Evaluation of the cabbage and cucumber juices as substrate for Lactobacillus acidophilus LA-5

The capacity of the juices obtained from cucumber, white and red cabbage respectively to represent a substrate for the growth of Lactobacillus (Lb.) acidophilus, in order to obtain probiotic products, was investigated. Lb. acidophilus was very well adapted to the cabbage as new substrate, because in the first 2h the pH has declined by one unit, while the microbial population has increased almost 100 times. After 48h the decrease of the reducing sugars ranged from 1.16 to 1.54 g/100ml and the titratable acidity was increased about 13 times. Lb. acidophilus was faster accommodated in cucumber juice, the maximum rate of acidification v(max) (dpH/dt) being achieved in 2h (9.33x10(-3) units/min). If some differences were established referring to time to reach pH 5.0 (more than 2h in the case of the red cabbage), the time to complete the fermentation (t(pH 4.2), hours) was for all the batches about 6h. Applying the multivariate statistical methods, the variables were classified into three clusters and the tree chart was described as well. The Principal Component Analysis (PCA) reduced the five original analytical variables to one independent component, which accounted for 80.43% of the total variance.