肉糜流水线在保鲜肉生产加工中的应用

<正> 肉糜,作为一种大众食品,在中国具有良好而广阔的市场。目前国内肉糜的销售方式以集市无包装销售和超市的速冻包装为主。速冻肉糜鲜度、口感差,都不能满是人们对新鲜食品的质量要求。在一些发达国家,肉食品普遍采用保鲜包装并在低温冷藏链下流通,这种保鲜包装鲜肉要求在0～5℃低温下储存和销售,既保持了鲜肉的营养和质地风味,又达到卫生标准,避免了冷冻肉因冷冻带来的品质下降和解冻时的营养损失。     

熟肉制品卫生的监督结果分析

通过对仓山区1996～1998年熟肉制品监督抽查的结果分析,讨论分析了影响熟肉制品卫生合格率的几个主要因素,提出提高熟肉制品卫生合格率的关键措施在于改善生产销售环境和加强监督力度。而加强基层监督力量和加强从业人员岗位卫生培训应是今后进一步提高熟肉制品卫生监督有效性的关键。     

肉品微生物污染现状分析与安全对策

从我国肉品微生物污染来源,畜禽的屠宰加工状况,肉品加工和检验人员素质,肉品微生物法规与标准等方面对我国肉品微生物的污染现状进行分析,阐明我国肉品生产中微生物污染和肉品卫生检验方面存在的问题,并提出相应的安全对策。     

肉制品中亚硝酸盐替代物的研究进展

亚硝酸盐是食品加工行业中较为常见的一种添加剂,主要应用于腌腊肉制品,亚硝酸盐不仅能够保持肉制品的风味、色泽同时还具有良好的防腐抗氧化作用。但是亚硝酸盐存在一定的毒性,若过量使用会产生致癌物致使肉制品的食用安全性降低。由于消费者担心亚硝酸盐对人体健康的影响,对天然有机的肉制品需求量逐渐增加,因此寻找出能够替代亚硝酸盐功效的新型添加剂势在必行。本文主要综述了国内外关于亚硝酸盐新型替代物在肉制品中应用情况的研究进展,包括植物性替代物、微生物替代物、有机酸类替代物等,并对这些替代措施今后的应用前景进行了展望,旨在为现代肉制品加工企业能生产出安全优质的肉制品提供一定的科学理论依据。     

Practical monitoring of the chill chain

Monitoring of temperature of chilled products at fresh food terminals is integrated into the quality assurance program of a retail chain. Each batch of products is examined on the receiving dock and rejected if the temperature is found above 7 degrees C, 5 degrees C being the legal maximal temperature. Measurement of temperature of processed meat products delivered to our company over a period of 14 months indicates that temperature abuse of chilled foods is not uncommon. Consistent rejection of batches because of high temperature resulted in a drop in the number of violations.     

A RESEARCH NOTE: DETECTION OF ADULTERATION IN PROCESSED TRADITIONAL MEAT PRODUCTS

Nondeclared protein addition is one of the most frequent adulterations used in meat products. Meat substitution with an unspecified specie, usually of less quality, is a fraudulent act in the industry and could have economic and health repercussions. In this study, we used an immunodiffusion assay in agar gel to identify bovine, porcine, equine and avion species in two slightly processed meat products, uncooked commercial hamburger and Mexican sausage (chorizo). Analysis of 40 samples from local food stores was performed. Undeclared equine specie was detected in 9 of the 23 of the hamburger meat samples. In Mexican sausage undeclared equine and porcine specie were also found in 5 of the 17 samples. These results showed violations in practices of the regional meat industry. It is suggested that regulatory agencies institute programs to ensure that meat products are properly labeled to protect consumers.     

Food provisioning and Spanish attitudes: A UK perspective

This paper reports on a survey carried out in northern Spain in 1991 to look at attitudes towards how products are used in food provisioning. The questionnaire was based on an earlier UK study and examines Spanish attitudes towards meat and fish. Multidimensional scaling is used to construct a more holistic picture and highlight those attitudes which are exclusively associated with meat and fish (both white and dark), as well as those attitudes which discriminate between the four products.     

