2017, 35(3):1-15. DOI: 10.3969/j.issn.2095-6002.2017.03.001
Abstract:Chemometrics is a novel and unique interdisciplinary technique that integrates mathematics, statistics, chemistry and computer science. Pattern recognition and multivariate calibration method, as the core aspects of the technique, have exhibited overwhelming advantages in massive data mining and processing, as well as resolution and analysis of analytic signals. In addition, it is able to solve complex problems which are difficult to be solved by conventional analytic methods, resulting in the method to be widely used in many research fields, including food analysis. This paper reviews the fundamental principles of chemometrics in regards of its advantages and disadvantages,applications, and recent progresses. Furthermore, the review has pointed out problems which need to be solved in current researches, and highlighted the prospective aspects of the technique.
2017, 35(3):16-24, 49. DOI: 10.3969/j.issn.2095-6002.2017.03.002
Abstract:Sports nutrition food is defined as food that meet the physiological metabolism, exercise ability and special needs for certain nutrients of exercisers. With the improvement of people's awareness of health concept and extensive participation in various exercise training, sports nutrition food market is also growing. In this paper, the research status and progress of some important hotspot nutrients and functional factors in the current sports nutrition food are reviewed, and the potential research and development direction is forecasted in order to provide clues and ideas for the development of sports nutrition food in China.
2017, 35(3):25-30. DOI: 10.3969/j.issn.2095-6002.2017.03.003
Abstract:With the increase of age, the prevalence rate of osteoporosis and fracture caused by osteoporosis and osteoarthritis is gradually increasing.Early prevention and intervention are the measures to fundamentally solve the problem and prevention is better than cure. Nutritional intervention is the supplement and update of the traditional osteoarthritis treatment method. In addition to lifestyle intervention, nutritional intervention plays an important role in balancing anabolic and catabolic metabolism of bone and cartilage tissues and metabolism, and regulating immune responses. Moreover, nutrition intervention has many advantages, such as less side effects and lower cost, which is easy to get some nutrients in the diet every day.Research progress on bone nutrition supplements, including whole bone nutrition, glucosamine and chondroitin sulfate, collagen peptide etc, were reviewed. We hope that this work can provide useful reference for related researches.
2017, 35(3):31-35. DOI: 10.3969/j.issn.2095-6002.2017.03.004
Abstract:In order to improve the extraction rate of peanut oil bodies, Viscozyme L. was used to assist the extraction of peanut oleosome. The effects of material ratio, enzyme concentration, incubation time, and incubation temperature on extraction rate of peanut oil body with compound plant hydrolase were investigated by using the single factor experiment. On the basis of single factor experiment, the orthogonal experiment was used to optimize the process conditions of extracting peanut oil body with compound plant hydrolase. The results showed that the influence order from high to low of the factors was material ratio, incubation temperature, incubation time, enzyme concentration. The optimum conditions were as follows:material ratio 1∶4 (g/mL), enzyme concentration 1.25%, the incubation time 80min and the incubation temperature 50℃. Under the optimum conditions, the extraction rate of peanut oil body was 48.92%.
2017, 35(3):36-42. DOI: 10.3969/j.issn.2095-6002.2017.03.005
Abstract:Protein cross-linking, belonging to protein modification, plays an important role in food restructure and new food preparation.Compared with chemical and physical cross-linking methods, enzymatic cross-linking has become the most acceptable cross-linking method of protein due to its mild reaction conditions, no by-products and good cross-linking characteristics. Apart from glutaminase, some oxidases have also been shown to form covalent bond between protein molecules and promote formation of covalent cross-linking. This paper summarizes the enzymatic properties, cross-linking mechanism of phenol oxidase (e.g., tyrosinase, laccase), peroxidase and lysyl oxidase. Lastly, the research status and application potential of these enzymes in food proteins are summarized.
2017, 35(3):43-49. DOI: 10.3969/j.issn.2095-6002.2017.03.006
Abstract:Lycium barbarum polysaccharide (LBP) is one of the major ingredients responsible for those biological activities in Lycium barbarum L.. It has been the hot spot in recent years because of its various important biological activities, such as antioxidant, immunomodulation and antitumor. The purpose of the present review is to summarize previous and current references regarding the preparation, biological activities as well as development of LBP. The preparation of LBP includes extraction, separation, and purification. The extraction methods contain water extraction and alcohol precipitation, alkali extraction, ultrasonic extraction, and microwave-assisted. Separation and purification methods consist of Sevage, TCA, protease, active carbon, polymer-salt aqueous two-phase systems and other methods. The above methods are used to remove free protein, pigments and other impurities from polysaccharides. After that, precipitation, cellulose ion exchange column chromatography, and gel filtration chromatography are used to purify single polysaccharide. Besides, this article introduces the application of LBP in the pharmaceutical, food, livestock feed, and other areas. The future research directions are suggested for the further study and utilization of LBP.
