动植物蛋白复合型午餐肉的研究

本文研究了大豆粉和大豆分离蛋白对午餐肉感官指标的影响,通过配方筛选和感官评价实验,获得最佳配方,不仅产品品质提高,蛋白质含量增加3.6％,脂肪含量降低33.2％,而且成本能节约32％。     

Beef and sheep mortadella: formulation, processing and quality aspects

Beef and lamb mortadella samples were prepared under controlled conditions and stored for 16 weeks under refrigeration. Moisture, protein, fat, ash and sodium chloride contents were measured initially and pH, percentage of free fatty acids, thiobarbituric acid values, total volatile nitrogen content, residual nitrite concentration and microbiological status were determined at regular intervals throughout storage. The sensory quality of the mortadellas during the first 2 months of storage was evaluated. The results of these tests permitted assessment of the quality and safety of beef and lamb mortadella. The products were satisfactory with regard to chemical and microbiological analyses, but after 2 months storage, the poor colour of lamb mortadella limited the sensory acceptability. Measurements of rancidity, caused by lipid deterioration and protein breakdown, were the best indicators of product quality.     

香辛料在肉制品中的应用探讨

探讨了香辛料的内涵,认为可以把利用香辛料原料提取有效成分的深加工产品包含在内。香辛料的分类可以从形态和气滋味两个角度进行。在肉制品中的使用原则为将以味道为主,香、味兼有和以香味为主这三类香辛料按6:3:1的比例混合使用,总量一般控制在0.08%～1%之间。最后探讨了在肉制品中应用的发展趋势。     

肉制品的质构特性及其评价

肉制品质构品质受添加物的种类和数量、肌肉蛋白质周围环境条件以及肉制品加工和贮藏方式的较大影响。文章针对含水量、pH及盐类、胶体和淀粉类、大豆蛋白质、生物酶制剂等影响肉制品质构品质特性的影响因素及其评价方法的研究进展进行综述。     

Effect of packaging and storage on the keeping quality of pickled quail eggs

Storage stability of quail eggs pickled in 50% vinegar solution and subsequently stored in glass jars with pickling solution or in flexible pouches without the solution at mean ambient (24°C, 58% RH) and refrigeration (5°C, 80% RH) temperatures was investigated. Pickle solution, egg white and yolk reached equilibrium pH (4.26–4.31) within 2 and 5 days of ambient and refrigeration storage, respectively. Eggs lost up to 12.2 and 8.8% of their weight within 48 h of ageing under ambient and refrigeration storage, respectively. Polypropylene (PP)-packed pickles suffered maximum weight loss followed by high-density polyethylene (HDPE)-packed eggs; losses were negligible in polyester/foil/polyethylene (PFP) laminate-packed samples. A decrease in phosphatidyl choline and phosphatidyl ethanolamine with simultaneous increase in lysophosphatidyl choline and lysophosphatidyl ethanolamine plus sphingomyelin occurred in pickled eggs during storage. Thiobarbituric acid (TBA) value increased and sensory quality declined with storage time. Aerobic plate counts remained fairly low throughout storage. HDPE (84 μm) was found to be an economic and efficient alternative packaging to glass jar for storage of pickled eggs without the pickle solution for up to 4 and 12 months of ambient and refrigerated storage, respectively.     

The effect of gamma irradiation on the microbial load,mineral concentration and sensory characteristics of liquorice (Glycyrrhiza glabra L)

Ground liquorice roots were exposed to various doses (0, 5, 10, 15 and 20 kGy) of gamma radiation from a ⁶⁰Co source. Irradiated and non‐irradiated samples were stored at room temperature. Microbial population, viscosity, concentrations of some minerals and the sensory properties of the extracts were evaluated after 0 and 12 months of storage. Tests carried out immediately after irradiation showed that the microbial count had been reduced and that the dose required to reduce the count by 1 log cycle (D₁₀) was about 2 kGy. No effect was observed on the total dissolved solids in extracts of liquorice roots. Glycyrrhizinic acid concentration in the extracts and the viscosities of suspensions produced from irradiated roots were lower than those from non‐irradiated ones. Sensory evaluation indicated that there were no significant differences (P < 0.05) in colour, taste or flavour between extracts produced from irradiated and non‐irradiated roots. However, after 12 months of storage, some mineral ion (Na⁺, Ca²⁺ and K⁺) concentrations in extracts produced from irradiated roots were lower than in those from non‐irradiated ones; no significant differences (P < 0.05) in viscosity were found between suspensions of irradiated and non‐irradiated roots. © 2002 Society of Chemical Industry     

抗氧化剂延长低温肉制品保存期研究

主要研究了D-异抗坏血酸钠,植酸钠,茶多酚三种抗氧化剂对低温肉制品保存期的影响,并将其复合使用取得良好防腐和抗氧化效果。通过对低温肉制品进行感官指标、pH值、菌落总数、过氧化值的测定。实验表明:就以上指标而言,除D-异抗坏血酸钠外,植酸钠,茶多酚单独使用时在提高肉制品保存期方面的效果并不明显,三种抗氧化剂和EDTA复合后使用防腐效果最佳,即D-异抗坏血酸钠0.5g/kg,植酸钠0.2g/kg,茶多酚0.3g/kg,EDTA0.25g/kg。按此量进行复配,对延长货架期有显著影响,可使低温肉制品保存期比对照延长7d,感官品质较好,延缓了低温肉制品中脂肪的氧化,抗氧化效果明显(p0.05).同时三种抗氧化剂单体与EDTA复合后的抑菌效果依次是D-异抗坏血酸钠植酸钠茶多酚。     

