The effects of in vitro gastrointestinal digestion on the controlled release and antioxidant properties of encapsulated grape skin anthocyanins (ACNs) from water-in-oil-in-water (W1/O/W2) double emulsions were determined. The double emulsions exhibited a bimodal distribution (d = (149.33 ± 1.44) nm) with an encapsulation efficiency of (82.99 ± 2.38)%. Oral digestion in vitro did not affect the structure of the emulsion droplets. After simulated gastric digestion, the double W1/O/W2 emulsions became a single W1/O emulsion due to proteolysis, and the released emulsion droplets were aggregated together leading to a significant increase (P < 0.05) in average droplet size. During subsequent intestinal digestion, the W1/O droplets were broken, so that the average droplet size (d < 150 nm) decreased significantly (P < 0.05), and the highest antioxidant activities were identified. Our results indicated that the encapsulated ACNs were effectively protected by the W1/O/W2 double emulsions against in vitro oral and gastric digestion, and were delivered to the target in the simulated small intestine.

In order to clarify the influence of different production processes on the stability of soybean oil, we used soybean oils obtained by pressing and extraction to deep-fat fry chicken fillets and we investigated the influence of frying time and temperature on the quality of the oil samples according to changes in acid value (AV) and carbonyl value (CV). Experimental results showed that AV changed only slightly with frying time. After being used at 220 and 240 ℃, the CV of pressed soybean oil was significantly higher than that of extracted soybean oil. Moreover, at 240 ℃, there were significant differences in both parameters (P < 0.05). Therefore, compared with the pressed oil, the extracted oil had better stability against frying at high temperature. At the same time, near-infrared (NIR) spectroscopy was used to predict the two stability indicators of soybean oil. A highly accurate predictive model was established using the characteristic bands selected by interval partial least square (IPLS) and successive projection algorithm (SPA). The AV prediction model had the best performance in the bands of 1 150–1 315 nm and 1 579–2 444 nm with a validation correlation coefficient of 0.955 and a root mean square error of prediction of 0.049. The CA prediction model had the best performance in the bands of 1 236–2 093 nm and 2 187–2 594 nm with a validation correlation coefficient of 0.946 and a root mean square error of prediction of 3.134. These results support that the accuracy of the model may be improved effectively by selecting the characteristic bands using IPLS and SPA.

The microstructure of whey protein (WP)/cyanidin-3-O-glucoside (C3G) nanoparticles was studied by a nanometer particle size analyzer, transmission electron microscopy and Fourier transform infrared spectrometry, and the digestion stability in vitro and storage stability were analyzed as well. Nanoparticles with an average diameter of (275.51 ± 3.15)nm, PdI of (0.28 ± 0.01), zeta potential of (?16.92 ± 1.04) mV, encapsulation efficiency of (97.09 ± 2.39)% and loading efficiency of (2.43 ± 0.05)% were prepared successfully under the following conditions: heating WP in a water bath at 80 ℃ for 30 min, homogenously mixing it with C3G: WP at a volume ratio of 1:80 after pH adjustment to 7, and finally adding 8 mmol/L CaCl2. Transmission electron microscopy showed that after encapsulating C3G, the nanoparticles changed from hollow nanospheres to typical “core-shell” structures. The results of infrared spectroscopy showed that the secondary structure of whey protein was changed after binding with C3G; the contents of α-helix and β-turn were reduced, while the contents of β-sheet and random coil were increased. After in vitro digestion, the release rate of C3G from the WP-C3G nanoparticles was (87.25 ± 3.72)%, and the degradation rate of C3G decreased by (51.34 ± 0.52)% as compared with free C3G. After being stored for 20 days in the dark, the retention rate of free and encapsulated C3G were (42.62 ± 2.33)% and (64.14 ± 1.70)%, respectively. The results showed that the gastrointestinal digestion stability and storage stability of C3G can be effectively improved after being encapsulated with whey protein.

In order to investigate the quality changes of specialty malt under different malting conditions, the present study investigated the effect of roasting temperature, roasting time and raw material quality on the color, α-amino nitrogen (α-AN) content, and the contents of 2,5-dimethylpyrazine and furfural in specialty malt. The results showed that the contents of water and α-amino nitrogen in specialty malt decreased significantly with the increase of roasting temperature (P < 0.05). When the temperature reached 160 ℃, the moisture content was lower than 1%, and the content of α-amino nitrogen in specialty malt germinated for 3 days decreased fastest, from 228.157 to 118.427 mg/L. The content of β-glucan in control malt (prepared by the traditional soaking-germination procedure) was the highest. The content of β-glucan decreased gradually with the increase of soaking and germination time. For both control and specialty malt, different raosting temperatures had little effect on the content of β-glucan. The chroma, reducing power, and 2-thiobarbituric acid (TBA) value significantly increased with the increase of roasting temperature (P < 0.05). The malt germinated for 3 days had the fastest growth and the highest reducing power, up to 1.303. Since it is proportional to the severity of beer aging, the TBA value should be reasonably controlled during the malting process. With the increase of roasting temperature, the content of 2,5-dimethylpyrazine decreased firstly and then increased. In contrast, the content of furfural change only marginally with increasing roasting temperature from 80 to 120 ℃, and then began to increase significantly. Both 2,5-dimethylpyrazine and furfural were mainly produced at 120–160 ℃.

In this study, the apparent viscosity, water-holding capacity and oil-holding capacity of different concentrations (1, 5, 10, 15, and 20 mg/mL) of chia seed peel polysaccharide were studied together with the droplet size distribution, emulsion stability, apparent viscosity and microrheology of oil-in-water (O/W) emulsions containing the polysaccharide. The results showed that within the concentration range of 1–20 mg/mL, the higher the concentration of the polysaccharide, the higher its viscosity was, which indicates that it behaves as a non-Newtonian fluid with a pseudoplastic behavior. It had certain water-holding capacity (WHC) (16.79%–25.39%) and oil-holding capacity (OHC) (4.89%–9.75%). With the increase in the polysaccharide concentration, the droplet size diameter of emulsions was decreased and concentrated, and the apparent viscosity was increased. The change in backscattered light intensity tended to zero, the stability index was decreased, and the stability was increased. The mean square displacement curve showed that in a short decorrelation time, as the concentration of the polysaccharide was increased, the emulsion droplets had strong interactions with each other, and the Brownian motion of the droplets was weakened to form a stable structure. The chia seed peel polysaccharide obtained in this study has potential application prospects in food processing.

