高温加工方式对肉品质的影响

以猪肉(红肉)、鸡鸭肉(白肉)为原料,以色泽、全质构(TPA)等为指标,研究高温加工方式(煎制、炸制、烤制)对常见红、白肉食用品质的影响。结果表明:3种加工工艺对3种肉样的色泽、剪切力、TPA影响均显著(P0.05)。经煎、炸、烤制工艺处理后,3种肉样L~*、b~*值均显著增大(P0.05),猪肉a~*值减小(P0.05),而鸡肉a~*值增大(P0.05);3种高温工艺处理后,猪肉、鸭肉剪切力值显著增大(P0.05),鸡肉剪切力变化均不显著(P0.05);煎、炸、烤3种工艺均能显著增大猪肉硬度(P0.05),对于白肉,除煎制2,3 min及炸制3min 3组外,肉样硬度均显著增大(P0.05);经3种高温工艺处理后,猪肉、鸡鸭肉弹性均显著增大(P0.05)。     

Changes in the nutrient quality of meat in an obesity context

Today, being either overweight or obese is becoming the norm both in developing and developed countries. Developing countries often experience a double burden of nutrition-related diseases, as both over and undernutrition are experienced, with overweight presently exceeding underweight in most developing countries. Global diet trends such as moving from a traditional diet to more refined foods and increased sugar and saturated fat intake are identified as contributing to excess energy intake. The nutritional content of meat is non-homogenous and dynamic and meat has changed considerably in fat content, in many countries, during the last decade due to consumer demand. Choosing a particular meat cut of a specific fatness level, prior to cooking and consuming it without added high energy condiments, as well as trimming on the plate, can make a significant contribution to decrease energy intake, from a total diet perspective. Prudent portion size is also of importance. Meat is recognised as an important source of protein, vitamin B(12), Vitamin D and essential Omega 3 fatty acids, as well as bio-available minerals such as iron, zinc and selenium.     

肉的品质及其相关质量指标

传统的肉品由于其典型的感官特性以及天然的来源而受消费者的欢迎。然而同时，它又显示出一些负面因素，从而有可能影响到肉的宰后变化以及品质。随着消费者对健康肉(“放心肉”)需求的增加，研究者、生产者以及销售者都对如何改善肉的品质产生关注。本文主要就肉色、pH值、嫩度、持水力和风味这五个相关指标对肉品的影响进行了讨论，旨在我们为肉的品质形成一个整体性的概念把握，试图为肉品工业能够向消费者提供高品质、便利的肉食产品探寻方向。     

Red meat and colon cancer: Should we become vegetarians,or can we make meat safer?

The effect of meat consumption on cancer risk is a controversial issue. However, recent meta-analyses show that high consumers of cured meats and red meat are at increased risk of colorectal cancer. This increase is significant but modest (20-30%). Current WCRF-AICR recommendations are to eat no more than 500 g per week of red meat, and to avoid processed meat. Moreover, our studies show that beef meat and cured pork meat promote colon carcinogenesis in rats. The major promoter in meat is heme iron, via N-nitrosation or fat peroxidation. Dietary additives can suppress the toxic effects of heme iron. For instance, promotion of colon carcinogenesis in rats by cooked, nitrite-treated and oxidized high-heme cured meat was suppressed by dietary calcium and by α-tocopherol, and a study in volunteers supported these protective effects in humans. These additives, and others still under study, could provide an acceptable way to prevent colorectal cancer.     

PSE肉的形成机理和控制措施

阐述了PSE肉的特点、形成机理,说明了影响PSE肉形成的因素和一些解决方法。最后还说明了对PSE肉的利用。     

优质鸡肉质性状相互关系的研究

本试验研究了优质鸡胸肌和腿肌肌肉性状间的相互关系,并对肉质性状进行了主成分分析。结果表明,肌肉IMF与pH1、pH2、肌纤维密度呈正相关,而与烹饪损失、肌肉剪切力、肌纤维直径呈负相关。肌肉pH与烹饪损失、剪切力、肌纤维直径呈负相关,而与肌纤维密度呈极显著正相关。滴水损失与烹饪损失、肌纤维密度呈负相关,而与剪切力、肌纤维直径呈正相关。肌肉烹饪损失、剪切力与肌纤维直径呈正相关,而与肌纤维密度呈显著负相关。另外,主成分分析表明,胸肌肉质性状可以用4个主成分因子进行表示,腿肌肉质性状可以用2个主成分因子进行表示。     

热鲜肉与冷却肉品质差异之管见

我国肉与肉制品中生鲜肉占比约80%,生鲜肉中热鲜肉占比约60%,而冷却肉占比不足30%。近年来研究表明,僵直前的热鲜肉更适合炖煮、炒制、涮制等传统烹饪方法,而解僵成熟后的冷却肉则更适合烘烤、烧烤等西式烹饪方法。基于热鲜肉和冷却肉各自不同的加工特性和优劣势,本文在综述热鲜肉与冷却肉品质研究最新进展的基础上,提出了建立适合我国消费者饮食习惯、个性化消费需求和精细化烹饪方式的生鲜肉加工理论、技术、标准与管理体系,以期为生鲜肉生产“定制化”新业态提供技术和理论支撑。     

The prevalence of PSE characteristics in pork and cooked ham — Effects of season and lairage time

A total of 180 pigs was slaughtered in the same slaughterhouse, but divided in six different trials distributed over Winter (December–March) and Summer (April–September). Meat quality measurements (pH, electrical conductivity, color and/or water-holding capacity) were carried out 30 min, 24 and/or 35 h after slaughter in three different muscles: M. gracilis, M. semimembranosus and M. longissimus dorsi. A tendency towards a higher proportion of PSE meat during Summer was found in the examined muscles. Moreover a higher protein, higher dry matter content, a lower water/protein ratio and a lower slicing yield were found for the cooked hams suggesting a higher PSE prevalence in the Summer. A lairage time between 2 and 4 h during Summer and less than 2 h during Winter was related to a lower proportion of PSE meat. The correlation coefficients between the individual meat quality variables were moderate, but showed the predictive power of the pH measured 24 h post-mortem in the M. gracilis for meat quality.     

