Listeria monocytogenes in ready-to-eat vacuum and modified atmosphere packaged meat and fish products of Estonian origin at retail level

The prevalence, counts and genetic diversity of Listeria monocytogenes in ready-to-eat (RTE) vacuum and modified atmosphere packaged meat and fish products was studied in Estonia. Within two consecutive years 370 RTE food samples were collected at retail level from which 11% were found to be positive for L. monocytogenes. Contamination was higher among RTE fish products (17%) than in RTE meat products (6%). Generally, the counts of L. monocytogenes in positive products remained under ten colony forming units (CFU) per gram of product. Only 1.6% of the RTE meat and fish products contained L. monocytogenes in range of 10–100 CFU/g and 0.3% more than 100 CFU/g at the end of shelf-life. The food category containing highest L. monocytogenes prevalence was RTE lightly salted fish products with the prevalence of 32%. Only one (0.3%) RTE food sample exceeded the 100 CFU/g food safety criterion set out in the EU Regulation 2073/2005. Pulsed-field gel electrophoresis (PFGE) characterization of the isolates showed an overall similarity higher than 70%, and nine clusters based on 100% similarity were revealed. PFGE genotyping revealed that the few predominant pulsotypes were associated with particular food plants.     

Effect of Penicillium nordicum contamination rates on ochratoxin A accumulation in dry-cured salami

Fungal starter, such as Penicillium nalgiovense, are commonly used to inoculate sausages before seasoning process. However, Penicillium nordicum, a well-known ochratoxin A (OTA) producer frequently isolated from seasoning rooms, could colonize the casing surface during the early stage of production. The relationship between OTA accumulation and simultaneous inoculation of P. nalgiovense and P. nordicum at different rates was evaluated. After 14 days of seasoning, the persistence of P. nordicum was assessed by LAMP assay revealing its capability to colonize and grow on salami surface at all the contamination rates. At the end of seasoning, OTA was accumulated both in mycelium and dry-cured meat when P. nordicum contamination rate ranged from 25% to 100% of inoculum, while no OTA was detected in dry-cured meat at 2.5% and 0.25%. Results demonstrated that contamination of fungal starter by P. nordicum could represent a serious concern during salami production and therefore represents an important critical point to be monitored.     

成型火腿制品的生产原理和质量控制

成型火腿的生产现已很普及,生产成型火腿的三个关键点是：肉块表面蛋白基质的形成、原料肉的软化、使肉表面蛋白基质变性凝固的加热过程,生产成型火腿的关键控制点有原料肉的选择、腌制液的配制、滚揉、热处理等,要生产高质量的成型火腿,不仅要保证原料肉、时辛料和腌制剂的卫生质量。同时还必须在生产过程中对关键点进行控制。     

2001年肉蛋类商品产销走势浅析

本文概括了 2 0 0 0年肉蛋类商品的产销状况 ,着重分析了 2 0 0 1年肉蛋类商品产销的发展趋势     

我国肉类食品的市场特点及冷藏运输需求

介绍了我国肉类食品的发展概况,分析了我国肉类食品市场的特点与发展趋势及对冷藏运输的需求,指出了发展过程中存在的问题,并提出了相应的建议.     

肉类风味的研究

本文介绍了有关肉风味形成的前驱性物质,概述肉味形成和Maillard反应,类脂类物质的热降解,氨基酸和肽的热降解以及糖类物质的降解反应的关系,并且着重介绍了多种肉香挥发性化合物。     

Effect of irradiation and packaging conditions after cooking on the formation of cholesterol and lipid oxidation products in meats during storage

The effect of irradiation and packaging conditions on the content of cholesterol oxidation products (COPs) and lipid oxidation in cooked turkey, beef, and pork during storage was studied. Ground turkey leg, beef, and pork were cooked, packaged either in oxygen-permeable or oxygen-impermeable bags, and irradiated at 0 or 4.5 kGy. Lipid oxidation and COPs were determined after 0 and 7 days of storage at 4°C. Packaging of cooked meat was more important than irradiation in developing COPs and lipid oxidation in cooked meats during storage. 7-Hydroxycholesterol, 7β-hydroxycholesterol, β-epoxide, and 7-ketocholesterol were among the major COPs formed in cooked turkey, beef, and pork after storage, and their amounts increased dramatically during the 7-day storage in aerobic conditions. Irradiation had no significant effect on the amounts of any of the COPs found in cooked turkey and beef, but increased (P<0.05) the amounts of - plus 7β-hydroxycholesterol, β-epoxide, 7-ketocholesterol, and total COPs in aerobically packaged cooked pork. The amounts of COPs and lipid oxidation products (TBARS) closely related to the proportion of polyunsaturated fatty acids in meat. The results indicated that the composition of fats in meat is important on the oxidation rates of lipids and cholesterol, and packaging is far more important than irradiation in the formation of COPs and lipid oxidation in cooked meat.     

双螺杆挤压机工艺参数对组织蛋白的影响

本文采用新型双螺杆食品挤压机,进行了挤压加工大豆组织蛋白和工程内制品的试验研究,获得了螺杆转速,含水量和温度对挤压过程和产品组织化质量的影响规律,研究表明,螺杆转速在80r/min,100r/min之间,含水量在38％－44％之间,大豆组织蛋白的挤压组织化质量良好,螺杆转速在60r/min,80r/min这间,含水量在60％－65％之间,工程内制品的挤压组织化质量良好,优化的机筒温度和机头温度分布为：30℃－45℃－80℃100℃－130℃－150℃－100℃。     

积极发展绿色肉食品 适应国内外市场需求

阐明了我国发展绿色肉食品的必要性和有利条件,提出了开发绿色肉食品的几点建议。     

Analysis of visible reflectance spectra of stored, cooked and diseased chicken meats

Visible spectra of cold stored, cooked, and diseased chicken meats were collected. Changes in ratios of R₁=A_{485 nm}/A_{560 nm} and R₂=A_{635 nm}/A_{560 nm,} which are related to absorbances of the bands at 485 (metmyoglobin), 560 (oxymyoglobin), and 635 nm (sulfmyoglobin), were observed to be useful for studying the variation of meat color under the conditions of cold storage and cooking process. Such a strategy was also applied to classify fresh-raw wholesome and unwholesome meats into respective classes, and the result was compared with that produced from a chemometric model. The strategy might be used as a simple methodology for monitoring the color variation of meats where the development of the chemometric model is either impractical or not desirable.