By fractional ultrafiltration followed by DEAE-52 anion-exchange column chromatography, an enzymatic hydrolysate of Crassostrea rivularis was fractionated into three polysaccharides named CRP-1, CRP-2 and CRP-3. The molecular masses and purity of the polysaccharides were determined by high performance gel permeation chromatography combined with Sephadex G-100 column chromatography, and their structures were elucidated by determining glycosyl groups as well as using high performance liquid chromatography and Fourier transform infrared (FTIR) spectroscopy. The results showed that the total sugar content of CRP-1 was (32.40 ± 0.89)% with a molecular mass of 124.5 kDa. It was composed of mannose, ribose, glucosamine, glucuronic acid, galacturonic acid, glucose, galactosamine, galactose, arabinose, with a molar ratio of 5.55:0.32:9.08:0.47:0.66:48.13:3.57:8.53:0.30. The total sugar content of CRP-2 was (78.50 ± 1.90)% with a molecular mass of 67.0 kDa. CRP-2 was composed of mannose, ribose, glucosamine, glucose, galactose and galactose with a molar ratio of 7.79:0.41:12.69:32.08:4.98:15.92. The total sugar content of CRP-3 was (73.46 ± 2.19)%, with a molecular mass of 8.3 kDa. It was composed of glucosamine, galactose acid and glucose with a molar ratio 8.91:5.71:10.15. FTIR analysis showed that CRP-1 was a polyaldehyde pyranoside. CRP-2 was an unsaturated polyhydroxyketone while CRP-3 was a polyunsaturated polyhydroxyketone containing carboxyl groups. All the polysaccharides displayed immunomodulatory activity in mouse macrophage line RAW264.7.

In this study, micronized shiitake powder was added to crispy instant noodle dough in different amounts (1%, 3%, 5%, 7%, and 9%). By measuring the starch gelatinization properties, texture properties and dynamic rheological properties of dough, and the moisture content and oil content and distribution of crispy instant noodles, we investigated the effect of the addition of different amounts of shiitake on dough rheological properties and oil penetration into crispy instant noodles. The results showed that with increasing level of shiitake addition, the peak viscosity, trough viscosity and final viscosity of dough significantly decreased, hardness increased and cohesiveness, elasticity, and elastic modulus and viscous modulus decreased first and then rose. The crisp instant noodles with 5% shiitake powder had the highest moisture content and the lowest oil content. A dense internal structure was observed in the noodles, which exhibited the weakest fluorescence intensity and an even oil distribution. The results show that adding a proper amount of shiitake powder to dough can change its rheological properties, and inhibit the penetration of oil during the frying process of crisp instant noodles.

In this work, the interaction between curcumin (Cur) and Cynanchum auriculatum Royle ex Wigh protein (CAP) or soy protein isolate (SPI) was characterized by a combination of steady-state fluorescence spectroscopy, far-ultraviolet circular dichroism (CD) spectroscopy, differential scanning calorimetry (DSC), and dynamic light scattering (DLS). The protective effects of the two proteins on the chemical stability of Cur were further investigated. Results showed that Cur quenched the intrinsic fluorescence of the proteins in a static manner. The complexation of Cur with either protein was a spontaneous reaction characterized by a decrease in Gibbs free energy and mainly driven by hydrophobic interaction. Cur bound more readily to SPI than to CAP. Fourier-transform infrared spectroscopy (FTIR) analysis suggested that in addition to hydrophobic interactions, hydrogen bonding might also be involved in the formation of Cur-protein complexes. Cur binding resulted in a reduction in the α-helix structure in CAP with a paralleled increase in the contents of three other secondary structures, as well as reduced the thermal stability of CAP. Compared with SPI, Cur-SPI complex contained less α-helix and β-turn structures and presented a higher thermal stability. The complexation of Cur with CAP and SPI afforded nanoparticles with a diameter of 159.98 and 244.34 nm, respectively. The thermal stability of Cur at 40 and 90 ℃ was improved remarkably after being bound with CAP or SPI, and the protective effect of SPI appeared to be more pronounced.

The effect of different pH conditions on the biosynthesis of S-adenosylmethionine (SAM) and glutathione (GSH) by Candida utilis under high cell density culture was investigated. Moderate acid stress (pH 3.5) was found to be beneficial for SAM and GSH biosynthesis and consequently the high-yield co-production of SAM and GSH by the yeast cells. By measuring the key enzymes activities, energy supply, and the intracellular redox environment, moderate acid stress was shown to be able to increase the activities of SAM synthase, γ-glutamylcysteine synthase, hexokinase, ATP synthase and catalase, and elevate the intracellular levels and regeneration abilities of NADH and ATP, thereby ensuring sufficient substance and energy supply for the over-production of SAM and GSH. Results obtained in this study present adequate evidence to reveal the physiological mechanism of moderate acid stress in improving SAM and GSH biosynthesis, which may provide a feasible idea for the over-production of other similar small molecular bioactive compounds.

The effects of different concentrations of oleic acid on the growth and freeze-drying survival of Lactobacillus plantarum LIP-1 were studied. The results showed that low concentration of oleic acid (≤ 0.2 g/L) could increase the viable count and freeze-drying survival rate in MRS medium. The optimum concentration of oleic acid was 0.1 g/L, increasing the viable bacteria count and the freeze-drying survival rate by 9 × 108 CFU/mL and 8.38% as compared with the blank control group without oleic acid, respectively. When the concentration of oleic acid was higher than 0.3 g/L, the growth of the strain was inhibited. The fatty acid composition of the cell membrane was analyzed by gas chromatography (GC). The results showed that the ratio of unsaturated fatty acids to saturated fatty acids (UFA/SFA) was increased by 0.45% and the proportion of cyclopropane fatty acids by 8.35% in the 0.1 g/L oleic acid group as compared with the blank control group. There was a significantly negative correlation between stearic acid and oleic acid as well as between palmitic acid and cyclopropane fatty acids. The number of cells exhibiting green fluorescence in the experimental group was significantly higher than that in the control group, which indicated that the integrity of the cell membrane was maintained well in the experimental group during freeze-drying. The activity of β-galactosidase in the supernatant of freeze-dried L. plantarum LIP-1 in the experimental group was lower than that in the MRS group, indicating that low concentration of oleic acid (≤ 0.2 g/L) could maintain the integrity of the cell membrane and reduce the leakage of β-galactosidase. Conclusion: Adding low concentration oleic acid to the medium can promote the synthesis of cyclopropane fatty acids, induce the transformation of saturated fatty acids into unsaturated fatty acids, and improve the resistance of this strain to freeze-drying.

In order to fully reveal the dynamic change of fungal community structure in Xiangyang pickled kohlrabi during its fermentation process, Illumina MiSeq high-throughput sequencing technology was used to investigate the fungal community diversity in pickle juice samples at different fermentation times during its industrial production. A total of 303 species in 190 genera in 106 families in 56 orders in 19 classes in 4 phyla with 516 operational taxonomic units (OTUs) were identified in 24 samples. Collectively, cluster analysis and principal component analysis showed that the 24 samples could be divided into three clusters based on the structural characteristics of fungal community, i.e. early, middle and late stages of fermentation. The total number of OTUs common to the three fermentation stages was 124. Except for unclassified fungi, the dominant phylum in all samples was Ascomycota, with a relative abundance of 74.2% to 99.8%, followed by Basidiomycota. At the level of order, Xylariales was the dominant fungus at the early fermentation stage, with a relative abundance of 45.7% to 60.2%. Subsequently, Saccharomycetales became absolutely dominant instead of Xylariales, with a relative abundance of 63.6% to 99.5%. At the level of genus, Monographella was the dominant fungus at the early fermentation stage while Debaryomyces and Zygosaccharomyces were the dominant fungi at the middle and late stages.

