Contents of creatine, creatinine and carnosine in porcine muscles of different metabolic types

Creatine, creatinine and carnosine have been analyzed by hydrophilic interaction chromatography (HILIC) in seven different pork muscles of different metabolic type (Semimembranosus, Biceps femoris, Gluteus maximus, Longissimus dorsi, Gluteus medius, Trapezius and Masseter). As reported in previous literature, carnosine contents are related with the type of metabolism, being higher in those muscles with glycolytic metabolism. Creatine and creatinine also showed significantly higher concentrations in glycolytic muscles such as Semimembranosus, Biceps femoris, Gluteus maximus and Longissimus dorsi. Masseter, a red oxidative muscle, was characterized by the lowest contents of creatine, creatinine and carnosine and, finally, Gluteus medius and Trapezius, both intermediate muscles, had also intermediate contents of these studied compounds. Finally, a correlation between initial content of creatine and creatinine formation after cooking has been verified using pure standards and two different metabolic type muscles, Longissimus dorsi and Masseter, obtaining slightly higher creatinine amounts in Longissimus dorsi, probably due to its higher initial creatine content and its lower pH.     

Concentration of free amino acids and dipeptides in porcine skeletal muscles with different oxidative patterns

Free amino acids and natural dipeptides, have been analyzed in pork muscles having different metabolic type (masseter, trapezius, semimembranosus and longissimus dorsi). Carnosine and anserine showed significantly higher (p < 0.05) concentrations with the glycolytic activity of the muscle while taurine and glutamine were significantly higher in the oxidative muscles. Non-essential free amino acids also showed significant (p < 0.05) increased content in the oxidative muscles.     

不同杂交肉牛背最长肌氨基酸含量分析

分析研究不同杂交肉牛背最长肌肉氨基酸含量。试验选择年龄、体质量和体况接近的安格斯、利木赞、西门塔尔牛与本地黄牛的杂交公牛18头;按不同杂交牛种分为1组(AG×L)、2组(LM×L)、3组(SM×L),每组为6头,各组随机选择3头屠宰,取其背最长肌为实验材料。结果表明:1)不同杂交肉牛粗蛋白(CP)及总氨基酸(TAA)、必需氨基酸(EAA)和风味系游离氨基酸(FAA)含量为试验1组>2组>3组;其氨基酸组成即EAA/TAA和EAA/UAA(非必需氨基酸)为试验1组>3组>2组(P>0.05)。2)氨基酸评分,根据FAO/WHO模式比例,其蛋氨酸、缬氨酸是限制性氨基酸,其他必需氨基酸含量均高于FAO/WHO标准值。     

Lipolysis in muscles during refrigerated storage as related to the metabolic type of the fibres in the rabbit

The relation between lipolysis and the metabolic fibre type was investigated during refrigerated storage of rabbit muscles. Free fatty acid, monoacylglycerol and diacylglycerol contents and free fatty acid composition were compared in five muscles immediately after slaughter and after a 7-day-storage at 4°C. The results showed that. (1) The amount of free fatty acids sharply increased during the refrigerated storage (from 2-10 to 11-32 mg/100 g of muscle), especially that of long chain polyunsaturated fatty acids (from less than 0.1 to 1.4-3.3 mg/100 g of muscle). (2) The glycolytic muscles contained 1.5 times less free fatty acids than the oxidative ones. However, the rates of phospholipid and triacylglycerol hydrolysis were not related to the metabolic type of the fibres. (3) The contribution of phospholipids to free fatty acid fraction was twice that of triacylglycerols in the glycolytic muscles whereas it was similar or lower to that of triacylglycerols in the oxidative muscles.     

The influence of fibre-type composition and associated biochemical characteristics on the acid buffering capacities of several beef muscles

Several beef forequarter muscles were investigated for fibre-type composition, total pigments, total nitrogen, non-protein nitrogen, anserine, carnosine and inorganic phosphorus contents, ultimate pH (pH(u)) and acid buffering capacities. In general, the predominantly 'red' fibre-type muscles had significantly higher (P<0·05) pH(u) values and total pigment concentrations than the predominantly 'white' fibre-type muscles which had significantly higher (P< 0·05) total nitrogen, non-protein nitrogen and carnosine contents and also significantly higher (P< 0·05) acid buffering capacities. The relationships between the various biochemical parameters of all the muscles studied and their acid buffering capacities were investigated by correlation matrix. The higher buffering capacities of the 'white' fibre-type muscles over the pH range pH(u) to pH 5·0 were attributed to their higher contents of carnosine and inorganic phosphorus. However, over the pH ranges pH(u) to pH 4·5 down to pH(u) to pH 3·0, the higher buffering capacities of the 'white' fibre-type muscles were attributed primarily to their higher lactic acid concentrations, as indicated by their low pH(u) values, and also to their higher non-protein nitrogen contents.     

