Cured products from different animal species

An assessment was made of the proximate composition, pH and a_W of raw beef, horsemeat and the meat of wild boar, deer and goat. The same assessment, together with one of fatty acids, cholesterol and free amino acids, was made of the same meats as cured products. The raw meat of the different animal species was found to have a reduced lipid, but high protein content. The cured meat of the horse and wild boar had low saturated fatty acid levels; the wild boar, goatmeat and beef were quantitatively similar with regard to monounsaturated fatty acids (MUFA) while in the horsemeat the polyunsaturated fatty acids (PUFA) were more raised, at an intermediate level in deer and extremely reduced in the beef final product. The cholesterol content in the cured product was markedly reduced in the horsemeat. The free amino acids content in the cured deer, wild boar and goat meat was more elevated, than in beef and horse cured meat.     

驴腿肉与其他畜腿肉挥发性风味物质差异研究

利用气相电子鼻和气相色谱—质谱联用分析仪等对4种畜腿肉挥发性风味物质进行定性和定量检测,并通过气相色谱分析仪进行脂肪酸组成测定。气相电子鼻结果表明驴腿肉与猪腿肉风味差异最小,与牛腿肉差异最大。GC-MS共检出76种挥发性物质,以醛类为主,驴、猪、牛、羊腿肉中醛类占比分别为70.71%,75.36%,48.76%,55.94%,其中具有清香和青草气味的正己醛含量最高,贡献风味比例依次为29.89%,20.46%,12.74%,10.78%。驴、猪、牛、羊腿肉中的主要饱和脂肪酸总含量依次为30.01%,39.05%,36.34%,48.42%;不饱和脂肪酸总量依次为63.19%,57.10%,49.03%,43.71%。综上,影响驴腿肉风味特征的主要化合物为正己醛,其来源于亚油酸的氧化分解。     

Fatty acid composition of adipose tissue and muscle from Jersey steers was affected by finishing diet and tissue location

To determine the impacts of finishing diet and tissue type and location on fatty acid composition and palatability of Jersey beef, twenty steers were assigned to a factorial treatment design with initial weight (Light vs. Heavy) and finishing diet (70 vs. 85% concentrate) as treatments. Ribeye steaks were collected for sensory evaluation. Muscle, seam and subcutaneous (s.c.) fat from steaks, kidney fat (KF) and omental fat (OMF) were collected for fatty acid analysis. Initial weight and finishing diet had little impact on beef palatability. The 85% concentrate decreased polyunsaturated fatty acids (PUFA) in muscle and increased trans fatty acids in all tissues (P < 0.05). The monounsaturated:saturated fatty acid ratio (MUFA:SFA) was highest in s.c. fat, intermediate in muscle and seam fat, and lowest in KF and OMF. The PUFA:SFA was highest in muscle, intermediate in s.c. and seam fat, and lowest in KF and OMF. Fatty acid composition differed greatly among tissues and the lower concentrate diet increased omega-3 and PUFA percentages in muscle.     

Fatty acid content and composition of UK beef and lamb muscle in relation to production system and implications for human nutrition

Although ruminant meats normally have a low ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (P:S ratio), the muscle contains a range of C(20) and C(22) PUFA of both the n-6 and n-3 series of potential significance in human nutrition. However, information on the amounts of these fatty acids in muscle and how they are modified by production system is limited In this study, the content and composition of fatty acids was determined in several muscles from beef steers fed grass (grazed) and bulls fed cereal concentrates. These are the two main types of beef production in the UK and Europe. Muscle fatty acids were also determined in lambs fed grass (grazed on pasture). The total fatty acid content of all muscles studied was less than 35 g kg(-1). The percentages in total fatty acids of all n-3 PUFA were higher in muscles from steers fed grass than from bulls fed concentrates whereas all n-6 PUFA were higher in the latter. The gluteobiceps muscle contained the largest amounts of fatty acids including PUFA and the m. longissimus dorsi the least amounts of PUFA in beef and lamb, and m. longissimus contained the lowest percentages of PUFA. Arachidonic acid was the major fatty acid in the C(20) + C(22) PUFA in beef from both production systems with twice as much in muscles from bulls fed concentrates. The P:S ratios were higher in the latter animals, range 0.21-0.34 compared with 0.08-0.13 in the steers fed grass. However, the n6:n-3 ratio was much less desirable in the bulls, 15.6-20.1 compared with 2.0-2.3 in the steers fed grass. These effects of production system in ruminants are larger than previously reported. Lamb muscle P:S ratios resembled those in grass-fed beef but the n-6:n-3 ratios were lower. The percentage of trans unsaturated 18:1 fatty acids was similar in both cattle production systems but lamb muscles contained twice as much as beef. Although the concentrations of the C(20) and C(22) PUFA are much lower than in fish, maintaining high n-3 levels in ruminant meats through grass feeding may be advantageous in human nutrition since meat is more widely consumed.     

