Akalin A S, Gönç S, Unal G, Fenderya S
Ege Univ., Faculty of Agriculture, Dept. of Dairy Technology, 35100 Bornova, Izmir, Turkey.
J Food Sci. 2007 Sep;72(7):M222-7. doi: 10.1111/j.1750-3841.2007.00436.x.
Viability of yogurt starter cultures and Bifidobacterium animalis was assessed during 28 d storage in reduced-fat yogurts containing 1.5% milk fat supplemented with 1.5% fructooligosaccharide or whey protein concentrate. These properties were examined in comparison with control yogurts containing 1.5% and 3% milk fat and no supplement. Although fructooligosaccharide improved the viability of Streptococcus thermophilus, Lactobacillus delbrueckii subs. bulgaricus, and Bifidobacterium animalis, the highest growth was obtained when milk was supplemented with whey protein concentrate in reduced-fat yogurt (P < 0.05). Supplementation with 1.5% whey protein concentrate in reduced-fat yogurt increased the viable counts of S. thermophilus, L. delbrueckii subs. bulgaricus, and B. animalis by 1 log cycle in the 1st week of storage when compared to control sample. Similar improvement in the growth of both yogurt bacteria and B. animalis was also obtained in the full-fat yogurt containing 3% milk fat and no supplement. Addition of whey protein concentrate also resulted in the highest content of lactic and acetic acids (P < 0.05). A gradual increase was obtained in organic acid contents during the storage.
在含有1.5%乳脂肪并添加1.5%低聚果糖或乳清蛋白浓缩物的低脂酸奶中，评估了酸奶发酵剂培养物和动物双歧杆菌在28天储存期间的活力。将这些特性与含有1.5%和3%乳脂肪且未添加任何物质的对照酸奶进行了比较。尽管低聚果糖提高了嗜热链球菌、德氏保加利亚乳杆菌亚种和动物双歧杆菌的活力，但在低脂酸奶中添加乳清蛋白浓缩物时，细菌生长最为显著（P<0.05）。与对照样品相比，在低脂酸奶中添加1.5%的乳清蛋白浓缩物可使嗜热链球菌、德氏保加利亚乳杆菌亚种和动物双歧杆菌的活菌数在储存的第1周增加1个对数周期。在含有3%乳脂肪且未添加任何物质的全脂酸奶中，酸奶细菌和动物双歧杆菌的生长也有类似的改善。添加乳清蛋白浓缩物还导致乳酸和乙酸含量最高（P<0.05）。在储存期间，有机酸含量逐渐增加。