Comparative lipid composition of porcine muscles at different anatomical locations

The influence of anatomical location on the intramuscular lipids was studied in Large White pigs. The amount of total, neutral and polar lipids and the composition of fatty acids of the above three fractions were determined for Longissimus dorsi (LD) at two points and Transversus abdominis (TA) and Biceps femoris (BF) taken from the two half carcasses of an animal. The symmetrical samples from the same animal had identical intramuscular lipid characteristics. The three muscles did not show significant differences in their total (2·8 to 2·4g/100g) and neutral (2·1 to 1·4g/100g) lipid contents. The amount of polar lipids was characteristic of every muscle (0·65 g, 0·84 g and 0·97 g per 100 g, respectively, in LD, BF and TA). The fatty acid composition of neutral lipids was influenced by the type of muscle. Polar lipid had similar fatty acid composition in the three muscles. The intramuscular lipids contained appreciable amounts of essential fatty acids of the family n-6; interestingly, a part of which (25% of EFA) was the long chain fatty acid (C20 and C22) located in the polar lipids.     

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。     

内蒙古地区不同养殖草食动物背最长肌氨基酸组成及营养价值评价

以内蒙古地区集约化养殖草食动物牛、绵羊、山羊和驴背最长肌为研究对象,以鸡胸肉为参照,采用全自动氨基酸分析仪内标法检测氨基酸含量,评价肌肉氨基酸组成及营养价值。结果表明：各氨基酸在不同动物肌肉中的含量均呈显著差异（P＜0.05）;鸡胸肉、牛肉和山羊肉总必需氨基酸含量显著高于绵羊肉（P＜0.05）,驴肉与其他肉无显著差异;牛肉和驴肉总非必需氨基酸含量显著高于山羊肉（P＜0.05）,其他肉无显著差异。不同草食动物肌肉必需氨基酸指数（essential amino acid index,EAAI）均高于95,属于优质蛋白质来源,EAAI顺序为山羊肉＞鸡胸肉＞绵羊肉＞牛肉＞驴肉;驴肉甜味氨基酸含量显著高于其他肉（P＜0.05）,牛肉和绵羊肉鲜味氨基酸含量显著高于其他肉（P＜0.05）,鸡胸肉苦味氨基酸含量显著高于其他肉（P＜0.05）,牛肉和绵羊肉总呈味氨基酸含量显著高于其他肉（P＜0.05）;以氨基酸相对含量聚类,绵羊肉和牛肉在图谱中最接近,驴肉处于图谱最远端。     

玉山黑猪肉营养特性分析

研究在优质肉生产中科学利用玉山黑猪这一优良地方猪种资源.对9头玉山黑猪的背最长肌中肌内脂肪、氨基酸、肌苷酸以及脂肪酸和背脂中的脂肪酸,从营养学角度进行分析评价.结果表明:玉山黑猪背最长肌中17种氨基酸总含量为19.16％,其中鲜味氨基酸和必需氨基酸占总氨基酸的比例分别为38.96％和44.78％,具有较浓的鲜味和较高的蛋白质“生物效价”,而且氨基酸评分结果表明玉山黑猪的必需氨基酸比例适宜,有利于人体吸收;玉山黑猪肉中肌内脂肪、肌苷酸含量分别为6.62％、2.99％,是其肉质鲜嫩多汁的物质基础;此外,玉山黑猪背最长肌和背脂的不饱和脂肪酸的比例都较高,其背最长肌亚油酸和亚麻酸的含量分别为12.73％和0.86％,表明玉山黑猪脂肪酸的营养价值比较高.     

