100 g·48 h), respectively. The numbers of mold, yeast and bacteria in the daqu were 9.8×106, 9.4×105 and
5.7×106 CFU/g, respectively. Under the same fermentation conditions, the tea-flower daqu resulted in higher contents of
volatile aroma compounds in Chinese liquor than the traditional daqu.

Preparation and Antibacterial Effect of Chlorogenic Acid Nanoliposome
XU Xian-zhu, WEI Yun, RAO Hua, WANG Man-ying*
2014, 35(20):  62-66.  doi:10.7506/spkx1002-6630-201420013
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Objective: To investigate the preparation and antibacterial effect of chlorogenic acid (CA) nanoliposome.
Methods: CA nanoliposomes were prepared by film-ultrasonic dispersion method and the products were characterized with
scanning electron microscopy (SEM) and particle size analyzer. The effects of cholesterol/lecithin mass ratio, CA/film
(lecithin + cholesterol) mass ratio and ultrasonication time on the encapsulation efficiency of liposomes were investigated.
Finally, the stability and the bacteriostasis ability of the prepared liposomes were evaluated. Results: Oval-shaped liposomes
were prepared by ultrasonication for 15 min at a cholesterol/lecithin mass ratio of 1:8 and a CA/film ratio of 1:10, which
showed regular morphology, a particle size of approximately 110 nm in diameter, good dispersity, an encapsulation
efficiency of up to 87.5%, and a drug loading of up to 36%. UV spectroscopy showed that CA was encapsulated successfully
into nanoliposomes. In vitro test showed that the drug could be sustained-released from liposomes without a burst release
and with stability for 24 h and 14 days. Comparing with CA and tetracycline, the nanoliposomes had better bacteriostasis
ability. Conclusion: CA nanoliposomes prepared by film-ultrasonic dispersion method have a regular shape, good dispersion
ability and persistent antibacterial ability.

Mechanical Shaking Extraction and Antioxidant Activity of Anthocyanins from Rubus coreanus Maq. Fruits
JIANG Hua-mei1, SHI Deng-hong2, WANG Xiang-qian3, GOU Xian-mei1, YIN Liang-ping1, YANG Guang-qin1
2014, 35(20):  67-72.  doi:10.7506/spkx1002-6630-201420014
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Mechanical shaking extraction with ethanol was applied to extract anthocyanins from the fruits of Rubus coreanus
Maq., and the optimal extraction conditions were determined by orthogonal array design. An extraction temperature of 50 ℃
and 1 h extraction repeated twice using a 30-fold volume of 85% ethanol aqueous solution containing hydrochloric acid
(pH 3) as the extraction solvent provided optimum extraction of anthocyanins. An anthocyanin yield of 211.05 mg/100 g
was achieved. In addition, the anthocyanins from fresh fruits of Rubus coreanus Maq. were evaluated for their antioxidant
activity. It was found that the anthocyanins displayed dose-dependent reducing power and strong abilities to scavenge
hydroxyl, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free
radicals in decreasing order with linear concentration dependence in the concentration range investigated here. The IC50
values for hydroxyl, DPPH and ABTS free radicals were 1.71, 2.27 and 3.44 μg/mL, respectively, indicating much higher free
radical scavenging activity than VC and BHT as positive controls. These results demonstrate that anthocyanins from Rubus
coreanus Maq. possess potent antioxidant activity and thus deserve to be used as natural antioxidants and functional foods.

Effect of Modification with Ferulic Acid on Properties of Collagen-Chitosan Edible Films
CHEN Da-jia, ZHAO Li*, YUAN Mei-lan, SU Wei, LIU Hua
2014, 35(20):  73-78.  doi:10.7506/spkx1002-6630-201420015
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The aim of this work was to develop composite edible film based on Amiurus nebulosus skin collagen and
chitosan using ferulic acid to modify functional properties of the composite film. The effects of ferulic acid concentration,
temperature and heating time on the water vapor permeability and mechanical properties of the edible film were investigated
by using an orthogonal array design. The results showed that all the investigated variables could affect significantly the
properties of the films. The tensile strength, elongation at break, water vapor permeability, solubility, and light transmittance
of the composite film prepared by adding 2% ferulic acid and heating at 70 ℃ for 30 min were (24.72 ± 0.86) MPa,
(102.99 ± 1.58)%, (0.25 ± 0.01) (g·mm)/(h·m2·kPa), (27.96 ± 0.76)%, and (84.1 ± 0.9)%, respectively.

Ultrasonic-Assisted Enzymatic Extraction and Antimicrobial Activity of Sweet Corncob Flavonoids
LIU Xiao-fei, LIU Ning, ZHANG Na, JING Li-rong, YU Zi-bing, MA Yong-qiang
2014, 35(20):  79-82.  doi:10.7506/spkx1002-6630-201420016
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Flavonoids were extracted by ultrasonic-assisted enzymatic hydrolysis of sweet corncobs using cellulase and the
optimal extraction conditions were established by orthogonal array design. An ultrasonication time of 20 min followed by
enzymatic hydrolysis at 55 ℃ and pH 4.8 for 1.5 h with an enzyme dosage of 0.008 g/2.0 g substrate provided maximum
extraction yield of 0.318%. The flavonoids extracted from sweet corncobs had significant antibacterial activity against white
Staphylococcus, Escherichia coli and Bacillus subtilis. The minimum inhibitory concentrations were 0.5, 0.25 and 2 mg/mL
respectively.

Optimization of Ultrasound-Assisted Extraction of Tartaric Acid from Wine Lees
QU Hui-ge, SONG Jian-qiang, ZHANG Ming
2014, 35(20):  83-87.  doi:10.7506/spkx1002-6630-201420017
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The ultrasound-assisted extraction of tartaric acid from wine lees using sulfuric acid as the extraction solvent was
optimized by single factor and orthogonal array designs to obtain higher tartaric acid yield. Analysis of the experimental
data was carried out using SPSS 21 software. The results showed that ultrasound enhanced the extraction of tartaric acid
with sulfuric acid. The ultrasonic treatment time had the greatest impact on tartaric acid yield, followed in decreasing order
by ultrasonic power, extraction temperature and extraction time. The optimal extraction parameters were determined as
1:3, 0.06 mol/L, 500 W, 6 min, 75–80 ℃, and 15–20 min formaterial-to-liquid ratio, sulfuric acid concentration, ultrasonic
treatment power, ultrasonic treatment time, extraction temperature, and extraction duration, respectively. Experiments
carried out under these optimal conditions led to an extraction yield of 74 g/kg .

Preparation and Antioxidant Activity of Xylooligosaccharides from Wheat Straw by Enzymatic Hydrolysis with Xylanase
TIAN Long1,2, WANG Yun1, MA Xiao-jian2
2014, 35(20):  88-92.  doi:10.7506/spkx1002-6630-201420018
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The enzymatic hydrolysis of wheat straw for preparing xylooligosaccharides using xylanase was optimized using
an orthogonal array design, and the xylooligosaccharides obtained were assessed for antioxidant activity. A hydrolysis
temperature and 4 h hydrolysis at an enzyme concentration of 3 g/L and a substrate concentration of 70 g/L with an
initial pH of 6.0 proved optimal for the preparation of xylooligosaccharides. The optimized conditions yielded 9.5 g/L
of reducing sugar and 26.3 g/L of soluble sugar in the product with an average degree of polymerization of 2.77. The
xylooligosaccharides showed dose-dependent radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH),
hydroxyl and superoxide anion radicals.