2017, 35(3):50-54. DOI: 10.3969/j.issn.2095-6002.2017.03.007
Abstract:Effects of Russula polysaccharide on mice hepatic insufficiency were investigated in this study. The senile model mice were established by D-galactose and mice were treated by 75mg/L and 150mg/L Russula polysaccharide. After 8 weeks, liver index, serum and hepatic GSH-Px, SOD activity, MDA contents, Ca2+-ATPase activity and hematoxylin-eosin staining of mice were determined. The results showed that the treatment of 150mg/L Russula polysaccharide could increase liver index, GSH-Px and SOD activity, and decrease the MDA content, which could inhibit the aging of liver.
2017, 35(3):55-60. DOI: 10.3969/j.issn.2095-6002.2017.03.008
Abstract:Synergistic effect of vitamin C (VC) and Hanzhongxianhao tea polyphenols on in vitro antioxidant capacity of was investigated by DPPH· and ABTS+· assays. Antibacterial activity of the mixtures of tea polyphenols and VC against Escherichia coli was analyzed by broth dilution method and Oxford cup method. The mixtures of tea polyphenols and VC [m (tea polyphenols)∶ m(VC)=1∶1,1∶2,2∶1] exhibited strong ability to scavenge DPPH·, and their EC50 values were lower than those of tea polyphenols and VC. Moreover, the more VC the mixture contained, the lower EC50 value was. EC50 value of the mixture of tea polyphenols and VC [m (tea polyphenols)∶m(VC)=1∶1] for ABTS+· was slightly lower than that of VC. Mathematical model based on dose-effect relationship between antioxidant capacity and sample concentration possessed high goodness of fit. Minimum inhibitory concentrations against Escherichia coli of the mixtures of tea polyphenols and VC [m (tea polyphenols)∶m(VC)=1∶1,2∶1] were 38 and 46mg·mL-1. Antibacterial activity of the mixture of tea polyphenols and VC [m (tea polyphenols)∶m(VC)=2∶1] was higher than those of VC and tea polyphenols due to its relatively large diameter of inhibition zone. After tea polyphenols were mixed with special quantity of VC, their free radical-scavenging abilities were slightly improved and antibacterial activities were notably increased.
2017, 35(3):61-65, 94. DOI: 10.3969/j.issn.2095-6002.2017.03.009
Abstract:In this study, the screening of α-amylase producing strains from endophytic bacteria in Siraitia grosvenorii and surrounding soil were preformed, and the optimum fermentation conditions for α-amylase producing strains were performed. Our results showed that 15 strains were isolated from the Siraitia grosvenori and 8 strains from surrounding soil. High amylase producing strains 2-1 (surrounding soil) and R-4 (root endophytic bacteria) were isolated. The identification results showed that 2-1 strain was staphylococcus and R-4 strain was bacillus, which were gram positive bacteria. The appropriate condition of enzyme production for strains 2-1 and R-4 were determined. For strain 2-1, the appropriate conditions were 1.0% ammonium chloride, 0.5% yeast powder, 1.0% soluble starch, 0.4% sodium chloride, fermentation temperature 40℃, and fermentation time 3 days and the enzyme production was 127.65U/mL under these conditions. For strain R-4, the appropriate conditions were 0.5% yeast powder, 1.0% ammonium chloride, 0.05% sodium chloride, 2.0% soluble starch, fermentation temperature 40℃, and fermentation time 3 days, and the enzyme production was 197.21U/mL under these conditions.