脆肉鲩不同部位肌肉的质构特征分析

为了探讨影响脆肉鲩肌肉不同部位质构的因素,以基本营养成分、氨基酸、脂肪酸、矿物质为对象进行了研究。结果显示,三个部位的硬度、弹性和咀嚼性之间的差异性显著(p<0.05)。腹部的水分、粗蛋白和灰分均比背部和尾部低,而脂肪含量却最高,说明背部的脆性与低水分、高蛋白、低脂肪含量有关。对于氨基酸,背部的甘氨酸和脯氨酸含量分别比腹部和尾部高11.45%、25.49%和8.08%、6.67%,且含硫氨基酸含量最高,但含羟基氨基酸的含量却最低,而背部和尾部的疏水性氨基酸含量分别比腹部高出3.96%和2.88%,说明了高甘氨酸、脯氨酸、含硫氨基酸和疏水性氨基酸是决定脆肉鲩不同部位特殊脆性的关键因素。三个部位的油酸、棕榈油酸和亚油酸与质构存在极强的相关性;对于矿物质,K、Na和Ca是脆肉鲩肌肉中主要的矿物质,不同部位的K、Na和Ca具有显著性差异(p<0.05),而尾部的Fe、Zn、Cu含量与背部和腹部具有非常显著差异(p<0.01),进一步说明脆肉鲩不同部位的脆性与金属含量的差异有关。总而言之,脆肉鲩不同部位肌肉质构特征的差异与肌肉中的物质密切相关。     

Concentrations in beef and lamb of taurine, carnosine, coenzyme Q(10), and creatine

Levels of taurine, carnosine, coenzyme Q(10), and creatine were measured in beef liver and several muscles of beef and lamb and in cooked and uncooked meat. The amino acid taurine has numerous biological functions, the dipeptide carnosine is a buffer as well as an antioxidant, coenzyme Q(10) is also an antioxidant present within mitochondria, and creatine along with creatine phosphate is involved with energy metabolism in muscle. Large differences were shown for all compounds between beef cheek muscle (predominantly red fibres) and beef semitendinosus muscle (mainly white fibres), with cheek muscle containing 9.9 times as much taurine, and 3.2 times as much coenzyme Q(10), but only 65% as much creatine and 9% as much carnosine. Levels in lamb relative to beef semitendinosus muscles were higher for taurine but slightly lower for carnosine, coenzyme Q(10) and creatine. Values for all the compounds varied significantly between eight lamb muscles, possibly due in part to differences in the proportion of muscle fibre types. Slow cooking (90 min at 70?°C) of lamb longissimus and semimembranosus muscles led to significant reductions in the content of taurine, carnosine, and creatine (P<0.001), but a slight increase in coenzyme Q(10). There was also a four-fold increase in creatinine, presumably due to its formation from creatine. It is concluded that biologically, and possibly nutritionally, significant levels of taurine, carnosine, coenzyme Q(10), and creatine are present in beef and lamb, but that these levels vary between muscles, between animals, and with cooking.     

3种养殖模式澳洲淡水龙虾肌肉的氨基酸比较分析与评价

目的 为研究不同养殖模式下澳洲淡水龙虾肌肉中的氨基酸组成差异。方法 本研究通过氨基酸自动分析仪测定土池、水泥池和稻田3种模式下养殖的澳洲淡水龙虾成虾肌肉中氨基酸含量,并进行氨基酸品质比较分析。结果 3种养殖模式澳洲淡水龙虾成虾肌肉均含有17种氨基酸,含量最高的均为谷氨酸(P＜0.05),次之均为天门冬氨酸(P＜0.05),最低均为蛋氨酸(P＞0.05),但17种氨基酸中有11种氨基酸相互呈显著性差异;3种成虾肌肉中的E/T值(40.87%~41.35%)和E/NT值(69.11%~70.51%)符合FAO/WHO提出的优质食物蛋白质E/T值应达到40%左右且E/NT值应大于60%的标准要求;Met+Cys为第一限制性氨基酸;澳洲淡水龙虾肌肉蛋白与鸡蛋评价模式蛋白较为贴近,其必需氨基酸指数EAAI大小顺序是土池养殖模式(76.47)＞稻田养殖模式(72.14)＞水泥池养殖模式(71.93)。结论 澳洲淡水龙虾属于优质食物蛋白质,其氨基酸品质以土池养殖模式为最佳,稻田次之,本研究结果为澳洲淡水龙虾养殖及饲料开发等提供了理论参考。     

不同规格秋刀鱼肌肉的营养成分分析与品质评价

摘 要: 目的 对比分析不同规格秋刀鱼肌肉的营养价值。方法 参照国家标准方法测定大、中、小3种规格秋刀鱼肌肉的基本营养成分、脂肪酸组成和氨基酸组成, 比较其营养价值。结果 随着秋刀鱼规格的增大, 秋刀鱼肌肉中的粗脂肪含量增大, 而粗蛋白、水分含量减小; 3种规格秋刀鱼肌肉中均检测出18种氨基酸, 氨基酸总量为50.93~59.50 g/100 g, 且谷氨酸含量最高(7.00~8.39 g/100 g); 根据氨基酸评分,第一限制性氨基酸均为缬氨酸; 中规格秋刀鱼肌肉蛋白的必需氨基酸指数最高为88.44, 是良好蛋白源。不同规格秋刀鱼均富含多不饱和脂肪酸(47.23%~49.66%), 其中, 中规格秋刀鱼二十碳五烯酸和二十二碳六烯酸占总脂肪酸的比例最高为27.56%。结论 3种规格的秋刀鱼均属于高蛋白、高脂肪鱼类, 氨基酸和脂肪酸种类丰富且比例适中; 中规格秋刀鱼必需氨基酸指数最高, 二十碳五烯酸和二十二碳六烯酸的比例也最高, 营养价值相对较高。     