Incidence and control of Listeria monocytogenes in foods in Denmark

The Danish regulatory policy on Listeria monocytogenes in foods is based on the principles of HACCP and was developed using a health risk assessment approach. The Danish policy focuses examinations and criteria for L. monocytogenes in ready-to-eat foods and is based on a combination of inspection and product-testing. Based on current epidemiological information from several countries, a concentration of L. monocytogenes not exceeding 100 cfu/g of food at the time of consumption, seems to be of low risk to the consumers. In Denmark, ready-to-eat foods have been placed into six categories where absence of L. monocytogenes in 25 g is required in foods heat treated in the final package and in heat-treated as well as preserved, non heat-treated foods which can support growth within the shelf life. This level is necessary in foods capable of supporting growth, in order not to exceed 100 L. monocytogenes per g at the point of consumption. In heat-treated and preserved foods, which are not supportive of growth within the shelf-life and for raw, ready to eat foods, a level below 10 L. monocytogenes per g is regarded acceptable. A level between 10 and 100 L. monocytogenes per g is not satisfactory and a level above 100/g is not acceptable. Data on the qualitative and quantitative occurrence of L. monocytogenes in foods in Denmark are presented and discussed. In 1997 and 1998, greater than 15,000 samples from different categories of food were examined (semi-quantitatively) for the presence of L. monocytogenes. A significant difference could be seen in the number of samples containing more than 100 L. monocytogenes per g, between different categories of foods (1997, P = 0.001; 1998, P = 0.016). In 1997, preserved meat products and preserved fish products and to a lesser extent vegetables and meat or vegetable mayonnaise were more likely to contain high numbers (i.e. above 100 cfu/g) of L. monocytogenes than other food categories. In 1998, preserved meat products, but also heat-treated meat products, vegetables and meat or vegetable mayonnaise had the highest frequency of samples with > 100 L. monocytogenes per g. In a survey performed in 1994 and 1995, 1.3% of ready-to-eat food samples (heat-treated meat products, preserved meat and fish products) were found to be contaminated with L. monocytogenes at a level above 100 cfu/g. The samples included in this survey were primarily products produced by authorized companies and were comprised mainly of vacuum packed products or products packed in modified atmosphere and with long shelf lives, typically above several weeks. The corresponding percentages of positive samples primarily processed in the retail outlets (heat-treated meat products, preserved meat and fish products) in 1997 and 1998 were 0.3% and 0.6%, respectively. The results suggest that ready-to-eat meat and fish products with extended shelf-lives produced by authorized companies are more likely to contain high numbers (> 100 cfu/g) of L. monocytogenes than products processed in the retail sector which often have a shorter shelf life.     

采用浮选法分离鱼骨架上残留鱼肉的初步研究

在罗非鱼鱼片的加工过程中会产生约占鱼体重60%的鱼骨架、鱼鳃、鱼鳞、鱼皮、内脏等下脚料,其中鱼骨架(指鱼头、鱼脊骨、肋排、鱼尾部分)超过鱼重的40%,而鱼骨架中仍残留有大量的鱼肉,如何高效地分离出鱼骨架上残留的鱼肉,实现对鱼骨架的高值化利用是鱼片加工业的一个技术难题。本文介绍了一种利用浮选法分离鱼骨架上鱼肉的中试设备,初步研究了加热处理对鱼骨架分离的影响,并利用该设备研究了搅拌速度、进流方向、进流速度对鱼骨鱼肉分离效率的影响。实验结果表明,当设备以搅拌转速为1000 r/min,以切线方向进流且进流速度为30 L/min时,能显著提高设备的分离效率。经试验证实,本设备能够将经过高温蒸煮的鱼骨架高效的分离为鱼肉、鱼骨、鱼汁三部分,且得到的鱼肉、鱼骨产品质量好、利用价值高,可进一步开发成高附加值的食品。     

