White grape juice added with Lactobacillus paracasei ssp. probiotic culture

Abstract

Purpose The purpose of this study is to evaluate the effect of the probiotic addition (Lactobacillus paracasei ssp.) on the physicochemical characteristics and antioxidant capacity of white grape juice during refrigerated storage (4°C/28 days). This paper also aims to evaluate the survival of the probiotic culture in the product and under simulated gastrointestinal conditions. Design/methodology/approach Two formulations of white grape juices were evaluated, one with 2 per cent of probiotic culture addition and the other of pure juice. Findings The addition of probiotic culture resulted in products with a darker-reddish coloration (L* = 30.6-30.8 and a* = 0.6-0.9) and a lower content of total phenolic compounds (599-697 µg EAG mL−1) (p = 0.05). However, it improved the color stability and maintained the antioxidant activity 1,1-diphenyl-2-picrylhydrazyl (p > 0.05). The viability of the probiotic culture (>109 colony forming unit · 200 mL−1) in the juice was maintained during 21 days of storage, but in simulated gastrointestinal conditions, the functional properties could be guaranteed during the 28 days of refrigerated storage. Practical implications The white grape juice is a suitable medium for incorporation of Lactobacillus paracasei. Originality/value The survival of the probiotic cultures to the simulated gastrointestinal tract may be significant, even if the product does not have the recommended minimum counts.