Optimization of Extraction Parameters and Simultaneous Determination of Free Amino Acids in Milk Powder
JIALIEXI·Manafu1, DENA·Turehan2, LI Jun-fang1
2014, 35(20):  93-97.  doi:10.7506/spkx1002-6630-201420019
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Three variables (operating parameters) affecting the extraction efficiency of free amino acids from milk powder,
solid-to-solvent ratio, zinc sulfate concentration (for protein precipitation), and centrifugation time, were optimized by
response surface analysis (RSA) based on a Box-Behnken design. Simultaneous determination of mixed free amino acids
and free amino acids in milk powder samples was performed by visible spectrophotometry combined with partial least
square (PLS). The results showed that under the optimal conditions: solid-to-solvent ratio, 1:3.02 (g/mL); zinc sulfate
concentration, 10.23%; and centrifugation time, 6.79 min, the extraction yield was 170 μg/g. The complexation of copper
sulfate with glycine, glutamic acid, valine and phenylalanine resulted in highly overlapping absorption spectra when mixed
together, which made it difficult to simultaneously determine the individual components. The simultaneous determination of
mixed free amino acids using PLS demonstrated that the recovery rate was 98.2%–99.2% and the relative prediction error
(RPE) was 1.7%–2.9%.

Optimization of Microwave-Assisted Extraction of Seed Oil from Salicornia bigenlovii Torr. Using Response Surface Methodology
FU Qing-quan
2014, 35(20):  98-104.  doi:10.7506/spkx1002-6630-201420020
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The microwave-assisted extraction of seed oil from Salicornia bigenlovii Torr. using petroleum ether as the
extraction solvent was optimized by response surface methodology. The extraction yield of seed oil was investigated with
respect to extraction temperature, extraction time, solid-to-liquid ratio, and microwave power. The results showed that the
optimal extraction conditions for Salicornia bigenlovii Torr. seed oil were as follows: temperature, 55 ℃; extraction time,
5 min; solid-to-liquid ratio, 1:10 (g/mL); and microwave power, 700 W. Under these optimal conditions, the extraction yield
of Salicornia bigenlovii Torr. seed oil was 32.58%, a 0.15% increase over that obtained by traditional Soxhlet extraction.
Moreover, the extraction time was only 1.39% of that required by Soxhlet extraction.

Analysis & Detection
Determination of Four Fat-Soluble Vitamins in Vitamin Tablets by Pressurized Capillary Electrochromatography with UV Detection
ZHENG Shu1, SHI Wen-jun1, WANG Xiao-xi1, LI Jing2, GU Xue1, YAN Chao1,*
2014, 35(20):  105-109.  doi:10.7506/spkx1002-6630-201420021
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An effective, convenient and fast method for the analysis of fat-soluble vitamins in vitamin tablets was developed
using pressurized capillary electrochromatography (pCEC) with ultra violet (UV) detection. The separations was performed
on a reversed-phase C18 capillary column with a certain detection wavelength-time program. The mobile phase was 95%
(V/V) methanol containing 0.05% TFA (pH 3.3) at a flow rate of 0.2 mL/min with a separation voltage of 15 kV. Four fatsoluble
vitamins (vitamin A, vitamin D3, vitamin E, and vitamin K3) were baseline separated within 5 min in an isocratic
pCEC mode. The detection limits for vitamin A, vitamin D3, vitamin E, and vitamin K3 (RSN = 3) were 1.5, 3.0, 15 and
1.5 μg/mL with good linearity, respectively. The interference on the analysis of vitamin tablets was effectively eliminated.
The recoveries of spiked fat-soluble vitamin samples were 90.0%–110.0% with RSD ranging from 0.53% to 5.46%. This
method is simple, rapid, repeatable and accurate.

Application of LF-NMR for Detection of Sesame Oil Adulteration
SHAO Xiao-long1,2, ZHANG Lan-yue1, FENG Suo-lan1
2014, 35(20):  110-113.  doi:10.7506/spkx1002-6630-201420022
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To evaluate the ability of low field nuclear magnetic resonance (LF-NMR) in detecting oil adulteration, LF-NMR
and principal component analysis (PCA) were applied jointly to discriminate pure soybean oil from pure sesame oils (refined,
cold pressed and hot pressed), and partial least squares (PLS) regression was applied to analyze three sesame oils adulterated
with soybean oil and mixtures of two different sesame oils. The results showed that transverse relaxation time (0 to 900 ms)
was an important signal region for discrimination of oil samples. LF-NMR could completely distinguish four different pure
oil samples. The limit of detection (LOD) for sesame oil adulteration with soybean oil was 5% to 10%, and the LOD for
refined sesame oil adulteration with cold or hot pressed sesame oil was 10% to 20%. Therefore, LF-NMR can be used as a
rapid screening method to detect adulteration of oil.

Determination of Six Organic Acids in Yongchuan Douchi, a Chinese Traditional Fermented Soybean Product, by HPLC
YE Xiu-juan1, ZHENG Jiong1,2,*, SUO Hua-yi1,2, KAN Jian-quan1,2
2014, 35(20):  114-118.  doi:10.7506/spkx1002-6630-201420023
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A high performance liquid chromatographic (HPLC) method was established for the simultaneous determination
of organic acids in Yongchuan douchi, a Chinese traditional fermented soybean product. The optimal chromatographic
conditions were determined. An Agilent ZORBAX SB-Aq (4.6 mm × 250 mm, 5 μm) column was used to separate the
organic acids. The mobile phase was a mixture of 0.01 mol/L (NH4)2HPO4 (pH 2.5) and methanol solution at a flow rate of
0.6 mL/min. The column temperature and UV detection wavelength were set as 30 ℃ and 220 nm, respectively. The six
organic acids were successfully separated and determined under the chosen experimental conditions. The calibration curves
for all these organic acids displayed a good linear relationship with correlation coefficients above 0.999 9 and precision
relative standard deviations (RSDs) of 0.07%–0.36% (n = 5) and repeatability RSD of 0.97%–3.04% (n = 5). The recovery
rates of the six organic acids were in the range of 94.89%–104.28%. The method is convenient, rapid, accurate, reproducible
and applicable to determine organic acids in Yongchuan douchi.

An Organic Phase Horseradish Peroxidase Sensor Based on Nanomaterials for the Determination of Peroxide Value in Vegetable Oils
WANG Li-ran, ZHANG Yuan-yuan, LI Shu-guo*
2014, 35(20):  119-125.  doi:10.7506/spkx1002-6630-201420024
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An organic phase chitosan-ferrocene horseradish peroxidase multiwalled carbon nanotubes (CS-FC/HRP/
MWCNTs) enzyme sensor for the determination of peroxide value of vegetable oils was studied. The catalytic effect of
CS-FC/HRP/MWCNTs enzyme sensor on the electrochemical reduction of lipid hydroperoxide in organic phase was
investigated by cyclic voltammetry. The mechanism of the redox process of lauroyl peroxide and HRP was expounded.
The electrode process of CS-FC/HRP/MWCNTs enzyme-based sensor was typically controlled by the electrochemical
reaction on the electrode surface, instead of the diffusion of HRP protein. The micro-grid structure in three dimensions
which facilitated electrocatalytic reaction of enzyme sensor was observed by scanning electron microscopy technique (SEM).
The increase in catalytic reduction current of lauroyl peroxide at the CS-FC/HRP/MWCNTs enzyme sensor was linearly
correlated with substrate concentration in the range of 2.5 × 10-6 -3.0 × 10-5 mol/L (y = 0.108 5x – 0.354 8, R2 = 0.992 3).
Meanwhile, the limit of detection of this enzyme sensor was 2.0 × 10-7 mol/L (RSN = 3). The developed method was applied
to the determination of peroxide value of soybean oil and grapeseed oil, and the results well agreed with those obtained by
the classical iodometric titration method. Being more precise and accurate than iodometric titration method, it is a practical
method for rapid determination of peroxide value in vegetable oils.

