Oommen B S, McMahon D J, Oberg C J, Broadbent J R, Strickland M
Western Dairy Center, Department of Nutrition and Food Sciences, Utah State University, Logan 84322-8700, USA.
J Dairy Sci. 2002 Nov;85(11):2750-8. doi: 10.3168/jds.s0022-0302(02)74362-2.
Low-moisture part-skim Mozzarella cheeses were manufactured from 2% fat milk and aged for 21 d. Treatments included cheeses made with one of three different strains of Lactobacillus delbrueckii ssp. bulgaricus in combination with a single strain of Streptococcus thermophilus. A fourth, control treatment consisted of cheeses made with only S. thermophilus. Although total proteolytic ability of these strains, as indicated by the o-phthaldialdehyde analysis, was similar in each of the three strains of L. bulgaricus, these strains exhibited different proteolytic specificities toward the peptide, alpha(s1)-CN (f 1-23). On the basis of their alpha(s1)-CN (f 1-23) cleavage patterns and a previously described classification, these strains were assigned to the groups I, III, and V. The objective of this study was to investigate the influence of lactobacilli proteolytic systems, based on specificity toward alpha(s1)-CN (f 1-23), on functionality of part-skim Mozzarella cheese. Moisture, fat, protein, salt-in-moisture, and moisture in nonfat substances content of cheeses made with groups I, III, and V strain were similar. Control cheese had a lower moisture content than did other treatments. Significant differences were observed in functional properties between cheeses manufactured using groups III and V strains. Cheeses made with groups I and III strains were similar in their meltability, hardness, cohesiveness, melt strength, and stretch quality. Meltability and cohesiveness increased with age, while melt strength and stretch quality decreased with age for all cheeses. Additionally, HPLC showed that total peak areas of water-soluble peptides derived from cleavage of alpha(s1)-CN (f 1-23) by different strains of lactobacilli could be highly correlated to meltability and stretch characteristics of cheeses made with those strains.
低水分部分脱脂马苏里拉奶酪由2%脂肪含量的牛奶制成，并陈化21天。处理组包括用三种不同的德氏乳杆菌保加利亚亚种菌株之一与单一嗜热链球菌菌株组合制作的奶酪。第四组为对照处理组，由仅用嗜热链球菌制作的奶酪组成。尽管通过邻苯二甲醛分析表明，这三种德氏乳杆菌保加利亚亚种菌株的总蛋白水解能力相似，但这些菌株对αs1-酪蛋白（f 1-23）肽表现出不同的蛋白水解特异性。根据它们对αs1-酪蛋白（f 1-23）的裂解模式以及先前描述的分类，这些菌株被归为I、III和V组。本研究的目的是基于对αs1-酪蛋白（f 1-23）的特异性，研究乳杆菌蛋白水解系统对部分脱脂马苏里拉奶酪功能特性的影响。用I、III和V组菌株制作的奶酪的水分、脂肪、蛋白质、水分中的盐分以及非脂肪物质中的水分含量相似。对照奶酪的水分含量低于其他处理组。在使用III组和V组菌株制作的奶酪之间，其功能特性存在显著差异。用I组和III组菌株制作的奶酪在融化性、硬度、内聚性、融化强度和拉伸质量方面相似。所有奶酪的融化性和内聚性随陈化时间增加，而融化强度和拉伸质量随陈化时间降低。此外，高效液相色谱法显示，不同乳杆菌菌株对αs1-酪蛋白（f 1-23）裂解产生的水溶性肽的总峰面积与用这些菌株制作的奶酪的融化性和拉伸特性高度相关。
