Chemical analysis and flavour compound changes of vegetable blend slurry fermented with selected probiotic bacteria

Abstract

A vegetable blend slurry consisting of aloe vera (Aloe barbadensis miller), garlic (Allium sativum), ginger (Zingiber officinale), liquorice (Glycyrrhiza glabra) and pumpkin seeds (Cucurbita pepo L.) was used as a probiotic medium to evaluate the impact of probiotic fermentation on its chemical composition and flavour compound changes. Two commercial probiotic bacteria, Bifidobacterium animalis subsp. lactis HN019 and Lactobacillus acidophilus La-14, were used for monoculture and coculture fermentation over 72 h. After fermentation, sugars, organic acids and amino acids changed differently due to differences in metabolic pathways. In addition, there was a significant decrease in organosulfur compounds (from 10.56 ± 0.98 mg/L to 6.14 ± 0.83 mg/L, 7.80 ± 1.09 mg/L and 6.02 ± 0.61 mg/L for B. lactis HN019 monoculture, L. acidophilus La-14 monoculture, and coculture fermentation, respectively) and total phenolic contents (TPC, from 24.61 ± 1.23 mg gallic acid equivalent (GAE)/g dry extract (DE) to 16.29 ± 1.22 and 15.66 ± 1.03 mg GAE/g DE for L. acidophilus La-14 monoculture and coculture fermentation, respectively). Interestingly, no significant changes in oxygen radical absorbance capacity (ORAC), total dietary fibre content and fat content after fermentation. Coculture fermentation did not show any significant synergistic or antagonistic effect. Our results suggest that the vegetable blend and the bacterial strains used have potential to create a novel probiotic product.