Flavor Compounds of Fresh and Deodorized Grass Carps as Determined by Electronic Nose Combined with GC-MS
CUI Fang-chao1, LI Ting-ting2, YANG Bing1, LIU Ying1, LI Jian-rong1,*, LI Hong-jun3, LI Min-zhen4
2014, 35(20):  126-130.  doi:10.7506/spkx1002-6630-201420025
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Grass carp muscles were deodorized by using citric acid, yeast or NaHCO3. The volatile compounds in
undeodorized and deodorized fish meats were identified by electronic nose and head-space solid-phase microextraction
coupled with gas chromatography and mass spectrometry (HS-SPME-GC-MS). The results revealed that electronic nose
could discriminate among undeodorized and deodorized fish meats by flavor characteristics. Principal component analysis
(PCA) showed that the apparent difference among undeodorized and deodorized samples could be well discriminated by
electronic nose. Meanwhile, GC-MS analysis showed that 35, 20, 21, and 29 volatile compounds were identified in fresh
meat and samples deodorized with citric acid, NaHCO3 and yeast, respectively. Moreover, the deodorized samples were less
rich in volatile compounds, and citric acid resulted in the most significant reduction in the number of volatile compounds
and peak area, followed in decreasing order by NaHCO3 and yeast. The GC-MS results were consistent with those from
electronic nose.

Determination of Total Number of Colonies by Fluorescence Labeling Method
ZHANG Yong-shuai, SUN Jun-liang*, LIANG Xin-hong, LI Yuan-zhao
2014, 35(20):  131-134.  doi:10.7506/spkx1002-6630-201420026
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After complete disruption of the microbial cell wall with thymol, the nucleic acids or DNAs were labeled with
propidium iodide for the detection of fluorescence values. A standard curve was established for extrapolating total number
of colonies based on the fluorescence values. The results showed that the optimal thymol concentration for breaking the
microbial cell wall was 4 mmol/L. The relative standard deviation of this method for the determination of the fluorescence of
B. subtilis colonies was 1.29%, and the recovery rate was 98.4%. This method is accurate, reliable, simple and rapid without
the use of a large amount of plates.

Determination of Inorganic Elements in Different Parts of Hop Plant (Humulus lupulus) by Using ICP-MS
WANG Yao1,2, MU Shu-yong2, LIU Yu-mei1,*
2014, 35(20):  135-138.  doi:10.7506/spkx1002-6630-201420027
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A method based on wet digestion and inductively coupled plasma-mass spectrometry (ICP-MS) was established
for simultaneous determination of fourteen inorganic elements (Al, Pb, As, Cd, Ba, Ni, Mn, Cu, Sr, Co, Cr, Zn, Li, and V)
in different parts of the hop plant (Humulus lupulus). The linear correlative coefficients for all the elements were higher than
0.999, the three multiplied detection limits (3MDLT) were between 0.12 and 2.16 μg/L, and the precision values expressed
as relative standard deviations (RSDs) were less than 5%. The spiked recovery rates were between 87.35% and 106.88%.
In conclusion, the method was accurate and reliable. As determined by this method, there were no significant differences in
the contents of the 14 inorganic elements among 3 hop cultivars (Marco Polo, SA-1 and Tsingdao Flower). This method was
used to investigate the distribution of essential elements in different parts of the plant during the growth process.

Analysis of Novel Compound ZJ3757 Using High Performance Liquid Chromatography
ZHOU Hong-xia1, HUA Chun1, TANG Hui-min2
2014, 35(20):  139-142.  doi:10.7506/spkx1002-6630-201420028
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A high performance liquid chromatography (HPLC) method for the quantitative and qualitative analysis of
ZJ3757, an insecticide suspension, was established using a C18 column as the stationary phase, methanol and water as the
mobile phase, and UV detection at 250 nm. Results showed that the recovery of spiked samples was 97.1%–105.6% with
relative standard derivation (RSD) of 0.27%, and the linear correlation coefficient was 0.999 8.

PCR-DGGE Analysis of Dominant Bacterial Populations on the Surface of Grass Carp Meat under Different Packaging Conditions
TU Zong-cai1,2, MA Da1, WANG Hui1, SHI Yan1, SHA Xiao-mei1, HUANG Xiao-qin2
2014, 35(20):  143-147.  doi:10.7506/spkx1002-6630-201420029
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Changes in dominant bacterial populations (DBP) on the surface of grass carp meat packaged under three
different atmospheric conditions (air, vacuum and modified atmosphere packaging environment) and then irradiated by Co-
60 gamma ray at six different doses (0, 2, 4, 6, 8, and 10 kGy) after subsequent storage at 4 ℃ for 18 days were investigated
by polymerase chain reaction-denaturing gradient gel electrophoresis analysis (PCR-DGGE). The bacteria on the surface
of fish meat samples were washed and collected, and their DNA was then extracted. The V3 variable region of 16S rDNA
was amplified with PCR. Identification of DBP was performed with DGGE. The amounts and species composition of
DBP varied with the type of packaging. Pseudomonas sp. was dominant on all fish samples. Lactic acid bacteria and Serratia sp.
were also dominant on air-packaged samples, and Serratia sp. was inhibited when the irradiation rose was more than
8 kGy. Pseudomonas sp., Serratia sp., Brochothrix thermosphact, and Yersinia sp. were identified as the dominant bacteria
on vacuum-packaged samples; Serratia sp. was inhibited when the irradiation dose was above 6 kGy, Yersinia sp. could
be inhibited even when the irradiation dose exceeded 2 kGy, and B. thermosphact exhibited high irradiation resistance for
its occurrence even at doses of 6 and 8 kGy. For modified atmosphere packaged fish, the DPB were Pseudomonas sp. and
Lactobacillus sp.; however, lactic aci bacteria were dominant only when the irradiation dose was 2 or 8 kGy. In conclusion,
PCR-DGGE provides a good way to analyze dominant bacterial populations on the surface of grass carp meat.

Establishment of a Loop-Mediated Isothermal Amplification Method for Detection of Mustard Allergen in Foods
CHENG Jin-xia1,2, ZHOU Xi-cheng1, MA Dan1, LIU Li1, ZENG Jing1,*
2014, 35(20):  148-152.  doi:10.7506/spkx1002-6630-201420030
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Objective: A loop-mediated isothermal amplification (LAMP) method was established for the detection of
mustard allergen in foods and was compared with real-time polymerase chain reaction (RT-PCR). Methods: The Sin A1 gene
of Sinapis alba was used to design LAMP primers. The specificity and sensitivity of LAMP were compared with those of
RT-PCR. Results: The specificity of LAMP method was tested with 13 different crops. The results showed that the LAMP
method was highly specific to mustard. No cross-reaction was found. The limit of detection (LOD) for LAMP was 0.5%
in base-material addition test, which was consistent with that of the RT-PCR method. For 25 real food samples, the LAMP
results were consistent with the RT-PCR results. Conclusion: The LAMP method of established in this study was simple,
economical and reliable and could effectively reduce the detection time.

Effects of Different Curing Agents on Volatile Compounds of Chinese Fermented Sausages
CHEN Xiao, YU Xiang, WANG Yong-li, TANG Jing, ZHANG Jian-hao*
2014, 35(20):  153-157.  doi:10.7506/spkx1002-6630-201420031
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The volatile compounds in Chinese fermented sausages cured with three different curing agents (sodium nitrate,
sodium nitrite, and their combination) were extracted and analyzed by SPME-GC-MS, and the effects of these curing agents
on flavor compounds including those derived from branch-chain amino acids were explored. The results showed that the
curing agents affected the content of flavor compounds. Sodium nitrate contributed to the formation of flavor compounds
such as ethyl acetate, butanoic acid, 2-butanone, 2-pentanone, 2-heptanone, 1-hexanol, 1-pentanol, etc.

