Abstract:Polyglycerol fatty acid ester is a safe, efficient, and multifunctional non-ionic emulsifier, which is widely used in food, cosmetics, medicine, and other fields. In recent years, many studies had focused on the synthesis, properties, and applications of polyglycerol fatty acid ester emulsifiers. The synthetic methods of polyglycerol fatty acid esters via chemical synthesis and enzymatic synthesis were summarized. The essential properties of polyglycerol fatty acid esters such as safety, surface interfacial properties, emulsifying properties, and bacteriostatic properties were introduced. The application on the encapsulation and delivery of functional ingredients, the regulation of oil crystallization, dough condi-tioners and softeners, and foam properties in the food industry were described. Moreover, the prospects for future research directions were presented.

Abstract:China has the largest cultivated area and production quantity of peach in the world. In 2017, cultivated area and yield of peach in China were accounted for 51.17% and 57.96% of total in the world, respectively. The harvested period of peach was short and seasonal, which was mainly in summer. In order to avoid wasting, the processing products and technologies of peach were developed. This paper reviewed the development situation of peach industries in China and abroad. Technologies of peeling, sterilization and texture maintenance in canned peaches industry, color maintenance and stabilization processing technologies during peach juice production, and hot air drying, freeze drying and instant controlled pressure drop drying technologies during dehydrated peach products processing were emphatically introduced. The development direction of peach processing technologies and equipments for productions of canned peach, peach juice, dehydrated peach products, and fermentation peach were also focused. It also discussed the necessity of transforming peach industry from traditional processing to modern processing industry, and promoting health and rapid development of peach industry in China. Finally, the prospect of development trend of peach processing industry in China was also expected.

Abstract:As a primary species belongs to the genus Vaccinium, blueberries are rich in phenolic compounds such as anthocyanins and flavonoids in addition to basic nutrients,which have important effects on reducing inflammatory reaction, preventing cancer, scavenging free radical and protecting eyesight. However, the perishable property of fresh blueberries has determined additional processing should to be done. Meanwhile, the properties of health care were contributed to increasing demand of customers for processed blueberries products. Application of advanced technologies contributed to retention of functional ingredients was the driving force for the development of blueberry industry. This paper summarized recent research progress in processing techniques and functional components of blueberry juice, blueberry wine, drying, and extraction of functional ingredients which might help build a theoretical basis for blueberries processing.

Abstract:Curcumin has strong physiological and pharmacological activities. However, its bioavailability and application in food industry is limited due to the low solubility in water. In order to improve the bioavailability of curcumin and exert its antioxidant properties, this study first dissolved curcumin in flaxseed oil by ultrasound, then prepared high concentration emulsion of curcumin-egg white protein, and finally used this high concentration emulsion to replace backfat in emulsified sausages. The antioxidant and bioacceptability of high concentration emulsion with different concentrations curcumin (800,0, 1000, 1100, 1200mg/L) were measured, and then the backfat in emulsified sausages was replaced by high concentration emulsion loaded curcumin at different mass fractions (25%, 50%, 75%, 100%). The texture and color difference of emulsified sausages were determined. The results showed that curcumin had the best antioxidant activity and bioacceptability at the concentration of 1200mg/L. After replacing backfat, the brightness and yellowness of emulsified sausages were increased, along with decreasing cooking loss, reducing hardness and increasing elasticity. Considering all the indexes, replacing 75% backfat with high concentration emulsion loaded curcumin was acceptable. The final amount of backfat in emulsified sausages was reduced 25%, and the bioavailability of curcumin in oil phase of emulsified sausages was up to 0.112mg/g.