In this paper, Saccharomyces cerevisiae was used as a model fungus to study the changes in cell growth, morphology and intracellular reactive oxygen species (ROS) under the combined effects of different concentrations of ε-poly-L-lysine (ε-PL) and the exogenous antioxidant N-acetylcysteine (NAC). Meanwhile, the antifungal activity of ε-PL on S. cerevisiae was explored. The results showed that the surface of cells treated with ε-PL at sublethal concentration was unsmooth with pits and the cells exhibited an increased intracellular content of ROS. Fluorescence microscopy observation revealed phosphatidylserine externalization, chromatin pyknosis, mitochondrial transmembrane potential dissipation and DNA damage, which together indicate that the cells entered the early stage of apoptosis. Cells treated with ε-PL at lethal concentration had a rough surface with pits and dumps and showed decreased content of intracellular ROS. Moreover, the cells displayed obvious fluorescence characteristics and entered the late stage of apoptosis and even died. After adding NAC, the content of intracellular ROS was decreased and the fluorescence characteristics were attenuated. Therefore, it is suggested that ε-PL can induce an increase in intracellular ROS, consequently leading to cell apoptosis and inhibiting cell activity. In addition, NAC could reduce the antimicrobial activity of ε-PL.

In this study, a method for detecting inositol in food samples was established based on the relationship between the growth of an inositol-deficient yeast strain and the content of inositol in its culture broth. The inositol-deficient yeast Saccharomyces uvarum CICC 1465 was selected from six yeast strains based on its growth specificity for inositol. When it was employed to determine inositol contents in four kinds of foods, the method showed good precision with relative standard deviation (RSD) less than 10%, recoveries (92.3%-114.3%) and reproducibility (RSD less than 10%), indicating that the developed method can be used for the quantitative determination of inositol in food samples.

Bee bread is a fermented food with great development potential. The objective of this study was to analyze the dynamic changes in microbial communities of bee bread during fermentation, and to evaluate the effect of fermentation time on the microflora compositions. Bee bread samples of Apis mellifera carnica fermented for 0.5, 4, 7 and 12 d were collected, and their microbial 16S rDNA sequences were evaluated by high-throughput sequencing. The microbial community diversity and composition in these samples were comparatively analyzed. A total of 27 phyla and 112 genera of bacteria were identified in the 4 samples. Besides, there were 25 genera common to the 4 samples. Moreover, the sequencing depth in this study effectively covered all the microbial species, along with the fermentation process, microbial richness and diversity were increased first and then decreased. Oxyphotobacteria and Proteobacteria were dominant at the phylum level. At the genus level, unidentified Oxyphotobacteria was the dominant microorganism in bee bread. Along with the fermentation process, the unidentified Oxyphotobacteria increased first and then decreased.

In this paper, fermented duck thigh was manufactured with a mixed starter culture of Lactobacillus plantarum and Saccharomyces cerevisiae, and its physicochemical indexes and changes in quality characteristics during storage were evaluated. The results showed that the optimum processing conditions were determined as follows: inoculum amount 2%, ratio of L. plantarum to S. cerevisiae 1:2, fermentation time 24 h, and temperature 30 ℃. The pH, Escherichia coli count, nitrite, histamine and peroxide value of the fermented product generated under the optimized conditions were all within the requirements of the national standards. As storage time increased, the sensory score gradually decreased, and the thiobarbituric acid (TBA) value and total volatile basic nitrogen (TVB-N) value gradually increased. The changes in all these parameters in the uninoculated control group were greater than those of the inoculated group. The total number of colonies and the content of nitrite in the inoculated group increased during the first 30 d of storage, and then decreased from day 30 to 50 whereas the two parameters in the control group continued to increase. The contents of all tested biogenic amines in the inoculated group showed an upward trend in the early stage of storage. The contents of tryptamine, cadaverine, tyramine and spermidine decreased after day 30, and the contents of phenylethylamine, putrescine and spermine decreased after day 40. In contrast, the total content of biogenic amines in the control group kept increasing. In summary, inoculation with the mixed starter could improve the taste of the product, and significantly retard the deterioration in the sensory quality, fat oxidation and the production of undesirable biogenic amines during prolonged storage.

To understand the bacterial flora structure and microbial safety of red sufu as a traditional Chinese fermented food, the V1-V3 region of the bacterial 16S rDNA from red sufus produced in the east, north and northeast of the country was sequenced by high-throughput sequencing and the differences in the structure and diversity of microbial community was analyzed among these samples. The results showed that the sequencing depth effectively covered the microbial species in the samples, and the bacterial communities in them were rich and diverse. At the phylum level, Firmicutes, Actinobacteria and Proteobacteria were dominant in all samples. A total of 296 bacterial genera were detected, with Corynebacterium, Tetragenococcus, Leuconostoc, Rummeliibacillus, Lactococcus, Weissella, Streptococcus, Comamonas, Bacillus and Trabulsiella being common to these samples. At the same time, clustering analysis demonstrated that there was a relationship between the bacterial community structure and the geographical origin of red sufu. The main dominant bacteria in the samples from North China were Candida, Lactobacillus and Tetraphylococcus, while those in the red sufu samples from Northeast China were Bacillus and Halanaerobe. This study gives further insights into the structure and diversity of microbial community in red sufu, providing a theoretical basis for production of traditional fermented foods with higher quality and safety.

The diacetyl and acetoin production characteristics of eight lactic acid bacteria (LAB) strains isolated from Tibetan kefir and Inner Mongolia dairy tofu were studied. For this purpose, the six key genes related to the production of the flavor compounds including diacetyl and acetoin in the 8 strains were determined using genome-wide annotation analysis. The amounts of diacetyl produced by Streptococcus thermophilus GST-6, Lactobacillus rhamnosus 5-1, and L. paracasei N1115 in fermented milk were 0.72, 0.53 and 0.47 μg/mL, respectively, significantly higher than those produced by five other strains (P < 0.05), and were increased up to 6.23, 5.28 and 4.47 μg/mL, respectively, when citric acid was added to the milk. Correlation analysis showed that the oxaloacetate decarboxylase (OAD) gene was strongly correlated with the yield of diacetyl with Pearson correlation coefficient of 0.898 (P < 0.01), while the lactate dehydrogenase (LDH) and acetyl lactate synthase (ALS) genes were not significantly correlated with the yield of diacetyl (P > 0.05). The relationship between the yield of acetoin and each of the key genes was not significant (P > 0.05). Using gas chromatography-mass spectrometry (GC-MS), a total of 24 volatile compounds were detected in all the fermented milk samples. Principal component analysis showed that organic acids, acetoin and diacetyl were the characteristic flavor compounds of the strains. Heptanone and 2-nonanone were also important volatile flavor compounds.

