公犊肉加工腊肠试验

本试验在对初生公犊肉质研究的基础上,针对其肉色浅、水分含量高、系水率低、脂肪含量低等缺点,设计相应的配方和改进加工工艺,试制出符合国家标准的腊肠,探索尽可能提高公犊肉和猪肥膘利用率的可行途径。     

肉品质光谱检测中探头与样品距离对结果影响的校正

针对畜肉品质光谱检测中光纤探头与样品表面不同检测距离对预测结果影响较大的问题,分析了光谱曲线随检测距离变化的变化规律,提出光谱数据的校正方法。通过猪肉嫩度预测,验证校正效果。分别采集光纤探头固定时和光纤探头与样品表面检测点距离在4~18 mm变化范围内的猪肉背肌可见/近红外光谱。对每种情况下的光谱数据进行相同预处理,建立猪肉嫩度PLSR预测模型。探头固定时,预测集猪肉嫩度预测值和实测值相关系数为0.82,均方根误差为5.82 N。五次多项式拟合光纤探头与样品表面检测点距离在4~18 mm范围内380~1 050 nm各个波段的相对光谱数据,拟合相关系数R均大于0.999,均方根误差在0.018 7~0.242 2范围内。利用拟合方程校正后的光谱数据和最优嫩度预测模型对预测集进行预测,光纤探头与样品表面检测点距离在4~17 mm范围内时预测集嫩度预测值和实测值的相关系数在0.83~0.90之间,均方根误差在4.80~5.75 N之间。结果表明:对不同光纤探头与样品表面检测点距离采集的漫反射光谱数据进行校正,能够较好地克服光纤探头与样品表面检测点距离对猪肉嫩度预测模型的影响。     

基于多光谱成像技术的猪肉新鲜度无损快速检测装置

基于多光谱成像技术设计了猪肉新鲜度的关联复合品质参数无损伤快速检测装置,包括硬件与软件设计.硬件系统由单片机控制单元、光源单元、图像采集单元、数据处理单元和LCM液晶显示单元组成,软件系统在ICCAVR开发环境下设计,采用C语言编程,包含图像采集模块、滤光片切换模块、LCM显示模块、与PC机通信模块等.经过软件与硬件系统调试、实验,该装置检测速度为每10s检测一个样品,具备无损伤、快速检测的功能.     

猪肉品质及其影响因素的研究概况

随着猪肉生产中瘦肉率的提高,以及有害添加剂的饲喂,猪肉品质恶化。而另一方面,人们的保健意识增强,对各种畜禽肉质和风味提出了更高的要求。本文综述了常规肉品质性状,以及品种和营养对它的影响。     

Effect of sire and sex on the intramuscular fatty acid profile and indices for enzyme activities in pigs

In this study, the effect of sire, sex and intramuscular fat content on the intramuscular fatty acid profile, in particular the long chain polyunsaturated fatty acids (PUFA) was investigated. Therefore, pork samples of the Longissimus thoracis were taken from 121 females and castrates that were the progeny of 5 boars. All animals had been fattened on the same diet and were slaughtered at a live weight of approximately 110 kg. Indices for the activities of Δ9, Δ6 and Δ5 desaturase, as well as elongase activity were estimated from ratios of product to precursor fatty acids. Intramuscular fat content was positively related to the total saturated fatty acid proportion (r = 0.376; p < 0.01) and the total monounsaturated fatty acid proportion (r = 0.579; p < 0.01), and inversely correlated with the total PUFA proportion (r = − 0.637; p < 0.01). A significantly higher index for Δ5 and Δ6 desaturase and elongase activity for PUFA metabolism was observed in females compared to castrate males. Sire had a significant effect on the intramuscular fatty acid profile, notably on the total n − 3 PUFA, and on most individual long chain n − 6 and n − 3 PUFA. The cis-9 C18:1/C18:0 index for Δ9 desaturase activity and the cis-11 C18:1/cis-9 C16:1 elongase activity index, as well as the combined desaturase and elongase enzyme activities in both the n − 6 and n − 3 PUFA chains were significantly influenced by sire.     

Prevalence and Risk Factors for Bacterial Food‐Borne Zoonotic Hazards in Slaughter Pigs: A Review

The Hygiene Package and Regulation EC‐2160/2003 require information flow from farm to slaughterhouse to enhance European consumers protection in a ‘farm to fork’ approach. This obligation especially concerns food‐borne zoonotic hazards transmitted to humans through pork consumption, such as thermophilic Campylobacter spp., Listeria monocytogenes, Salmonella enterica and Yersinia enterocolitica. Prevalence estimates of these four hazards are affected by the sampling strategy and diagnostic procedure. Individual prevalence estimates for pig carriage (from digestive contents or lymph nodes collected at slaughterhouse) were higher than individual prevalence estimates for pig shedding (from faeces). Among risk factors described in the literature, poor pen cleaning and disinfection after pig departure to slaughterhouse and poor bio‐security measures are of major significance. Moreover, whereas wet feed increases the risk of pig infection by L. monocytogenes, dry feed is a risk factor for Salm. enterica. Mixing batches of pigs, notably in fattening herds, represents a risk for the transmission of Salm. enterica and Y. enterocolitica. Whereas small herds are more infected by thermophilic campylobacters and Y. enterocolitica, higher prevalence of Salmonella is observed in large herds due to a more frequent mixing of batches. Antibiotic treatment during the finishing period increases the risk of transmission of Salm. enterica. The forenamed elements should be taken into account to characterize farms in a risk assessment approach and to improve zoonotic hazard management in the pork food chain.     

