不同部位新疆褐牛肉的品质差异分析

为明确新疆褐牛不同部位肉的营养品质、食用品质和加工特性等方面的差异,测定新疆褐牛黄瓜条、臀肉、外脊、牛腩、霖肉、肩肉和牛腱7个部位的蛋白质、水分、脂肪、胶原蛋白含量、质构、剪切力、色差、pH值及加工特性.结果表明:不同部位新疆褐牛肉的蛋白质含量19.57％～22.90％,脂肪含量0.98％～2.85％;牛腱脂肪含量显著...     

The analysis of polyunsaturated fatty acids in meat by capillary gas-liquid chromatography

Polyunsaturated fatty acids (PUFA) of lean meat from domesticated and wild ruminants (cattle, sheep, goat, sambar deer and buffalo) and non-ruminants (pig, horse and kangaroo) have been examined by capillary gas-liquid chromatography. Ten different PUFA were found in all specimens with linoleic acid accounting for at least 50% of the total, and arachidonic and linolenic acids being the next most abundant. The total PUFA content for the ruminants ranged from 9 % in beef to 31 % in sambar deer and for the non-ruminants from 25 % in pig to 43 % in horse. In all species the meat phospholipids ( PL ) were rich in PUFA (range 24–46% of PL fatty acids), whereas the triglycerides were relatively more saturated (PUFA content range 2–17%). Overall, horse and kangaroo meat had the combination of lowest fat and highest PUFA content, whilst beef and sheep had the highest fat and lowest PUFA content. These results indicate that significant reductions in total fat intake and increases in the proportion of polyunsaturated fat in the diet could be achieved without necessarily requiring a diet low in meat.     

An exploratory observational study to develop an improved method for quantifying beef carcass salable meat yield

Eighty-seven grain-finished steers were harvested, evaluated, and fabricated into wholesale cuts to determine what measured composition indicators most accurately describe the percentage of closely trimmed salable meat yield. Indicators of lean and fat composition present at the cross-section between the 12th and 13th ribs were objectively evaluated using Assess image analysis software. Salable meat yield ranged from 50.18% to 72.92%, trimmable fat yield ranged from 12.87% to 36.69%, and bone yield ranged from 10.07% to 19.21%. Regression models were developed to estimate percentage of total salable meat yield. Composition indicators chosen to predict salable meat yield included hot carcass weight (HCW), perinephric fat weight, longissimus muscle area (LMA), subcutaneous fat thickness (SFT), ratio of LMA to subcutaneous fat area, and ratio of subcutaneous fat depth to HCW. These results indicate that prediction of beef carcass salable meat yield can be improved via modification to current measures used in the USDA yield grade equation and addition of new measures.     

新疆褐牛不同部位肉品质特性差异分析

为了探究新疆褐牛不同部位肉品质特性的差异及加工适宜性,为新疆褐牛肉的精细化加工提供理论依据,本实验选取2岁龄新疆褐牛霖肉、外脊、牛腩、肩肉、牛腱、臀肉、黄瓜条等7个部位肉样,进行营养及食用品质特性的研究。结果显示:新疆褐牛上述7个部位肉品质特性差异较大。霖肉的胶原蛋白含量(13.02%)较高,凝胶特性和乳化特性也较好;外脊的脂肪(2.31%)含量较高,嫩度较好,但保水性较差;牛腩具有解冻损失(1.79%)小而蒸煮损失(37.27%)大的特点;肩肉具有良好的凝胶特性和乳化特性及嫩度;牛腱的水分含量(76.48%)较高且解冻损失(1.70%)较小;臀肉具有较高的胶原蛋白含量(18.49%)和良好的保水性;黄瓜条具有最高的营养品质、较好的嫩度和较小蒸煮损失(30.49%)的特点。结果表明,新疆褐牛不同部位肉品质特性存在差异,各部位肉有其适宜的加工方式。     