Development of Multiplex PCR Coupled with Liquid Bead Array for the Detection of Nine Genetically Modified Rice Events
HUANG Wen-sheng, FU Kai, DENG Ting-ting, LI Fu-wei, LIU Hao, CHEN Ying*
2014, 35(20):  158-163.  doi:10.7506/spkx1002-6630-201420032
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A multiplex PCR assay coupled with liquid bead array was developed for simultaneous identification of nine
genetically modified rice (Oryzae sativa) lines. Based on the junction sequences between host plant genome DNA and the
exogenous gene of the GM rice events (BT63, KF6, KF8, M12, KMD1, T1C-19, T2A-1, LL601, and LL62), the eventspecific
primers and probes were designed for each event. In addition, in order to reduce the number of PCR reactions, two
multiplex PCR systems were adopted and optimized by adjusting the concentration of each primer. Detection specificity was
provided by capture probes designed for each GMO rice event which were covalently attached to florescent coding beads.
The PCR amplicons were biotin-labeled and directly hybridized with the capture probes on the beads, and then the beads
were detected according to protocol of Bio-Rad. The sensitivity of the assay was evaluated and the results indicated that
the limit of detection was around 0.1% for 9 events. With improved detection efficiency and accuracy, the detection system
complied with the requirements of current regulations in EU, Japan and China for the thresholds for the labeling of GMO,
and could be applied in the enforcement of GM regulation in China.

Determination of Eight Saccharides in Teas by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry
WANG Chuan-pi, ZHU Li, LIU Xin*, ZHANG Ying-bin, ZHOU Su-juan
2014, 35(20):  164-169.  doi:10.7506/spkx1002-6630-201420033
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An ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed
for the qualitative and quantitative determination of eight saccharides including rhamnose, xylose, arabinose, fructose,
mannose, glucose, sucrose, and raffinose in teas. Samples were extracted with the assistance of ultrasound. The extract was
separated on a Waters Acquity BEH Aminde HPLC column (2.1 mm × 150 mm, 1.7 μm) using acetonitrile-water mixture
(each containing 0.1% ammonia) as the mobile phase. The electrospray ionization tandem quadrupole mass spectrometric
analysis was carried out in the negative ion mode using multiple reaction monitoring (MRM). The limits of detection were
0.01–0.54 mg/L and the linear ranges were 1.0–200.0 mg/L. The average recoveries were 80.2%–103.2% at spiked levels of
10.0 and 100.0 mg/L. The method was applied to analyze 20 tea samples including green tea, oolong tea, Pu’er tea and black
tea. Glucose, fructose, sucrose and raffinose were detected in most of the samples, and their contents were in the ranges of
0.39–17.64, 0.53–22.83, 2.07–40.70, and 0.57–14.67 g/kg, respectively. However, rhamnose, xylose, arabinose and mannose
were not detected in all the samples.

Simultaneous Determination of Four Mycotoxins in Citrus Fruits by Ultra Performance Liquid Chromatography- Electrospray Ionization Tandem Mass Spectrometry Combined with Modified QuEChERS
SHI Wen-jing1,2, ZHAO Qi-yang1, JIAO Bi-ning1,2,3,*
2014, 35(20):  170-174.  doi:10.7506/spkx1002-6630-201420034
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A method was developed for simultaneous determination of four mycotoxins (aletrnariol monomethyl ether,
tentoxin, alternariol, and citrinin) in citrus fruits using ultra-performance liquid chromatography-tandem mass spectrometry
combined with optimized QuEChERS. Samples were extracted with acetonitrile, salted out with anhydrous MgSO4 and
NaCl, cleaned up with C18 and then analyzed using UPLC-MS-MS in multiple reaction monitoring (MRM) mode with
electrospray ionization. The separation of the target mycotoxins was performed on an ACQUITY UPLC BEH C18 liquid
chromatography column through gradient elution using a mobile phase consisting of acetonitrile and 0.1% formic acid
aqueous solution and the matrix-matched external standard calibration was used for quantitation. This method had a good
linearity in the concentration range of 5.0–200 μg/L with correlation coefficients (R2) more than 0.992 7, and the limit of
detection of the established method was in the range of 0.2–0.7 μg/kg. The average recoveries of the four mycotoxins in
different matrixes (citrus pulp, peel and whole fruit) at three spiked levels ranged from 78.0% to 103.3%, with relative
standard deviations (RSDs) of 2.6%–10.6%. This method is simple, quick, accurate, sensitive, and suitable for the quick
confirmation and quantitative determination of the four mycotoxins in citrus fruits.

Determination of Boscalid and Pyraclostrobin in Mango by Ultra Performance Liquid Chromatography
TANG Yong-jiao1,2, YUAN Hong-qiu2, ZHU Zhu2, Lü Dai-zhu2,*
2014, 35(20):  175-179.  doi:10.7506/spkx1002-6630-201420035
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An ultra performance liquid chromatography (UPLC) method was established for the determination of boscalid
and pyraclostrobin in mango. Samples were extracted with acetonitrile, purified on NH2 column, and analyzed by gradient
elution using acetonitrile-water as the mobile phase. The residues were determined by dual-wavelength ultraviolet detector,
and quantified by an external standard method. An excellent linearity for boscalid and pyraclostrobin was observed in the
range of 0.10–4.00 μg/mL and 0.02–1.00 μg/mL with correlation coefficients higher than 0.999, respectively. The limit of
detection for both pesticides was 0.002 mg/kg. The average recovery rate for the pesticides from mongo at three spiked
concentrations was in the range of 76.00%–103.00% with relative standard deviations of 1.07%–13.28%.

2-DE Analysis of Whey Protein Extracted by Different Isoelectric Precipitations and Ultracentrifugation Methods from Cow Milk
CHEN Jing-ting1,2, BU Deng-pan1,3,4,*, MA Lu1, YANG Yong-xin1, LI Fa-di2
2014, 35(20):  180-184.  doi:10.7506/spkx1002-6630-201420036
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The objective of this study was to investigate the effect of extraction methods on two-dimensional electrophoresis (2-
DE) maps of whey proteome in cow milk and to explore an optimal extraction method. Samples were extracted from cow milk
by different isoelectric precipitations and ultracentrifugation methods. 2-DE maps were analyzed by PDQuest 8.0 software. The
results of 2-DE maps showed that milk whey protein could be effectively extracted by the above methods with less background,
no significant strips and good repeatability. However, there were still some residual caseins appearing in each map. 2-DE maps
of whey protein refined by isoelectric precipitations were relatively informative when compared with the gel maps obtained by
ultracentrifugation. Moreover, the richness of different whey proteins in various maps extracted by adjusting pH to 4.6 as isoelectric
point was slightly higher than adjusting pH to 4.8. The results indicated that adjusting pH to 4.6 as isoelectric point to extract whey
protein had some advantages than adjusting pH to 4.8 and ultracentrifugation. However, all the methods used in this study could
effectively remove high abundant casein to improve the detection sensitivity of low abundance proteins.

Quantitative Detection of Escherichia coli O157:H7 Based on Visual Antibody Macroarray Technology
LI Hao-lin1,2, LIU Qing2, LIU Fang3, DONG Qing-li2, QIU Shi2, YANG Yu-ping2, GUO Hui-qing4, HAN Shun-yu1,*
2014, 35(20):  185-191.  doi:10.7506/spkx1002-6630-201420037
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Purpose: To establish a new rapid quantitative assay for detecting Escherichia coli O157:H7. Methods: Using
nitrocellulose membrane as substrate, an antibody macroarray was fabricated with a biochip spotting robot, and then a
double antibody sandwich method was developed for quantitative detection of E. coli O157:H7. Results: The limit of
detection (LOD) for E. coli O157:H7 was 3.4 × 105 CFU/mL, and a good linear relationship was observed between grey
value for the macroarray and bacterial concentration in the range of 105–107 CFU/mL. This method could allow simultaneous
determination of different concentrations of E. coli O157:H7 in multiple samples. Conclusions: As evaluated by applying
it to standard strains and simulated enrichment culture, the antibody macroarray-based method could provide stable and
accurate results visible to naked eyes with simple operation and low costs without the use of large equipment. Moreover, the
antibody macroarray developed in this study could be used to rapidly assess E. coli O157:H7 pollution in food, especially
suitable for rapid screening of samples in grassroots-level laboratories.

