2016, 34(5):1-11. DOI: 10.3969/j.issn.2095-6002.2016.05.001
Abstract:In recent years, fatty acids with the characteristics of the basic taste has been reported, and the point that fatty acids are the sixth basic taste has been proposed. Based on several aspects, such as electrophysiological characteristics of organisms, psychophysics characteristics, the main taste receptors, compared with other basic taste, the significance of fat taste, this paper reports that the evidence about the fat taste as the sixth basic taste is insufficient based on the existing literatures and the argument conditions of the basic taste.
2016, 34(5):12-20. DOI: 10.3969/j.issn.2095-6002.2016.05.002
Abstract:Rice is the staple food in China. With the rapid development of industry, agriculture, and urbanization, heavy metal pollution of rice has become an important problem. In this study, kinds of heavy metal pollution and the formation reasons were analyzed. Meanwhile, the control technology and countermeasures were recommended, which would be helpful for the solution of the heavy metal pollution in rice.
2016, 34(5):21-25, 32. DOI: 10.3969/j.issn.2095-6002.2016.05.003
Abstract:Barley is the largest cereal import in China. Nearly half a century, there has been a growing tendency of barley production and requirement, resulting in increasing activity of global trade of barley. This paper reviewed the nutrient content of barley and the development condition of barley industry in China. The reasons for the quality safety problems of barley and its products were introduced, and then some suggestions were made to safeguard the barley products quality safety, thus to provide some useful considerations and references for the healthy and rapid development of barley industry.
2016, 34(5):26-32. DOI: 10.3969/j.issn.2095-6002.2016.05.004
Abstract:The hydrolysis conditions of antioxidant peptides from Spirulina powder using alcalase were optimized by single factor methods and the Box-Behnken experiments, in order to improve the antioxidant abilities and the yield of Spirulina peptides.The results showed that alcalase has the highest hydrolysis ability compared with other commercial proteases, incluing papain, trypsase and flavourzyme, and it's optimum hydrolysis conditions were 55.46℃, pH 6.71 and the solid liquid ratio was 1∶10.83. When the Spirulina powder were hydrolyzed for 240min under the optimized conditions, the yield of the Spirulina peptides was 58.50%, increasing by 15.61% compared with the control. The DPPH radical scavenging ability of Spirulina peptides reached 77.597%, at the mass fraction of Spirulina peptides was 0.86g/L, increased by 7.62% compared with the control.
2016, 34(5):33-42. DOI: 10.3969/j.issn.2095-6002.2016.05.005
Abstract:The solubility, foaming, emulsification, hygroscopic, moisture and stable performance of grass carp peptides were researched in this study. The amino acid content and composition proportion of grass carp peptides were also determined and the nutrition value of grass carp peptides was evaluated. The results showed that the grass carp peptides had good function properties. Grass carp peptide had 18 kinds of amino acids and the content of amino acids was 90.94%. The content of essential amino acids was 41.33%. The biological value, essential amino acid index, nutritional index and amino acid ratio coefficient of grass carp peptide were 71.51,6.34,4.81 and 77.19, respectively. The results showed that grass carp peptide had reasonable amino acids composition, which could be high-quality protein resource.
2016, 34(5):43-47. DOI: 10.3969/j.issn.2095-6002.2016.05.006
Abstract:Monacolin K is one of the important secondary metabolites of Monascus sp. The influence of Monacolin K production for Monascus M1 on four kinds of fermentation substrate were studied.And the mRNA expression of Monacolin K biosynthesis gene cluster was measured by RT-qPCR. The result showed that the concentration of Monacolin K was the highest(8.49mg/L)cultured by buckwheat while the concentration of Monacolin K was 7.12,4.77,2.11mg/L cultured by brown rice, oats, and rice. And there was positive correlation between the expression genes related to MK and the MK production, except for MKB and MKC. The different kinds of culture medium could influence the secondary metabolites production by stimulating the gene clusters.
2016, 34(5):48-54. DOI: 10.3969/j.issn.2095-6002.2016.05.007
Abstract:The cross-linked enzyme aggregates method was a new carrier-free immobilized enzyme technology. In order to improve the stability of xylanase, the technology was applied for the preparation of the acid-stable xylanase from Penicillium janthinellum. This study explored conditions of the preparation of cross-linked xylanase aggregates. The results showed that the crude xylanase at the concentration of 0.36mg/mL was precipitated with 85% saturated ammonium sulfate for 30min at 40℃. Then the aggregates were cross-linked by 0.14% glutaraldehyde solution for 4h at 40℃. The obtained activity of cross-linked xylanase aggregates remained 42.2% of total enzyme activity, which is helpful for the further application of acid xylanase in the industry.