This study attempted to improve the expression level of recombinant human lysozyme in Pichia pastoris by co-expression of the chaperone protein disulfide isomerase (PDI) and the transcriptional activator of ferrous transport-1 (Aft1) from P. pastoris. The constructed expression plasmids, pG418-PDI and pG418-Aft1, were linearized and integrated into the genome of P. pastoris KM71-HLY through homologous recombination by electroporation. The positive transformants were selected based on G418 resistance, yielding two recombinant strains, KM71-HLY-PG418-PDI and KM71-HLY-PG418-Aft1. Shake flask fermentation was performed to analyze the expression level of HLY in the engineered yeasts. Experimental results showed that KM71-HLY, KM71-HLY-pG418-PDI and KM71-HLY-pG418-Aft1 all produced human lysozyme (14.7 kDa) with inhibitory effects on Micrococcus lysodeik under the induction of methanol. These recombinant strains exhibited only a slight difference in the cell growth at the early stage of induction. However, the biomasses of KM71-HLY-PG418-PDI and KM71-HLY-PG418-Aft1 were lower than that of KM71-HLY after 70 h and their optical density values (OD600 nm) at the end of fermentation were 92.8% and 84.1% as compared to KM71-HLY, respectively. When induced by methanol for 168 h, the yields of total secretory protein of KM71-HLY, KM71-HLY-PG418-PDI and KM71-HLY-PG418-Aft1 were 324.02, 350.87 and 474.8 mg/L, and the lysozyme activities of the fermentation supernatants were 34 880, 45 600 and 50 180 U/mL, respectively. As compared to KM71-HLY, KM71-HLY-PG418-PDI and KM71-HLY-PG418-Aft1 increased total secretory protein production by 8.3% and 46.5%, and extracellular lysozyme activity by 30.7% and 43.9%, respectively.

Proteases were extracted from shrimp heads as a byproduct from the processing of Pacific white shrimp (Penaeus vannamei). The types of enzymes contained in the extract and the effect of salt concentration on these protease activities were investigated. The extract mainly contained trypsin, cathepsins and aminopeptidases. At NaCl concentration of 25%, trypsin, cathepsin B+L and cathepsin K retained about 10% of their initial activity while the activity of phenylalanine aminopeptidase remained 30% of its initial level. High salinity (25%) had an activating effect on alanine aminopeptidase and methionine aminopeptidase, increasing them by 31% and 91%, respectively. The crude proteases were used to degrade waste proteins from soy sauce production. The degradation efficiency and the inhibitory activity of the resulting products against angiotensin I-converting enzyme (ACE) were evaluated. It was found that the proteases were still able to digest the proteins even at high salinity. After enzymatic hydrolysis, the polypeptide content increased from 96.16 to 1 049.55 μg/mL, the proportion of proteins with molecular mass higher than 5 kDa decreased from 43.78% to 16.85%, and the proportion of peptides with molecular mass lower than 1 kDa increased from 28.50% to 58.96%. The total amount of free amino acids increased from 3.01 to 97.16 mg/100 mL. The utilization rate of soybean proteins increased by about 11.82%. The IC50 value of the resulting hydrolysate for inhibition of ACE was 90.02 μg/mL. Our present study provides a theoretical basis for high-valued utilization of by-products from the processing of soy sauce and shrimp.

Post-fermentation of Pixian broad-bean paste was conducted for 90 days at a constant temperature in a semi-closed system designed by the authors, and this was compared with the tradition natural post-fermentation process. The contents of total acid, amino nitrogen, reducing sugar, free amino acids and moisture and chromaticity at the end of traditional natural fermentation were 1.13%, 0.27%, 2.81%, 19.68 mg/g, 48.80%, and 0.784 while those at the end of constant temperature fermentation were 0.78%, 0.20%, 2.12%, 16.11 mg/g, 60.21% and 1.025, respectively. The results showed that the fermentation of Pixian broad-bean paste proceeded normally in the semi-closed system and the product was in accordance with the quality criteria. All quality parameters evaluated changed more greatly during the traditional fermentation process and more violent physical and biochemical reactions took place. The spatiotemporal distribution of temperature and change in moisture content had a great influence on the fermentation process. Both fermentation processes had their own advantages, and the constant-temperature fermentation process should be optimized by referring to the important conditions for traditional natural fermentation.

Cholesterol-lowering Bifidobacteria and lactic acid bacteria were used as mixed starter cultures to produce yoghurt from a mixture of skim milk powder and saccharified potato pulp in this paper. The effect of 19 different strains on the quality of yoghurt was studied, and the effects of different combinations of selected strains and inoculum size on the concentration of acetaldehyde and diacetyl as the major flavor compounds, determined by titration and colorimetric assay using o-phenylenediamine, respectively, as well as sensory evaluation were also examined. The results showed that the sensory evaluation score and flavor compounds concentrations exhibited strain specificity. The interaction among Bifidobacterium animalis subsp. lactis BZ11, Lactobacillus pentosus MT-4, B. longum BL1 and Streptococcus thermophiles Q-1 affected flavor formation in yogurt fermented by their mixed cultures. The total probiotic count in the yogurt produced under the optimized conditions was 6.3 × 108 CFU/mL. Notably, the Bifidobacterium count was up to 3.6 × 108 CFU/mL. In addition, the contents of reducing sugar and free amino acids were 1.94% and 136.64 mg/100 g, both higher than those before fermentation and those of commercial yogurt. The degradation percentage of cholesterol in yoghurt containing the mixed culture was 20.45%, which was 1.86%–15.57% higher than that obtained using individual strains alone. The probiotic potato not only had an excellent flavor, but also could be expected to have health benefits due to its nutritional and functional properties.