Detection of Klebsiella pneumoniae in Milk Powder by Real-Time Fluorescence Loop-Mediated Isothermal Amplification Method
CHEN Wen-xiu, JIANG Xuan, MA Xiao-yan, ZHANG Wei*
2014, 35(20):  192-197.  doi:10.7506/spkx1002-6630-201420038
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Klebsiella pneumoniae which can cause diseases such as pneumonia was identified as a new foodborne
pathogenic bacterium in recent years. Using an ESE-Quant tube scanner, a new real-time fluorescent loop-mediated
isothermal amplification method for detecting K. pneumoniae was established with the primers designed based on the phoE
gene sequence published in GenBank. The results showed that this method had high specificity and sensitivity than PCR
method. Among 21 tested strains, 4 were identified as K. pneumoniae, and the other 17 were negative. The detection limit of
K. pneumoniae in artificially contaminated milk powder was 79 CFU/g, 100 times more sensitive than the conventional PCR
method. Moreover, the positive results could be directly identified immediately through the data and chart collected by the
ESE-Quant tube scanner so that real-time results could be provided.

Determination of Malathion in Apple Fruit Based on Surface Enhanced Raman Scattering on Golden vs Silver Sols
LIU Cui-ling, MIAO Yu-qing, SUN Xiao-rong, ZHAO Qi
2014, 35(20):  198-201.  doi:10.7506/spkx1002-6630-201420039
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Confocal Raman micro-spectrometry combined with surface enhanced Raman scattering (SERS) was used for
collecting surface enhanced Raman spectra of apple samples containing the pesticide malathion. Stepwise multiple linear
regression (SMLR) method was used to build two mathematical models for quantitative analysis based on golden and silver
sols, respectively. The results showed that within the linear range of 0.01–0.5 mg/kg, the correlation coefficient of the gold
sol model was 0.999 6, with root mean square error of calibration (RMSEC) of 0.001 86 mg/kg, and the maximum difference
between the actual and calculated values was less than 0.003 mg/kg. The correlation coefficient of the silver sol model was 1,
with RMSEC of 0.000 78 mg/kg, and the maximum differences between the actual and calculated value did not exceed 0.001 2 mg/kg.
The prediction standard deviations for the golden and silver sol models were 0.213 mg/kg and 0.146 mg/kg, respectively.
These results indicate that the effect of silver sol in quantitative analysis of malathion is better than that of gold sol.

Determination of 10 Kinds of β-Agoinsts in Meat and Meat Products by Matrix Solid-phase Dispersion-High Performance Liquid Chromatography Tandem Quadrupole Linear Ion Trap Mass Spectrometry
ZHANG Yi, ZHAO Shan-zhen*, QU Li, CAO Chen, SHI Yi-yin, YI Xiong-hai
2014, 35(20):  202-207.  doi:10.7506/spkx1002-6630-201420040
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A method based on matrix solid-phase dispersion-high performance liquid chromatography tandem quadrupole
linear ion trap mass spectrometry (HPLC-q/LTQ-MS) for the determination of 10 kinds of β-agoinsts in meat and meat
products was presented. Clenbuterol, salbutamol, ractopamine, tulobuterol, terbutaline, clorprenaline, penbutolol, cimaterol
and fenoterol were extracted with acetonitrile, followed by a further clean-up procedure using QuEChERS method. A
multiple reaction monitoring (MRM) as survey scan and an enhanced product ion (EPI) scan as dependent scan were
performed in an information dependent acquisition (IDA) experiment. The identification of the compounds was carried out
by library search with a precursor ion MS-MS library based on EPI spectra at three different collision energies in a positive
mode. The results showed that clenbuterol was in the range of 0.05–0.5 ng/mL, and 9 other kinds of β-agoinsts residues were
in the range of 0.5–5 ng/mL with correlation coefficients (r2) higher than 0.99. The limit of quantification was 0.05 μg/kg for
clenbuterol and 0.5 μg/kg for 9 other kinds of β-agoinsts. The recoveries of spiked standards in pork, casing and luncheon
meat ranged from 85.6% to118.4%, 85.6% to119.2%, and 80.4% to 118.4%, with relative standard deviation (RSD) of
1.47%–14.4%, 2.45%–15.4%, and 1.04%–12.5% (n = 6), respectively. This method can be used for simultaneous analysis of
10 kinds of β-agonists in meat and meat products.

Determination of Selenium in Infant formulas by Microwave Digestion-Hydride Generation Atomic Fluorescence Spectrometry
LU Li1, WEI Xiao-qun1, LIU Er-long2, LIU Jiang-hui1, QIN Xiao-yan1, YAO Hong1, CHEN Wen-rui1,*
2014, 35(20):  208-212.  doi:10.7506/spkx1002-6630-201420041
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A method for the determination of selenium in infant formulas was developed using microwave digestionhydride
generation atomic fluorescence spectrometry. Effects of reagents, pre-reducing methods, the presence or absence of
potassium ferricyanide, and reserving time of the sample digestion solution of certified reference material and the reducing
agent on the test results of selenium were studied. Under the appropriate reagent and pre-reducing condition, without using
potassium ferricyanide as masking agent, the linear regression equation was I = 38.440 4C+1.362 7 in the linear range
of 1.0–10 ng/mL (r = 1.000 0). The limit of detection (LOD) was 0.084 ng/mL, and the recovery rate of selenium from
spiked samples was 90.4%–109%, with relative standard deviation (RSD) of 2.9% (n = 6). The digestion solution of the
certified reference material GBW10017 (GSB-8 milk powder) could be stored at room temperature for three days before
determination and the reducing agent was valid within at least one week under refrigeration. The method was characterized
by simple operation, high efficiency, reagent-saving, easy operation and no pollution, and was suitable for rapid and accurate
determination of selenium in infant formulas.

Uncertainty Evaluation for the Determination of Basic Orange in Chili Powder by High Performance Liquid Chromatography
ZHANG Jin-yan, HU Li-fang, LI Wei-hong, GUO Xiao-pei, LUO Lin-guang*
2014, 35(20):  213-216.  doi:10.7506/spkx1002-6630-201420042
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Based on Evaluation of Uncertainty in Chemical Analysis Measurement, the uncertainties in the determination
of basic orange in chili powder by HPLC were evaluated. According to the developed mathematic model, the sources of
uncertainty were analyzed. The uncertainty components affecting the results were evaluated. The uncertainties from the
preparation of standard solution, the calibration of the standard curve fitted by least square regression, the measurement of
the sample weight, the adjustment of the sample volume, sample treatment, and the repeatability of the results were 0.008 3,
0.056, 0.002 5, 0.005 0, 0.012, and 0.022, respectively. The content of basic orange in spiked chili powder was (30 ± 3.73) mg/kg as
obtained by multiplying the combined uncertainty from the uncertainty components by the expansion factor 2 at 95%
possibility. It was also found that the uncertainty from the standard curve fitted by least square regression had the
largest effect on the results, and the uncertainties from sample treatment and the repeatability of the results could not
be overlooked.

Qualitative Discrimination of Adulterated Soymilk Using Optical Density Method
LI Dong-hua, PAN Yuan-yuan, LI Gen
2014, 35(20):  217-219.  doi:10.7506/spkx1002-6630-201420043
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Soymilk protein content is a major index for quality evaluation. In this study, near infrared spectra were obtained
for 83 adulterated soymilk samples and then the spectra and optical density of these adulterated samples were analyzed
by statistical methods. The feasibility for qualitative discrimination of soymilk quality was studied by using protein as the
major qualitative index. At last, qualitative discrimination standard was established. The experimental results indicated
that the spectral peak changed obviously in the wavelength range from 742.59 to 810.96 nm with an increase in soymilk
protein content. The optical density OD810.96 nm and OD742.59 nm were used to plot distribution diagram. Based on optical
density distribution diagram of 83 calibration samples, the soymilk classification model of OD difference was confirmed as
following: when its value of ΔOD742.59-810.96 nm was more than 0.062 9, the soymilk sample was classified into adulterated
sample, otherwise it was normal soymilk sample. Totally 37 prediction set samples were classified according to the model;
100% of adulterated soymilk in the prediction set were classified as adulterated samples, and 2 of 20 normal soymilk
samples were classified wrongly into adulterated samples. The preferable prediction results indicated that the accuracy of the
developed method was superior. The feasibility of soymilk quality evaluation based on optical density combined with near
infrared spectral data was confirmed. The method was simple and reliable, and could provide certain references for the rapid
detection of soymilk quality.