Effect of slaughter season and muscle type on the fatty acid composition, including conjugated linoleic acid isomers, and nutritional value of intramuscular fat in organic beef

BACKGROUND: Consumer awareness regarding the intake of beef of organic origin is strongly associated with the beneficial outcomes to human health, the environment and animal welfare. In this paper the effects of slaughter season and muscle type on the fatty acid composition, conjugated linoleic acid (CLA) isomeric profile, total cholesterol, α‐tocopherol and β‐carotene contents and nutritional quality of intramuscular fat in organic beef (n = 30) are reported for the first time. RESULTS: Organic beef showed a very low total lipid content, with seasonal changes in the levels of some fatty acids, CLA isomers, n‐6/n‐3 polyunsaturated fatty acid (PUFA) ratio, total cholesterol and β‐carotene. In addition, differences between longissimus lumborum (relatively red) and semitendinosus (relatively white) muscles were found for many fatty acids, specific CLA contents, many CLA isomers and both PUFA/saturated fatty acid (SFA) and n‐6/n‐3 ratios. However, in spite of the seasonal and carcass variations, all organic meats analysed had values of beef similar to pasture‐fed cattle. CONCLUSION: From a nutritional perspective, organic meat from both slaughter seasons seems to have high CLA contents, PUFA/SFA and n‐6/n‐3 indices within the recommended values for the human diet. The data indicate that intramuscular fat in organic meat has a high nutritional value throughout the year. Copyright © 2012 Society of Chemical Industry     

Nutrient composition of australian fresh retail sausages and the effects of cooking on fat content

Three types of fresh sausages (beef, thick and thin; and pork, thick) were purchased in ten Sydney suburbs and analysed as composite samples for proximate principles, carbohydrates, vitamins, minerals, fatty acids and cholesterol. Fat, moisture and meat species were also analysed in individual purchases. In a controlled experiment replicate samples of sausages were analysed for moisture and fat, raw and after cooking by grilling, dry-frying, shallow-frying and deep-frying. Results indicated widespread use of cow, pig and sheep meat in all types of sausages regardless of label identification. Some purchased sausages exceeded regulation limits for fat and starch content. Fat retention was lowest in beef sausages cooked by frying rather than grilling. Pork sausages retained most of their fat on cooking, regardless of method.     

欧洲肉鸽与其他畜禽肉品质及主要营养成分比较分析

目的测定欧洲肉鸽胸肌肉的常规肉品质(肉色、p H、失水率和剪切力)和主要营养成分(蛋白、脂肪、氨基酸和脂肪酸)。方法使用色差仪、p H计、膨胀仪、肌肉嫩度仪等测定品质指标,参照国标方法和常用方法测定营养成分,并与其他禽肉进行比较分析。结果与其他常规畜禽肉相比,欧洲肉鸽肉色偏红偏暗,p H适中,失水率最高,剪切力最低;鸽肉的水分含量高于其他肉类,蛋白质含量最高为20.5%,脂肪含量最低仅2.7%;鸽肉中氨基酸含量丰富,必需氨基酸含量占40.80%,鲜味氨基酸含量占43.42%,均高于其他畜禽肉;鸽肉中脂肪酸种类丰富(11种),所含多不饱和脂肪酸含量最高,其中亚油酸的含量明显高于其他畜禽肉类。结论欧洲肉鸽色泽红润,滑嫩多汁,氨基酸含量丰富,脂肪酸组成优化,是一种高蛋白、低脂肪的理想型食用肉类。     

