干酪的凝乳及成熟条件对感官品质的影响

研究了干酪的最佳凝乳及成熟条件。结果表明,以63℃,30min杀菌乳为基础,添加3%的发酵剂,0.01%的CaCl2及40mg/kg的凝乳酶,在32～35℃下凝乳35～40min,干酪的产率可达13.2%。向凝乳粒中添加3%的食盐,然后压榨成型,在温度为8℃,相对湿度80%～85%的条件下,成熟50d,干酪的风味品质良好,pH值4.6,SN为7.29%。在干酪成熟前期(20d),乳酸菌数虽然显著下降,但仍具有较高的发酵产酸活性,pH值降至最低(5.95)。然后,随着蛋白质水解产物的积聚,pH值开始回升,30d后pH值基本稳定在6.10～6.15。随着成熟时间的延长,蛋白质水解程度(pH值4.6 SN和12%TCA SN)逐渐增大,从而引起干酪的色泽逐渐变黄,硬度降低,弹性下降。

The Effects of Curd and Ripening Condition of Cheese on Sensory Quality

In this paper,the optimization technology of curd and aging had been studied.The results showed that the optimization technology of curd was adding 3% lactic acid starter culture,0.01% CaCl2 and 40mg/kg rennin on the pasteurized milk(63℃,30min)in 32～35℃ curding 35～40min with which the 13.2% yield of cheese obtained.The optimal adding salt amount on the curdling granule before hoping and pressing and aging technology parameter were 3% and 8℃,RH 80%～85% for 50d respectively,for the good flavor quality of the cheese which pH 4.6 SN 7.29%.In the pre-mature stage of the cheese(20d),though the count of lactic acid bacteria dropped,its high activity of producing lactic acid resulted in pH fell quickly.Then,with the product set of proteolysis the cheese pH risen gradually level of 6.10～6.15.In the aging processing,the white of the cheese changed yellow,hardness and flexibility vanished gradually with the degree of proteolysis increased.