Cadmium Levels of Edible Offal from Saanen Goat Male Kids

Concentration of cadmium was investigated in the heart, tongue, lungs, spleen, liver, kidney, testis, brain and thymus of 15 Saanen goat male kids. This element was determined by inductively coupled plasma optical emission spectrometry (ICP-OES), after microwave digestion. The cadmium concentration was significantly influenced by the type of edible offal. Mean cadmium concentrations ranged from 0.018 mg/kg (heart) to 0.114 mg/kg (kidney). The maximum cadmium concentrations found in the kidney (0.133 mg/kg) and liver (0.075 mg/kg) were below maximum levels (1.0 and 0.5 mg/kg, respectively) set by legislation for these tissues.     

肉品检测技术的研究进展

目前肉类食品的检验正朝着更加安全和卫生的方向发展,检验质量不断提高.该文介绍了当代肉类品质检测技术,包括物理分析法中的计算机视觉技术、超声波技术、电磁学检测技术;仪器分析法的高效液相色谱、毛细管电泳安培法、近红外光谱分析技术、核磁共振波谱分析技术;现代分子生物学技术的核酸探针检测技术、生物芯片检测技术和微生物快速检验方法.     

Application of chitosan-incorporated LDPE film to sliced fresh red meats for shelf life extension

Chitosan lactate was impregnated as an antimicrobial additive into low density polyethylene (LDPE) with different concentrations. The antimicrobial effectiveness was tested with three pathogenic bacteria, specifically Listeria monocytogenes, Escherichia coli and Salmonella enteritidis. Also, these chitosan incorporated films were applied on red meat surfaces to determine the effectiveness of chitosan on color shelf life extension and microbial growth inhibition. Chitosan was exposed to 0.1% peptone water containing the three pathogens in separate tests and inhibited microbial growth a higher levels with increasing concentration of chitosan in the film matrix. Oxygen permeability was not affected by the incorporation of chitosan, while the water vapor permeability increased with the addition of chitosan. Film elongation decreased with the addition of chitosan. When chitosan incorporated films were applied on fresh red meat, microorganisms on the meat surface were not inhibited but significant extension of red color shelf life were observed in refrigerated, sliced red meats.     

近红外光谱分析技术在肉类产品检测中的应用研究进展

近年来,近红外光谱技术(Near Infared Spectroscopy,NIRS)作为一种新型光学检测技术在食品工业中得到越来越广泛的应用,被证实为肉和肉制品品质检测中最为有效、先进的方法之一。文章综述了近红外光谱技术在肉类行业应用中近年来的研究进展,主要包括肉品化学成分、感官指标、物理性质的检测及肉品品种、等级的鉴定,并且展望了该技术的发展前景,认为标准化取样、改善参考方法将有助于提高近红外光谱技术的预测精度。      

Microbiological quality of freshly shot game in Germany

In the framework of a project on the hygiene status of freshly shot game 289 samples were microbiologically analysed: 127 samples from wild boars, 95 from roe deer and 67 from red deer. The microbiological parameters evaluated were the mesophilic aerobic count (APC), which showed mean log10-counts of 2.6 cfu/cm² for roe deer, 2.9 cfu/cm² for red deer and 3.2 cfu/cm² for wild boars and the numbers of Enterobacteriaceae, which gave mean log10-values of 2.1 cfu/cm² for all three species with differing ranges. The concentrations of coagulase positive staphylococci were >2.0 log10 cfu/cm² between 3.2 and 6.3%, according to species. Listeria was found in 14 samples and three samples gave a positive result for Campylobacter. Salmonella was not found in any of the samples analysed.     

对超临界CO_2用作肉及肉制品杀菌剂的探讨

本文提出用超临界CO2作为肉及肉制品的杀菌剂,重点概述了超临界CI2对肉及肉制品中微生物的致死作用和对肉及肉制品的品质影响情况.另外,展望了超临界CO2杀菌技术在未来肉品工业中的发展前景.     

贮藏温度对马肉不同部位嫩度变化的影响

研究不同贮藏温度对马肉不同部位嫩度变化的影响。将宰后马肉的臀肌、肩肌和背最长肌在15、4、-18℃3种不同的温度条件下贮藏24h后,分析测定其水分、脂肪、胶原蛋白和剪切力等指标的变化情况,并对上述指标进行相关性分析。结果显示:臀肌和肩肌的剪切力值均与水分含量呈极显著负相关（p<0.01）,臀肌的剪切力值与胶原蛋白含量呈显著负相关（p<0.05）。肩肌剪切力值与总胶原蛋白含量呈极显著负相关（p<0.01）,与不溶性胶原蛋白含量呈负相关。背最长肌剪切力值与总胶原蛋白含量呈负相关,与不溶性胶原蛋白含量呈显著负相关（p<0.05）。在15、4、-18℃下,3个部位的剪切力值与蒸煮损失呈负相关,与脂肪含量、系水力呈正相关。肩肌和背最长肌的剪切力值与pH呈负相关,而臀肌相反。15、4、-18℃下马肉3个部位肌肉的各项指标不能统一达到相对最佳点。