Department of Production Sciences, Engineering, and Economics for Agricultural Systems (PrIME), University of Foggia, Via Napoli, 25, 71100 Foggia, Italy.
J Dairy Sci. 2012 Jul;95(7):3489-500. doi: 10.3168/jds.2011-4814.
Lamb rennet pastes containing encapsulated Lactobacillus acidophilus and a mix of Bifidobacterium longum and Bifidobacterium lactis were produced for Pecorino cheese manufacture from Gentile di Puglia ewe milk. Cheeses were denoted as RP cheese when made with traditional rennet paste, RP-L cheese when made with rennet paste containing L. acidophilus culture, and RP-B cheese when made with rennet paste containing a mix of B. lactis and B. longum. Biochemical features of Pecorino cheese were studied at 1, 15, 30, 60, and 120 d of cheese ripening. The effect of encapsulation and bead addition to rennet acted on a different way on the viability of probiotic. Lactobacillus acidophilus retained its viability for 4 to 5 d and then showed a fast reduction; on the other hand, B. longum and B. lactis experienced kinetics characterized by an initial death slope, followed by a tail effect due to acquired resistance. At 1 d of ripening, the levels of L. acidophilus and bifidobacteria in cheese were the lowest, and then increased, reaching the highest levels after 30 d; such cell loads were maintained throughout the ripening for L. acidophilus, whereas bifidobacteria experienced a decrease of about 1 log cfu/g at the end of ripening. Enzymatic activities and biochemical features of cheeses were influenced by the type of rennet used for cheesemaking. Greater enzymatic activity was recorded in RP-L and RP-B cheese due to the presence of probiotic bacteria released from alginate beads. A positive correlation was found between enzymatic activities and water-soluble nitrogen and proteose-peptone in RP-B and RP-L cheeses; water-soluble nitrogen and proteose-peptone were the highest in RP-B. Principal component analysis distinguished RP-L from the other cheeses on the basis of the conjugated linoleic acid content, which was higher in the RP-L due to the ability of L. acidophilus to produce conjugated linoleic acid in the cheese matrix.
用含有包埋嗜酸乳杆菌的绵羊凝乳酶糊和长双歧杆菌与乳双歧杆菌混合物的绵羊凝乳酶糊生产 Gentile di Puglia 母羊奶干酪。用传统凝乳酶糊制作的干酪称为 RP 干酪，用含有嗜酸乳杆菌培养物的凝乳酶糊制作的干酪称为 RP-L 干酪，用含有乳双歧杆菌和长双歧杆菌混合物的凝乳酶糊制作的干酪称为 RP-B 干酪。研究了干酪成熟 1、15、30、60 和 120 d 时 Pecorino 干酪的生化特性。包埋和添加珠粒对凝乳酶的作用方式不同，对益生菌的存活率有影响。嗜酸乳杆菌在 4 到 5 d 后保持其活力，然后迅速减少；另一方面，长双歧杆菌和乳双歧杆菌经历了一个初始死亡斜率的动力学特征，然后由于获得抗性而出现滞后效应。在成熟 1 d 时，干酪中嗜酸乳杆菌和双歧杆菌的水平最低，然后增加，在 30 d 后达到最高水平；这种细胞负荷在整个成熟过程中对嗜酸乳杆菌保持不变，而双歧杆菌在成熟结束时下降约 1 个对数 cfu/g。凝乳酶的类型影响干酪的酶活性和生化特性。由于从藻酸盐珠粒中释放出益生菌，RP-L 和 RP-B 干酪的酶活性更高。在 RP-B 和 RP-L 干酪中，发现酶活性与水溶性氮和蛋白水解肽之间存在正相关；在 RP-B 中，水溶性氮和蛋白水解肽最高。主成分分析根据共轭亚油酸的含量区分 RP-L 与其他干酪，由于嗜酸乳杆菌在干酪基质中产生共轭亚油酸的能力，RP-L 中的共轭亚油酸含量较高。
