2013, 31(4):1-5. DOI: 10.3969/j.issn.2095-6002.2013.04.001
Abstract:The dairy industry is related to the people's livelihood and a lot of attentions have been paid to its current situation and future development tendency. This paper introduced the current situation of Chinese dairy industry and analyzed the main problems occurred during the developing process. Moreover, the development tendencies of the basic research, and quality control were also discussed.
2013, 31(4):6-9. DOI: 10.3969/j.issn.2095-6002.2013.04.002
Abstract:The recent safety events in dairy industry, particularly the processing and package, were analyzed compared with the technical regulation system in some developed countries, suggestions and countermeasure to avoid the food safety incidents were provided. Meanwhile, the prospects of food safety in the dairy industry was put forward.
2013, 31(4):10-14. DOI: 10.3969/j.issn.2095-6002.2013.04.003
Abstract:This paper focus on the recent quality and safety incidents about consumed dairy products in China, which included both the domestic and imported dairy products. Based on the analysis of reasons, some countermeasures and suggestions about increasing the quality and safety of Chinese consumed dairy products were put forward.
2013, 31(4):15-18. DOI: 10.3969/j.issn.2095-6002.2013.04.004
Abstract:Soil selenium content and capacity of enrichment selenium of tea leaves in Hanyin tea garden were studied. Tea leaves and corresponding soil samples were collected from the typical tea gardens in Hanyin. And the selenium content was detected using atomic fluorescence spectrometry to study the capacity of enrichment selenium of tea leaves. Different parts of the tea plant samples were also collected to study the ability of accumulating selenium. The results showed that the selenium content of spring tea was higher than autumn tea. And the Longjing long leaf tea was higher than Longjing 43 tea. The capacity of enrichment selenium of tea was higher than other crops. Different parts of the tea plant had different capacity of enrichment selenium. And the order was as follows: burr point >the first leaves>old leaves>the second leaves>stems. Burr point with apical dominance had the highest selenium content.
2013, 31(4):19-22. DOI: 10.3969/j.issn.2095-6002.2013.04.005
Abstract:With milk as raw material, fat in milk was removed by centrifugation and protein was precipitated using different concentrations and dosages TCA. Afterward, the lactose was concentrated and cAMP was extracted. The best conditions of high-performance liquid chromatography(HPLC） were obtained to determine the content of cAMP in milk. The results showed that the cAMP content in the 10% TCA treatment group was significantly（P<0.05） higher than the other two groups with different TCA concentrations. The cAMP content in the highest-dosage （8mL）TCA treatment group was significantly lower（P<0.05） than that in the other two TCA treatment groups with the same concentration and different dosages. The highest cAMP content（（29.02±1.58）μg/mL） was obtained under the condition of 4mL of 10% TCA. In this study, the extraction method of cAMP from milk was established and could be used to extract cAMP from by-product of cheese, whey, and unqualified raw milk, which had great significance in reducing the extraction cost of cAMP, utilizing waste materials, and increasing the additional value of milk.
2013, 31(4):23-27. DOI: 10.3969/j.issn.2095-6002.2013.04.006
Abstract:The calcium concentrations in soybean milk and its material were determined by flame atomic absorption spectrometry（FAAS）. The optimal dilution ratio of soybean milk and the amount of digestion acid were discussed by single-factor experiments. Effect of Lanthanum oxide solution on the determination of calcium in soybean milk was also studied. The results showed that the optimizing dilution ratio of soybean milk was 1∶3; the digestion acid consumption of soybean milk and soybean meal was 30mL and 35mL, respectively. The addition of lanthanum oxide resulted in the better sensitivity （0.136μg/ （mL·%））, lower detection limits（0.01μg/mL）, and higher recovery（98.1%）. The calcium concentration decreased 10.4% in the soybean milk processing.
2013, 31(4):28-31. DOI: 10.3969/j.issn.2095-6002.2013.04.007
Abstract:The gelatin was irradiated by 60Co-γ with the dosages of 0-527kGy and the parameters including viscosity, gel strength, protein component and molecular weight were determined immediately. The results showed that the intrinsic viscosity, relative viscosity, gel strength, molecular weight, and melting point decreased with the increasing of the dosage. The content of high molecular weight components decreased. The number average molecular weight and weight average molecular weight were in the range of 7839-1061 and 32444-36506. The polydispersity was between 336 and 445. Compared with the intact gelatin, the irradiated one had the wider distribution of molecular weight and higher gelling temperature, the range of which was 398-427℃. Moreover, the membrane was smoother. The results indicated that the main reaction of gelatin during the irradiation was degradation under the condition of limited water and oxygen.
2013, 31(4):32-36. DOI: 10.3969/j.issn.2095-6002.2013.04.008
Abstract:In order to control the main residual bacterial population of baked abalone, the streak plate separating technology was used to isolate the primary residual bacterial floras. And the main bacteria were identified according to the colony morphology observation, gram staining, and 16S rDNA sequence alignment. The result indicated that the primary residual bacteria in baked abalone were Shewanella sp., Acinetobacter sp., Kurthia sp., Myroides pelagicus, Bacillus cereus, Enterobacter sp., Proteus penner, and so on.
2013, 31(4):37-41. DOI: 10.3969/j.issn.2095-6002.2013.04.009
Abstract:The freezing point temperature （FPT） of five representative cultivars of yellow peach fruits was determined, and the correlations between the FPT and fruit volume, fruit weight, fruit density, and total soluble solids （TSS） were analyzed by grey correlation degree analysis （GCDA） and SPSS software. The results indicated that the yellow peach cv. ‘5823’ and yellow peach cv. ‘guan 5’ had the highest（-1.40℃） and lowest （-1.20℃）FPT, respectively. The FPTs in yellow peach cv. ‘Jintong 8’, ‘Hongwangzi’ and ‘Juhuang’ cultivars were -1.32℃, -1.33℃, and -1.30℃,respectively. The density of the five yellow peach cultivars was less than 10g/cm3. The analysis with GCDA showed that TSS was the main impact factor on the FPT, whereas the influences of fruit density, fruit volume, and fruit weight on FPT were not significant. The regression analysis showed that the TSS could be used to predict the FPT of yellow peach cultivars.
