Change of phytochemicals and bioactive substances in Lactobacillus fermented Citrus juice during the fermentation process

This study evaluated the conversion of bioactive substances and phytochemicals in the 96 h of fermented Citrus juice by L. brevis, L. plantarum, L. paracasei, and L. fermentium, results showed fermentation maintained a higher vitamin C, antioxidant activity, enhanced the contents of total phenolic, total flavonoid and amino acids in Citrus juice. The steady acidity and sweetness, as well as the greatest increase of total flavonoids were found in L. fermentium 252 fermented Citrus juices from 54.30 ± 11.41 mg/L to 127.82 ± 6.41 mg/L. Furthermore, a high level of phenyllactic acid was detected with 17.69 ± 1.26 mg/L, 53 kinds of flavonoids were identified in fermented samples with L. fermentium 252, the flavanones and flavones increased significantly (P < 0.05), such as naringenin-7-glucoside, hesperetin and nobiletin. Another interesting founding, L. fermentium 252 likely inclined to remove one glycosyl instead of the disaccharide residue. Hence, L. fermentium 252 may be the most promising Lactobacillus for fermentation of Citrus juice among the four strains.