熟食肉鱼制品氧化安全性评价

对市售火腿肠、肉片、肉松、腊肠和鱼片5类19种熟食肉鱼制品的氧化产物丙二醛(MDA)和亚硝酸盐(NO2)这2种致癌物的含量进行了测定和分析。结果表明,只有1种鸡肉卷火腿肠的NO2残留量(36mg/kg)超标,其余熟食制品的NO2含量均在允许安全范围。猪肉和牛肉火腿肠的MDA值均低于05mg/kg,未出现任何异味,表现出很高的安全性,但是脂肪和蛋白质含量普遍偏低,影响了口感和应有的品质。鸡肉火腿肠的MDA值在05～10mg/kg范围内,出现氧化异味。肉片、鱼片、肉松及腊肠制品的MDA值在抽样时多数都超过10mg/kg,氧化安全期与标签保质期相差42～177d,对这类熟食肉鱼制品在标签保质期内所存在的氧化安全隐患,应引起足够的重视。     

Quality of ready to serve tilapia fish curry with PUFA in retortable pouches

Studies on the physical, chemical, and microbiological qualities of fresh tilapia meat revealed its suitability for the preparation of ready to eat fish curry packed in retort pouches. Studies on the fatty acid profile of tilapia meat suggest fortification with polyunsaturated fatty acid (PUFA) to increase the nutritional value. Based on the commercial sterility, sensory evaluation, color, and texture profile analysis F(0) value of 6.94 and cook value of 107.24, with a total process time of 50.24 min at 116 °C was satisfactory for the development of tilapia fish curry in retort pouches. Thermally processed ready to eat south Indian type tilapia fish curry fortified with PUFA was developed and its keeping quality studied at ambient temperature. During storage, a slight increase in the fat content of fish meat was observed, with no significant change in the contents of moisture, protein, and ash. The thiobarbituric acid (TBA) values of fish curry significantly increased during storage. Fish curry fortified with 1% cod liver oil and fish curry without fortification (control) did not show any significant difference in the levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), during thermal processing and storage. Sensory analysis revealed that fortification of fish curry with cod liver oil had no impact on the quality. Tilapia fish curry processed at 116 °C and F(0) value of 7.0 (with or without fortification of cod liver oil) was fit for consumption, even after a period of 1-y storage in retort pouch. PRACTICAL APPLICATION: Tilapia is a lean variety of fish with white flesh and therefore an ideal choice as raw material for the development of ready to serve fish products such as fish curry in retort pouches for both domestic and international markets. Ready to eat thermal processed (116 °C and F(0) value of 7.0) south Indian type tilapia fish curry enriched with PUFA and packed in retort pouch was acceptable for consumption even after a storage period of 1 y at ambient temperature.     

EFFECT OF SLAUGHTER METHOD ON DEGRADATION OF INTRAMUSCULAR TYPE V COLLAGEN DURING SHORT-TERM CHILLED STORAGE OF CHUB MACKEREL SCOMBER JAPONICUS

The present paper demonstrates that a nonstntggling slaughter method can delay degradation of type V collagen in meat of chub mackerel Scomber japonicus and softening of the meat during postharvest chilled storage. The fish were slaughtered by piercing a knife into nape (nonstruggling method) or by leaving on ground (struggling method) and then stored in an ice box. Sensory study revealed that the postharvest softening of the meat was moderated at 4 and 8 h by the non‐struggling slaughter method in comparison with the struggling method. On the basis of the specific solubilization of type V collagen and reduced tyrosine content in it, a cleavage of the nonhelical regions (telopeptides) of the type V collagen occurred during the chilled storage in the fish slaughtered by the struggling method. The degradation of type V collagen was also slower in the meat of the fish slaughtered by the nonstruggling method, which can be directly linked to the moderation of the postharvest softening.     

鱼及肉制品真空冻干技术研究现状

本文对鱼、肉类真空冷冻干燥在国内外的研究及发展的历史和现状进行阐述.主要内容包括真空冷冻干燥理论研究的基本方法,理论模型研究的主要成果和最新进展;国内外真空冻干特别是在鱼、肉类冻千方面的理论、技术的发展及应用的历史和现状,国内外对真空冻干技术的最新研究成果;本文侧重鱼、肉类真空冻干的阐述,着重阐明了鱼及肉类应用真空冷冻干燥技术进行贮藏的优势和必要性,结合生产实践说明真空冻干的效果以及在实际应用中所存在的主要问题,高能耗所带来的高成本依然制约着鱼、肉类真空冻干技术的迅速发展,如何降低能耗而得到高质量的产品,将是鱼及肉类真空冻干技术研究发展的主要方向.     