Influence of type of muscles on nutritional value of foal meat

The effect of type of muscle on nutritional characteristic (fatty acid profile, amino acid content, cholesterol and major and minor mineral) of foal meat was investigated. Six muscles: longissimus dorsi (LD), semimembranosus (SM), semitendinosus (ST), biceps femoris (BF), triceps brachii (TB) and psoas major & minor (PM) from twelve foals slaughtered at 15 months from an extensive production system in freedom regimen were extracted for this study. Horse meat is characterized by low fat, low cholesterol content, rich in iron and in vitamin B. Statistical analysis showed that the cholesterol content did not show significant differences (P > 0.05) among muscle with mean value range between 0.62 and 0.57 mg/100 g. Most fatty acid presented significant differences (P < 0.05) with respect to the type of muscle. The obtained results showed that except for the polyunsaturated linoleic acid, the highest contents of fatty acids were found in the hindquarter muscles. Regarding amino acid profile, significant differences (P < 0.05) were observed among muscles and our results indicated that, 100 g of foal meat covered from 80.6 to 86.7% for the daily requirement for an adult man weighing 70 kg for essential amino acids for ST and LD muscles, respectively. Statistical analysis showed significant differences (P = 0.050) for the EAA (essential amino acids) index, which was highest for TB muscle, followed by BF and SM muscles, while the lowest values were reported by ST muscle. Finally, foal meat seems to be a very good nutritional source of major and minor minerals. The higher nutritional value of foal meat will be of great importance in the promotion of this meat.     

蒙古斑点马不同部位脂肪和肌肉组织中脂肪酸组成的比较研究

通过对蒙古斑点马不同部位脂肪和肌肉组织中脂肪酸组成进行分析比较,旨在明确蒙古斑点马体脂脂肪酸组成特点。选择3 匹成年蒙古斑点马,屠宰后采集肾周、肠周和皮下脂肪以及肩肌、背最长肌和臀肌样品,利用气相色谱法测定脂肪酸组成及含量。结果表明：蒙古斑点马不同脂肪组织中均检出19 种脂肪酸,其中饱和脂肪酸（saturated fatty acid,SFA）含量34.77%～37.38%,不饱和脂肪酸（unsaturated fatty acid,UFA）含量达60%以上,UFA中单不饱和脂肪酸（monounsaturated fatty acid,MUFA）含量33.04%～36.39%,多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）含量26.47%～27.51%,其中皮下脂肪C10:0、C18:0、C20:0含量显著低于肾周和肠周脂肪（P＜0.05）;MUFA在皮下脂肪的沉积程度较其他2 个部位高,但均无统计学差异;PUFA中C18:3 n-3含量最高,其在各脂肪组织间无显著差异。3 个不同部位肌肉中均检出15 种脂肪酸,其中SFA含量占总脂肪酸含量的38.32%～40.04%,MUFA含量占35.70%～40.19%,PUFA含量占15.25%～20.33%;SFA中背最长肌和臀肌C12:0含量显著高于肩肌（P＜0.05）,其余SFA在不同部位肌肉间无显著差异;MUFA中背最长肌C16:1含量显著高于肩肌和臀肌（P＜0.05）;肩肌n-6/n-3 PUFA比值显著高于背最长肌和臀肌（P＜0.05）;皮下脂肪的C18:3 n-3和总PUFA含量显著高于背最长肌（P＜0.05）。综上所述,蒙古斑点马不同部位脂肪和肌肉组织脂肪酸组成各具特点,但UFA含量均较高。     

棘胸蛙肌肉营养成分季节变化分析与评价

棘胸蛙肌肉营养成分受季节变化影响显著,分析不同季节棘胸蛙肌肉营养成分的组成,旨在为后续产品深加工提供理论依据,在加工过程中可以依据产品需求选择合适季节的棘胸蛙.以春、夏、秋、冬四个季节的棘胸蛙(Quasipaa spinose)成蛙为试验对象,采用索氏提取法、凯氏定氮法和色谱法等分析其肌肉常规营养成分、氨基酸和脂肪酸组...     

