Bio-nutritional aspects of Tungrymbai, an ethnic functional fermented soy food of Khasi Hills, Meghalaya, India

Abstract

•Traditional Tungrymbai of Khasi tribes of Meghalaya was prepared.•The product was made under laboratory conditions following traditional practices using indigenous Lactobacillus spp.•The laboratory made Tungrymbai showed potential bio-functional properties during storage.•Laboratory made Tungrymbai had a similar taste and flavour like traditional one. Background & aimsTungrymbai is a fermented soy product which is a sticky food that exhibits unique flavour and texture which is exclusively made by the local Khasi tribes of Meghalaya (India). A similar kind of product was prepared under laboratory conditions followed by shelf-life study and analysis of its bio-functional attributes with comparison to the traditionally made product.MethodsThe traditional practice for the preparation of Tungrymbai was closely monitored and a similar product preparation was made in laboratory conditions using indigenous Lactobacillus cultures. The shelf life study (physicochemical, microbial and organoleptic attributes) was conducted for 4 days for the Tungrymbai products. Further, the bio-functional properties such as ACE-inhibitory, antioxidative activity and biotransformation of Isoflavones were analysed for laboratory made Tungrymbai products with inoculation of Lactobacillus cultures as well as without inoculation (control).ResultsOut of all the quality attributes of the various Tungrymbai samples, Tungrymbai with 1% cell biomass of Lactobacillus culture in combinations was mostly preferred by the sensory panellists than other samples with a sensory score >6. ACE inhibitory activity of Tungrymbai prepared under laboratory condition increased from 30.75% at day 0–83.55% at day 5, followed by a reduction after day 10 (36.98%) and the antioxidative activity was maximum at day 0 (99.14%) followed by a decrease at day 2 (81.01%). After fermentation of 4 days, production of soy isoflavones in agyclones were 34.70% genistein and 29.37% daidzein for traditionally made Tungrymbai and 55.44% genistein and 86.58% daidzein for laboratory made Tungrymbai infused with Lactobacillus cultures.ConclusionHence, the Lactobacillus culture combinations of Lactobacillus rhamnosus K4E and L. helveticus K14 could serve as potential candidates for the preparation of novel ethnic fermented foods in Meghalaya with more improved bio-functionality. Tungrymbai is a fermented soy product which is a sticky food that exhibits unique flavour and texture which is exclusively made by the local Khasi tribes of Meghalaya (India). A similar kind of product was prepared under laboratory conditions followed by shelf-life study and analysis of its bio-functional attributes with comparison to the traditionally made product. The traditional practice for the preparation of Tungrymbai was closely monitored and a similar product preparation was made in laboratory conditions using indigenous Lactobacillus cultures. The shelf life study (physicochemical, microbial and organoleptic attributes) was conducted for 4 days for the Tungrymbai products. Further, the bio-functional properties such as ACE-inhibitory, antioxidative activity and biotransformation of Isoflavones were analysed for laboratory made Tungrymbai products with inoculation of Lactobacillus cultures as well as without inoculation (control). Out of all the quality attributes of the various Tungrymbai samples, Tungrymbai with 1% cell biomass of Lactobacillus culture in combinations was mostly preferred by the sensory panellists than other samples with a sensory score >6. ACE inhibitory activity of Tungrymbai prepared under laboratory condition increased from 30.75% at day 0–83.55% at day 5, followed by a reduction after day 10 (36.98%) and the antioxidative activity was maximum at day 0 (99.14%) followed by a decrease at day 2 (81.01%). After fermentation of 4 days, production of soy isoflavones in agyclones were 34.70% genistein and 29.37% daidzein for traditionally made Tungrymbai and 55.44% genistein and 86.58% daidzein for laboratory made Tungrymbai infused with Lactobacillus cultures. Hence, the Lactobacillus culture combinations of Lactobacillus rhamnosus K4E and L. helveticus K14 could serve as potential candidates for the preparation of novel ethnic fermented foods in Meghalaya with more improved bio-functionality.