Effect of feeding growing–fattening rabbits a diet supplemented with whole white lupin (Lupinus albus cv. Amiga) seeds on fatty acid composition and indexes related to human health in hind leg meat and perirenal fat

A total of 20 weaned rabbits (33 days old) (10 per treatment) were fed one of two diets that included 150 g of sunflower meal (SF)/kg of diet or 120 g of whole white lupin (WL)/kg of diet for 42 days. The WL diet contained less saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) but more monounsaturated fatty acids (MUFA) than the SF diet. The WL diet significantly decreased SFA and PUFA content, as well as the PUFA n − 6/PUFA n − 3 ratio and saturation, atherogenic and thrombogenic indexes in hind leg meat. The fatty acid composition in perirenal fat was similar to that of hind leg meat; however, significantly higher MUFA levels were observed in rabbits fed the WL diet. Thus, feeding rabbits the WL diet affected the fatty acid profile of hind leg meat and perirenal fat in a favourable manner.     

LIPID CHARACTERISTICS OF EMU MEAT AND TISSUES

Twenty four (24) samples of emu meat (drumstick) and fat (abdominal fat (AF) and back fat (BF)), liver and heart tissue were collected from three (3) farms, and twelve (12) samples of chicken (drumstick) and beef (steak) were collected from supermarkets. The AF and BF of emu contained over 99% triacylglycerols. Monounsaturatedfatty acids (MUFA) constituted to 56% in AF and BF, saturated fatty acids (SAFA) at 31% and polyunsaturated fatty acids (PUFA) constituted to 13%. Oleic acid (C18:1n-9) was the predominant MUFA at 48%. The emu leg meat total lipids were up to 3%. Phospholipid constituted the major lipid class in emu and chicken meat at 64%, higher (P<0.05) than beef meat (47%). The emu drumstick contained higher (P<0.05) linoleic (C18:2n-6), arachidonic (C20:4 n-6), linolenic (C18:3 n-3) and docosahexaenoic (C22:6 n-3) acids than chicken drumstick and beef steak. The ratio of polyunsaturated fatty acids to saturated fatty acids in emu meat was 0.72, higher (P<0.0001) than chicken meat, 0.57 and beef meat, 0.3. The ratio of n-6 to n-3 fatty acids did not differ (P>0.05) among the three sources of meat.     

Composition of phospholipid fraction in raw chicken meat and pre-cooked chicken patties: influence of feeding fat sources and processing technology

The effect of dietary lipid sources (animal fat, AF vs. vegetable oil, VO) was investigated on the phospholipid (PL) fraction of raw chicken meat and pre-cooked chicken patties. PL classes were determined on extracted lipids by high-performance liquid chromatography (HPLC) connected with an evaporative light-scattering detector (ELSD). The HPLC-ELSD method showed good intraday repeatability (less than 5% for different PL) and limits of detection ranging from 0.006 mg/mL (phosphatidylethanolamine) to 0.045 mg/mL (sphingomyelin). Diet did not consistently influence PL in chicken breast. A significant difference was assessed in meat batter where total PL were at levels of 349.0 and 388.2 mg/100 g of product in batter from broilers fed AF and VO diet, respectively. Cooking oil absorption caused an important decrease in PL (lower than 300 mg/100 g of product in pre-fried patties). Diet was an effective means to control the PL fatty acid profile in chicken, particularly the levels of polyunsaturated fatty acids (PUFA). In minced breast and thigh and meat batter from birds fed a VO-supplemented diet, the relative amount of PUFA was 46, 81 and 28% higher than that determined in the corresponding samples obtained from broilers fed an AF-based diet.     

澳洲美利奴羊肉脂肪酸组成

选择3 只澳洲美利奴羔羊的背最长肌、臀肌及臂三头肌,利用气相色谱-质谱联用技术对其脂肪酸含量进行测定及分类探讨。结果表明：澳洲美利奴羊肉中共含有脂肪酸35 种,其中C15:1、C16:0、C17:1、C18:0、C18:1 n-9c脂肪酸含量较高,3 个部位肌肉中：不饱和脂肪酸含量＞饱和脂肪酸含量＞单不饱和脂肪酸含量＞多不饱和脂肪酸含量,且每个部位肌肉中单不饱和脂肪酸含量比多不饱和脂肪酸含量均高出2～3 倍;n-3脂肪酸亚麻酸甲酯（C18:3 n-3）在臂三头肌中的含量显著高于背最长肌（P＜0.05）;与另外2 个部位相比,臂三头肌总脂肪酸、饱和脂肪酸、不饱和脂肪酸、中链脂肪酸及长链脂肪酸含量均最高;臂三头肌中多不饱和脂肪酸与饱和脂肪酸含量比值最高,背最长肌中最低。     