Effect of gamma irradiation and frozen storage on chemical and sensory characteristics of rainbow trout (Oncorhynchus mykiss) fillet

The present study was conducted to evaluate the combined effect of low‐dose gamma irradiation (1, 3 and 5 kGy) and frozen storage (5 months at ?20 °C) on chemical and sensory characteristics of rainbow trout (Oncorhynchus mykiss) fillet. Our statistical analysis showed that irradiation process and frozen storage time had a significant effect (P < 0.05) on total volatile nitrogen (TVN), peroxide value (PV), thiobarbituric acid (TBA) and pH. The level of all of these factors increased with increasing frozen storage time. At the end of the fifth month of frozen storage, the lowest and the highest level of TVN, PV and TBA were corresponding to the irradiated samples at 3 and 5 kGy, respectively. In terms of the overall acceptability of their texture, odour, colour and taste, irradiated samples at 3 kGy had the best quality and remained acceptable after 5 months frozen storage. The optimum dose of gamma radiation of rainbow trout fillets according to chemical and sensory analysis was obtained at 3 kGy.     

Danish initiatives to improve the safety of meat products

During the last two decades the major food safety problems in Denmark, as determined by the number of human patients, has been associated with bacterial infections stemming from meat products and eggs. The bacterial pathogens causing the majority of human infections has been Salmonella and Campylobacter, and to a lesser extent Yersinia, Escherichiacoli O157 and Listeria. Danish initiatives to improve the safety of meat products have focused on the entire production chain from the farm to the consumer, with a special emphasis on the pre-harvest stage of production. The control of bacterial pathogens which are resistant to antibiotics has been a new area of attention in the recent decade, and recently, the increasing globalization of the domestic food supply has called for a complete rethinking of the national food safety strategies. The implementations of a “case-by-case” risk assessment system, as well as increased international collaboration on surveillance, are both elements in this new strategy.     

新型辅助加工技术提高肉制品消化特性的研究进展

随着国民生活质量的提高,人们对肉制品的需求也不再仅仅局限于感官质量和卫生质量等基本特性。肉制品中蛋白质含量高达10%-20%,是人体不可缺少的营养物质。近年来,如何提高肉制品的消化率这一问题受到了广泛的关注。目前,改善肉制品中蛋白质的结构和功能特性是提高消化率的主要可行性途径。在传统蒸煮、烘烤等加工方式的前提下,肉制品的制作过程中辅以新型加工技术(如超声波,超高压,脉冲电场,真空低温烹饪,酶解技术等),可以达到改变蛋白质结构、提高蛋白质分解酶活性的目的,从而提高肉制品的消化率。本文系统综述新型辅助加工技术在提高肉制品消化特性方面的研究进展,旨在探求更经济有效的加工方法,为改善提高肉制品的消化特性提供理论基础。     

Quality and safety aspects of meat products as affected by various physical manipulations of packaging materials

This article explores the effects of physically manipulated packaging materials on the quality and safety of meat products. Recently, innovative measures for improving quality and extending the shelf-life of packaged meat products have been developed, utilizing technologies including barrier film, active packaging, nanotechnology, microperforation, irradiation, plasma and far-infrared ray (FIR) treatments. Despite these developments, each technology has peculiar drawbacks which will need to be addressed by meat scientists in the future. To develop successful meat packaging systems, key product characteristics affecting stability, environmental conditions during storage until consumption, and consumers' packaging expectations must all be taken into consideration. Furthermore, the safety issues related to packaging materials must also be taken into account when processing, packaging and storing meat products.     

Effect of irradiation, packaging, and postirradiation cooking on the thiamin content of chicken meat

The effect of irradiation with X rays or electrons, irradiation and storage temperature, and postirradiation cooking on the thiamin content of vacuum- or air-packaged minced chicken meat was examined. Samples irradiated with 3-kGy X rays (50 Gy/min) or electrons (5 kGy/min) contained less thiamin than the control specimens, but no differences between both irradiation methods were detected. The thiamin content in samples stored and/or irradiated at 5 degrees C was between 13 and 24 microg per 100-g product lower than in samples stored and/or ionized at -18 degrees C. The same difference in thiamin content was found for specimens packaged in a vacuum or air package, respectively. Vacuum packaging lead to a greater loss of drip than air-packaged samples. The biggest loss of thiamin, 31.1 and 28.0% for X rays and electron beams, respectively, was measured for vacuum-packaged specimens stored and irradiated at 5 degrees C. Compared with the cooked minced chicken breast meat, a higher thiamin content (6 to 17 microg of thiamin per 100-g product) was obtained for the raw samples. When irradiation and vacuum packaging were compared as two separate preservation techniques, the two methods had approximately the same effect on the thiamin content of the minced chicken meat. The mean temperature of the samples after cooking was 87.2 +/- 4.9 degrees C. However, significant differences in internal temperature after cooking of the samples were measured between air- and vacuum-packaged samples.     