2016, 34(5):55-63. DOI: 10.3969/j.issn.2095-6002.2016.05.008
Abstract:The objective of this study was to investigate the endophytic bacterial communities in seeds of Beijing high-quality hybrid maize varieties, which had genetic relationships used microbial culture-dependent methods. The results of this study indicated that the hybrid maize, which had same male parent Jing 2416, Jinghua 8, Jingnongke 728,Jingdan 68 and NK718 had 10,4,13 and 18 OTUs, respectively. The first dominant species (Microbacterium maritypicum DSM 12512T) (AJ853910) of the hybrid Jingnongke 728 was consistent with the second dominant species of the hybrid Jingdan 68 and consistent with the tied for third dominant species of the hybrid NK718. The tied for second dominant species (Microbacterium saperdae IFO 15038T) (AB004719) of the hybrid Jingnongke 728 was consistent with the tied for second dominant species of the hybrid Jingdan 68. Jingke 968 and Jingke 665 with the same male parent Jing 92 had 14 and 7 OTUs, The second dominant species (Bacillus horneckiae DSM 23495T (FR749913)) of the hybrid Jingke 968 was consistent with the first dominant species of the hybrid Jingke665. The result indicated that the endophytic bacterial diversity had certain relevance in the seeds of hybrid maize which were genetically related. Hybrid maize with the same male parent had same dominant species and had similar OTU number while hybrid maize with different male parents had different OTU numbers and community structures. Accrording to the available literature, this was the first research reported in world on the diversity of endophytic bacterial communities in seeds of Beijing high-quality hybrid maize varieties.
2016, 34(5):64-69. DOI: 10.3969/j.issn.2095-6002.2016.05.009
Abstract:In order to delay the occurrence of browning of fresh-cut Agaricus bisporus under cold storage, effects of filling nitrogen in different vacuum (0, -20, -40, -60, -80, -98kPa) combined with heat treatment on color, enzyme activities of peroxidase, polyphenol oxidase and phenylalanine ammonia-lyase, and total phenolic content of fresh-cut Agaricus bisporus were evaluated. The results showed that filling nitrogen in vacuum combined with heat treatment slowed down the decrease rate of L* value (brightness) of fresh-cut Agaricus bisporus, inhibited its color development to red and yellow, and finally delayed browning of fresh-cut Agaricus bisporus. In comparison with control (0kPa) and other filling nitrogen in vacuum combined with heat treatment, both -40kPa and -80kPa of filling nitrogen in vacuum combined with heat treatment (hot-water temperature 40℃ and heat treatment time 5min) kept the POD and PPO activities at a lower level, and maintained PAL activity and total phenolic content at a higher level of fresh-cut Agaricus bisporus, which also delayed the senescence and improved its resistance of fresh-cut Agaricus bisporus.
2016, 34(5):70-77. DOI: 10.3969/j.issn.2095-6002.2016.05.010
Abstract:Effects of high pressure processing (HPP), including high pressure and high pressure treatment time, on the drip loss of sausages with reduced-fat were investigated. Analysis of variance (ANOVA) was performed to evaluate the effect of fat content, high pressure and high pressure treatment time on drip loss of emulsion-type sausages. And then a three-factor-three-level Box-Behnken design was adopted to study the simultaneous effects of one compositional variable (15%, 20% and 25% fat content) and two processing variables (150,0 and 250MPa high pressure, along with 5,6 and 7min high pressure treatment time) on drip loss of emulsion-type sausages. Also, the potential interactive and quadratic effects between these variables and drip loss were evaluated in this study. The adequacy of the model equation for predicting the optimum response values was effectively verified. And the interaction effects of fat content, high pressure treatment and high pressure treatment time on drip loss were significant. The results showed that the processing conditions for an optimum gel setting were found at high pressure of 198.47MPa,pressure treatment time of 5.92min,and fat content of 20.51%, and the sausages reduced their drip loss of 9.71%, compared with the control samples. The newly designed process can serve the meat industry to develop reduced-fat sausage using optimum high pressure conditions.
2016, 34(5):78-83, 88. DOI: 10.3969/j.issn.2095-6002.2016.05.011
Abstract:One kind of composite solid beverage was studied using pomegranate powder, sweetener, and citric acid as materials. The formulation was optimized by the fuzzy mathematics method of sensory evaluation combined with the orthogonal experiment. The results showed that effects of different factors were pomegranate powder adding amounts > sweeteners > seabuckthorn powder adding amounts > citric acid. The sensory evaluation score was 4 and the optimal combination of test score was 3.56 based on the poor analysis and sensory evaluation, which demonstrated that sensory quality of product could be rated as excellent. The optimized formula was pomegranate powder 60%, seabuckthorn powder 2%, sweetener 25%, citric acid 3%, and accessories 10%. The product has good color, flavor, and texture, which will have a broad development prospect.
2016, 34(5):84-88. DOI: 10.3969/j.issn.2095-6002.2016.05.012
Abstract:In this study, effects of different rolling pressures (1-5MPa) on qualities of wheat noodles were analyzed. Qualities of wheat noodles were analyzed by the texture profile analysis (TPA) while the correlations between the rolling pressures and qualities of wheat noodles were obtained. The results showed that the lower rolling pressures (1-2MPa) had significant effects on the qualities of wheat noodles while the hardness, adhesiveness, springiness, chewiness, and gumminess increased and the cohesiveness decreased with the increasing rolling pressures. However, the higher rolling pressure did not significantly affect qualities of wheat noodles. This study can provide a reference for improving qualities of wheat noodles in rolling process.
2016, 34(5):89-94. DOI: 10.3969/j.issn.2095-6002.2016.05.013
Abstract:Food safety problem has been a hot topic of national concern, which related to many areas of society. In order to know hot issues that relate to food safety in timely, food safety hot topics and other hot topics of the similarities and differences in detection methods were compared. The food safety surveillance topic detection model was constructed and the clustering algorithm was used for text mining for food safety data to achieve the topic detection. Through the experimental results, the evaluation of the Single-Pass algorithm was better than the K-Means algorithm, which could effectively detect food safety topics.