市售黑猪和白猪营养成分分析及评价

对比市售2 款黑猪（吉神黑猪（BP1）和太湖黑猪（BP2））和2 款白猪（均为大三元杂交猪种（WP1,WP2））背最长肌的一般营养成分、脂肪酸组成和氨基酸组成。结果表明：白猪WP2和黑猪BP2脂肪含量显著高于白猪WP1和黑猪BP1,分别为2.88、2.98 g/100 g,WP1水分含量显著高于WP2,为74.3 g/100 g,所有样品蛋白质含量无显著差异;WP2棕榈油酸和油酸含量较高,单不饱和脂肪酸相对含量最高,为52.72%,多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）相对含量最低,为5.28%;BP2 PUFA相对含量最高,为12.30%,Σn-6PUFA/Σn-3 PUFA比值最低,为8.5;WP2和BP1的必需氨基酸（essential amino acid,EAA）占比显著高于BP2,分别为41.35%和41.38%,各样品氨基酸总量、EAA、非必需氨基酸和鲜味氨基酸含量均无显著差异;经蛋白质营养价值评价,赖氨酸氨基酸比值系数最高,为1.44,缬氨酸（除蛋氨酸＋胱氨酸外）是限制性氨基酸,其他氨基酸均接近于1,说明所有猪肉样品氨基酸构成比例较合理,蛋白质营养价值较高。     

Innovations in beef production systems that enhance the nutritional and health value of beef lipids and their relationship with meat quality

Consumers are becoming more aware of the relationships between diet and health and this has increased consumer interest in the nutritional value of foods. This is impacting on the demand for foods which contain functional components that play important roles in health maintenance and disease prevention. For beef, much attention has been given to lipids. This paper reviews strategies for increasing the content of beneficial omega-3 polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA) and reducing saturated fatty acids (SFA) in beef. Particular attention is given to intramuscular fat (IMF) and the relationships between fatty acid composition and key meat quality parameters including colour shelf life and sensory attributes. Despite the high levels of ruminal biohydrogenation of dietary PUFA, nutrition is the major route for increasing the content of beneficial fatty acids in beef. Feeding grass or concentrates containing linseed (rich in α-linolenic acid, 18:3n-3) in the diet increases the content of 18:3n-3 and its longer chain derivative eicosapentaenoic acid (EPA, 20:5n-3) in beef muscle and adipose tissue, resulting in a lower n-6:n-3 ratio. Grass feeding also increases docasahexaenoic acid (DHA, 22:6n-3). Feeding PUFA rich lipids which are protected from ruminal biohydrogenation result in further enhancement of the PUFA in meat with concomitant beneficial improvements in the ratio of polyunsaturated:saturated fatty acids (P:S ratio) and n-6:n-3 ratio. The main CLA isomer in beef is CLA cis-9, trans-11 and it is mainly associated with the triacylglycerol lipid fraction and therefore is positively correlated with level of fatness. The level of CLA cis-9, trans-11 in beef is related to (1) the amount of this isomer produced in the rumen and (2) synthesis in the tissue, by delta-9 desaturase, from ruminally produced trans vaccenic acid (18:1 trans-11; TVA). Feeding PUFA-rich diets increases the content of CLA cis-9, trans-11 in beef. Trans-fatty acids in foods are of rising importance and knowledge of the differential effects of the individual trans isomers is increasing. TVA is the major trans 18:1 isomer in beef and as the precursor for tissue CLA in both animals and man should be considered as a neutral or beneficial trans-isomer. Increasing the content of n-3 PUFA in beef can influence colour shelf life and sensory attributes of the meat. As the content of n-3 PUFA increases then sensory attributes such as "greasy" and "fishy" score higher and colour shelf life may be reduced. Under these situations, high levels of vitamin E are necessary to help stabilise the effects of incorporating high levels of long chain PUFA into meat. However, grass feeding not only increases n-3 PUFA and CLA but, due to its high content of vitamin E, colour shelf life is improved. It is evident that opportunities exist to enhance the content of health promoting fatty acids in beef and beef products offering opportunities to add value and contribute to market differentiation. However, it is imperative that these approaches to deliver "functional" attributes do not compromise on the health value (lipoperoxidation) or the taste of beef products.     