Rapid Analysis of Caffeine in Tea and Drink by Electrochemical Method
CHEN Li-xin1, JIANG Fan2, DANG Li-min1, ZHOU Yuan1
2014, 35(20):  220-223.  doi:10.7506/spkx1002-6630-201420044
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A rapid method for the determination of caffeine in tea and drink has been established. Cyclic voltammetry (CV),
square wave voltammetry (SWV) and differential pulse voltammetry (DPV) were used to investigate the electrochemical
behavior of caffeine at a glassy carbon electrode. The caffeine showed a sensitive oxidation peak at + 1.486 V using CV
in a NaH2PO4-K2HPO4 buffer solution at pH 6.60. The impacts of buffer solution, pH, accumulation time and scan rate
were discussed. The peak current was linear to caffeine concentration ranging from 2.0 × 10-6 to 2.0 × 10-3 mol/L with
a detection limit of 3.0 × 10-7 mol/L by SWV, and ranging from 1.8 × 10-6 to 1.0 × 10-3 mol/L with a detection limit of
5.0 × 10-6 mol/L by DPV. In addition to satisfactory reproducibility and reversibility, the methods exhibited sufficient
selectivity and thus were suitable for rapid determination of caffeine in tea and drink.

Analysis of Aroma Composition of Litchi Ice Wine by Different Extraction Fibers
LU Ke1, XUE Chu-ran1, QIAO Hui1, LIU Shu-wen1,*, XU Xiang-wen2
2014, 35(20):  224-229.  doi:10.7506/spkx1002-6630-201420045
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The aroma compounds of litchi ice wine were analyzed by head-space solid-phase micro-extraction (HSSPME)
coupled to gas chromatography-mass spectrometry (GC-MS). The efficiency of three different extraction fibers was
evaluated by comparing the number, chemical group and cumulative area normalization value (CANV) of the extracted
compounds. The results indicated that the extraction efficiency of aroma compounds were very different in litchi ice wine
because of different fibers. Totally 62, 56 and 52 aroma compounds in litchi ice wine were extracted through PA, CAR/
PDMS and DNB/CAR/PDMS, respectively. The major constituents were esters, alcohols, acids, ketones, aldehydes, and a
few terpenes. The most important aroma compounds were ethyl caprylate (38.96%), ethyl caprate (25.14%), ethyl caproate
(9.31%), isoamyl alcohol (7.89%), methyl methacrylate (1.52%), ethyl laurate (1.49%), 3-furaldehyde (1.26%), decanoic
acid (1.25%), benzyl alcohol (1.21%), damascenone (1.21%), and phenethyl alcohol (0.30%). The analysis of cumulative
area normalization value indicated that 85 μm PA was more sensitive to extract acids but least sensitive to other compounds,
75 μm CAR/PDMS was more sensitive to esters and alcohols, and 50/30 μm DNB/CAR/PDMS was more sensitive to
ketones and aldehydes. Considering all factors above, 75 μm CAR/PDMS was the optimal fiber for the extraction of aroma
compounds in litchi ice wine.

Prediction of Kiwifruit Quality during Cold Storage by Electronic Nose
SONG Xiao-qing, REN Ya-mei*, ZHANG Yan-yi, LI Ying, PENG Guo-yong, MA Ting
2014, 35(20):  230-235.  doi:10.7506/spkx1002-6630-201420046
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In order to explore the applicability of electronic nose technique for rapid and non-destructive evaluation of
kiwifruit quality, the volatile compounds of “Qinmei” kiwifruit during cold storage were studied by electronic nose. Multiple
linear regression (MLR), partial least-squares regression (PLS) and back-propagation (BP) network were applied to predict
the firmness, soluble solid content (SSC) and pH of kiwifruit based on the signal of electronic nose. The results showed that
the response values of sensors S1, S2, S3, S4, S7, S8, S9 and S10 were relatively high and changed significantly during 45
days of storage (P < 0.05). In addition, aromatic benzene, nitrogen oxide, ammonia, hydrogen, hydrogen sulfide, ethanol,
organic sulphur compounds and aromatic alkane also exhibited a significant change during cold storage. Linear discriminant
analysis was able to better distinguish among different storage periods of kiwifruit than principal component analysis.
PLS, MLR and BP network were able to predict the firmness, soluble solid content and pH of kiwifruit during cold storage.
However, BP network led to more precise predictions than PLS and MLR. The results indicate that it is possible to use this
non-destructive technique for measuring quality characteristics of kiwifruit, and electronic nose technique provides a method
for rapid and non-destructive evaluation of kiwifruit quality.

Preparation and Fluorescence Microscopic Characterization of Surface Molecularly Imprinted Polymer of Rhodamine B
ZHAO Chen, JIA Guang-feng, LU Wen-zong, NI Yuan
2014, 35(20):  236-241.  doi:10.7506/spkx1002-6630-201420047
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Poly (methacrylic acid) was grafted onto the surface of bulk SiO2 by solution polymerization to produce a
molecularly imprinted polymer with a two-layer PMAA/SiO2 bulk structure (surface molecularly imprinted polymer,
SMIP). The morphology of SMIP was characterized by scanning electron microscopy (SEM) and fluorescence microscopy
(FM). The SEM image demonstrated that imprinted cavities were formed on the surface of SMIP. The FM image showed
that rhodamine B (Rh B) could be combined and eluted quickly and effectively. SMIP had better binding property and
selectivity as detected by a fluorescence spectrophotometer. The Kd of Rh B was 163.6, which was higher than that (50 and
54.5, respectively) of Rh 6G and butyl Rh B. Compared with the traditional detection method (HPLC-UV), the molecular
imprinting method had better sensitivity and lower detection limit (0.1 mg/L) for trace-level determination of Rh B.

Simultaneous Quantification and Comparison of 8 Components in Different Parts of Glycyrrhiza uralensis Using Ultra-High Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry
YE Ri-gui 1, GAO Jie 1, WANG Bing 1, LI Er-hu1, ZHANG Yan1, JIANG Fei1, CAO Rui1, HATTORI Masao2, WANG Shi-ming3, MA Chao-mei1,*
2014, 35(20):  242-247.  doi:10.7506/spkx1002-6630-201420048
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An ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QQQMS)
with dynamic multiple reaction mode was developed to simultaneously quantify 8 constituents including 22-hydroxyglycyrrhetinic
acid, 3-epi-glycyrrhetinic acid, glycyrrhetinic acid, glycyrrhizic acid, liquiritin, glycycoumarin, formononetin
and isoglycyrol in Glycyrrhiza uralensis. Cholic acid and abrusin 2”-O-β-apioside were used as the internal standards for
triterpenoid and phenolic components, respectively. The internal standards were added to methanol before being used to
extract samples. The separation was performed on an Agilent ZORBAX RRHD Eclipse Plus C18 column (50 mm × 2.1 mm,
1.8 μm) with methanol-0.1% formic acid as the mobile phase at a flow rate of 0.4 mL/min. As a result, the linear ranges of
22-hydroxy-glycyrrhetinic acid, 3-epi-glycyrrhetinic acid, glycyrrhetinic acid, glycyrrhizic acid, liquiritin, formononetin,
isoglycyrol and glycycoumarin were 0.048 8–12.500 0, 0.048 8–12.500 0, 0.012 2–12.500 0, 0.048 8–50.000 0, 0.048 8–
50.000 0, 0.012 2–12.500 0, 0.012 2–15.000 0 and 0.195 2–12.500 0 μg/mL, respectively, with correlation coefficients higher than
0.99. The average recovery rate of the developed method ranged from 97.2% to113.0% and the intra-day and inter-day relative
standard deviations (RSDs) were 2.63%–4.47% and 1.75%–3.72%, respectively. This method is sensitive, simple, fast, and
accurate, and can be used for the quality control of different parts of Glycyrrhiza uralensis and related food products.