To develop a new biosorbent for the removal of heavy metals, we studied the adsorption characteristics and mechanism of Pb2+ by Wickerhamomyces anomalus QF-1-1, with high Pb2+ adsorption capacity. The shaking flask method was used to investigate the effects of initial Pb2+ concentration, initial pH value, microbial cell concentration and adsorption time on Pb2+ adsorption by this strain. The adsorption mechanism was studied by group making, chemical treatment and desorption experiments. The results showed that the optimum conditions for obtaining maximum adsorption capacity of 7.29 mg/g and Pb2+ removal rate of 97.89% were found to be pH 5.5, initial Pb2+ concentration 100 mg/L, yeast cell concentration 11 g/L, and absorption time 140 min. After making the –COOH, –NH2 and –PO3 groups on the cell surface, the removal rate of Pb2+ by QF-1-1 decreased from 92.61% to 34.13%、38.69%、77.84%, respectively. Therefore, in terms of decreasing contribution to Pb2+ adsorption, the three groups could be ranked in the following order: –COOH > –NH2 > –PO3. Different chemical treatments had different effects on the Pb2+ adsorption capacity of QF-1-1, which significantly decreased after acid treatment (P < 0.01). The Pb2+ adsorption process was reversible and the adsorbed Pb2+ could be eluted by 0.1 mol/L HCl, 15 mmol/L HNO3, and 1.0 mmol/L ethylenediaminetetraacetic acid (EDTA). The remaining intracellular Pb2+ accounted for less than 4.1% of the total adsorption amount after 4 times elution. Surface adsorption might be the main factor for the removal of Pb2+ by QF-1-1.

An esterifying enzyme was immobilized by embedding onto sodium alginate-microporous starch and then used to catalyze esterification in a new vinegar to accelerate its aging. The optimum immobilization conditions were obtained as follows: sodium alginate concentration 2.5 g/100 mL, microporous starch concentration 1.5 g/100 mL, enzyme concentration 6 g/100 mL, CaCl2 concentration 3 g/100 mL, and immobilization time 1 h. Under these optimized conditions, the enzymatic activity recovery was 60.13%. After the vinegar was aged for 48 h at 40 ℃ after adding the immobilized enzyme to it at a level of 4.5 g per 500 mL, the total ester content increased by 0.304 g/100 mL, reaching 1.329 g/100 mL, 29.66% higher than that before the treatment.

In this study, two acid-tolerant, salt-tolerant and high glucose-tolerant strains were isolated from naturally fermented apple puree samples from the apple-producing area of Yiyuan Mountain in Shandong province through primary screening using MRS medium at pH 2.0 and secondary screening using MRS medium supplemented with 10% sodium chloride and 30% glucose. They were identified to be Lactobacillus plantarum S3-10 and L. casei R10 by physiological, biochemical and molecular biology characterization. The fermentation performances of the strains in MRS medium and fruit and vegetable puree were studied by measuring the dry cell mass, viable cell count, pH value and acidity. Results showed that the two strains had the characteristics of vigorous growth and rapid acid production. The growth and acid production of L. plantarum S3-10 were significantly higher than those of L. casei R10. Both strains display excellent fermentation performance, and have broad application prospects in fermenting fruit and vegetable juices and and developing functional probiotic products.

In order to fully utilize corn cob powder as an agricultural by-product, the submerged fermentation of Aspergillus niger using corn cob powder as a substrate was optimized for enhanced xylosidase activity. Firstly, one-factor-at-a-time method was used to investigate the effects of fermentation period, temperature, inoculum size, initial fermentation pH, medium volume and shaker speed on xylosidase activity. The results showed that a fermentation period of 144 h, a temperature of 34 ℃, an inoculum size of 7%, an initial fermentation pH of 3.0, a shaking speed of 180 r/min, and a medium volume of 110 mL in 300-mL shake flasks were found to be the best conditions. Further, using the Plackett-Burman design, lowest addition experiments, the steepest ascent method, and response surface methodology with central composite design, the optimal levels for medium components were determined as follows: corn kernel powder 31.55 g/L, yeast powder 8.00 g/L, peptone 5.48 g/L, magnesium sulfate 0.70 g/L, sodium chloride 1.00 g/L, and calcium chloride 1.50 g/L. A quadratic polynomial model was developed with a determination coefficient R2 of 0.991 0, and an adjustment coefficient R2 of 0.982 9. The analysis of variance (ANOVA) showed that the model was significant with a P value greater than 0.05 for lack-of-fit, supporting its use for the theoretical prediction of enzyme production. Under the optimized conditions, an 8.89-fold increase was observed in xylosidase activity of Aspergillus niger.

To efficiently select microbial strains capable of biotransforming cinnamaldehyde into cinnamyl alcohol, a new method for the rapid determination of cinnamyl alcohol, cinnamaldehyde and cinnamic acid in the biotransformation products of cinnamaldehyde was established using multi-order derivative ultraviolet (UV) spectrometry. Based on their second (for cinnamaldehyde and cinnamic acid) or third (for cinnamyl alcohol) order derivative UV absorption spectra, 320, 306 and 256 nm were selected as suitable wavelengths for determination of cinnamaldehyde, cinnamic acid and cinnamyl alcohol, respectively. Good linearity was observed in the concentration range of 0.52–9.27, 0.51–9.24 and 0.55–5.47 mg/L for the three compounds, respectively. Their average recoveries were 103.3%, 104.1% and 98.0% with relative standard deviations (RSDs) of 4.1%, 2.1% and 3.5% (n = 3), respectively. The measurement could be carried out on samples after dilution without extraction or separation, which could be used for rapid screening for strains capable of biotransforming cinnamaldehyde into cinnamyl alcohol.

Fresh tea leaves of the cultivar Baojing Huangjincha 1 were used to manufacture Congou black tea by the sequential steps of withering, rolling, fermentation and drying. Our aim was to investigate the influence of these steps on the formation of main taste compounds. The results showed that withering had the greatest influence on the formation of free amino acids in tea, and the variation in total free amino acids after withering accounted for 375% of the total variation over the whole manufacturing process, whereas it had only a slight effect on the formation of other taste compounds. The contents of water extract, tea polyphenols, total catechins, soluble sugar, and free amino acids were decreased after rolling, which had greater effects than the other processing steps on the formation of theaflavins and thearubigins, and the variation in these two compounds after rolling accounted for 260% and 164% of the total variation, respectively. The fermentation process increased the contents of total flavones, soluble sugar, thearubigins, and theabrownins, and the variation in soluble sugar and total free amino acids accounted for 195% and 183% of the total variation, respectively. The drying process increased the contents of gallic acids, total flavones, and caffeine, and contributed 148% and 98% to the total variation of soluble sugar and theaflavins during the entire manufacturing process, respectively.

In this study, an electronic nose and an electronic tongue as well as gas chromatography-mass spectrometry (GC-MS) were employed to evaluate the flavor compounds of rye tea made from ungerminated and germinated rye seeds. Qualitative analysis was performed based on retention indices. The results showed that the flavor of rye tea apparently changed after germination. The bitter and sour taste detected using the electronic tongue both decreased, reaching the lowest level on the third day of germination. The relative contents of aldehydes, ketones and phenolics contributing to the aroma of rye tea reached the maximum on this day, increasing by 22.09%, 2.07% and 2.75% as compared with those before germination, respectively. A total of 13 aroma components were newly formed in rye tea during the 3-day germination period.

