Abstract: The aim of this study was to investigate optimum condition for extraction of flavonoids and the antioxidant activities from the Black Beauty potato. The results showed that extraction rate of the flavonoids from Black Beauty potato is affected in turn temperature, solid to liquid ratio and the concentration of ethanol .The optimum conditions of flavonoids extraction were temperature78℃, 62% ethanol, solid to liquid ratio 1g:35mL.Under the optimal conditions,the maximum response value yield (1.037%) was consistent with the experimental value (1.025%) ,indication the feasibility and validity of response surface methodology in optimizing the extraction of flavonoid from the Black Beauty potato. Black beauty potatoes flavonoids compared with VC and rutin , the ability of scavenging DPPH free radical was flavonoids＞VC＞rutin, When the concentration of flavonoids solution was less than 20μg/mL, ability of scavenging ABTS free radical and antioxidant were higher than VC, but always greater than rutin.The results indicated that the flanonoids have significant antioxidant activities,which can be used as a source of potential antioxidant or function food material.

Response surface methodology was employed to optimize the extraction condition of polyphenols from carga cathayensis sarg peels treated with cellulase. On the basis of one-factor-at-a-time experiments, a four-factor, three-level quadratic general rotary unitization design was employed to establish a quadratic polynomial mathematical model that describes extracting rate as a function of four process conditions, and the established model was analyzed by drawing response surface and contour plots. The optimal extraction conditions were determined as follows: 4U/g substrate at pH 6 and 70℃ for 70min. Under these conditions, the extracting rate of carga cathayensis sarg peels was predicted to 63.43% and observed to 61.72% with a relative error of 2.77%.

Optimal processing parameters for extraction of Phellinus igniarius polysaccharides in fermentation liquor with the content of polysaccharides as index were determined. On the basis of single factor experiments, the method of response surface method(RSM) for optimal parameters was adopted. Finally,The results of the study shows the optimal extraction process was obtained as follows: extraction pH12, extraction temperature 96℃, extraction time 1.6h. Under these conditions，the content of Phellinus igniarius polysaccharides reached 11.67mg/ml. The model turned out to be with good fitting degree and good feasibility.

Application HS-SPME and GC-MS method extraction the volatile components of the solid phase micro of the Chinese white wine fermented grains. Different types of SPME fibers, the water bath temperature, ultrasonic extraction time, and sample extraction on the extraction efficiency of trace volatile components. The results showed that the optimum condition for 65μm the PDMS / DVB SPME fibers, water bath temperature is 60℃, extraction without ultrasonic and the amount of fermented grains powder 10g. Throughout the fermentation process, this method detected 105 kinds of trace volatile components from fermented grains ,and we get the variation of the number and relative content of volatile substances species over time.

A high performance liquid chromatography- tandem mass spectrometry（HPLC- MS/MS）method for determination of 18 kinds of food additives and 9 kinds of illegal additives in vegetable oil and seasoning oil has been developed. Samples were diluted by hexane, extracted by acetonitrile and the acetonitrile layer was made up to constant volume before tested the 18 kinds of food additives. Hexane layer was concentrated before it cleansing through GPC, and the eluent was concentrated, made up to constant volume, at last the treated samples used HPLC-MS/MS assay. In the electrospray ion mode and MRM mode，27 kinds of compounds in the range show a good linear relationship, linear coefficients were greater than 0.983. The average recoveries ranged from 78.2% to 108.3%, the relative standard deviation is within0.9%-17.7%.This method can be used for testing the food additives and illegal additives in vegetable oil and seasoning oil. Applied this method in market samples detection，we found TBHQ in five kinds of samples，but，all of them was below the maximum limit in China.

The total of 66 aroma compounds were determined by headspace solid-phase microextraction followed by GC-MS on the basis of micro volatile compounds and aroma compounds of Yanghe supple and mellow aroma type liquors. Ethyl hexanoate is the key aroma of supple and mellow aroma style liquors by calculation of odor activity values (OAVs) of aroma compounds; OAV is more than 27000, and average OAV of 4 samples is 24799. Ethyl 2-methylbutanoate, dimethyl trisulfide, ethyl pentanoate, ethyl butanoate, and ethyl octanoate are important aroma compounds. Pentanoic acid, ethyl 2-methylpropanoate, 3-methylbutanal, ethyl 3-methylbutanoate, and hexanoic acid contribute to aroma and flavor of Yanghe liquors. The results showed the key aroma compound of supple and mellow aroma type liquor was same to strong aroma type liquor, whereas the important aromas were different.

