羊奶及其制品稳定性的研究进展

对羊奶的热稳定性、酒精稳定性、凝乳特性及羊奶制品(羊奶粉、羊奶酸奶)稳定性的影响因素进行综述.研究表明:温度、pH值、离子浓度等对羊奶的稳定性都有显著的影响.温度在120～140℃范围内时,随着加热温度的升高,羊奶的热稳定性明显降低；30～80℃范围内,酒精稳定性随温度的升高而降低.pH6.7时,羊乳的热稳定性最好,pH6.4～7.2时,随pH值升高,羊乳的酒精稳定性增强.无机盐离子Ca2+对羊奶热稳定性和酒精稳定性的影响作用相似,稳定性均随Ca2+浓度的增大而降低.对于羊奶制品,降低水分活度可以提高其贮藏稳定性,乳清蛋白和酪蛋白含量的增加会降低酸奶贮藏期间的滴定酸度、黏度及持水性.另外,发酵酸奶所用稳定剂的不同、贮藏温度的不同也会影响制品的稳定性.

Research Progress on the Stability of Goat Milk and Products

This paper provides a systematic review of the thermal stability, alcohol stability and coagulation properties ofgoat milk and factors that influence the stability of goat milk products (milk powder and yogurt). It has been reported thattemperature, pH and ion concentration have significant impact on the stability of goat milk. The thermal stability of goatmilk declines considerably as the heating temperature increases from 120 to 140 ℃, and the alcohol stability decreasesnoticeably with increasing temperature from 30 to 80 ℃. Goat milk has the best thermal stability at pH 6.7. The alcoholstability of goat milk becomes better with increasing pH from 6.4 to 7.2. The thermal and alcohol stability of goat milk aresimilarly affected by Ca2+ in a negative manner. The storage stability of goat milk products can be enhanced by reducingwater activity. Increasing casein and whey protein decreases the titratable acidity, viscosity and water holding capacity ofgoat milk yogurt during storage. Moreover, its stability is also affected by stablizers and temperature.