Lactic acid fermentation of guava juice: Evaluation of nutritional and bioactive properties, enzyme (α-amylase, α-glucosidase, and angiotensin-converting enzyme) inhibition abilities, and anti-inflammatory activities.

ABSTRACT

In the present research, the impact of fermentation with two strains of Lactiplantibacillus plantarum subsp. plantarum (PTCC 1896 and PTCC 1745) on physicochemical properties, antioxidant bioactive compounds, and some health-promoting features of guava juice was investigated. Results showed a significant (p < .05) decrease in pH, total soluble solids, glucose and fructose residues, vitamin C, and total carotenoids after 32 h of fermentation. Total phenolic content, free radical scavenging abilities, and ferrous reducing power were markedly enhanced during the fermentation process. Moreover, fermented juice represented good enzyme inhibition abilities (α-amylase and α-glucosidase) and anti-inflammatory activities. The initial amount of angiotensin-converting enzyme inhibitory activity (26.5%) increased to 72.1% and 66.4% in L. plantarum subsp. plantarum 1896 and L. plantarum subsp. plantarum 1745 treatments, respectively. These findings reveal that guava juice fermentation with the studied Lactobacillus strains can be a promising strategy to augment the functional properties of the fruit-based beverage.