The components, concentrations and compositions of volatile organic sulfur compounds (VOSCs) emitted from Newhall navel orange (Citrus sinensis L. Osbeck) were investigated during the laboratory-incubated decay under uncontrolled conditions for a period of one month, using preconcentrator coupled with gas chromatography-mass spectrum (GC-MS). In total, three VOSCs including dimethyl sulfide (DMS), carbon disulfur (CS2) and dimethyl disulfide (DMDS) were determined in the gases released from fresh and decaying navel oranges. For total volatile organic sulfur compounds (TVOSCs) or individual VOSCs, their concentrations were very low when naval oranges fresh, and increased with decay time to attain the maximum and then decreased to be very low and steady until the end of the experiment. CS2 dominated in VOSCs released from navel oranges when fresh and in the early 2 day of incubation, while DMS was the most abundant VOSCs after 2 days of incubation.

The aroma components of bagged or non-bagged Anyue lemons, including their peels and pulps, were detected and analyzed by solid phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Simultaneously, the effect of bagging technology were analysed on the aroma components. Components semi-quantitative evaluation was carried out by comparing peak area of each compound with that of the internal standard. The results showed that volatile compounds mainly were consisted of hydrocarbons, alcohols, aldehydes, esters and ketones in a mass to little of sequence. The aroma components in peel always were more abundant than in pulp whether been bagged or not. Aroma quality of lemon was mainly reflected in peel. Compared with non-bagged lemons (CK), the types of the majority volatile compounds would be hardly changed, and the relative contents of oxygenated compounds were reduced after bagged, whose decrement was under 2.91%. So bagging would lower the aroma quality of lemon, but not serious. The tow isomers and points of Citral, whose relative amounts possess a conclusive lemon odor, had stable mass ratios of neral and geranial, which are about 2-3 in peel and 1-2 in pulp.

A high performance liquid chromatography (HPLC) method for the fast qualitative analysis and accurate quantitative analysis of the artificial sweetener neotame in wines was developed. Neotame was fast qualitative analysis on a Waters Nova-Pak C18 column with an ultraviolet detector at 218 nm using acetonitrile: ion-pair reagent=40:60 (V/V) as mobile phase, and the retention time of neotame was about 13.4 min. The contents of neotame in the suspected samples were determined under gradient elution condition, and the retention time of neotame was about 15.9 min. The detection limit of the developed method was 0.37 μg/mL, and the mean spike recoveries for neotame in a blank wine sample were between 99%～101% , with a relative standard deviation below 1.0% (n=5). The method proved to be simple, accurate and practical, and it can save 50% time in analysis of large quantities of samples.

In order to analysis bacteria community structure overally and systematically in Cantonese Sausage, and to find out the dominating microbial species, which provided a basis for the research of culture starter.The traditio- nal culture method in combination and PCR-DGGE fingerprint technology was applied to study bacteria populati- on structure in Cantonese Sausage, and fermentation advantage bacterial community of Cantonese sausage has been analysised. The results showed that 19 strains of staphylococcus, 12 strains of lactic acid bacteria has been obtained by the traditional culture method, four strains of staphylococcus (named P1 to P4) and two strains of lactic acid bacteria (named L1 and L2) was identified by using physiological-biochemical characteristics. Three bands in the DGGE profiles of total bacterial DNA of Cantonese Sausage were not recovered by cultivation. Conversely, one bacterial species did not exhibit bands in DGGE fingerprints of total bacterial DNA. sequence analysis and similarity comparison showed that the P1 and P4 pertain to Staphylococcus xylosus, P2、 P3、 L1、L2 respectively pertain to Staphylococcus cohnii, Staphylococcus epidermidis, Lactococcus garvieae, Lactobacill- ales bacterium. The main culturable predominant bacteria in Cantonese Sausage were Staphylococcus saprophyti- cus, Lactobacillales bacterium, Staphylococcus xylosus. Conclusion：a combination of traditional separation and PCR-DGGE method could been applied to analysis of the bacteria community structure and advantage bacterium in Cantonese Sausage effectively and comprehensively, Screened advantage strains, layed the foundation for the research of developing of culture starter.