沃金黑牛母牛与阉公牛牛肉品质比较及影响因素分析

目的 对比沃金黑牛母牛与阉公牛牛肉品质, 分析其影响因素。方法 随机选取18头健康、无病、发育正常的30个月龄沃金黑牛(母牛9头, 阉公牛9头)为研究对象, 测定其背最长肌的水分、粗蛋白、肌内脂肪、氨基酸、脂肪酸、质构特性, 并基于主成分分析考察影响沃金黑牛肉肉质的因素。结果 母牛和阉公牛牛肉的水分、粗蛋白、肌内脂肪以及各氨基酸含量无显著差异(P>0.05)。母牛牛肉必需氨基酸(essential amino acid, EAA)/总氨基酸(total amino acid, TAA)为39.74%, 阉公牛EAA/TAA为39.83%, 符合联合国粮食及农业组织/世界卫生组织(Food and Agriculture Organization/World Health Organization, FAO/WHO)的理想模式。母牛和阉公牛牛肉氨基酸评分(amino acid score, AAS)接近1, 化学评分(chemical score, CS)与标准蛋白的组成还有一定差距。母牛牛肉单不饱和脂肪酸(monounsaturated fatty acid, MUFA)含量极显著低于阉公牛(P<0.01), 而多不饱和脂肪酸(polyunsaturated fatty acid, PUFA)含量显著高于阉公牛(P<0.05)。母牛牛肉MUFA:饱和脂肪酸(saturated fatty acid, SFA)极显著低于阉公牛(P<0.05), PUFA:SFA显著高于阉公牛(P<0.05)。母牛和阉公牛各质构指标均无显著差异, 咀嚼度、黏性、硬度、黏合力为影响肉质的主要因素, 且质构指标优先性强于营养指标。结论 阉公牛脂肪酸含量与母牛差异显著, 水分含量、粗蛋白含量、粗脂肪含量、氨基酸含量与组成、质构指标之间差异均不显著。质构指标比营养指标更能影响沃金黑牛肉的品质。     

Occurrence and survival of verocytotoxin-producing Escherichia coli O157 in meats obtained from retail outlets in The Netherlands.

In 1996 and 1997, 2,941 fresh and processed meat products obtained from supermarkets and butcher shops in The Netherlands were examined for the presence of verocytotoxin-producing Escherichia coli of serogroup O157 (O157 VTEC). Additionally, the fate of O157 VTEC in raw meat products stored at low temperatures and the effect of different additives were evaluated. O157 VTEC strains were isolated from 6 (1.1%) of 571 samples of raw minced beef, 2 (0.5%) of 402 samples of raw minced mixed beef and pork, 1 (1.3%) of 76 samples of raw minced pork, 1 (0.3%) of 393 samples of other raw pork products, and 1 (0.3%) of 328 samples of cooked or fermented ready-to-eat meats. Other raw beef products (n = 223) and meat samples originating from poultry (n = 819), sheep or lamb (n = 46), or wild animals (n = 83) were all found to be negative for O157 VTEC. For the survival experiments we used tartaar (minced beef with a fat content of less than 10%) and filet americain (tartaar mixed with a mayonnaise-based sauce [80 to 20%]). The O157 VTEC strain tested was able to survive in tartaar and filet americain stored at -20, 0, 5, or 7 degrees C for 3 days. At both 7 and at 15 degrees C, O157 VTEC counts in tartaar and filet americain remained virtually unchanged throughout a storage period of 5 days. Addition of acetic acid (to pH 4.0), sodium lactate (1 and 2% [wt/wt]), or components of the lactoperoxidase-thiocyanate-hydrogen peroxide system to filet americain did not result in a reduction of viable O157 VTEC cells during storage at 7 or 15 degrees C. It was concluded that raw meat contaminated with O157 VTEC will remain a hazard even if the meat is held at low or freezing temperatures.     

