LIN Hong , LI Meng , CAO Li-min
2012, 30(1):1-5. DOI: 10.3969/j.issn.2095-6002.2012.01.001
Abstract:The research on aquatic products safety and the quality control technology was summarized and analyzed to reveal the present situation of aquatic products safety and quality control in China. Most of the research was focus on quality detection and control technology, others were about tracing system, early warning mechanism and risk assessment. At present, the enormous progress was made in technologies of quality detection and control. However, comparing with the advanced technology at abroad, the technology and management system in China still need to be improved. In the future, the aquatic food quality security technology should be promoted furtherly.
2012, 30(1):6-9. DOI: 10.3969/j.issn.2095-6002.2012.01.002
Abstract:With the social development and improvement on quality of life, the focus of food consumption is altering from quantity to quality. The problem of veterinary drug residues, one of the important factors that influence the safety of animal derived food, has turned into a social focal problem. The hazard, causes and monitoring measures of veterinary drug residues were summarized in this review.
2012, 30(1):10-16. DOI: 10.3969/j.issn.2095-6002.2012.01.003
Abstract:The hazard origins of quality safety in animal products were summarized in this paper, and the reasons for producing the veterinary drug residues were analyzed in detail. Finally, some recommendations and countermeasures to solve the veterinary drug residues were put forward.
2012, 30(1):17-19. DOI: 10.3969/j.issn.2095-6002.2012.01.004
Abstract:Food safety hazard caused by veterinary drugs residue and coping strategy were discussed from four aspects, which include the present situation of veterinary drugs residue in food at home and abroad, constraint elements of food safety, toxicological analysis of veterinary drugs and how to establish rapid detection techniques in food safety having Chinese characteristics. Finally the development tendency of rapid detection techniques in food safety was presented.
ZHANG Di , JI Bao-Ping , ZHOU Feng , WU Wei
2012, 30(1):20-25. DOI: 10.3969/j.issn.2095-6002.2012.01.005
Abstract:The assessment of antioxidant activity in vitro is an important area in functional food research. However, there were many problems, such as the confusing specification of antioxidant capacity and the improper application of antioxidant activity assessment assays, which hampered the comparison and selection of antioxidant functional foods greatly. Thus, development of a validated method for antioxidant activity assessment is a worldwide problem. In this study, the characteristics and shortcomings of the antioxidant activity assessment methods (the chemical and cellular assays) were discussed in terms of inducing method, reaction mechanisms, and result indicators. In addition, the development prospects of the antioxidant activity assessment methods were proposed.
2012, 30(1):26-29. DOI: 10.3969/j.issn.2095-6002.2012.01.006
Abstract:Microwave-assisted extraction of rosmarinic acid in perilla frutescens leaves was optimized by response surface method. The optimal process conditions were as follows, the microwave power 560W, processing time 4.5min, solid-liquid ratio 1∶33 (1g sdid in 33mL solvent). Under the optimal conditions, the rosmarinic acid yield reached 2.55g/mg. Compared with conventional extraction process of rosmarinic acid in perilla frutescens leaves, microwave-assisted extraction process is feasible.
LIN Xiao-zi , LIANG Zhang-cheng , HE Zhi-gang , LI Wei-xin , REN Xiang-yun
2012, 30(1):30-35. DOI: 10.3969/j.issn.2095-6002.2012.01.007
Abstract:The probiotic properties of two self-chosen lactobacillus strains were studied to provide the theorerical foundation for the research and development of lactic acid fermentation beverage. The stress resistance of lactobacillus plantarum R23 and lactobacillus casei R35 were investigated in a simulated enviroment of gastric acidity and bile salts, the adhesion ability were determined such as their aggregation properties and cell-surface hydrophobicity. The antioxidation of the broth including the scavenging effects on superoxide radical and hydroxyl radical was evaluated in vitro. The results showed that the stress resistance of the both strains was superior to the control group lactobacillus delbrueckii subsp 6045. The tolerance of pH value was 2.5 and bile salt was 5g·L-1 for the lactobacillus plantarum R23, showing the strongest stress resistance. The adhesion of the lactobacillus casei R35 was the strongest in contrast with the control group, the hydrophobicity of the lactobacillus paltarum R23 was stronger, while its aggregation properties was weaker. The extracellular products of three strains had antioxidant capacity after 24h culture, while lactobacillus paltarum R23 showed the best. Its scavenging rate to superoxide radical and hydroxyl radical was 77.8% and 80.94% respectively, which was 36.72% and 5.81% higher than the control group.
