本试验以不同泌乳期羊乳为原料,研究其基本理化特性(色泽、膻味、pH值、酸度、密度、乳化学成分)及酶凝固特性(硬度、内聚性、弹性)和持水力,以便为羊乳制品的开发提供更适宜的生产原料。结果表明,不同泌乳期羊乳的各理化特性和酶凝固特性差异较大。随着泌乳期的延长,羊乳由乳黄色逐渐变为乳白色,其膻味逐渐变淡,pH值缓慢上升,而酸度、密度、乳化学成分含量及酶凝固特性、持水力均呈下降趋势。经综合分析,建议将泌乳第120 - 150 d的羊乳作为稀奶油生产的较优质原料;泌乳第4 -150 d的羊乳更适合用于凝固型酸奶和奶酪的加工;而泌乳第7 - 240 d的羊乳均可用于生产液态羊奶或羊奶粉,但需要对其主要化学成分进行标准化处理。
In this study, the physicochemical
characteristics (color, odor, pH value, acidity and milk composition)of goat
milk during lactations, theircoagulation characteristics by chymosin(hardness,
cohesiveness and elasticity) andwater holding capacities were investigated to
provide the suitable materials for the development of goat milk products. The
results showed that the physicochemical characteristics of goat milk during
lactations and theircoagulation characteristics varied. With the prolongation
of lactation, the color of goat milk gradually changed from milky yellow to
milky white, and the odor of goat faded, but pH values graduallyrised.The acidity,
density, its main chemical components, the coagulation characteristics andwater
holding capacities all declined. By comprehensive analysis, goat milk at 120 -
150 d lactation were the better materials for the production of cream, while
the milk at 4 -150 d lactation would be suitable for the production of set
yogurt and cheese. Goat milk at 7 - 240 d lactation could be used for the
production of liquid milk or the milk powder, but the standardization process
should be needed.