夏南牛不同部位加工特性及牛肉干加工适宜性评价

夏南牛是我国自主培育的第一个专用肉牛新品种，为促进夏南牛肉及其深加工产品的工业化和科学化发展，本实验研究不同部位牛肉的理化指标和加工品质指标的差异，并评价其牛肉干加工适宜性。选取并测定20 个原料肉理化指标和9 个牛肉干产品加工品质指标，利用相关性分析和主成分分析筛选关键指标，并建立评估方程。结果表明：不同部位牛肉理化特性存在明显差异。臀肉的水分质量分数（75.47%）和蛋白质量分数（21.51%）最高，脂肪质量分数（2.39%）最低（P＜0.05），凝胶和乳化性能较好。肩肉的脂肪质量分数最高（8.69%），质构特性较好，剪切力较小。牛腱的解冻损失率（1.81%）和蒸煮损失率（24.08%）最低，剪切力最小（4.99 kg）。霖肉的解冻损失率（6.36%）和蒸煮损失率（34.22%）最大。2）牛肉干加工适宜性综合评价模型为Y＝0.197 9A＋0.026 0B＋0.312 8C＋0.218 8D＋0.245 5E（A、B、C、D和E分别代表a*、硬度、羟脯氨酸含量、蒸煮损失率和乳化稳定性）。3）肩肉和黄瓜条适合加工牛肉干，而霖肉和牛腱不适合；4）以感官评价结果为因变量，以综合品质评价结果为自变量，建立回归方程为y＝3.646 5x＋4.556 2（R2＝0.824 2）。综合评价模型可以较好地预测肉干加工适宜性。本研究为夏南牛加工特性补充和更新了必要的参数，此外，还找到了更适合牛肉干加工的部位。     

Collagen content of some Australian canned meats

Eleven manufacturers supplied 146 samples of canned corned beef, corned beef with cereal, ham, cured pork shoulder and comminuted ham products. All cans were analysed for salt, moisture, fat, protein and collagen. The mean collagen content ranged between 0.99 and 4.08%. These results are discussed in relation to current international interest in establishing minimum limits for collagen-free meat protein in processed meat products.     

不同部位牦牛肉氨基酸、脂肪酸含量分析与营养价值评价

为明确不同部位牦牛肉氨基酸、脂肪酸等营养物质含量,采集西藏那曲牦牛的上脑、里脊、外脊、米龙、臀肉、腱子肉、腹肉、肩肉及胸肉9 个部位分割肉,测定其蛋白质、脂肪、灰分、氨基酸和脂肪酸组成。结果表明：不同部位牦牛肉的蛋白质含量为19.30%～24.20%,其中腹肉中蛋白质含量最低,外脊中最高;脂肪含量为1.03%～22.47%,腹肉中脂肪含量显著高于其他各部位,米龙、外脊、臀肉和肩肉中脂肪含量较低,不足1.5%。在测定的18 种氨基酸中,谷氨酸含量最高,其次是赖氨酸、天冬氨酸、亮氨酸和精氨酸;腹肉中氨基酸含量显著低于其他部位（P＜0.05）,9 个不同部位牦牛肉中必需氨基酸占总氨基酸的比例为39.03%～40.00%,与联合国粮农组织/世界卫生组织的推荐值接近;里脊和外脊能够满足所有膳食氨基酸需要,上脑、米龙、臀肉、腱子肉、腹肉、肩肉及胸肉中,缬氨酸是限制性氨基酸。脂肪酸总量由大到小为腹肉＞上脑＞里脊＞臀肉＞外脊＞胸肉＞肩肉＞腱子肉＞米龙,油酸、棕榈酸和硬脂酸是牦牛肉中主要的脂肪酸,二十二碳六烯酸、二十碳五烯酸等n-3脂肪酸含量较少,n-6/n-3比值高于膳食推荐值。以常规营养组分、氨基酸组成和脂肪酸组成分别进行聚类分析,总体可分为腹肉、上脑与其他部位肉三大类。综上所述,不同部位牦牛肉中蛋白质、脂肪、氨基酸及脂肪酸等营养物质含量存在差异。     

The bacterial quality of red meat and offal in Casablanca (Morocco)