不同热加工温度对牛肉干脂肪酸及脂肪氧化的影响

采用气相色谱-质谱联用技术,测定牛肉干中脂肪酸的组成,研究失水率相同时,不同干燥温度（25、55 ℃）及熟制温度（85、150 ℃）对牛肉干中脂肪酸组成和脂肪氧化的影响。结果表明：经热加工后,牛肉干的脂肪酸含量和脂肪氧化程度均有不同程度的变化。经55 ℃干燥后,不饱和脂肪酸（unsaturated fatty acid,UFA）、多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）和单不饱和脂肪酸（monounsaturated fattyacid,MUFA）含量显著低于25 ℃干燥（P＜0.01）,饱和脂肪酸（saturated fatty acid,SFA）含量显著高于25 ℃干燥（P＜0.01）,且脂肪氧化程度低于25 ℃干燥;熟制阶段,25 ℃干燥后熟制,SFA、UFA、MUFA和PUFA含量变化不显著（P＞0.05）,而55 ℃干燥后,经150 ℃熟制,UFA、MUFA和PUFA含量显著低于85 ℃熟制（P＜0.01）,SFA含量显著高于85 ℃熟制（P＜0.01）,且脂肪氧化程度高。综上所述,不同干燥温度及熟制温度对牛肉干脂肪酸及脂肪氧化的影响不同,干燥阶段,较高温度（55 ℃）干燥对牛肉干脂肪氧化的影响小于25 ℃干燥;熟制阶段,较低温度（85 ℃）熟制对牛肉干脂肪氧化影响较小。因此,55 ℃干燥、85 ℃熟制得到的牛肉干产品,其UFA、MUFA和PUFA含量最高,SFA含量最低,脂肪氧化程度最小,牛肉干营养价值损失最小。     

Fat deposition, fatty acid composition and meat quality: A review

This paper reviews the factors affecting the fatty acid composition of adipose tissue and muscle in pigs, sheep and cattle and shows that a major factor is the total amount of fat. The effects of fatty acid composition on meat quality are also reviewed. Pigs have high levels of polyunsaturated fatty acids (PUFA), including the long chain (C20-22) PUFA in adipose tissue and muscle. The full range of PUFA are also found in sheep adipose tissue and muscle whereas cattle ‘conserve’ long chain PUFA in muscle phospholipid. Linoleic acid (18:2n − 6) is a major ingredient of feeds for all species. Its incorporation into adipose tissue and muscle in relation to the amount in the diet is greater than for other fatty acids. It is deposited in muscle phospholipid at a high level where it and its long chain products eg aracidonic acid (20:4n − 6) compete well for insertion into phospholipid molecules. Its proportion in pig adipose tissue declines as fat deposition proceeds and is an index of fatness. The same inverse relationships are not seen in ruminant adipose tissue but in all species the proportion of 18:2n − 6 declines in muscle as fat deposition increases. The main reason is that phospholipid, where 18:2n − 6 is located, declines as a proportion of muscle lipid and the proportion of neutral lipid, with its higher content of saturated and monounsaturated fatty acids, increases. Oleic acid (18:1cis − 9), formed from stearic acid (18:0) by the enzyme stearoyl Co-A desaturase, is a major component of neutral lipid and in ruminants the same enzyme forms conjugated linoleic acid (CLA), an important nutrient in human nutrition. Like 18:2n − 6, -linolenic acid (18:3n − 3) is an essential fatty acid and is important to ruminants since it is the major fatty acid in grass. However it does not compete well for insertion into phospholipid compared with 18:2n − 6 and its incorporation into adipose tissue and muscle is less efficient. Greater biohydrogenation of 18:3n − 3 and a long rumen transit time for forage diets also limits the amount available for tissue uptake compared with 18:2n − 6 from concentrate diets. A positive feature of grass feeding is that levels of the nutritionally important long chain n − 3 PUFA are increased ie EPA (20:5n − 3) and DHA (22:6n − 3). Future research should focus on increasing n − 3 PUFA proportions in lean carcasses and the use of biodiverse pastures and conservation processes which retain the benefits of fresh leafy grass offer opportunities to achieve this. The varying fatty acid compositions of adipose tissue and muscle have profound effects on meat quality. Fatty acid composition determines the firmness/oiliness of adipose tissue and the oxidative stability of muscle, which in turn affects flavour and muscle colour. Vitamin E is an essential nutrient, which stabilises PUFA and has a central role in meat quality, particularly in ruminants.     