Abstract: Objective To analyse of amino acid compositions in eri silkworm pupa, and offer scientific grounds for comprehensive utilization research of eri silkworm pupa. Method Kjeldahl method and Auto amino acid analyzer. Result The content of protein in eri silkworm pupa is 66.94±0.89%, and there are 17 kinds of amino acids, including glutamic acid(Glu)5.180±0.15%, aspartic acid(Asp) 4.317±0.08%, glycine(Gly)3.431±0.06%, leucine(Leu)3.184±0.21%, valine(Val)2.662±0.07%, phenylalanine(Phe)2.510±0.07%, tyrosine(Tyr)2.489±0.08%, lysine(Lys)2.365±0.12%, arginine(Arg)2.334±0.15%, alanine(Ala)2.205±0.18%, isoleucine (Ile)2.166±0.19%, proline(Pro)2.089±0.14%, threonine(Thr)1.901±0.16%, serine(Ser)1.863±0.13%, histidine(His) 1.722±0.12%, methionine(Met)0.983±0.11%, cysteine(Cys)0.696±0.04%.

Abstract: A method was studied for analysis of Pb，Cd，Cr，Cu and As in tea-camellia seed oil by using ICP-MS. The instrument parameter and microwave digestion condition were optimized and internal standard of 187Re，103Rh and 45Sc was selected to compensate the drift of analytical signals. The detection limits of these 5 elements were 0.36-1.64μg/kg. The addition standard recovery was 84%—111% ，and the RSD was 1.6%-7.6%（n=5） for 5 elements. The accuracy of the method was evaluated by the analysis of corresponding trace heavy metal elements in standard reference material (GBW10016 and GBW10019). The analytical method presented was characterized with rapidness, good precision, accuracy, low limits of detection.

A rapid method for qualitative and quantitative analysis of 11 flavonoids in citrus was developed using ultra performance liquid chromatography (UPLC) coupled with photodiode array detector. Under the condition of methanol-.acetic acid water solution as mobile phase and gradient elution, 8 flavanones and 3 polymethacrylate flavones were separated to baseline within 11 min. The detection wavelengthes were 283nm and 330nm. The limits of detection (LODs) were from 0.005 to 0.02mg/kg (S/N=3) and good linearity was observed with the correlation coefficient (r2)≥0.9991.The influencing factors sample preparation were optimized by using Orthogonal experimental design and the recoveries of compounds analyzed from peel and juice samples were in the range of 94.6–101.2% with RSD between 1.1 and 3.7%, and in the range of 94.5–101.8% with RSD between 0.9 and 3.9%, respectively.Compared with the existing, this method was more effective, environmentally friendly and reproducible.

Alternation and analyses of components and fermented favor substances of Libo sour meat in Guizhou during fermentation were investigated in this paper. The results showed that pH value of sour meat trended to decrease, especially at first 10 days, lowering from pH 7.20 to 4.50, and further to 3.60 at 45 days. Protein and fat of sour meat displayed an increasing tendency with decreasing water, but an opposite trend was found for total sugar. Metabolites such as total acids, amino acids nitrogen, free amino acids and total volatile salt-basic nitrogen increased gradually with the fermentation period. 34 spices of compounds related to flavor of traditional sour meat were found, including 15 acids, 11 aldehydes, 1 hydrocarbon, 1 allyl, 3 estercoholdens, and 3 alcohols, with acids being the major compound which accounts for 44% of total flavor compounds.

Abstract: In order to investigate the nutritional and functional composition of natural green eggs in Changbai Mountain area, the content of moisture, crude fat, ash, protein, mineral (sodium, potassium, calcium, iron, magnesium, zinc), vitamin A, vitamin E and other nutrients, as well as cholesterol and lecithin and other functional components of the natural green eggs were measured. And then the contents were compared with those of conventional eggs and free range eggs. The results obtained from the study show that, the moisture content in the natural green eggs is lower, and there is no obvious difference in the crude fat content among the three kinds of eggs, but the ash and protein contents are higher than those of the other two kinds of eggs. Potassium, sodium, calcium, magnesium contents in the natural green eggs, but the content of iron and zinc were close to conventional eggs, and below free range eggs. The natural green eggs also have fine quality with high vitamin A, vitamin E, lecithin yet low cholesterol.