The present study aimed to evaluate the bacteriological quality of beef (n = 52), lamb (n = 52) and beef offal (n = 52) marketed in Casablanca, Morocco. Meat and offal samples (n = 156), were collected randomly from butcheries, supermarkets, and slaughterhouses. Two sampling periods were considered, one during the hot season and the second one during the cold season. The samples were analyzed for the presence of the following bacteria: Escherichia coli, coagulase-positive Staphylococcus, Clostridium perfringens, Salmonella, and Listeria monocytogenes. Results indicated that counts of the aerobic plate count, and fecal coliforms were particularly high in all the samples analyzed. E. coli, coagulase-positive Staphylococcus and C. perfringens were detected in 37.8, 16, and 4.5% of the meat samples, respectively. Neither Salmonella nor L. monocytogenes were isolated from meat samples. Approximately 26.9% of beef, 34.6% of lamb and 28.8% of beef offal samples contained bacteria above the maximum limits established by the Moroccan regulatory standards for meat and meat products. Seasonality and the distribution location significantly (p < 0.05) affected bacterial populations: the hot season and butcheries appeared to be cases where the highest populations of bacteria in meat were observed. These high levels of microbiological contamination attest the poor hygienic quality of meat and offal, possibly due to uncontrolled processing, storage, and handling of these products.     

Effects of incorporating roasted lupin (Lupinus angustifolius) flour on the physicochemical and sensory attributes of beef sausage

The effects of incorporating lupin flour on the physicochemical and sensory characteristics of beef sausages were explored. Lupin (Lupinus angustifolius) flour was roasted, then hydrated to match the moisture content of beef meat. The beef sausage samples were manufactured for six treatments by replacing beef with hydrated lupin flour from 0% to 36% (w/w). Proximate analysis revealed that carbohydrate (dietary fibre) level was increased from 9.62% to 19.31%, whereas fat content was decreased from 11.62% to 7.91%. Inclusion of lupin flour increased the meat emulsion stability (fluid released decreased from 9.35% to 1.53%) and decreased cooking loss from 22.70% to 14.30%. Softer texture and greater adhesiveness were observed in lupin-incorporated formulations. Sensory evaluation indicated no significant difference between control and 12% lupin-enriched beef sausage formulation in appearance, aroma, flavour and overall liking, suggesting lupin flour can be added to beef sausage at this level without compromising consumer acceptance.     

National Beef Market Basket Survey - 2006: External fat thickness measurements and separable component determinations for beef from US retail establishments

A market basket survey for beef retail cut composition at the retail level (four stores each from two chains in each city) was conducted in 11 US cities from January to March 2006. Beef cuts (n=17,495) were measured for external fat thickness with cuts from the chuck (0.05cm), round (0.05cm), and miscellaneous (0.04cm) having less (P<0.05) fat than cuts from the loin (0.11cm) and rib (0.11cm). Beef cuts (n=1327) were separated physically into separable components with round cuts having more (P<0.05) separable lean (96.63%) than chuck cuts (86.81%) and miscellaneous cuts (86.18%), which had more (P<0.05) separable lean than loin cuts (84.53%) with rib cuts (69.34%) having the lowest (P<0.05) separable lean. Chemical fat from the separable lean differed (P<0.05) between each cut category: round cuts (3.71%), miscellaneous cuts (4.99%), loin cuts (5.60%), chuck cuts (6.90%), and rib cuts (8.61%). Ground beef samples (n=235), with declared lean/fat percentages ranging from 73/27 to 96/4, had overall chemical fat values of 13.41% and moisture values of 67.42%. This survey documents the current beef retail cut and ground beef composition, which is helpful to those who need this information for various dietary and marketing purposes.     

Prevalence and level of Escherichia coli O157 on beef trimmings, carcasses and boned head meat at a beef slaughter plant

