Effects of fermenting with Lacticaseibacillus rhamnosus GG on quality attributes and storage stability of buffalo milk yogurt incorporated with bael (Aegle marmelos) fruit pulp

Abstract

Background: Producing functional food by adding fruits or fruit pulps have attracted great attention. Simultaneously, buffalo milk is gaining an increasing demand as an alternative to cow milk. Thus, value addition and diversification of buffalo milk products have gained much commercial and research interest. Hence, we aimed to investigate the potentials of developing and characterizing probiotic enriched buffalo milk yogurts with bael fruit pulp using exopolysaccharides producing probiotic Lacticaseibacillus rhamnosus GG (LGG). Methods: Four types of buffalo milk yogurts were tested, e.g. fermenting with the yogurt starter culture only (e.g., control) and fermenting with the combination of yogurt starter culture and LGG with varying levels (w/v) of bael fruit pulp incorporations, i.e., 0%, 5% and 10%. Variation in pH, syneresis, hardness, probiotic viability and sensory attributes during 21 days of storage in 4 °C were assessed for all treatments. Results: Fermenting with LGG had a positive effect on post-acidification and syneresis rate compared to the control yogurt. Bael incorporation did not affect the post-acidification, but significantly decreased the level of syneresis at the end of storage. All probiotic formulations maintained LGG counts of >107 CFU/mL and the highest counts were observed in 5% (w/v) bael incorporated yogurt. Conclusions: Results confirmed the possibility of using buffalo milk yogurt as an ideal matrix to deliver LGG with promising probiotic capacity. The use of 5% bael incorporation provides an optimal combination for synbiotic product development.

Keywords

• Buffalo milk fermented gel
• Bael fruit pulp
• Lacticaseibacillus rhamnosus GG
• Probiotic yogurt
• Value-added fermented milk