Effect of gamma irradiation on microbial load and quality characteristics of minced camel meat

The effect of gamma irradiation on microbial load, chemical and sensory characteristics of camel meat has been evaluated. Camel meat was irradiated at doses of 0, 2, 4 and 6 kGy of gamma irradiation. Irradiated and non-irradiated meat was kept in a refrigerator (1–4 °C). General composition and sensory evaluation of camel meat was done two days after irradiation, whereas, microbiological and chemical analysis was done immediately after irradiation and throughout the storage periods. The results indicated that all doses of gamma irradiation reduced the total mesophilic aerobic plate counts (TPCs) and total coliforms of camel meat. Thus, the microbiological shelf-life of camel meat was significantly extended from less than 2 weeks (control) to more than 6 weeks (samples irradiated with 2, 4 or 6 kGy). No significant differences in moisture, protein, fat, thiobarbituric acid (TBA) values, total acidity and fatty acids of camel meat were observed due to irradiation. There were slight effects of gamma irradiation in both total volatile basic nitrogen (VBN) and lipid oxidation values in camel meat. Sensory evaluation showed no significant differences between irradiated and non-irradiated camel meats.     

Innovative active packaging systems to prolong the shelf life of Mozzarella cheese

In this work the effectiveness of different antimicrobial packaging systems on the microbial quality decay kinetics during storage of Mozzarella cheese was evaluated. Lemon extract, at 3 different concentrations, was used as active agent, in combination with brine and with a gel solution made of sodium alginate. Shelf life tests were run at 15°C to simulate thermal abuse. The cell load of spoilage and dairy functional microorganisms were monitored at regular time intervals during storage. By fitting the experimental data through a modified version of the Gompertz equation, the shelf life of dairy products packaged in the different systems was calculated. Results show an increase in the shelf life of all active packaged Mozzarella cheeses, confirming that the investigated substance may exert an inhibitory effect on the microorganisms responsible for spoilage phenomena without affecting the functional microbiota of the product.     

Quality,functionality, and shelf life of fermented meat and meat products: A review

Fermentation of meat is a traditional preservation method used widely for improving quality and shelf life of fermented meat products. Fermentation of meat causes a number of physical, biochemical, and microbial changes, which eventually impart functional properties, sensory characteristics, and nutritional aspects to these products and inhibit the growth of various pathogenic and spoilage microorganisms. These changes include acidification (carbohydrate catabolism), solubilization and gelation of myofibrillar and sarcoplasmic proteins of muscle, degradation of proteins and lipids, reduction of nitrate into nitrite, formation of nitrosomyoglobin, and dehydration. Dry-fermented sausages are increasingly being used as carrier of probiotics. The production of biogenic amines during fermentation can be controlled by selecting proper starter cultures and other preventive measures such as quality of raw materials, hygienic measures, temperature, etc.     

包装材料、储存环境及储油罐充氮对亚麻籽油保质期的影响

亚麻籽油富含多不饱和脂肪酸,易氧化,保质期较短。以过氧化值为评价指标,研究包装材料、储存环境及储油罐充氮对亚麻籽油保质期的影响。结果表明：避光包装材料、暗光条件储存,亚麻籽油的保质期可适当延长;不论什么包装材料的亚麻籽油,最佳食用时间限制在3个月内;包装瓶的气密性和灌装压盖的质量一定程度上影响亚麻籽油的保质期;储油罐间歇充氮方式较连续充氮方式节能,两者效用相同,均可延长亚麻籽油的保质期。     

Effects of type of packaging materials on physicochemical,microbiological and sensory characteristics of durian fruit leather during storage

A study on storage stability of durian leather was carried out at room temperature using four types of packaging materials—laminated aluminium foil (LAF), high-density polyethylene (HDPE), low-density polyethylene (LDPE) and polypropylene (PP) films—for 12 weeks. Analyses on physicochemical, microbiological and sensory characteristics were conducted at weeks 0, 2, 4, 8 and 12. Analyses for sugar, fat and caloric contents were conducted at the beginning and the end of storage period. Moisture contents and water activity (A_w) fluctuated during storage but tended to decrease after week 8. Non-enzymatic browning increased significantly (P<0·05) for all samples in packaging materials used; the highest increases were observed in LDPE-packed leather. The increases were related to the changes in colour of samples during storage. The longer storage time, the higher L and b values and the lower a value. The pH, although it fluctuated in the first weeks, slightly increased at the end of the storage period, while the hardness for each sample gradually increased during the storage. Microbial analyses showed that total mesophilic bacteria (TMB) and total moulds and yeast (TMY) counts were low, where after 12-week storage TMB and TMY were less than 60 and 140 cfu g⁻¹, respectively. Organoleptically, for all attributes evaluated, all samples were acceptable by panelists during the 12-week storage period. © 1998 SCI.