Sodini I, Lucas A, Oliveira M N, Remeuf F, Corrieu G
Unité Mixte de Recherche de Génie et Microbiologie des Procédés Alimentaires, Institut National Agronomique de Paris Grignon/Institut National de la Recherche Agronomique, Thiverval Gignon, France.
J Dairy Sci. 2002 Oct;85(10):2479-88. doi: 10.3168/jds.S0022-0302(02)74330-0.
In the present work, the compared effect of milk base and starter culture on acidification, texture, growth, and stability of probiotic bacteria in fermented milk processing, was studied. Two strains of probiotic bacteria were used, Lactobacillus acidophilus LA5 and L. rhamnosus LR35, with two starter cultures. One starter culture consisted only of Streptococcus thermophilus ST7 (single starter culture); the other was a yogurt mixed culture with S. thermophilus ST7 and L. bulgaricus LB12 (mixed starter culture). For the milk base preparation, four commercial dairy ingredients were tested (two milk protein concentrates and two casein hydrolysates). The resulting fermented milks were compared to those obtained with control milk (without enrichment) and milk added with skim milk powder. The performance of the two probiotic strains were opposite. L. acidophilus LA5 grew well on milk but showed a poor stability during storage. L. rhamnosus LR35 grew weakly on milk but was remarkably stable during storage. With the strains tested in this study, the use of the single starter culture and the addition of casein hydrolysate gave the best probiotic cell counts. The fermentation time was of about 11 h, and the probiotic level after five weeks of storage was greater than 106 cfu/ml for L. acidophilus LA5 and 10(7) cfu/ml for L. rhamnosus LR35. However, an optimization of the level of casein hydrolysate added to milk base has to be done, in order to improve texture and flavor when using this dairy ingredient.
在本研究中，研究了乳基和发酵剂对发酵乳加工过程中益生菌的酸化、质地、生长和稳定性的比较效果。使用了两种益生菌菌株，嗜酸乳杆菌LA5和鼠李糖乳杆菌LR35，并搭配两种发酵剂。一种发酵剂仅由嗜热链球菌ST7组成（单一发酵剂）；另一种是含有嗜热链球菌ST7和保加利亚乳杆菌LB12的酸奶混合发酵剂（混合发酵剂）。对于乳基制备，测试了四种商业乳制品原料（两种乳蛋白浓缩物和两种酪蛋白水解物）。将所得发酵乳与用对照乳（未强化）和添加脱脂奶粉的乳所获得的发酵乳进行比较。两种益生菌菌株的表现相反。嗜酸乳杆菌LA5在牛奶上生长良好，但在储存期间稳定性较差。鼠李糖乳杆菌LR35在牛奶上生长较弱，但在储存期间非常稳定。对于本研究中测试的菌株，使用单一发酵剂和添加酪蛋白水解物可获得最佳的益生菌细胞计数。发酵时间约为11小时，储存五周后，嗜酸乳杆菌LA5的益生菌水平大于10^6 cfu/ml，鼠李糖乳杆菌LR35的益生菌水平大于10^7 cfu/ml。然而，必须对添加到乳基中的酪蛋白水解物水平进行优化，以便在使用这种乳制品原料时改善质地和风味。