This study investigated the prevalence and level of Escherichia coli O157 on samples of beef trimmings (n=1351), beef carcasses (n=132) and bovine head meat (n=132) in a beef slaughter plant in Ireland. The survey also included an assessment of the prevalence of virulence genes in the E. coli O157 isolates obtained. Samples were examined for the presence of E. coli O157 by direct plating on SMAC-CT and by enrichment/immunomagnetic separation (IMS) with plating of recovered immunobeads onto SMAC-CT agar. Presumptive E. coli O157 isolates were confirmed by PCR targeting a range of genes i.e. vt1, vt2, eaeA, hlyA, fliC(h7) and portions of the rfb (O-antigen encoding) region of E. coli O157. Enterobacteriaceae on head meat samples were estimated by direct plating onto Violet Red Bile Glucose agar. E. coli O157 was recovered from 2.4% (32/1351) of beef trimmings samples, at concentrations ranging from<0.70-1.61 log10 cfu g(-1). Of the 32 positive isolates, 31 contained the eaeA and hylA genes while 30/32 contained the fliC(h7) gene and 31/32 contained vt1 or vt2, or both vt genes. E. coli O157 was recovered from 3.0% (4/132) of carcass samples, at concentrations ranging from <0.70-1.41 log10 cfu g(-1). All of the carcass isolates contained the eaeA, hylA and fliC(h7) genes. E. coli O157 was recovered from 3.0% (3/100) of head meat samples, at concentrations of 0.7-1.0 log10 cfu g(-1). All of the head meat isolates contained the eaeA, hylA, fliC(h7) and vt2 genes. No head meat isolates contained the vt1 gene. Head meat samples (n=100) contained Enterobacteriaceae, at concentrations ranging from 0.70-3.0 log10 cfu g(-1). Overall, the qualitative and quantitative data obtained for E. coli O157 on beef trimming samples in this study could be employed as part of a quantitative risk assessment model.     

原料肉部位对牛干巴肉质特性的影响

选取（30±2） 月龄云岭去势公牛6头,屠宰后经7d低温（0～5 ℃）排酸,精细分割后各取500 g西冷和针扒2 个部位原料肉进行肉质分析。采用腌制、烤干工艺将原料肉加工成牛干巴,测定原料肉和牛干巴水分、粗蛋白、粗脂肪、灰分含量、失水率、蒸煮损失率、pH值、总挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量、亚硝酸盐含量、剪切力、肉色和氨基酸含量。结果表明：西冷和针扒2 个部位原料肉的粗蛋白含量、粗脂肪含量、灰分含量、剪切力和黄度值（b*）差异显著（P＜0.05）,水分含量、失水率、蒸煮损失率和亮度值（L*）、红度值（a*）差异不显著;加工成牛干巴后,2 个部位水分含量、粗脂肪含量、粗蛋白含量、剪切力和L*存在显著差异（P＜0.05）,灰分含量、b*和a*差异不显著,pH值、TVB-N含量、亚硝酸盐含量均在合理范围内;牛干巴氨基酸含量高于原料肉,原料肉总氨基酸（total amino acid,TAA）、必需氨基酸（essential amino acid,EAA）、非必需氨基酸（non-essential amino acid,NEAA）含量差异均不显著,牛干巴TAA、EAA、NEAA含量均差异显著（P＜0.05）;原料肉西冷的剪切力、肌间脂肪指标均优于针扒,经相同工艺制成牛干巴后,嫩度、脂肪含量受原料肉品质影响较大。     

The influence of cooking and fat trimming on the actual nutrient intake from meat

The effects of cooking and trimming of visible fatty tissue on the content of fat, fatty acids, minerals and vitamins was studied in six meat cuts (beef rib-eye and brisket, pork neck steak and belly, veal chop and rolled breast) in order to improve the estimates of the actual nutrient intake from meat. Cooking decreased the absolute fat content by about 17.9-44.4% and therefore concomitantly influenced the content of different fatty acids. The trimming of visible fatty tissue additionally decreased the fat content by about 23.8-59.1%. Calcium, sodium, potassium, magnesium and phosphorus decreased during cooking in all cuts and cooking processes, while iron and zinc were found to increase in beef. All vitamins decreased during cooking, with thiamine showing the highest losses, from 73% up to 100%. In conclusion, the cooking and trimming of meat cuts considerably affected the nutrients in various ways and to different degrees, which should be taken into account when the nutrient intakes of meat are estimated.     

