白牦牛乳营养成分及风味物质分析

目的:分析白牦牛乳营养成分及风味物质。方法:采集18头白牦牛的乳汁,用常规方法测定常量营养素,等离子体发射光谱仪分析矿物元素,氨基酸分析仪测定氨基酸并计算AAS,GC-MS法分析挥发性风味物质。结果:白牦牛乳干物质含量18.38%,蛋白质6.53%,乳脂率5.64%,矿物质0.87%;TAA6.36%,EAA总量2.56g/100g,Met、Trp为限制性氨基酸,EAA/TAA为40.25%,EAA/NEAA为67.37%;检测出酯、酮、醇、醛类等7种独特风味物质。结论:白牦牛乳乳汁浓稠、风味纯香浓厚,含有高蛋白、高脂肪、高钙,氨基酸种类齐全,含量丰富,是一种优质的营养资源。

ANALYSIS OF THE NUTRITIONAL COMPONENTS AND FLAVOROUS SUBSTANCES OF WHITE YAK''''S MILK

Objective: To analyse the nutritional components and flavorous substance of the white yak,s milk. Method: In collecting the raw milk of eighteen white yaks,dry substance,protein,fat and ash were detected by routine methods;mineral elements by ICPV-1000S inductively coupled plasma atomic emission spectroscopy,amino acids by 835-Shimadzu amino acid analyzer,volatile substances by GC-MS. Results: The milk of white yak contained dried substance (18.38%),protein (6.53%),fat (5.64%),minerals (0.87%), TAA(6.36%), EAA(2.56%),two limiting amino acids (Met and Trp), EAA / TAA (40.25%), EAA/ NEAA (67.37%); seven flavorous substances: esters, alcohols,ketones and aldehydes,etc. Conclusion: The milk of white yak has distinct propertis: high protein,high fat,high energy,abundant minerals,agreeable flavor,abundant amino acid. So the milk of white yak is an excellent nutritional resource.