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。     

Fatty acid composition and quality characteristics of low-fat cooked sausages made with beef and chicken meat, tomato juice and sunflower oil

Low-fat (5.9-10.3% fat) cooked sausages were produced with seven different formulations. Sausages produced with total replacement of fat with sunflower oil had significantly lower oleic acid (C18:1) and higher linoleic (C18:2) and behenic (C22:0) fatty acid contents. Their ratio of TUFA/TS was 3.65 compared to 0.95-1.14 for the other sausages. Also these sausages had the lowest moisture content, highest overall palatability and were less firm. Sausages with tomato juice had the lowest pH value, total aerobic count and nitrite content, but were firmer. Sausages produced with reduced beef contents had lower fat contents, lower stearic (C18:0) and higher oleic (C18:1) fatty acid contents than sausages of high beef content, their texture was very soft and had the lowest score for juiciness. Finally the sausages with chicken meat had the lowest fat and highest salt contents, and lower stearic (C18:0) and higher linoleic (C18:3) fatty acid contents than those made with beef . Also their colour was lighter, less red and more yellow and they had the lowest flavor intensity and overall acceptability.     

Effect of a supplementation of Euphorbia heterophylla on nutritional meat quality of Guinea pig (Cavia porcellus L.)

The aim of the present work was to study the effect of dietary supplementation of Euphorbia heterophylla on the quality of the Guinea pig meat. Forty guinea pigs were divided into two groups fed ad libitum during 46 days a Panicum maximum diet (Panicum diet) or a mixed diet (75% Panicum maximum + 25% Euphorbia heterophylla) (Paneuphorbia diet) to compare their effects on performances and on the composition of guinea pig tissues and carcass. Daily weight gain, liver weight, carcass yield, and the lipid content of both the carcass and the perirenal fat were significantly increased by the Paneuphorbia diet. Feeding Paneuphorbia diet increased (P < 0.05) the n-3 PUFA content in perirenal fat, muscle, liver and in the carcass and decreased (P < 0.05) the n-6/n-3 ratios in all these tissues and the carcass. In conclusion, this study shows that Euphorbia heterophylla is a source of n-3 fatty acids which can improve significantly the n-3 PUFA content of Guinea pig meat and carcass.     

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。     

中国地方猪种与国外猪种猪肉脂肪酸组成的对比分析

为深入了解猪肉脂肪酸组成,提高猪肉营养品质、促进优良猪种资源的保护和开发提供科学依据。采用气相色谱法测定猪肉脂肪酸组成,比较了10个猪种肌肉内15项脂肪酸、饱和与不饱和脂肪酸、必需脂肪酸的相对含量,并对脂肪酸组成指标进行因子分析和系统聚类分析。饱和脂肪酸中,南阳黑猪肌肉中棕榈酸相对含量最高(31.45%),滇南小耳猪肌肉的硬脂酸相对含量最高(17.79%),单不饱和脂肪酸和多不饱和脂肪酸相对含量最高的猪种分别为撒坝猪(49.02%)和南阳黑猪(25.55%)。主成分分析获得的前5个主成分可以解释全部变异的92.709%,基于主成分值的UPGMA聚类图将10个猪种归为六大类。动物脂肪酸组成受不同品种影响,中国地方猪种与国外猪种猪肉脂肪酸构成和相对含量呈现不同程度的差异。仅以猪肉脂肪酸的构成及营养价值的角度来衡量,中国地方猪种南阳黑猪猪肉在10个猪种中品质更优。