Investigation for possible source(s) of contamination of ready-to-eat meat products with Listeria spp. and other pathogens in a meat processing plant in Trinidad

In 2003, there was a recall of three processed (chicken franks, spice ham and turkey ham ready-to-eat (RTE) meat products by a large processing plant in Trinidad as a result of contamination by Listeria monocytogenes. The study was conducted to investigate the possible source(s) of Listeria contamination of recalled RTE meat products and to determine the prevalence of Listeria spp., Salmonella spp., Escherichia coli and Campylobacter spp. in the products and air within the plant. Raw and processed meat products, as well as food contact surfaces were also tested for Salmonella spp., Listeria spp. and Campylobacter spp. initially after thorough clean-up and close-down of the plant. Faecal and effluent samples from the piggery, in close proximity to the plant, were tested for the presence of Salmonella spp., Listeria spp. and Campylobacter spp. Air samples and food contact surfaces were negative for the tested organisms. Ten (58.8%) of the 17 effluent samples and 4 (11.8%) of the 34 faecal samples were positive for Campylobacter coli. Of the 11 raw meat products tested, 10 (90.9%) were positive for E. coli and Listeria spp. either singly or in combination. Of the 32 processed RTE products tested, 11 (34.4%) were positive for E. coli, Salmonella spp., Listeria spp. and Campylobacter spp. in combination or singly. Eleven (61.1%) of 18 processed products contained unacceptable levels of aerobic bacteria using international standards. Four months later, following the implementation of recommended cleaning, sanitizing and hygienic practices at the plant, pre- and post-processed products were sampled and Listeria spp. were identified in 4 (80.0%) of the 5 raw products and in 1 of the 5 (20.0%) finished products. Two (40.0%) of the finished products contained unacceptable microbial levels. It was concluded that the close proximity of the piggery to the processing plant was not the probable source of Listeria contamination of the recalled meat products. The data suggested that improved sanitary practices on food contact surfaces and during handling of products, reduced the risk of Listeria spp. and other pathogens studied. The problem at the plant can therefore, be inferred to be due to lapses in good sanitary practices, inadequate heat treatments or the presence of pathogens particularly Listeria in biofilms on different surfaces continuously or occasionally contaminating finished products.     

Gel properties of silver carp (Hypophthalmichthys molitrix) and chicken mixture gels as affected by setting temperatures

This study aimed to evaluate the effect of setting temperatures (30°C, 35°C, 40°C, 45°C, and 50°C) on gel properties and protein profiles of paste gels derived from silver carp (Hypophthalmichthys molitrix) and chicken meat. The mixture composed of 50% (w/w) chicken meat and 50% (w/w) silver carp meat, and the three paste gels, were assessed based on color, gel strength, TPA, water distribution, chemical interactions, and SDS-PAGE. Chicken gels had better gel properties and a higher content of immobilized water than the mixture or fish gels, regardless of setting conditions. On the other hand, an appropriate setting temperature for the three paste gels promoted aggregation of the myosin heavy chain (MHC) and the formation of hydrophobic interactions and disulfide bonds, which resulted in superior gel properties. Pre-incubation at 40°C enhanced gel properties of fish meat, but pre-incubation at 45°C and 50°C were appropriate for achieving better gels for the mixture and chicken, respectively. These results indicated that there is the potential to obtain mixed products and new meat products by utilizing chicken and fish meat that have improved gel properties.     

Prevalence and typing of Listeria monocytogenes in ready-to-eat food products on the Belgian market

Listeria monocytogenes is a major concern to producers of ready-to-eat foods because of the high mortality rate associated with listeriosis and the widespread nature of the organism. To investigate the prevalence of this pathogen in different ready-to-eat food products on the Belgian market, a variety of 252 ready-to-eat food products, mainly fish and meat products, were analyzed. Overall, L. monocytogenes was detected in 23.4% of the samples. The highest prevalence of L. monocytogenes was found in prepared minced meat (42.1%) and smoked halibut (33.3%). Contamination levels were in most cases low (<10 CFU/g); however, levels higher than 100 CFU/g were detected in some samples of smoked salmon, smoked halibut, and prepared minced meat. A high prevalence of Listeria innocua (15.8%) and Listeria welshimeri (36.8%) was detected in prepared minced meat. L. monocytogenes strains isolated from different contaminated products were subjected to repetitive element sequence-based PCR (REP-PCR) typing to determine possible associations with product type, producer, or market. REP-PCR patterns were analyzed using BioNumerics software, and seven different groups with at least 90% similarity were identified. The cluster analysis indicates that cross-contamination occurred at the producer and retail level. Serotype identification of the strains by PCR revealed that most belonged to the 1/2a(3a) serotype group.     