2017, 35(3):66-70. DOI: 10.3969/j.issn.2095-6002.2017.03.010
Abstract:To detect authenticity and species of 23 suspected shark fin samples. DNAs from either shark fin or shark fin derived soup were extracted, and then 12S rRNA gene of mitochondrial DNA that was special for animal species identification was amplified. PCR product was sequenced and homology comparison was deployed by BLAST search in GenBank database with related species sequences. The results showed that, among a total of 23 suspected shark fin samples, 18 soup-sourced, two vermicelli-like, and a fin-like one were failed to extract DNA or amplify target fragments, while the remaining two samples were successful to extract genome DNA and amplify the corresponding 12S rRNA gene fragments. Sequence analysis indicated nucleotide sequences of the 12S rRNA gene fragment from the two samples matched 99% identity to Carcharhinus limbatus and Rhizoprionodon terraenovae, respectively. For those samples containing shark components, high temperature soaking treatment was carried out. High temperature soaking treatment showed gelatin was precipitated in a sample (22#).These results indicated 12S rRNA gene sequence determination could accurately and quickly identify whether the samples contained shark ingredients. If combined with the high temperature soaking treatment to observe whether there was a gelatin precipitation, we can comprehensively judge the authenticity of shark's fin.
2017, 35(3):71-77. DOI: 10.3969/j.issn.2095-6002.2017.03.011
Abstract:During the preparation process of sausages, different substitution degrees of short-chain inulin (0,0%, 30%, 50%, 70% and 100%) for fat, maize distarch phosphate (MDP), and soy protein isolate (SPI) were separately investigated. Textural properties and sensory evaluations of sausages were determined. The feasibility of inulin instead of fat, MDP or SPI was discussed. For inulin replacing fat, the hardness, adhesiveness and resilience (except for the substitution degree of 50%) increased, and the chewiness and cohesiveness of sausages decreased. However, the mouthfeel of sausages deteriorated when the substitution degree exceeded 50%. For inulin replacing MDP, the inulin-containing sausages had an overall improvement in mouthfeel. The hardness, chewiness, cohesiveness (except for the substitution degree of 70%) and gumminess of sausages decreased, but the adhesiveness and resilience increased. For inulin replacing SPI, the textural properties and sense scores decreased, except for no significant changes in resilience and smell. Generally, it was feasible to replace fat or MDP in sausages by inulin, and the appropriate substitution degree for fat and MDP with inulin were 50% and 70%. However, inulin was not suitable to replace SPI in sausages.
2017, 35(3):78-82. DOI: 10.3969/j.issn.2095-6002.2017.03.012
Abstract:In this study, the optimal processing of enzymatic hydrolysis of shiitake mushrooms has been studied using three enzymes, in order to improve the enzymatic efficiency and sensory evaluation. First, the hydrolysis conditions of cellulase were optimized by orthogonal experiments. The results showed that the optimum hydrolysis conditions were temperature 40℃, hydrolysis time 1h, and enzyme dosage 0.5%. Second, bromelain and flavourzyme were screened out using α- amino nitrogen content and sensory evaluation as indicators. Third, the enzyme hydrolysis conditions were optimized by the response surface test. The results showed that the optimum conditions were hydrolysis temperature 58.6℃, hydrolysis time 2.02h, and concentration 15.24mL/g (water volume:shiitake mushroom powder quantity). Under the optimum conditions, the α-amino nitrogen content was 0.0901g/100mL and the sensory score was 7.4, belonging to the category of favorite.
2017, 35(3):83-88. DOI: 10.3969/j.issn.2095-6002.2017.03.013
Abstract:Bubbles are widely existed in nature with its irreplaceable roles in the practical application and a large number of experimental researches have been conducted. Depending on the different diameters of bubbles, bubbles were divided into large bubbles, micro-bubbles, micro-nano-bubbles, nano-bubbles. In this study, the properties of micro-nano-bubbles were introduced base on the characteristics of small volume and longer residence time in water. The application and development prospects of the micro-nano-bubbles in fruits and vegetables were discussed and their applications in other fields were also suggested.
2017, 35(3):89-94. DOI: 10.3969/j.issn.2095-6002.2017.03.014
Abstract:Mass torts in the field of food safety are different from behaviors in general infringement. The victims in the cases of food security infringement always face the situation which is extremely hard to claim. Meanwhile, there are series of difficulties upon the realization of the priority principle of civil compensation liability in Tort Liability Act and Food Safety Law. The legal remedy for mass tort in the field of food safety can not meet the demand of the reality, so there are a lot of issues that need to be addressed in legislation. With the further study of the food mass torts status and infringement damages conditions and the thought of judicial practice in our country, this essay makes several proposals on establishing the damage relief system, which includes substantial relief, litigation relief, and socialization relief.