Rheological and some physicochemical properties of probiotic boza beverage fermented with Lactobacillus casei Shirota: application of principal component analysis for the characterisation

Abstract

Boza is a cereal-based fermented beverage. Lactobacillus casei Shirota, which rates among probiotic bacteria, is a member of starter culture combinations used for the production of industrial Yakult, a Japanese beverage. In this study, boza was produced using different starter culture combinations (Weisella paramesenteroides, L. casei Shirota and Lactobacillus acidophilus with two/three bacterial combinations) and principal component analysis was used for characterisation of their quality parameters. In the results, boza fermented with commercial boza (control) and with L. acidophilus + L. casei Shirota had the highest sensorial scores. Total lactic acid bacteria counts of the boza samples ranged from 9.09 to 10.48 log cfu/ml while pH was the lowest (4.08±0.02) in the boza produced with L. acidophilus + L. casei Shirota. Boza samples showed non-Newtonian pseudoplastic behaviours. Apparent viscosity values decreased with increasing shear rate. The first two principal components explain 80.71% of the total variation for measurements, with 54.90% of the total variance explained by the first principal component.