Abstract:Different concentrations of oat β-glucan (0,0.2%, 0.4%, 0.6%, 0.8% and 1.0%) were added to pork myofibrillar protein. The effects of oat β-glucan on the emulsifying properties and gel pro-perties of myofibrillar protein were studied. The emulsifying properties included the emulsifying activity, emulsifying stability, particle size distribution and zeta potential. The gel properties included water holding capacity, gel strength, whiteness, internal water distribution, rheological properties and microstructure. The experimental results demonstrated that the emulsifying activity, stability and absolute value of zeta potential of myofibrillar protein were significantly increased, and the particle size was decreased with the increase of oat β-glucan addition (P<0.05). Meanwhile, the addition of oat β-glucan significantly increased the water holding capacity, gel strength and whiteness (P<0.05). Oat β-glucan could remarkably shorten the relaxation time of the gel, and the peak area percentage of immobilized water was significantly increased. The gel storage modulus and loss modulus at the end of heating were significantly increased with the increase of oat β-glucan addition (P<0.05). Scanning electron microscopy revealed that the gel network of the loose protein gel became dense and uniform with the addition of oat β-glucan. The addition of oat β-glucan could enhance the emulsification of the myofibrillar protein by forming a protective film on the surface of the protein to inhibit the droplets aggregation, and improve the gel properties by interacting with the myofibrillar protein during heating. The above results revealed that addition of 1.0% oat β-glucan had the best effect on the emulsification and gelation of myofibrillar protein.

Abstract:In order to explore the effect of psyllium husk powder addition on the quality of meat patties, using pork as raw material, the effects of the powder addition on the cooking loss, water retention, oil retention and sensory quality of meat patties and their causes were studied. The results showed that the addition of the powder could significantly improve the water retention of the meat emulsion. When the addition amount was 0.5%-1.0%, it could simultaneously promote the oil-water emulsion stability of the meat emulsion and improve the oil retention of the meat patties compared to the control group. When the powder was added to 1.0%, the cooking loss of the meat patties was reduced from 19.05% to 4.30%, and the brightness value was higher. At this time, the main component of the powder (psyllium polysaccharide) could be evenly distributed and promotes texture properties of meat emulsion products in the system. When the amount of the powder was increased to 2.0%-3.0%, the oily water emulsification was hindered due to the strong water absorption of the powder, and resulted in reducing oil retention of the meat patties and increasing cooking loss. Meanwhile, the gel system exhibited obvious phase separation, and the continuity of the three-dimensional network of the myofibrillar protein gel was blocked, leading to the decrease of the texture characteristics of the meat patties. Polysaccharides (gum) in the powder increased the viscosity of the meat patties and made meat products easy to shape. This study was supposed to provide a theoretical basis for the application of psyllium husk powder in meat emulsion products.

Abstract:The volatiles of two samples from Laobaigan base Baijiu fermented by “Laowuzeng” and “Sanpaijing” processes were respectively analyzed by headspace solid phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC×GC-TOF/MS). In the GC×GC-TOF/MS analysis, 234 and 253 volatiles were identified respectively, and a total of 273 volatiles were identified in the two kinds of base Baijiu samples, including 85 esters, 35 aldehydes,44 alcohols, 11 acids, 35 ketones, 5 phenols, 8 ethers, 9 furans, 11 acetals, 8 nitrogen-containing compounds, 11 sulfur-containing compounds, 3 lactones and 8 terpenes, among which the contents of ethyl lactate, ethyl acetate and ethyl decanoate were higher. The contents of aldehydes, phenols, nitrogen-containing compounds and sulfur-containing compounds in the base Baijiu of “Laowuzeng” process were 1.64,2.34,1.43 and 1.73 times of those in the base Baijiu of “Sanpaijing” process, which made the base Baijiu of “Laowuzeng” process had richer aroma including grass, malt, smoky, roasted and sulfur. However, the contents of esters, alcohols, furans, lactones and terpenes in the base Baijiu of “Sanpaijing” process were 1.30,1.27,1.31,1.65 and 1.57 times of those in the base Baijiu of “Laowuzeng” process, which made the base Baijiu of “Sanpaijing” process have stronger aroma of fruity, floral and sweet and the flavor was felt more elegant.