不同日龄、性别、部位Hyla兔系肌内脂肪酸组成变化

以Hyla配套系肉兔为对象,研究不同日龄、性别、部位Hyla兔系肌内脂肪酸组成的动态变化,探讨肉兔生长过程中脂肪酸的沉积规律及营养价值。结果表明：随着日龄的增加,Hyla公兔和母兔背部最长肌（longissimus dorsi,LD）、左后腿肌（left-hind leg muscle,LL）和腹肌（abdominal muscle,AM）的肌内总脂肪含量均显著增加（P＜0.05）,且AM中含量最高,LL次之,LD最低,公兔整体低于母兔;经气相色谱分析,共鉴定出21 种脂肪酸,其中不饱和脂肪酸（unsaturated fatty acids,UFA）的含量丰富,尤其是长链（C20～22）多不饱和脂肪酸（polyunsaturated fatty acids,PUFA）;随着Hyla兔的生长,3 个部位肌内脂肪的PUFA/SFA值、n-6 PUFA含量及n-3 PUFA含量显著下降（P＜0.05）,n-6/n-3值因日龄、性别和部位的差异有着不同的动态变化,比值范围为6.5～8.5;经偏最小二乘回归分析可知,日龄、性别与部位均能够显著影响Hyla兔系肌内脂肪酸组成,其中,幼龄公兔LL脂肪酸组成更优,而成年母兔LD更适宜加工。     

Oxidative and lipolytic deterioration of different muscles from free-range reared Iberian pigs under refrigerated storage

Three different type of muscles, two glicolytic (Serratus ventralis and Longissimus dorsi) and one oxidative (Masseter) were displayed under refrigeration at +4?°C during 10 days to evaluate differences in lipolytic and oxidative changes of different muscles with different metabolic pattern. Thiobarbituric acid reactive substances (TBARS), phospholipid content, hexanal content and fatty acid profiles of neutral and polar lipid fractions were analysed at day 0 and day 10. Phospholipid content (g phospholipids/g intramuscular fat) significantly (P<0.035) decreased from day 0 to day 10 in m. Masseter (0.33 vs. 0.25, respectively), but not in m. L. dorsi (0.12 vs. 0.09, respectively) and m. S. ventralis (0.19 vs. 0.14, respectively). Changes in fatty acid profiles of neutral and polar lipids significantly differed among muscles after storage. Slight differences were found in neutral lipids from m. L. dorsi and m. S. ventralis, while neutral lipids from m. Masseter were highly altered. Great changes affected fatty acid profiles from polar lipids in the three muscles. m. Masseter muscle showed significantly higher (P<0.000) TBARS values (1.13, 0.65 and 0.60 mg MDA/kg meat, respectively) and hexanal content (689.2, 241.2 and 355.8 μg/g meat, respectively) than m. L. dorsi and m. S. ventralis. In conclusion, oxidative meat is more prone to oxidative and lipolytic deterioration than glycolytic muscles during refrigerated storage and as a consequence of that a lower shelf-life.     

Water-soluble precursors of beef flavour: I. Effect of diet and breed

The effects of diet and breed on the concentration of water-soluble flavour precursors, namely sugars, free amino acids, ribonucleotides, creatinine, carnosine and creatine, were studied in beef longissimus lumborum muscle. Diet had a significant effect on the concentration of free amino acids, with animals fed on grass silage having higher free amino acid levels than animals fed on a concentrate diet, whereas animals fed concentrates had a higher total reducing sugar content. Differences between a beef breed (Aberdeen Angus×Holstein-Friesian) and a dairy breed (Holstein-Friesian) were generally small.     

Fatty acid composition of intramuscular lipids in various muscles of Holstein-Friesian bulls slaughtered at different ages

Holstein-Friesian bulls were slaughtered at 7, 14 and 19 months of age. Samples were collected from the psoas major, longissimus and semitendinosus muscles. The total lipids (TL) of the samples were extracted and the fatty acid compositions were analysed by gas chromatography. Both the slaughtering age and the type of muscles had significant effects on the intramuscular TL contents and fatty acid compositions. The longissimus muscle had higher intramuscular TL both at 14 and 19 months than at 7 months of age. As the bulls became older the proportion of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) increased in the TL of each muscle tested, whereas that of polyunsaturated fatty acids (PUFA) decreased. Among the muscle types, the semitendinosus had the lowest, intramuscular TL at each slaughtering age and the psoas major the highest. Except for SFA at 7 months of age, the semitendinosus showed lower levels of SFA and MUFA and higher proportions of PUFA than the other two muscles.