A method for the determination of organic and inorganic selenium in duck eggs by Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS)had been developed. A sample was extracted with the buffer solution of Tris (hydroxymethyl) aminomethane-hydrochloric acid (Tris-HCl) in PH=8.6，deposited with Ammonium sulphate. The total selenium and inorganic selenium content were detected with HG-AFS. The content difference between total selenium and the inorganic selenium was organic selenium content. The detection limit for selenium was 0.003mg/kg under the optimum condition. The linear range was 2.0-50μg/L.The relative standard derivation was less than3.21%. The recoveries was 82.8-91.0%. The inorganic selenium and organic selenium content were detected respectively from the selenium enriched duck eggs by this method. This method met the determination of organic selenium in duck eggs．

Abstract: To investigate the influence of aging on the aroma components in the purple potato wine, the solid-phase micro extraction (SPME) and the gas chromatography-mass spectrometry ( GC-MS) were adopted to separate and identify the aroma components during the aging. The relative contents of aroma components were determined by area normalizing method. The results demonstrated that 60 of aroma components were all identified in the aging with isoamyl alcohol, ethyl decylate, ethyl octanoate and so on. Among those, the relative contents of Isoamyl alcohol, ethyl octanoate, benzyl ethanol and so on were higher. But the species, main compound and its relative content were different during the aging. The relative contents of esters and ketones increased totally, and the relative contents of alcohol decreased. The relative contents of acids changed slightly, and the relative contents of phenols increased slightly.

The volatile compounds of fish sauce made from different fish by traditional processing were investigated by GC-MS and electronic nose respectively. The results were compared by original fish sauce with best flavor quality. The results showed that fish sauce made from different fish has different volatile compounds indeed. Fish sauce made from brown-striped mackerel scad has more volatile compound, the 19 volatile compounds involved 3 sulfur-containing compounds, 6 aldehydes and 4 volatile fat acids. Fish sauce made from Bluefin leatherjacket has 9 volatile compounds. Anchovy decayed easily especially young anchovy, so it usually made for fish sauce, but the volatile compounds of anchovy fish sauce were not very abundant in fact, particularly for young anchovy. The study found that more content of protein and amino acids, especially for more sulfur-containing amino acids were more favorable for the characteristic volatile odor forming, fishes with more fat content are not suitable for fish sauce processing.

The objective of this study was to screen a suitable method for DNA extraction from soybean by comparison of five generally applied DNA extraction methods. After extraction, the quality of soybean DNA was examined with ultraviolet spectrophotometry, agarose gel electrophoresis and real-time fluorescent PCR, respectively. The results showed that the DNA extracted by Bayer method contained many PCR inhibitors; the purity and yield of DNA extracted by Monsanto method did not meet the demand of the quality standard of DNA in molecular experiment; DuPont method, Qiagen kit and Tiangen kit could extract high-quality DNA which was suitable for real-time fluorescent PCR, but Qiagen kit cost too much. These evidences indicated that DuPont method and Tiangen kit were suitable methods to extract DNA from soybean for detection of genetically modified ingredients.

Abstract： Objective: Determined the limonin in the citrus juice fermentative broth by UPLC- MS/MS, analyzed the limonin’s variation trend in citrus processing fermentation products. Method: The column was waters ACQUITY BEH C18 (50 mm x 2.5 mm，1.9μm); Mobile phase: Using gradient elution, A was acetonitrile and B was water, A: 10%（0min）-50%(3min)- 10%(4min)-10%(5min);The velocity of flow was 0.3 ml?min-1; column temperature was 40℃; Injection quantity was 5μL; Detection time was 5min; ESI (+) scan, the limonin’s parents were m/z=471.1 , daughter were m/z=425.3 and m/z=161.1; Result: Limonin can be detected at the analytical conditions, Limonin’s content was change from the fermentation time, preservation of the longer, lower the content of limonin. Conclusion: citrus juice fermentative broth is extended the storage time, which is conducive to the removal of bitter substances.

Abstract: Debittering the casein hydrolysate with flavor enzymatic, electronic tongue technology combined with the sensory evaluation method was used to evaluate the debittering effect, and the ACE inhibitory activity of hydrolysate before and after debittering was detected by HHL method. The results showed that there are some differences between sensory evaluation method and electronic tongue technology, the latter have more advantage at resolution, sensitivity, stability and so on than former. Indicating the debittering effect with bitterness and after-bitterness for the nine kinds of products from orthogonal test, The results showed that the sample 3 has the best debittering effect which was prepared under the conditions of that ratio of enzyme to substrate is 2800u/g, pH valule is 6.8, hydrolysed time is 2.5h, in order to obtain the more active sample, four samples (3, 6, 8, 9) with good debittering effect and casein hydrolysate without debitting were compared IC50. The results showed that IC50 of sample 9 (0.28mg/mL) was similar to IC50 of hydrolysate without debittering (0.27mg/mL).