In order to study the effect of different pretreatment methods on the release of flavor substances from Hypsizygus marmoreu, four pretreatments including water extraction at room temperature, cooking, sequential hydrolysis with cellulase followed by flavourzyme, and hydrolysis with mushroom hydrolase were used directly or after flash extraction to promote the release of flavor substances from H. marmoreus. The contents of free amino acids, tasty nucleotides, soluble sugar and organic acids and taste activity value (TAV) were analyzed for the resulting eight supernatant samples. The flavor characteristics were evaluated using an electronic tongue. Subsequently, principal component analysis (PCA) was performed on the data obtained. The results showed that the flash extraction method could promote the release of flavor substances from H. marmoreus. Cooking reduced the total amount of free amino acids and increased the total amounts of organic acids and nucleotides significantly (P < 0.05). The sequential enzymatic hydrolysis significantly increased the contents of bitter and tasteless amino acids as well as glucose, and reduced the contents of sweet amino acids and organic acids (P < 0.05). The one-step hydrolysis increased the contents of umami amino acids, and reduced the contents of bitter, sweet and tasteless amino acids. The radar map could reflect the taste characteristics of all tested samples. In the PCA, two principal components were extracted, accounting cumulatively for 87.79% of the total variation, and water extraction at room temperature was clearly distinct from the other seven treatments. Therefore, different pretreatment methods have different effects on the release of flavor substances from H. marmoreus, so that it should be treated according to different requirements for taste.

The flavonoid components of the supercritical CO2 extract of black Goji berries from Qaidam, Qinghai were analyzed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) employing PeakView workstation, and their structures were determined by analysis of the tandem mass spectra, ultraviolet (UV) spectroscopic analysis and comparison of the mass spectral data with the reference standards. As a result, a total of 13 flavonoids were identified, including 7 flavonol aglycones and flavonol glycosides, 3 dihydroflavonol aglycones, 2 flavonoid aglycones and 1 dihydrogen, namely rutin, quercetin-3-β-glucuronide, hyperoside, quercetin-3-O-galactopyranoside, dihydroquercetin, dihydroiso rhamnosin, dihydrokaempferol, quercetin, apigenin, hesperetin, alizarin, kaempferol, isorhamnetin, and kaempferol. It is noteworthy that hesperetin and alizarin were found in black Goji for the first time.

In this research, we aimed to investigate the differences in physicochemical properties including total acid, amino acid nitrogen, reducing sugar, moisture content, color value and pungency degree as well as volatile flavor composition among Pixian broad-bean pastes prepared with ‘Erjingtiao hot peppers from different growing areas in China during fermentation. Solid phase micro-extraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) and an electronic nose (EN) were used to evaluate the volatile components and discriminate flavor characteristics among Pixian broad-bean pastes. The results showed that Pixian broad-bean paste made with hot peppers from Bijie had the highest total acid content and color value. In contrast, the lowest values of the two indicators were observed in Pixian broad-bean paste made with hot peppers from Chaotian. In addition, Pixian broad-bean paste made with hot peppers from Luzhou contained the highest reducing sugar and moisture content, but lowest amino nitrogen content. Pixian broad-bean paste made with hot peppers from Jianyang had the highest amino nitrogen content and pungency degree. Pixian broad-bean paste made with hot peppers from Zitong had the lowest levels of pungency degree, reducing sugar and moisture content. A total of 176 volatile compounds were identified in the five samples, 41 of which were common to these samples. Aldehydes were the main volatile compounds found in Pixian broad-bean pastes made with hot peppers from Bijie and Luzhou, while esters were predominant in the remaining three samples. In principal component analysis (PCA) and linear discriminant analysis (LDA), the cumulative contribution of the first 2 principal components accounted for 99.81% and 99.35% of the total variance, respectively, suggesting that the sensors had high recognition performance and allowed excellent discrimination among the samples. These findings support the combined use of SPME-GC-MS and electronic nose to evaluate and discriminate flavor characteristics among Pixian broad-bean pastes prepared with hot peppers from different geographical origins, providing a guidance for the development of Pixian broad-bean paste products that can meet different demands.

Purpose: To understand the taste and flavor characteristics of laboratory-made (M1 and M2) and commercial (C1 and C2) fermented bean curds. Methods: An electronic tongue, an automatic amino acid analyzer and solid-phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS) were used to analyze quantitatively and qualitatively the flavor and chemical composition of fermented bean curd. Results: Electronic tongue analysis showed that the taste of M1 was similar to that of C1 and C2, while the bitterness and sourness of M2 were higher. Amino acid analysis showed that glutamic acid contributed most to the taste of the four fermented bean curds, and the content of bitter amino acids in M2 was the highest among these. Meanwhile, a total of 73 volatile compounds were detected by SPME-GC-MS, and the relative contents of terpenes and aromatic compounds in M1 and M2 were higher, while the relative contents of ethanol in C1 and C2 were higher. Conclusions: The results from this study provide a theoretical basis for research on fermented bean curd and its production, and combined use of the above three methods can provide complementary and reliable information.

In order to improve the drying efficiency and the quality of shiitake mushrooms under microwave drying, numerical simulation and bench test were used to study the absorption pattern of microwave energy in shiitake mushrooms at different microwave intensities and to investigate the variation characteristics of temperature and moisture during the drying process. The results showed that the characteristics of microwave drying temperature involved three stages: rising, remaining constant, and rising once again. The same trend was observed for the drying rate. As the temperature rose to 80–100 ℃ at the late stage of drying, the thermal runaway phenomenon appeared, and the internal temperature of shiitake mushrooms rose sharply. Hot spots appeared at the center of shiitake mushrooms during the drying process, and the internal microwave volume heat was significantly higher than that on the surface. In order not to exceed the temperature for thermal runaway, microwave drying should be carried out at microwave intensity of 2.4 W/g first and then 0.8 W/g with a 5 min interval, giving the highest drying uniformity and drying efficiency. The research results provide valuable guidance for the microwave drying of shiitake mushrooms.

The content of heavy metals in Pacific oyster shells was determined by inductively coupled plasma mass spectrometry (ICP-MS), confirming its potential as an excellent calcium source. This material was used to prepare calcium-chelating L-aspartate after being subjected to different pretreatments. The optimal pretreatment was selected based on the chelation efficiency and the product yield, and the resulting powder was fractionated by sieving. The preparation conditions including pH, temperature, time and molar ratio between L-aspartate and Ca2+ were optimized by one-factor-at-a-time and orthogonal array design methods. The obtained chelate was characterized by energy disperse spectrometry (EDS). The results showed that the chelating efficiency of oyster shell powder prepared by sequential grinding and sieving was higher than that of calcined and ball-milled shell powders. The fraction passing through 300–200 had the highest chelating rate with L-aspartate. The optimal conditions for preparing calcium-chelating L-aspartate were determined as follows: pH 4.5, 50 ℃, 100 min, and molar ratio of L-aspartate to Ca2+ 2:1. Under these condition, the chelation rate was as high as 98.5%. According to their scanning electron micrographs (SEM) and BET specific surface area characterization, the morphology of calcined, sieved and ball-milled shell powders was quite different, and their specific surface area increased in that order, corresponding to their respective chelation rates. The EDS results showed that calcium was successfully chelated to L-aspartate. This research provides a theoretical basis and new ideas for the value-added utilization of oyster shell waste and the production of calcium-chelating L-aspartate.

