高速离心生牛乳所得4种分离物的感官及 干燥失重分析

Sensory evaluation and dry matter analysis on 4 isolates obtained from high-speed centrifugation of raw milk

中文关键词:  牛乳  高速离心  感官评定  干物质

英文关键词:milk  high speed centrifugation  sensory evaluation  dry matter

中文摘要:

      目的 通过高速离心发现了牛乳一个被忽视的简单现象, 可用于鉴别牛乳的掺假问题。方法 本实验以奶牛场不同泌乳期的正常生牛乳为对象, 通过10000 r/min的转速进行高速离心20 min, 对离心产物进行感官和干燥失重分析。结果 高速离心能快速使生牛乳形成4种分离物, 分别为: 上层悬浮的奶皮, 静置20 min后会溶解消失、离心管壁上半部分附着的半圆形稀奶油、脱脂乳液体、离心管底部的沉淀物。对于泌乳期为2、4、6个月的正常乳, 4种产物的感官评定无显著差异, 4种产物的干物质占生牛乳总干物质质量百分比的平均值分别为8.2%、15.3%、72.0%、4.5%。结论 此方法为牛乳的掺假鉴别提出了一种新思路, 简单、快速、成本低、重现性好。

英文摘要:

      Objective A simple phenomenon after high-speed centrifugation of raw milk was used to evaluate milk adulteration. Methods Normal raw milk during different lactation period, obtained from dairy farm, was high-speed centrifuged at 10000 r/min for 20 min. Samples after centrifugation were analyzed upon dry matter and sensory evaluation. Results Four isolates appeared rapidly after the high-speed centrifugation of raw milk: the upper suspended milk skin, which was dissolved after standing for 20 min, the semicircle cream that adhered to the upper half wall of centrifuge tube, the liquid skim milk, and the sediment at the bottom of centrifuge tube. For normal raw milk during 2, 4, and 6 months of lactation, on average, sensory evaluation of the4 products showed no significant differences, the dry matter of these 4 isolates were accounted for 8.2%, 15.3%, 72.0%, and 4.5% (w:w), respectively, of the total dry matter of raw milk. Conclusion This is a new method for evaluation of milk adulteration which is simple and fast, with low cost and good reproducibility.