Effects of a dietary supplement of DHA-rich marine algae on Italian heavy pig production parameters

To evaluate the effects of dietary supplementation with a marine algae product (MA) containing a high level of docosahexaenoic acid (DHA) on heavy pig production performances (including meat and subcutaneous fat quality), a trial was conducted on sixty Landrace × Large White barrows with a starting average body weight (BW) of 118 kg. Pigs were allocated to four experimental groups: a control group (A) fed a maize/soybean diet and three treatment groups in which MA was added at 2.5 g kg^− 1 over the last 8 weeks prior to slaughtering (group B) or at 5 and 2.5 g kg^− 1 over the last 4 weeks prior to slaughtering (groups C and D, respectively). Vitamin E was added at 12.5 mg kg^− 1 in the diets for groups B and D and at 25 mg kg^− 1 in the diet of group C. The four diets were formulated so as to supply the same amount of nutrients, with exception of vitamin E. Pigs were fed at a rate of 9% of their metabolic BW (BW^0.75) up to a maximum of 2.9 kg of dry matter per pig per day. Pigs were slaughtered at about 160 kg BW. The dietary treatment did not affect either the growth or slaughtering parameters of pigs. No significant differences were observed with respect to pH values, meat colour, loin composition and the iodine number of subcutaneous fat. Pigs on MA diets showed a significant (P < 0.01) improvement in DHA levels both in loin and in subcutaneous fat. No significant differences in relative fatty acid composition were observed between pigs receiving the MA supplement at the lower level (2.5 g kg^− 1) over an 8-week period (group B) and pigs receiving the higher MA supplement (5.0 g kg^− 1) over a 4-week period prior to slaughter (group C).     

非洲猪瘟疫情对我国生猪生产与市场的影响

非洲猪瘟疫情对中国生猪产业可能产生巨大且长期的影响。一方面因为生猪饲养量大幅度减少,造成供给不足;另一方面,尽管猪肉消费在短期受到了一定程度的抑制,但由于消费偏好无法短期内改变,猪肉“刚需”仍然存在。预计2019年中国猪肉供需缺口将在1000万t左右,全年猪价将呈现“先抑后扬”态势,生猪价格将可能在近两年内都处在较高水平。猪价上升可能通过产业链波及至食品全行业,导致物价水平整体上涨。建议加大生猪生产扶持力度,调动生猪养殖积极性;明确政府管理权责,确保猪肉稳定供应;遵从产消对接、区域互补原则,以农牧结合为前提,构建生猪生产消费均衡区域布局。     

An epidemiological overview of swine trichinellosis in China

Trichinellosis is a major food-borne zoonosis with health, social, and economic impacts. Epidemiological data on swine trichinellosis in China from 2005 to 2009 were obtained from seven Provinces/autonomous regions/Municipalities (P/A/M) and analyzed and sero-epidemiological data were acquired from five P/A. The seroprevalence ranged from 0.01% to 29.95% as determined by enzyme-linked immunosorbent assay or an immunochromatographic strip method. The prevalence of Trichinella infection in swine slaughtered at abattoirs varied from 0% to 5.75% in five P/A. Between 2005 and 2009, endemic areas of swine trichinellosis were located mainly in the Western (Guangxi and Qinghai), central (Henan and Hubei), and North-eastern parts (Heilongjiang) of China.Swine trichinellosis in China is transmitted mostly through garbage. Pigs infected with Trichinella are predominately from small backyard farms where animals are raised under poor hygienic conditions, and from rural and mountainous areas where they range freely at pasture. The prevalence of Trichinella in pork sold at the market was reported in four P/A, and varied from 0.06% to 5.6% as determined by trichinoscopy or the digestion method. From 2005 to 2009, 15 outbreaks of human trichinellosis, with 1387 cases and 4 deaths, were recorded in three P/A of South-western China. Twelve (85.71%) of these 15 outbreaks were caused by the eating of raw or undercooked pork, which remains the predominant source of trichinellosis in humans. Pig-rearing practices must be improved, and mandatory inspection of pork further strengthened in rural and mountainous areas in Western China for the control of the disease.     

应用ELISA检测肉猪尿液中盐酸克仑特罗方法的研究

应用酶联免疫吸附法(ELISA)，检测肉猪尿液中盐酸克仑特罗残留，实现了肉猪活体盐酸克仑特罗快速测定。实验结果表明，盐酸克仑特罗的线性范围为200—2000ng/kg，最小检出限为100ng/L,样品不用前处理可直接检测，1个样品的2个平行样测定时间为45min。