The present study was done in order to optimize the clarification process of Chaenomeles sinensis juice supplemented glutinous rice wine (CRW) and to assess its quality. For the optimization, the effects of chitosan, egg white powder, gelatin and bentonite on the light transmittance of CRW were investigated using one-factor-at-a-time method and Box-Behnken design. The volatile aroma components of clarified CRW aged for 6 months were detected by head-space solid phase microextraction coupled with gas chromatography-mass spectrometry (GC-MS), and sensory evaluation was performed on the wine. The results showed that the optimum combination of clarifying agents that provided maximum light transmittance of 94.36% were chitosan 0.6 g/L, bentonite 0.7 g/L and gelatin 0.07 g/L. A total of 64 aroma components were detected in this wine, including 15 alcohols, 21 esters, 9 acids and 6 aldehydes. It was found to contain 14.8% alcohol (V/V), 0.35 mg/mL total flavonoids, and 0.045 mg/mL total triterpenes, and 0.93 mg/mL total flavonoids. The total antioxidant capacity, superoxide anion capacity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical rate of the wine were 24.63 U/mL, 178.59 U/L and 13.77%, respectively. The wine was clear and transparent and had the unique aroma of C. sinensis.

In order to improve the quality of composite gels as a fat substitute, the formulation was optimized using combination of Plackett-Burman design, steepest ascent method and Box-Behnken response surface methodology. Firstly, eight factors affecting the quality of composite gels were evaluated by Plackett-Burman design, and four of these were found to have significant effects on the response variable: the amounts of carrageenan, whey protein, water and sodium carbonate. Subsequently, the optimal response region was approached by the steepest ascent method. Finally, the response surface methodology was used to determine the optimal proportion of ingredients was carrageenan:whey protein:water:sodium carbonate:konjac fine powder:gelatin:soybean protein isolate:vegetable oil = 1.19:1:254.52:2:6:1.5:1:18.4. The validation experiments showed that the hardness of the composite gel prepared with the optimized formulation was 6.96 N, sensory elasticity 49.41%, chewiness 4.14 mJ, whiteness value 49.44, shrinkage rate 48.33%, and mass loss percentage 45.77%. These experimental values were close to the predicted values with relative error of 0.85%–1.7%. Thus, combination of Plackett-Burman design, the steepest ascent method and response surface methodology was feasible to optimize the formulation of composite gels, and the prepared composite gel could well simulate the animal fat in Chinese sausage.

In this work, ionic liquids (ILs) were used as extraction solvents to extract, separate and purify flavonoids from citrus peel by successive ultrasound-assisted extraction and aqueous two-phase extraction. Among nine ILs tested, it was found that tributylhexylphosphonium bromide ([P4446]Br) gave the highest yield (56.15 mg/g) of flavonoids from citrus peel. Using single factor experiments and response surface methodology, the optimum extraction conditions were determined as follows: [P4446]Br concentration 54%, solid-to-liquid ratio 1:10 (g/mL), extraction temperature 50 ℃, and ultrasonication time 10 min. Under these optimum conditions, the yield of flavonoids was 69.13 mg/g. After the ultrasound-assisted extraction, an aqueous two-phase system of [P4446]Br and sodium citrate was constructed by adding sodium citrate and used to further separate and purify the extracted flavonoids. The results showed that the extraction efficiency of flavonoids reached 98.20% when the tether length was 71.95 and the phase ratio was 1.13. After the aqueous two-phase extraction, butyl alcohol was used to back extract the flavonoids with a recovery of 80.11%.

The extraction of plamitoleic acid (POA) from sea buckthorn fruit oil (SBFO) by urea complexation followed by molecular distillation was optimized using a combination of one-factor-at-a-time method and response surface methodology, and the fatty acid composition of the product was analyzed by gas chromatography (GC). Then, an insulin resistance model was established in HepG2 cells treated with high concentration of insulin and was used to explore the ability of the extract to improve insulin resistance. The results showed that the optimal extraction conditions were as follows: ratio of urea to substrate 1.98:1 (g/g), ratio of solvent to urea 4.03:1 (mL/g), and reaction time 12.15 h for urea complexation; feeding rate 0.84 mL/min, scraping rate 116.02 r/min, and distillation temperature 99.75 ℃ for molecular distillation. The results of GC analysis showed that the plamitoleic acid content was significantly increased up to 72.19% (predicted value of 68.02%) under these optimal conditions, indicating that the established method could be used for the enrichment and purification of POA from SBFO. In vitro experiments showed that the palmitoleic acid at 100 mol/L could significantly improve the level of glycogen synthesis, and alleviate the decrease of glucose consumption caused by insulin resistance at 200 mol/L, proving that a certain dose of sea buckthorn plamitoleic acid could alleviate insulin resistance.

Considering the sugar content of saccharified purple sweet potato solution and the ability of its acylated anthocyanins to enhance the stability of anthocyanins, this study evaluated the effect of the type of ion exchange resins and flow rate on the deacidification of blackberry juice, and it also investigated the effect of saccharified purple sweet potato solution on the taste of blackberry juice. Changes in the anthocyanin content of blackberry-purple sweet potato juice blend, blackberry juice, and purple sweet potato juice during accelerated storage were compared to explore the effect of saccharified purple sweet potato solution on anthocyanin stability in blackberry juice. The results indicated that eight ion exchange resins could reduce the acid content of blackberry juice and absorption of anthocyanin and soluble solids to different extents. Among these, LXZ-67 resin was found to be the most suitable for the deacidification of blackberry juice. Using this sorbent, the deacidification rate was 55.6% and the retention rates of anthocyanins and soluble solids were 81.4% and 87.1%, respectively. Based on both the production efficiency and the retention rate of anthocyanins, the flow rate should be 20 BV/h. The optimal mixing ratio between blackberry juice and saccharified purple sweet potato solution was 4:1, resulting in a perfectly balanced sour-sweet taste with strong aroma. The rate of anthocyanin degradation in the three juices during accumulated storage could be ranked in decreasing order as follows: blackberry juice > blended fruit juice > purple sweet potato juice, which demonstrates that saccharified purple sweet potato solution could improve the stability of anthocyanins in blackberry juice.

