焙烤对宁夏滩羊肉脂肪酸、氨基酸及核苷酸含量的影响

Effects of Roasting on the Content of Fatty Acids,Amino Acids and Nucleotides of Tan Mutton from Ningxia

以宁夏盐池滩羊为研究对象,探究不同烤制时间对羊肉脂肪酸、氨基酸以及核苷酸含量的变化的影响。研究结果表明:烤制过程中,总蛋白质含量由19.92%上升到40.51%,总脂肪含量由3.51%上升到12.75%。总脂肪酸含量在烤制0~8min增加,8~12 min降低,12~20 min再增加,差异不显著(P>0.05)。在测出的25种脂肪酸中,油酸、硬脂酸和棕榈酸含量普遍较高,在100 mg/100 g以上。总水解氨基酸含量显著增加(P<0.05),由鲜羊肉中的18.5 g/100 g上升至49.42 g/100 g,其中以赖氨酸、亮氨酸和半胱氨酸增加最为明显。游离氨基酸中精氨酸、丙氨酸以及半胱氨酸含量上升,而组氨酸含量下降,其它游离氨基酸含量变化不显著(P>0.05)。滋味活度值(TAV)法确定了烤制滩羊肉中关键的鲜味氨基酸为谷氨酸,关键甜味氨基酸为丙氨酸,关键苦味氨基酸为蛋氨酸、苯丙氨酸、缬氨酸、精氨酸。烤制滩羊肉中的主要滋味物质5’-腺苷酸和5’-鸟苷酸的含量随着烤制时间的延长呈现上升趋势(P>0.05)。PCA分析表明滩羊肉中脂肪酸、水解氨基酸、游离氨基酸和核苷酸的含量在烤制过程中差异明显。

The content of fatty acids,amino acids,nucleotides of Tan sheep from Yanchi,Ningxia roasted for different periods were analyzed.The results showed that the total protein content increased from 19.92%to 40.51%,and the total fat content increased from 3.51%to 12.75%.The total fatty acid content increased first(roasted for 0-8 min)and then decreased(roasted for 8-12 min)and increased finally(roasted for 12-20 min)with no significant difference(P>0.05).The content of oleic acid,stearic acid and palmitic acid were the highest among 25 fatty acid identified in all samples and their content exceeds 100 mg/100 g.The content of total hydrolyzed amino acids increased significantly(P<0.05),increased from 18.5 g/100 g in fresh meat to 49.42 g/100 g.Among all amino acid,lysine,leucine,and cysteine showed the most significant increases.Among the free amino acids,the contents of arginine,alanine and cysteine showed an increasing trend,the contents of histidine showed an decreasing trend and the changes of other free amino acids were not significant(P>0.05).The taste activity value(TAV)method identified that the key umami amino acids in roasted Tan mutton was glutamic acid,the key sweet amino acid was alanine,and the key bitter amino acids were methionine,phenylalanine,valine,and arginine.The main taste substances 5'-adenylic acid and 5'-guanylic acid in roasted Tan mutton increased significantly with increase of time.Collectively,the results of PCA analysis indicated that fatty acids,hydrolyzed amino acids,free amino acids and nucleotides in Tan mutton were significantly different during the roasting process.