ZHANG Wei-hua , WANG Chao , LUO Jun-jie , SONG Juan , CHEN Mao-bin , LI Dong-sheng
2012, 30(1):36-40. DOI: 10.3969/j.issn.2095-6002.2012.01.008
Abstract:Direct drinking vinegar, especially Fruit vinegar production is one of the most important way for deep processing of agricultural byproducts. This article is based on acetic acid bacteria was cultured under the conditions with different temperature, rotation rate, alcohol concentration, and inoculation. The total acid content was determined, and the growth of bacteria on the semisolid culture medium with pear slag was observed. Finally, response surface analysis was used to optimize the growth condition of acetic acid bacteria, and the optimum conditions were found as follows: rotation rate was 136r·min-1, temperature was 32℃, the weight of the pear slag was 28%, alcohol content was 3.6%, inoculation was 4.0%. The result could provide a theory reference and practice basis for industrial production of the pear vinegar.
WANG Ran , LI Rui , SONG Huan-lu
2012, 30(1):41-45. DOI: 10.3969/j.issn.2095-6002.2012.01.009
Abstract:The volatile compounds of two kinds of luzhou-flavor liquor, Wuliangye and Yanjingfang, were analyzed qualitatively and quantitatively by gas chromatography-olfactometry-mass spectrometry (GC-O-MS). The main difference between the two kinds of wines were that esters and acids were in different proportions, and alcohols, aldehydes and ketones were different in types. In Wuliangye, there were four major esters, ethyl caproate, ethyl acetate, ethyl lactate and ethyl butyrate, the ratio of which was 1∶0.18∶0.07∶0.08, however in Yanjingfang, the ratio of the four esters was 1∶0.24∶0.24∶0.08. In Wuliangye, the ratio of acetic acid, butyric acid and caproic acid was 0.26∶0.10∶1, but the ratio was 1.17∶0.26∶1 in Yanjingfang.
LIU Xiao-ling , LI Ying , JIANG Yuan-xin , YU Xiang
2012, 30(1):46-50. DOI: 10.3969/j.issn.2095-6002.2012.01.010
Abstract:In order to provide a scientific reference for evaluation of the Liubao tea quality, main feature composition of seven Liubao tea and its original green tea produced from Guangxi Wuzhou region were analyzed in this paper. The results showed that the characteristic ingredients in Liubao tea were significant different compared with its original green tea. After piled fermentation of green tea, its total phenol content significantly decreased, total flavonoids slight decreased, catechins and caffeine content decreased, total soluble sugar and total free amino acid content increased and theabrownins highly formated. These components changes in Liubao tea made its color red, taste sweet and come up with a better mouth feeling. Hydroxyl radical scavenging experiments showed that Liubao tea exhibited a much stronger antioxidant capacity than its original green tea because of the higher theabrownins content in Liubao tea.
YUE Jian-wei , WANG Ping , ZHANG Yan-ping , JIU Wei-jing
2012, 30(1):51-56. DOI: 10.3969/j.issn.2095-6002.2012.01.011
Abstract:Two heterotrophic nitrification aerobic denitrifying bacteria strains, WXZ-2 and WXZ-8, were immobilized by PVA-boric acid method. The optimal embedding conditions were obtained by orthogonal test method. The Quantity of entrapped bacteria was 4%. The concentration of PVA was 5%. The crosslinking time was 12 h. And the diameter of the immobilized beads was 2.5 mm. Two different drying methods, freeze-drying and drying at 40℃, were compared to keep the beads. It was proved that the beads dried at 40℃ showed much better activity, mechanical strength and adsorption performance.