Simultaneous Determination of Nitrate, Nitrite and Polyphosphates in Seafood by Ion Chromatography
SHAO Hong-hong, ZHOU Xiang-yang, WANG Qi, ZHOU Xiu-jin, SHEN Biao, FU Mi-ni
2014, 35(20):  248-252.  doi:10.7506/spkx1002-6630-201420049
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A method for determining nitrate, nitrite and polyphosphates including phosphate, pyrophosphate, triphosphate
and trimetaphosphate in seafood using ion chromatography (IC) was proposed. The stability and contents of these
compounds in seafood were also investigated. The separation was achieved on hydrophilic anion exchange column through
gradient elution using potassium hydroxide as the elutant. The determination coefficients of the developed linear equations
for these analytes were in the range of 0.998 1–0.999 8, and the recoveries of spiked samples ranged from 79.2% to 93.6%
with RSD less than 8.2%. The total content of pyrophosphate, triphosphate and trimetaphosphate was stable within 14 h. This
method has been successfully applied to the determination of pyrophosphate, triphosphate and trimetaphosphate in different
kinds of seafood products from the East China Sea. The results showed that a wide variation in the contents of nitrate, nitrite
and polyphosphates existed among different seafood products, and all residual contents met the national maximum allowable
residue levels except that polyphosphates in one sample were more than 5 g/kg.

Simultaneous Determination of Seven Drug Residues in Bean Sprouts by High Performance Liquid Chromatography-Tandem Mass Spectrometry
HU Xiang-na1, GU Ya-ping1,*, LIN Hui-chun1, WANG Rui1, FANG Chang-fa2
2014, 35(20):  253-257.  doi:10.7506/spkx1002-6630-201420050
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A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) method was developed
for the simultaneous determination of seven drug residues including 6-benzylaminopurine, para-chlorophenoxyacetic acid,
2,4-D, gibberellin A3, carbendazim, procymidone, and enrofloxacin in bean sprouts. The seven compounds from samples
were simultaneously extracted with acetonitrile and analyzed by HPLC-MS-MS. The calibration curves showed good
linearity in the range of 0.01–10 μg/mL for 6-benzylaminopurine, para-chlorophenoxyacetic acid, 10-benzylaminopurine,
gibberellin A3, and procymidone, and in the range of 0.01–1 μg/mL for carbendazim and enrofloxacin with correlation
coefficients more than or equal to 0.987. The recoveries of these drug residues at three spiked levels (0.002, 0.2 and
0.5 mg/kg) ranged from 60.31% to 108.51%, with relative standard deviation (RSDs) between 1.03% and 13.10% and
method detection limit (MDL) between 0.010 5 and 0.125 μg/kg.

Determination of 14 Quinolone Residues in Ham by HPLC-MS-MS with Isotopic Internal Standard
ZHU Zi-tong, XU Jia-wen, LEI Mei-kang, PENG Fang, ZHANG Ying-jun
2014, 35(20):  258-264.  doi:10.7506/spkx1002-6630-201420051
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A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) was developed for
simultaneous determination of 14 quinolone residues (QNS) in ham. Ham sample was extracted with acetonitrile, defatted
with hexane saturated with acetonitrile and cleaned up by MAX solid phase extraction. The mass spectrometer was operated
in the positive ion mode using select reaction monitoring for qualitative and quantitative analysis. Isotope internal standard
was used for quantitative analysis. The limit of detection of the method was 0.6 μg/kg. Mean recovery rates for 14 QNS in
a negative ham sample spiked at three levels were between 70% and 115%, with RSD ranging from 1.2% to 15.6%. This
method proved to be of simplicity, high sensitivity and good selectivity. It has been used for routine test in our laboratory.

Processing Technology
Multivariate Analysis of the Effects of Controlled Atmosphere Treatment on Quality of Pleurotus eryngii Mushroom during Shelf-life
ZHANG Xuan1,2, HU Hua-li1, WANG Yu-ning1, LI Peng-xia1,*
2014, 35(20):  265-270.  doi:10.7506/spkx1002-6630-201420052
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The effects of controlled atmosphere (CA, 30% CO2 + 2% O2) on Pleurotus eryngii quality during shelf-life at
20-25 ℃and 90%-95% relative humidity (RH) were analyzed by one-way analysis of variance, principal component
analysis (PCA), correlation analysis, partial least squares regression, and path analysis. An atmosphere of 21% O2 and 0.03%
CO2 was used as control (CK). The results showed that CA alleviated weight loss, inhibited the decrease of hardness, protein
and total sugar content, maintained the lower electrical conductivity and pH, and contributed to the higher brightness and
sensory score of Pleurotus eryngii. PCA indicated that CA exhibited a significant influence on Pleurotus eryngii color; total
sugar, hardness, protein, weight loss, electrical conductivity, and pH changed dramatically during storage. Partial least squares
regression and correlation analysis showed that the hardness, protein, total sugar, L*, and h displayed a significantly positive
correlation with sensory quality score (P < 0.05) and the weight loss, a*, b*, and electrical conductivity had a significantly
negative correlation with sensory quality score. Path analysis suggested that L* was the main factor affecting the quality of Pleurotus
eryngii by exerting the direct (L*) and indirect (by affecting a*, b*, and weight loss) influence. In conclusion, CA has effects on several
physicochemical indexes of Pleurotus eryngii and mainly exerts its influence on color indexes (L*, a* and b*).

Packaging & Storage
Stability of Lutein in Bread during Processing and Storage
XIE Xiao-ye1,2, LI Da-jing1,2,*, SONG Jiang-feng2,LIU Chun-quan2
2014, 35(20):  271-275.  doi:10.7506/spkx1002-6630-201420053
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Lutein is a yellow pigment with a variety of nutritional functions. The stability of lutein from bread flour fortified
with water-soluble lutein microcapsule was studied during processing steps and subsequent storage. Results showed that
dough making, fermentation and baking caused a significant reduction in all-trans lutein and the formation of 13-cis, 13’-
cis, 9-cis, and 9’-cis-lutein, but baking had the greatest influence on the content of lutein. Dough making and fermentation
caused a decrease in the retention rate of total lutein by 3.24% and 5.40%, respectively, and baking led to a reduction in the
retention rate of total lutein in bread core and bread crust by 6.32% and 41.12%, respectively. After being stored at 20 ℃
in the dark for seven days, the retention rates of total lutein in bread core and bread crust decreased by 13.64% and 8.72%,
respectively, but color value changed little. The storage stability of bread was good, which could meet the requirement for
the shelf life of bread.

Changes in Mitochondrial Cytochrome c Oxidase in Two Peach Cultivars during Maturation and Senescence
KAN Juan, LU Yan-fei, LIU Jun, JIN Chang-hai*
2014, 35(20):  276-280.  doi:10.7506/spkx1002-6630-201420054
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The activity of cytochrome c oxidase (COX) and the expression levels of mitochondrial DNA (mtDNA)-encoded
COX subunits in two peach (Prumus persica) cultivars ‘Yuhuasanhao’ and ‘Jianayan’ were determined for analyzing their
relationship with peach fruit ripening and senescence. The results showed that COX activities in the two peach cultivars
increased in the early stages of maturity (Ⅰ–Ⅲ), followed by a decrease. COX activities were higher in ‘Jianayan’ peach
fruit than in ‘Yuhua 3’ peach fruit. The expression levels of mtDNA- encoded COX subunits were higher in the early stage
than in the later stage of maturity. MtDNA-encoded COX subunits played a major role in the early maturity stage of peach
fruit and provided the energy needed for peach growth and metabolism. In the later maturity stage, the decreases in the
abundance of catalytic subunits of mtDNA-encoded COX could underlie the senescence-associated loss of enzyme activity,
which could change a component of the mitochondrial electron transport chain and underlie the senescence-related decrease
in mitochondrial respiratory activity and reactive oxygen species accumulation.