Based on loop-mediated isothermal amplification (LAMP), a sensitive, specific, low-cost, visual and trace method was developed using a capillary as the reaction medium for the detection of the toxin genes tdh and trh of Vibrio parahaemolyticus. Six primer pairs were designed targeting either of the toxin genes. The concentrations of Mg2＋, dNTPs and Bst DNA polymerase, reaction time and temperature were optimized for the capillary LAMP (cLAMP) method. The sensitivity and specificity of the method were evaluated. The results indicated that optimum conditions of the cLAMP method were as follows: magnesium ion concentration 6 or 8 mmol/L dNTPs cocnetration 1.44 or 1.28 mmol/L, Bst DNA polymerase concentration 0.096 U/L (in a volume of 5 μL), reaction temperature, 65 ℃, and time, 60 min. The limits of detection (LODs) of the tdh and trh genes were 3 and 34 fg/μL for genomic DNA, and 9.85 × 103 and 8.25 × 105 CFU/mL for bacterial culture, respectively. No cross-reactivity was observed with other common bacterial pathogens, including cholera, V. vulnificus, V. alginolyticus, Aeromonas hydrophila, Escherichia coli, and Staphylococcus aureus. The results in this study provide technical support for the development of visual and trace detection kits for the foodborne pathogen V. parahaemolyticus.

A method for the determination of soybean protein in steak products by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. Firstly, the specific soybean peptides were identified and screened by high-resolution mass spectrometry based on the Unitprot database to obtain the peptide sequences for accurate identification of soybean protein. Then, the soybean peptide sequences were converted into ion pair information using the skyline software. Next, the specific soybean peptides were confirmed by LC-MS/MS, and further quantified. Finally, 3 peptides for quantitative analysis of soybean protein with good linearity and recovery rate were selected, which were GSDLVNVR, VSDDENNNYK, and LVCCPQQAEDDK. For all three peptides, the correlation coefficients were above 0.99, the spiked recoveries were 81.7%–115.8%, and the precision expressed as relative standard deviation (RSD) was less than 13%. The limit of detection (LOD) was 0.15%, and the limit of quantification (LOQ) was 0.5%. The soybean protein contents of 28 commercially available steaks were determined successfully using the proposed method. The results showed that the method was highly specific and accurate, and could be applied to other meat products.

An indirect competitive enzyme linked immunoassay (ic-ELISA) for the detection of amantadine residue in chicken muscle was developed in this paper. The hapten was synthesized via the reaction of N-(1-adamantylamino) carbamide with glyoxylic acid, and then conjugated to the carrier proteins keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA) by the active ester method to generate an immunogen and a coating antigen, respectively. BALB/c mice were immunized with the immunoantigen for antibody generation. Subsequently, a specific monoclonal antibody against amantadine was obtained. The optimal dilution of coating antigen and antibody concentration were 80 000 and 122.50 μg/L, respectively. Under the optimized experimental conditions, the ic-ELISA showed an IC50 of 0.69 μg/L with a limit of detection (LOD) of 0.21 μg/L. The linear range was 0.07–6.15 μg/L, and the recoveries for spiked chicken muscle were in the range from 101.69% to 108.71% with coefficients of variation less than 15%. Furthermore, the results of ic-ELISA were highly correlated with those of high performance liquid chromatography-mass spectrometry (HPLC-MS) (R2 = 0.97), which demonstrated that the established ic-ELISA is of high accuracy and good reliability. Therefore, the ic-ELISA proved to be a suitable method for the rapid detection of amantadine in real chicken samples.

A method for simultaneous determination of 9 inedible pigments in capsanthin was developed by a quick, easy, cheap, effective, rugged and safe (QuEChERS) pretreatment method coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) under the multiple reaction monitoring (MRM) mode. Capsanthin samples were extracted with acetonitrile-water, and then sodium chloride was added for salting out. The extract was cleaned up using C18 sorbent before being analyzed by UPLC-MS/MS. Matrix effect in the method was between ?0.17 and 0.07. The limits of detection (LODs) and limits of quantitation (LOQs) were in the range of 0.2–1.5 ng/g and 0.6–5.0 ng/g, respectively, and good linearity was found in the concentration range of 0.2–8 ng/mL for basic orange II, basic orange 21, basic orange 22 and solvent yellow 34; and of 2–40 ng/mL for sudan I, sudan II, sudan III, sudan IV and rhodamine B chloride with correlation coefficients (R2) higher than 0.995 0. The average recoveries of the 9 inedible pigments at three spiked concentration levels were between 69.6% and 92.5%, with relative standard deviations (RSDs) between 2.8% and 8.5% (n =5). This method proved to be simple, rapid, accurate, reliable, and suitable for the detection of inedible pigments in large quantities of natural plant extract samples.

Magnetic graphene oxide (Fe3O4/GO) was successfully prepared from graphite powder and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Raman spectroscopy (RS). Fe3O4/GO was used as a new purifying agent to improve the traditional method of quick, easy, cheap, effective, rugged, and safe (QuEChERS) for the pretreatment of dairy samples because of its strong adsorption capacity and magnetism. Using the improved pretreatment procedure combined with gas chromatography-mass spectrometry (GC-MS), 16 phthalate esters (PAEs) were analyzed. The optimum pretreatment conditions were determined by optimizing the type of extraction agent and the amount of purifying agent. The results showed that the calibration curves for all PAEs had a good linearity in the concentration range of 20–1 000 μg/L with correlation coefficients (R) ≥ 0.998 4. The lowest limits of detection were between 0.5 and 2.5 μg/kg. The average recoveries ranged from 85.7% to 117.7% at spiked concentration levels of 50, 100 and 200 μg/kg, with relative standard deviation (RSD) not exceeding 7.6%. Two milliliters of organic solvent and 155 mg of adsorbent were required for treatment of 1 g sample, which took about 8 min. The method only needs simple pretreatment and has good impurity removal effects and is suitable for the analysis of PAEs in dairy products.

A modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of perchlorate, chlorate and bromate in vegetables and fruits. The type and amount of sorbents including primary secondary amine (PSA), graphitized carbon black (GCB) and C18, were optimized based on the recoveries. Samples were extracted twice with 50% acetonitrile/water. The extract was purified with a mixture of 40 mg of GCB and 200 mg of C18, separated on an IC-PakTM Anion HR column, and detected by UPLC-MS/MS. The matrix-matched external standard method was used for quantitation. Good linearity was achieved for the analytes in the concentration range of 0.5–100 mg/L with correlation coefficients all greater than 0.99. The average recoveries for all the compounds at spiked concentration levels of 5.0, 20.0 and 50.0 μg/kg ranged from 80.3% to 110.1%, with relative standard deviations (RSDs) from 2.1% to 9.6%. The limits of detection (LODs) and the limits of quantification (LOQs) were 0.5–1.5 mg/kg and 2.0–5.0 mg/kg, respectively. The developed method proved to be rapid, convenient, sensitive, accurate, stable, and suitable for simultaneous determination of perchlorate, chlorate and bromate in vegetables and fruits.