Tomato fruit (Solanum lycopersicum L.cy.lichun) were used to study the effect of treatment spraying branches with 3% nanometer nutrient solution and fertilizing treatment mixing 3% nanometer nutrient significantly improved the titratable acid content by 20.4% and the soluble protein content by 37%.Fertilizing treatment significantly improved the titratable acid content by 22.2%, the soluble protein content by 30% and the lycopene content 1.9 times.Two treatment also significantly improved the content of sugar-acid ratio, total soluble sugar , Vitamin C, total phenols and flavonoids, but no significantly effect on reducing sugar content. Tomato aromatic substance detecting by GC-MS, showed that two treatments increased (Z)-3-Hexenal, (E)-2-Hexenal, 6-methyl-5-Hepten-2-one,Methyl salicylate, Ketone and esters increased by spraying treatment and Long Chain Alkane, and (E,E)-2,4-Hexadienal increased by fertilizing treatment is effective than spraying treatment.

The effect of final temperature(4℃、6℃、8℃) on the vacuum cooling performances of tofu was studied, including the cooling rate, weight loss and typical property changes (protein, water binding capacity, pH value, hardness, colour and luster) during the storage period of a week at 4℃. The results indicat that effects of final temperature on cooling rate and weight loss were not significant. However, the different final temperature(4℃、6℃、8℃) on the vacuum cooling performances for the quality of tofu（protein, water binding capacity, pH value, hardness, colour and luster） had significant influence. The conclusion was drawn that 4℃ is considered as the best final temperature for tofu ,which can be stored with 4℃ for five days without significant quality change.

Changes in adenosine triphosphate (ATP) degradation compounds measured by reversed phase-high performance liquid chromatography (RP-HPLC) were monitored during storage of chilled tilapia fillets, and new freshness indicators as Ki、H、Fr value were proposed. The fillet freshness were evaluated by integrated measurements of sensory attributes, total volatile basic nitrogen, psychrotrophic bacteria, ATP degradation compounds and their proportions as K related values. The results showed that the concentrations of ATP degradation compounds could be deceted exactly and rapidly by RP-HPLC; during chilled storage of tilapia fillets, it is found that ATP was degraded rapidly into inosine monophosphate (IMP); the content of ATP, adenosine diphosphate (ADP) and adenosine monophosphate (AMP) kept no more than 0.50μmol/g, IMP reached the highest level of 3.88 μmol/g initially and degraded into HxR (inosine) and hypoxantjine (Hx) with the storage time, and mainly accumulated Hx; Hx were in very low level initially, and increased gradually into the end level of 2.35 μmol/g with the decrease of freshness; rapid increase of Hx in spoilage phases were high correlation with microbiological metabolite off-odors. K value had highest correlation with sensory assessment and microbiological counts, H value and Hx could be alternated K value as freshness indicators.

Abstract: The effect of ginger extract on preservation of fresh-cut ‘Red Fuji’ apple was researched under immersing process with different concentrations, and physiological-quality indexes and microbial dynamic change were determined during the storage period. The results showed that: the respiratory rate and ethylene release quantity were significantly delayed. The weightlessness rate and the loss of acid titration were significantly reduced. The PPO activity and the accumulation of MDA were effectively inhibited. Combined with sensory quality that fuzzy evaluation, the best preservation effect was the 0.1g?ml-1ginger extract.

The fresh-keeping effect on litchi which were storaged at 4±1℃ after drug treatment of the complex agent comprised by the mixture of antibacterial agent (natamycin, sodium diacetate) and antioxidant (tea polyphenols, ascorbic acid) with chitosan was studied. The results showed that when sorted at 4±1℃, the complex of 10g/L chitosan, 0.2 g/L natamycin, 10 g/L tea polyphenols and 19.2 g/L citric acid had an effective inhibition on the decay of litchi, the color change of its pericarp, the increase of PPO and POD activity and the decrease of the soluble solid content. Furthermore, it had a relatively satisfactory effect on improving the sensory quality of litchi. No decay was detected on the litchi coated with this complex fresh-keeping agent after storage under 4±1℃ for 18 days. Namely, through a sensory evaluation, the color of the pericarp, taste and flavor of the pulp and overall acceptability of litchi were 7.0, 6.3, 8.0, 7.0, respectively, which was significantly better than that of control group, 4.1，4.0，2.9, 3.1, respectively. Meanwhile, the activity decrease was 47.4% for PPO and 49.0% for POD compared with the control group.