Comprehensive Freshness Evaluation of Grass Carp (Ctenopharyngodon idellus) during Refrigerated Storage
JIANG Yang1, LI Ting-ting2, JIN Gao-wei1, LI Jian-rong1,*, LI Min-zhen3
2014, 35(20):  281-285.  doi:10.7506/spkx1002-6630-201420055
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In order to evaluate the freshness of farmed grass carp stored at 4 ℃, changes in total viable count (TVC), total
volatile basic nitrogen (TVB-N), pH value, K value, and related values were investigated. Meanwhile, electronic nose was
used to analyze the volatile components. The results showed that total viable count and TVB-N value increased gradually
during storage and these changes were correlated with storage time. The values of K, Ki, Fr, G and P firstly increased and
then stabilized. These changes were correlated significantly with storage time with correlation coefficients of 0.955, 0.953,
-0.953, 0.958, and 0.957, respectively. Neither H value nor pH showed a significant correlation with each of the other
parameters . The TVC, K value and the other related values except H value of grass carp could be distinguished effectively
during different storage periods. Compared with TVC and TVB-N value, electronic nose as well as K value and the other
related values except H value were more sensitive to freshness evaluation, while pH value and H value were not appropriate
for the freshness evaluation. The shelf life of grass carp during 4 ℃ storage was 8 days, and fish samples stored for 12 days
reached the upper limit of processing and edibility.

Preservation Effect of Complex Biological Preservative Combined with Ice Temperature Storage on Penaeus vannamei
LIU Jin-fang1, LIU Hong-ying1,2,*, QI Feng-sheng2, QIN Hong-li1, WANG Hui-qing1
2014, 35(20):  286-290.  doi:10.7506/spkx1002-6630-201420056
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Objective: To explore the effect of composite biological preservative combined with ice temperature storage on
preventing deterioration and prolonging the shelf-life of Penaeus vannamei. Methods: Penaeus vannamei were treated with
a composite biological preservative consisting of nano-TiO2, chitosan, lysozyme, and propolis and then stored at different
temperatures. pH, sensory evaluation, total plate count, TVB-N value, Ca2+-ATPase activity, and TBA value were measured
during storage periods, and the experimental data were analyzed by analysis of variance. Results: The composite biological
preservative combined with ice temperature storage could prolong the shelf-life of Penaeus vannamei. Conclusion: The
shelf-life of Penaeus vannamei stored at ice temperature can be prolonged to 21 days by treatment with the composite
biological preservative.

Effect of Slow-Release Ethanol Treatment on Quality Traits of Tomatoes (Lycopersicon esculentum Mill.) during Postharvest Storage
QI Hong-yan, CHEN Jun-qiao, Lü De-qing, BAI Xiao-hang
2014, 35(20):  291-295.  doi:10.7506/spkx1002-6630-201420057
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Tomatoes from Fentailang cultivar were treated by slow-release ethanol (a solidified ethanol) in incubators at
20 ℃ and a relative humidity of 85%, and those without treatment were used as control. The changes in quality traits,
ethylene release, and polygalacturonase (PG) and cellulase activities were measured during storage periods. The results
showed that SRE treatment improved fruit brightness and alleviated the decrease in weight loss rate, reduced the soluble
solid loss, maintained fruit firmness at a certain level, increased the sugar/acid ratio at the later storage, and delayed fruit
red turning by 6 d in comparison to the control. Meanwhile, ethylene release and the activities of PG and cellulase were
significantly decreased. Taken together, these results indicated that slow-release ethanol could delay the ripening and
senescence and extend the shelf life of tomatoes, thus keeping the flavor quality of tomatoes for a long time.

Packaging & Storage
Effect of 1-Methylcyclopropene on Main Fruit Quality Traits and Aroma Components of “Early Red Comice” at Shelf Life after Storage
WANG Chuan-zeng1, DONG Fei2, SUN Jia-zheng1, JI Jing1, ZHANG Xue-dan1, WANG Dan1, WANG Chao3, WANG Shu-zhen1,*
2014, 35(20):  296-300.  doi:10.7506/spkx1002-6630-201420058
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The aim of this experiment was to analyze the fruit volatiles and the main fruit quality traits of “Early Red
Comice” pear fruits treated with 1-methylcyclopropene (1-MCP) at different concentrations: 0.5, 1.0 μL/L and control
(0 μL/L) on the seventh day of shelf life after storage at 0 ℃. The volatile components were identified using solid phase
microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). The results showed that: 1) 62 compounds,
categorized into seven different chemical classes, were detected in the mature fruits with 3 different treatments, including 32
esters as the most abundant compounds (accounting for 51.6% of the total aroma compounds) and less than 32 compounds
from six other classes each; 2) the number and amount of total volatiles, the number and total amount of unique aroma
components, and the amounts of ester and terpenes in the 1.0 μL/L 1-MCP treatment were significantly higher than in the
other treatments; 3) markedly lower firmness and decay incidence were observed by using 1.0 μL/L 1-MCP treatment.
Furthermore, we found that the results of volatile composition and fruit quality traits were consistent with sensory evaluation.

Storage Stability of Anthocyanins in Blackcurrant Juice
ZHAO Yu-hong1,2, JIA Lin-na1, ZHAO Tie-nan1, GAO Yu-mei1, ZHANG Li-gang3,*
2014, 35(20):  301-307.  doi:10.7506/spkx1002-6630-201420059
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In this work, we examined the effects of storage temperature, soluble solid content (SSC) and added antioxidant
(ascorbic acid) on the chemical stability, degradation kinetics and color change of anthocyanins in blackcurrant juice. Results
showed that blackcurrant anthocyanins were stable at 4 ℃ and an SSC of 9°Brix. With an increase in storage temperature
and SSC, the level of residual anthocyanins was decreased. The degradation of anthocyanins during storage followed a firstorder
reaction. The higher the reaction rate constant k, the smaller the half-life t1/2, and the lower the activation energy Ea.
Addition of 50 mg/L ascorbic acid resulted in a significant increase in the degradation rate constant k of blackcurrant juice
anthocyanins and a significant reduction in the half-life t1/2 and the thermal degradation activation energy Ea. Therefore,
adding ascorbic acid had a positive on the reduction of residual anthocyanins. As the storage period progressed, the content
of anthocyanins in blackcurrant juice declined, and significant browning was observed in the juice together with a reduction
in brightness and redness and an increase in yellowness. In addition, ascorbic acid could promote the color change of
anthocyanins during storage.

Technology Application
Optimization of Processing Conditions for Five-Spice Condiment Oil Based on Electronic Nose Analysis
XU Li-rong, SUN Pei-cheng, YU Xiu-zhu*, QU Qing-lu, ZHANG Zhi-yu
2014, 35(20):  308-313.  doi:10.7506/spkx1002-6630-201420060
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This study aimed to optimize the processing conditions for five-spice condiment oil. The oil was prepared using
five-spice powder and soybean oil as raw materials based on electronic nose analysis. The effects of ratio of soybean oil to
five-spice powder, initial oil temperature, extraction time, and holding time (at 70 ℃) on the flavor were examined using
single factor design and response surface methodology and physicochemical properties of five-spice condiment oil were
investigated. The results demonstrated that the optimal five-spice powder consisted of 20% Sichuan pepper, 25% star anise,
25% fennel, 12.5% cinnamon, 12.5% dry ginger, and 5% clove, and the optimum processing conditions for five-spice
condiment oil were as follows: mass ratio of oil to five-spice powder, 4:1; initial oil temperature, 150 ℃; extraction time,
10 min; and holding time, 18 h. All measured physiochemical indexes of five-spice condiment oil met the national standards
of third-grade soybean oil. The results show that it is feasible to optimize the processing conditions for five-spice condiment
oil based on electronic nose detection.