Quality characteristics of whey-based fruit beverages fermented with Lactobacillus plantarum

The current research aimed at developing different beverages through exploitation of sweet whey and incorporation of different proportions of cactus pear juice (10, 20 and 30 %, named C10, C20 and C30) and kaki juice (10 and 20 %, named K10 and K20). Quality attributes, probiotic viability, and beverages acceptability over 20 days were studied. The obtained findings indicated that fruit juices incorporation increased total solids, total soluble solids, and fiber content. Also, no significant changes (P < 0.05) in the viable numbers of L. plantarum due to the change in the concentration or type of the added fruit juices or during cold storage. However, higher viable numbers ranged between 7.59 and 7.89 log CFU/mL were obtained. Furthermore, acidity values gradually increased and pronounced changes were observed at 10 days. Total phenolic content (TPC) and antioxidant activity (AOA) significantly increased (P < 0.05) by increasing the added fruit concentrations. K20 treatment had the highest values of TPC (50.68 mg GAE/100 ml), AOA (44.64 %), viscosity (63.86) and WHC (20.67). C30 treatment obtained the highest score of sensory evaluation. Thus, it could be concluded that cactus pear and kaki juices improved the quality characteristics of whey beverages.