Abstract:The inhibition mechanism of antifungal substance generated by Streptomyces alboflavus against Fusarium moniliforme was investigated.The antifungal substance was qualitatively analyzed by pH paper and Doskochilova system chromatography. The destructive effects of antifungal substance on cell membrane and cell wall of Fusarium moniliforme were observed by fluorescence microscopy and scanning electron microscopy. The antagonistic effects of main components of cell membrane and wall on antifungal substance were explored. Furthermore, the inhibitory effect of antifungal substance on ergosterol in cell membrane of Fusarium moniliforme was detected by HPLC. The antifungal substance was neutral and non-water-soluble type I antibiotics by polarity test and Doskochilova system paper chromatography. Optical microscope was used to observe the inhibition of germination of Fusarium moniliforme spores, the mycelia were distortion, deformation and swelling when treated with the antifungal substance, and the fluorescence microscope revealed that the permeability of mycelial cell membrane was changed. Moreover, the results from scanning electron microscope showed that the surface of vesicular mycelia was uneven and fragments remained. The antagonism of antifungal substance effect on components of cell wall and cell membrane and the detection by HPLC showed that the synthesis of ergosterol in the cell membrane was affected by antifungal substance. The synthesis of ergosterol in the cell membrane of Fusarium moniliforme was affected by the antifungal substance produced by Streptomyces alboflavus. This study laid a theoretical foundation on the identification of antifungal substance and the application of antagonistic bacteria.

Abstract:Nitrosamines are a type of highly hazardous chemical carcinogens that are easily generated during the processing of meat products. The most common of these are nitrosodimethylamine, diethyl nitrosamine, nitrosopyrrolidine, nitrosopiperidine and nitrosodibutylamine. This article describes the formation mechanism of nitrosamines, the harm to human body and the factors that affect the formation of nitrosamines in meat products, including pH, temperature, food additives, tissue element and microorganisms,ect. And it also summarizes the research status of nitrosamine control on the basis of reducing the intake of precursors(control the use of nitrite and biogenic amines), blocking the formation of nitrosamine, and promoting the decomposition of nitrosamine (irradiation degradation and biodegradation). At present, controls of nitrosamines in meat products has been studied to some extent, which are blocking the source and promoting the way to provide some reference value for the control of nitrosamines in actual production. However, more studies are needed to explore ways to combine multiple methods to reduce the content of nitrosamines.

Abstract:Low-methoxy pectin/chitosan composite membranes were prepared through the tape casting method. The formation mechanism of the composite membranes and effects of pectin, chitosan, and glycerol on the structure and properties of the membranes were discussed.The results showed that —COOH in pectin bounded to —NH₂ in chitosan and promoted the formation of the composite membranes. The tensile strength and elongation at break of the composite membranes were increased firstly and then decreased with the increasing amount of pectin. And the composite membranes reached their maximum tensile strength (4.12MPa) and elongation at break (33.24%) when the addition of pectin was 4g. With the increasing chitosan addition, the elongation at break of the composites membranes was decreased, while the tensile strength was firstly increased and then decreased. The composites membranes attained its maximum tensile strength (4.13MPa)when the addition of chitosan was 4g. When the glycerol addition was 1mL, the composites membranes got a great tensile strength of 24.32MPa, with a poor elongation at break (4.86%). With the increase of glycerol addition, the tensile strength of the composites membranes was sharply decreased, while the elongation at break was rapidly increased.