INCIDENCE OF LISTERIA SPECIES IN INDIAN SEAFOODS AND MEAT

Thirty eight samples of fresh, frozen and dry seafoods and 27 samples of fresh and cold stored meat and meat products obtained from retail shops were examined for the presence of Listeria spp. Direct plating of the sample homogenate on Listeria Selective Agar (LSA) was compared with the two step enrichment method devised by Hao et al. for detecting Listeria spp. in vegetables. We report that modification of this methodology involving cold enrichment for 48 h in Brain Heart Infusion (BHI) at 10C followed by enrichment at 37C in Listeria enrichment broth (LE) resulted the enumeration of a large population of Listeria from flesh foods. Listeria isolates from fish and meat were identified by employing the cultural methods given in modified version of the Bacteriological Analytical Manual (Lovett and Hitchins 1988). Listeria spp. from seafoods were identified, with the order of predominance as L. grayi, L. innocua, L. murrayi, L. seeligeri. Samples of meat and their products were found to be contaminated mainly with L. innocua and L. murrayi. In contrast, screening of an independent batch of 20 fish and meat samples by adopting the PHLS (UK) method revealed predominance of L. grayi and L. seeligeri in fish and presence of additional species like L. seeligeri, L. ivanovii and L. welshimeri in meat products. None of the methods however could detect incidence of L. monocytogenes in any of the samples tested from local market in Bombay.     

低温肉制品加工过程卫生质量控制研究

以低温熏煮香肠为例研究了低温肉制品加工全程的环境、设备、人员等的卫生状况，对加工原料、辅料以及各加工工序后的半成品、成品的细菌总数进行了跟踪测定，分析了加工全程的微生物消涨规律和污染来源，确定了卫生和质量控制环节，根据HACCP体系全程质量控制原则对关键控制点指出了预防和控制措施。     

Oil-in-water emulsions as a delivery system for n-3 fatty acids in meat products

The oxidative and physical stabilities of oil-in-water emulsions containing n-3 fatty acids (25 wt.% oil, 2.5 wt.% whey protein, pH 3.0 or pH 6.0), and their subsequent incorporation into meat products were investigated. The physical stability of fish oil emulsions was excellent and neither coalescence nor aggregation occurred during storage. Oxidative stability was better at pH 6.0 compared to pH 3.0 likely due to antioxidative continuous phase proteins. Incorporation of fish oil emulsions into pork sausages led to an increase in oxidation compared to sausages without the added fish oil emulsion. Confocal microscopy of pork sausages with fish oil emulsions revealed that droplets had coalesced in the meat matrix over time which may have contributed to the decreased oxidative stability. Results demonstrate that although interfacial engineering of n-3 fatty acids containing oil-in-water emulsions provides physical and oxidative stability of the base-emulsion, their incorporation into complex meat matrices is a non-trivial undertaking and products may incur changes in quality over time.     

传统腌腊肉制品中微生物多样性研究进展

腊肠、腊肉和板鸭等是我国传统腌腊肉制品的典型代表。研究表明这些传统腌腊肉制品加工、贮藏过程中均有微生物存在和参与,并呈现多样性特征,主要的微生物菌群涉及乳酸菌、葡萄球菌、微球菌、酵母和霉菌等,这些微生物对腌腊肉制品的品质特性和感官特性会产生影响,且与产品质量和可贮性密切相关。因此研究腌腊肉制品中微生物多样性,对传统腌腊肉制品现代化加工中的品质和安全性提升有重要意义。该文对腊肉、腊肠、火腿、板鸭和腊鱼产品中的微生物多样性的研究进展进行概要综述。