2013, 31(4):42-47. DOI: 10.3969/j.issn.2095-6002.2013.04.010
Abstract:The changes of main components and organic acid profiles of Prunus mume during the pickling process were investigated through the analysis of salt, total acid, and reducing sugar and assay of organic acids in plum pulp and pickling liquid by reverse high performance liquid chromatography （HPLC）. The results showed that the salt penetrated to the fruit tissue continuously, and water, sugar, and acid penetrated to the liquid, which became to a dynamic balance during the pickling process of Prunus mume. When 300kg salt was added in every tons of fresh plum for pickling, after about 20 days, the contents of salt, total acid, and reducing sugar in the pulp and pickling liquid reached a balance. The contents of salt, total acid, and reducing sugar in fruit pulp were 24.42%, 5.18%, and 5.31%, respectively, while these parameters in pickling liquid were 27.06%, 4.91% and 4.79%, respectively. The HPLC analysis result showed that the main organic acid in Prunus mume was citric acid, followed by malic acid and oxalic acid and a small amount of tartaric acid, lactic acid, acetic acid, and succinic acid was also observed. There were some differences between total acids and organic acids in fruit pulp and pickling fluid during the pickling process. The organic acid profiles of fruits and pickling fluids during the pickling process were relatively stable and could be used as the fingerprints of the quality control for the subsequent processing products.
2013, 31(4):48-54. DOI: 10.3969/j.issn.2095-6002.2013.04.011
Abstract:The process control technology, playing a very important role on product upgrading and energy saving, has been widely used in food equipment. This study introduced the application of process control in food equipment and the latest technology of process control by analyzing the present development situation of food equipment at home and abroad. The development trend of process control in food equipment was presented based on the development aim of food equipment in our country.
2013, 31(4):55-58. DOI: 10.3969/j.issn.2095-6002.2013.04.012
Abstract:The colloidal gold strips method was used for the rapid quantitative detection of vomitoxin in grain. The results showed that the detection limit of vomitoxin was 118μg/kg. The quantitation limit was 316μg/kg and the correlation coefficient （r） was 0.9987 in the range of 500-5000μg/kg. Compared with the certified reference material, the accuracy was in the range of 90.3%-116.6% and the coefficient of variation was ranged from 4.7% to 19.6%. There were no significant differences between the colloidal gold strips and the high-performance liquid chromatography using the paired t-test.
2013, 31(4):59-63. DOI: 10.3969/j.issn.2095-6002.2013.04.013
Abstract:The effects of different color-protecting solutions on anti-browning effect and the quality of freezing-stored cultivated Agaricus bisporus slices were investigated in this research. The results showed that the polyphenol oxidase （PPO） activity in freezing-stored cultivated Agaricus bisporus slices soaked by different color-protecting solutions was in an order: L-cysteine < sodium pyrosulfite and citric acid < sodium pyrosulfite < sodium pyrosulfite and L-cysteine < citric acid < control check （CK） and the peroxidase -POD- activity was in another order: L-cysteine
2013, 31(4):64-68. DOI: 10.3969/j.issn.2095-6002.2013.04.014
Abstract:The effects of hot air drying and vacuum freeze-drying on the sensory quality, nutritional contents, color, and rehydration of chestnut powder were investigated in this study. And the nutrition label of two kinds of chestnut flour was developed. The results showed that the vacuum freeze-drying effectively saved the reducing sugar, total carbohydrate, and other nutrients of chestnut flour. The chestnut flour treated by vacuum freeze-drying had relatively light color, smaller particles, and slightly lighter flavor, which was suitable for the baked foods. When hot air drying parameters were 60℃ and 8h, the product had light yellow color with special chestnut aroma and most of the nutrients, which was suitable for the chestnut-flavor foods. Chestnut powder prepared by the two methods contains high protein, low fat, and high energy, which is rich in nutrient.
2013, 31(4):69-73. DOI: 10.3969/j.issn.2095-6002.2013.04.015
Abstract:The China's first "food safety law" was released in 2009, which improved our country's food standard from "health" to "safety" and established the scientific legal system. It is no doubt that the part of punitive damages is the more successful system design in the law. However, the system of punitive damages in the food safety legislation still has some problems, leading to difficulties in practice. In the new revision of "food safety law" , the scope of punitive damages should be scientifically determined and the amount of compensation of floating limits should be set . Moreover, the minimum amount of compensation should be determined and attentions should be paid to the cohesion between systems. The solutions of these problems can guarantee its scientificity and rationality in the legislation and its function in practice.
2013, 31(4):74-78. DOI: 10.3969/j.issn.2095-6002.2013.04.016
Abstract:In recent years, frequent food safety incidents in our country seriously endangered people's life and health. Therefore, perfecting the relevant legal system of food and improving the relevant laws and regulations become the urgent matter. The main problems existing in the China's food recall system are the conflicts of superior and inferior laws and regulations or new and old laws and regulations, the narrow food recall range, unclear supervision departments, insufficient law enforcement, the imperfect enterprise credit system and enterprise credit system, and the low violation cost. In view of the above problems, some suggestions about how to improve the current food recall system were given in this paper. The legal system of food recall should be perfected and the scope of food recall subjects should be enlarged. Moreover, the legal system of food enterprise credit can be established and perfected and the violation cost of food recall can be improved.