云南牛干巴肉质特性与食用品质相关性分析

从思茅江城、昭通大关、大理巍山和昆明寻甸地区各取6 份牛干巴,研究各地不同制作工艺小黄牛 牛干巴的肉质特性与食用品质间的相关性。结果表明：牛干巴样品的pH值在5.41～5.88之间,氯化钠含量为 2.25%～3.47%,亚硝酸盐含量低于我国国家标准和地方标准;牛干巴的亮度值（L*）和嫩度、嗅闻香气、嚼碎 易度、肉腥味、食欲、滋味、总体可接受性均呈显著正相关（P＜0.05）;黄度值（b*）和色泽呈极显著正相关 （r=0.991,P＜0.01）;挥发性盐基氮含量和嫩度、嗅闻香气呈显著负相关（P＜0.05）,和食欲、总体可接受性呈 极显著负相关（P＜0.01）,相关系数分别为－0.994和－0.998;剪切力和嫩度、嗅闻香气、嚼碎易度、食欲、滋 味、总体可接受性呈显著负相关（P＜0.05）;脂肪含量和嚼碎易度、滋味呈显著正相关（P＜0.05）;pH值、水分 含量、粗蛋白含量、灰分含量、亚硝酸盐含量、氯化钠含量和食用品质的相关性不显著（P＞0.05）;巍山牛干巴 的L*、b*最低,挥发性盐基氮含量、剪切力最高,嚼碎易度、嫩度、咀嚼香气、滋味及总体可接受性最低;江城牛 干巴的L*、b*最高,挥发性盐基氮含量、剪切力最低,各项指标的感官评价最好。挥发性盐基氮含量、L*、b*、剪 切力及脂肪含量可以作为评价牛干巴食用品质的关键指标。     

Physicochemical Effects of the Lipid Phase and Protein Level on Meat Emulsion Stability,Texture, and Microstructure

ABSTRACT: The effects of beef fat (25%) substitution with rendered beef fat, canola oil, palm oil, or hydrogenated palm oil at varying meat protein levels (8%, 11%, and 14%) were studied in emulsified beef meat batters. There was no significant difference in fat loss among meat batters made with beef fat, rendered beef fat, or palm oil. Hydrogenated palm oil provided the most stable batters at all protein levels. Increasing meat protein to 14% resulted in high fat loss in batters prepared with canola oil, which did not occur in the other formulations. This indicates that the physicochemical characteristics of fat/oil affect emulsion stability. Cooked batter hardness was higher (P < 0.05) when protein level was raised; highest in hydrogenated palm oil batters when compared at similar protein levels. As protein level was raised springiness values were increased in all the meat treatments. Springiness was higher in the canola oil treatments. Light microscopy revealed fat globule coalescence in canola oil meat batters prepared with 14% protein, as well as the development of fat channels and more protein aggregation; both seem to result in lower emulsion stability. Hydrogenated palm oil batters showed fat particles with sharp edges as opposed to the round ones seen in all other treatments.     

Physicochemical and technological properties of beef burger as influenced by the addition of pea fibre

This study aimed to evaluate the physicochemical characteristics and sensory attributes of beef burgers with the addition of pea fibre as a partial substitute of meat or fat. Three formulations were prepared: control (CON) – similar to the commercial formulation; fibre/less meat (FLM)—5% meat reduction and addition of 1% pea fibre; fibre/less fat (FLF)—7% fat reduction and addition of 1% pea fibre. Non-significant differences were obtained for pH, colour parameters (L* and b*), texture profile, cooking loss and size reduction among formulations. Moreover, sensory analysis with consumers of beef burgers did not indicate differences among the formulations for all the analysed attributes. Therefore, pea fibre is a promising partial replacer for meat and fat in beef burgers due to the preservation of technological parameters and sensory acceptance.     

Quantification of Connective Tissue (Hydroxyproline) in Ground Beef by Autofluorescence Spectroscopy

Autofluorescence spectra (excitation wavelengths 300, 332, 365, 380 and 400 nm) were obtained by an optical system to determine collagenous connective tissue (hydroxyproline) and fat content in ground beef. Chemically determined contents ranged from 0.72–7.12% connective tissue and 1.5–17.7% fat. Partial least squares regression (66 samples) resulted in the lowest root mean square error of 0.37% connective tissue (R=0.97) and 1.89% fat (R=0.84) for excitation wavelengths 380 and 332 nm, respectively. The wavelength 332 nm may be feasible for simultaneous determination of fat and connective tissue. Autofluorescence spectroscopy might be well suited for rapid on-line determination of collagen in ground beef.