Sensory, chemical and microbiological characteristics of cultured Oreochromis niloticus stored aerobically at low from 0 to 10 degree and ambient temperatures at 25 degree were carried out, and the shelf lives and bacterial flora at the end of shelf life were also studied, meanwhile the predictive model of shelf life using square-root relative spoilage rate equation was developed. The results showed that the freshness of cultured Oreochromis niloticus at the initial time was excellent, its mean values of total viable count, Pseudomonas spp count, H2S-producing bacteria count and total volatile basic nitrogen were 4.41±1.13、3.39±1.09、2.01±0.88 lg(cfu/g)和8.53±0.73mg/100g, respectively. The freshness index including total viable count, Pseudomonas spp count, H2S-producing bacteria count and total volatile basic nitrogen of cultured Oreochromis niloticus stored aerobically at low temperature reached 7.79±0.35、7.24±0.45、6.35±0.23 lg(cfu/g)和19.90±2.10mg/100g，the shelf life of fish stored at low temperature was from 5.5 days to 20.1 days, their dominated bacteria was Pseudomonas spp. The shelf life was 1.1 days at ambient temperature , its dominated bacteria was Aeromonas spp. The parameter(minimum temperature) of quality kinetics model of cultured Oreochromis niloticus stored from 0℃ to 25℃ was -8.9℃.The shelf life models of relative rate of spoilage were validated under isothermal (3and 8℃) and non-isothermal conditions,indicating the predictive model of shelf life can efficiently evaluate the quality of cultured Oreochromis niloticus stored from 0℃ to 25℃.

In order to understand the effect of ultra-high pressure (UHP) treatment on the shelf-life and quality index of Nanjing salted duck, the vacuum-packaged duck breasts were subjected to UHP (200 and 400 MPa) treatment at 20℃、30℃、40℃ for 10 min. All samples are stored at 4℃. Total counts of spoilage microorganisms in UHP-treated and control breasts, were determined every week of storage. In addition, pH color, TBARS were assayed and sensory analysis was performed. The results indicated that UHP treatment could effectively inactivate initial microorganisms and inhibit growth of microorganisms in Nanjing salted duck breast. At the beginning of storage, UHP-treated breasts revealed increased. However, at the late storage period, no evident change of TBARS value in breasts with UHP treatment was observed. Breasts after UHP treatment evidently have a higher pH value than untreated samples. UHP treated breasts can not be distinguished from untreated samples in sensory analysis. Therefore, UHP treatment can effectively extend the shelf-life of Nanjing salted duck, and will not result in obvious changes of quality index in Nanjing salted duck, thereby better maintaining original product quality and taste.

Carotenoids affect the external fruit quality and nutritional quality of citrus fruit greatly. In present study, effects of storage temperature (20°C and 4°C) on the carotenoid contents in fruit of ‘Cara Cara’ navel orange (C. sinensis Osbeck) was investigated. Results showed that the storage temperatures affected the carotenoids contents in peel and pulp of ‘Cara Cara’ in a tissue-specific manner. Room temperature (20°C) showed a positive role in pigmentation in peel of ‘Cara Cara’ only before 5 weeks of storage, but the total carotenoids remained a nearly stable level as time progressed. Low temperature (4°C) could maintain the carotenoid contents in the peel before early storage, but the contents were lower than those under room temperature. Except a slight increase in contents of β-carotene, lutein, α-cryptoxanthin at 10 weeks of storage, carotenoid contents in the pulp stored at 20 °C was not influenced. In contrast, the contents of carotenoid in the pulp under low temperature reached the peaks at 1 week of storage, and then remained nearly stable levels.

The objective of the present study was to elucidate the effect of fat addition and frozen storage time on the oxidation and gelation of myofibrils from frozen dumpling fillers. The oxidation and gelling ability of myofibril extracted from fillers in the frozen dumplings were studied in order to evaluate the quality deterioration mechanism of frozen dumpling during frozen storage. The carbonyl content, heat-induced gelatin viscosity and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrils of frozen dumplings were determined. The results indicated that with the prolongation of frozen storage time, the carbonyl content in the myofibrillar protein increased significantly (P < 0.05). The storage modulus (G') and the peak temperature of myofibril protein decreased gradually. The SDS-PAGE showed that the percent of myosin heavy chain (MHC) and actin reduced and myosin light chain2 disappeared at 180d of frozen storage. Because fat oxidation could cause protein oxidation, the myofibril protein denatured seriously for more addition of fat in dumpling, which would further affect the gelling ability and viscoelasticity of protein. Therefore the quality of frozen dumplings decreased with increasing fat content and extending storage time.