Abstract:In order to improve the processing characteristics (particle size, powder characteristics, color) and maintain the active substances such as deoxynojirimycin(DNJ), total polyphenols, total flavonoids and anthocyanins, the low-sugar mulberry extract powder with good nutrition and appearance quality was prepared by microbial fermentation technology. Two kinds of low-sugar mulberry extract powders (with or without soybean addition) were prepared by fermentation of mulberry protoplasm through Leuconstoc mesenteroides and Saccharomyces cerevisiae and freeze-drying. The processing characteristics and active substance contents of the low-sugar mulberry extract powder were compared with that of the mulberry powder directly crushed by dry mulberry. Compared with mulberry powder, the glucose content, fructose content, water content, water activity, hygroscopicity, bulk density, resting angle and particle size of two kinds of low-sugar mulberry extract powder were significantly decreased after fermentation and freeze-drying, and their processing properties such as color and fluidity were significantly improved. The DNJ content of mulberry powder was 0.68mg/g, which was significantly increased to 2.07mg/g after fermentation, 1.39mg/g after freezing-drying, and 1.03mg/g after freezing-drying and addition of soybean. The contents of total polyphenols and total flavonoids were not significantly affected by fermentation, freezing-drying and addition of soybean. The total polyphenols contents of mulberry powder, fermented mulberry, freeze-dried fermented mulberry, freeze-dried fermented mulberry with soybean addition were 27.70,8.55,5.83, and 25.85mg/g, and the contents of total flavonoids were 1.24,1.01,1.16 and 1.30mg/g, respectively. The content of anthocyanin decreased significantly after fermentation, while the content of anthocyanin did not change significantly after freezing-drying and soybean addition. After fermentation and freezing-drying, the processing characteristics of low-sugar mulberry extract powder were improved. The content of DNJ was increased, and the content of anthocyanin was decreased. However the contents of total polyphenols and total flavonoids were not significantly changed.

Abstract:In order to improve the extraction methods and the yield of anthocyanins from fruit of Rubus coreanus Maq., the effects of microwave-assisted extraction, ultrasonic-assisted extraction and ultrasonic-microwave synergistic extraction on the yield of anthocyanins were compared. Single factor experiments were used to examine the influence of microwave power, microwave treatment time and ethanol solvent concentration (pH=2) on anthocyanin yield. The selected key parameters were optimized using response surface methodology with Box-Behnken experimental design. Results indicated that the yield of anthocyanins by microwave-assisted extraction was much higher than that of ultrasonic-assisted and ultrasonic-microwave synergistic extraction. The optimal microwave-assisted extraction parameters for anthocyanins from fruit of Rubus coreanus Maq. were microwave powder 148W, microwave treatment time 1.10min, and ethanol solvent concentration 74% (pH=2). Under the optimal extraction conditions, the anthocyanin yield from fruit of Rubus coreanus Maq. reached 372.39mg/100g.

Abstract:In order to explore the application value of myrosinase in food field, the content of allyl isothiocyanate from 10 types of broccoli seeds was determined by HPLC, and the enzymatic activity of myrosinase was calculated at different pH and temperature. The optimum conditions for myrosinase from different seeds were variable, with a temperature range of 50-65℃ and a pH range of 5-8. Using the seed with the highest enzyme activity as the enzyme source and 10 vegetables were used for the substrates, the method of combined sensory evaluation with SPME-GS/MS was applied to evaluate the degree of aromas of various vegetables after hydrolysis by myrosinase in broccoli seeds. The results showed that broccoli seeds could restore the aromas of Cruciferous vegetables in a large extent and had the effect of partially restoring the aromas of some other vegetables.

Abstract:A method for simultaneous determination of 13 triazole pesticide residues in tea by gas chromatography-quadrupole-time of flight mass spectrometry was established. Samples were extracted homoge-neously with 1% (volume fraction ) acetonitrile acetate. The extracts were purified in a centrifugal tube containing three kinds of purification fillers:multi-walled carbon nano, N-propyl ethylenediamine, and graphitized carbon black. Capillary column VF-1701ms was used to collect the samples under the fullscan mode. Thirteen kinds of tea samples were quantified by the external standard method. The results showed that the detection limit of the experimental method was 1-50μg/kg. The recovery of 13 pesticides was 72%-110% at the levels of 10,0, and 100μg/kg. The relative standard deviation was less than 18% (n=5), and the correlation coefficient was greater than 0.995. The established method is accurate, sensitive, solvent-saving, convenient, and rapid, and can meet the qualitative and quantitative detection requirements of 13 triazole pesticide residues in tea.