CHEN Hao , ZHANG Li , WU Hong , ZHANG Shuo
2012, 30(1):57-61. DOI: 10.3969/j.issn.2095-6002.2012.01.012
Abstract:The dynamics analysis of vibration isolation system for compressor of food refrigerating unit, including Modal analysis and Harmonic analysis, were made by ANSYS software. The parameters such as the natural frequency of the system were obtained, which can be used to verify whether the isolation system design has successfully overcome the fatigue caused by the forced vibration, resonance and other hazards. The results are important for the vibration and isolation design of compressors in food refrigerating unit, and also provide the meaningful basis for the research on vibration and noise reduction in large-scale food refrigerating unit.
WU Qing , HAO Li-yan , REN Jing-sheng
2012, 30(1):62-65. DOI: 10.3969/j.issn.2095-6002.2012.01.013
Abstract:An improved structure of SL type static mixer was presented in this paper. The internal structure was described and two-phase flow field was analyzed. The comprehensive influencing factors were considered during analyzing the relationship of two-phase flowage parameters in practical device, and the theoretical study was carried out. The two-phase flow was impinged, separated, flowed around and merged by the two-phase flow. The mixture effect was strengthened. The analytic calculation was carried out according to the practicable turbulent flow pattern. The results are useful for the structure parameters effectively selection and the characteristic optimization for the improved structure of SL type static mixer.
WU Jing-zhu , LIU Cui-ling , XING Su-xia , SUN Mei
2012, 30(1):66-68. DOI: 10.3969/j.issn.2095-6002.2012.01.014
Abstract:There are some effects on near infrared analysis result caused by the type of near infrared spectrometer and working parameters settings. How the different spectral resolution on Fourier transform spectrometer impact quantitative NIR model of edible oil was discussed in this paper. The experiment collected near infrared spectrum of 60 edible oil samples using Vertex 70 spectrometer, in three kinds of spectral resolution (4, 8, 16cm-1) conditions, by the transmission type liquid optical fiber probe. Monte Carlo sampling method was used to analysis three groups of near infrared spectral sample set and eliminate the abnormal samples. The calibration set and validation set were divided according to Kennard-Stone method. The quantitative models of palm acid were established, optimized and validated. Experiments shown that the model built based on 16cm-1 had better performance than 4cm-1 and 8cm-1. The results can provided a reference spectral resolution while detecting uniform liquid by near infrared technology.
FU Yan , GUO Pei-yuan , SUN Mei , XU Ran-ran
2012, 30(1):69-73. DOI: 10.3969/j.issn.2095-6002.2012.01.015
Abstract:The artificial olfactory system (AOS) and artificial taste system (ATS) detection techniques, computer vision detection technology, near infrared spectroscopy(NIR) detection technology, and hyperspectral image detection technology were described in this paper. Hyperspectral image detection technology has become a research hotspot for meat quality detection. The basic principle of hyperspectral image detection technology and the research status in meat quality detection using hyperspectral image at home and abroad were introduced in the paper. The prospect of future research in meat quality detection using hyperspectral image detection technology was proposed to researchers on the related study as a reference.
2012, 30(1):74-80. DOI: 10.3969/j.issn.2095-6002.2012.01.016
Abstract:The quality of dairy products has a significant influence on consumers’ health. In recent years, dairy products safety scandals occur frequently, which not only impair the confidence of domestic consumers, but also hit the dairy industry heavily. There are some reasons. First, the social bases led to the frequent occurrence of dairy products security incidents. Second, the long industry chain of dairy production, the numerous links which were full of quality safety risk, and the fragmented cultivation of dairy cattle make it difficult to guarantee the quality of raw milk. Last but not least, the subjective factors, such as lacking of regulation and insufficiency of cracking down illegal act also lead to the frequent scandals. To ensure quality and safety of dairy products, the quality and safety of raw milk must be assured in the first place. Secondly, in order to guarantee the quality of dairy products, the dairy enterprises must establish effective controlling system. Third, the government should strengthen legislation, and monitor the quality and safety of dairy products constantly. In particular, the government should strengthen regulation and crackdown of making adulterated milk and other illegal activities.