Molecular Characterization of Non-lactic Bacteria in Lactic Fermented Tigernut-milk Drink and Effect of Ambient and Refrigeration Temperature Storage on Sensory Properties of the Drink Spiced with Ginger and Garlic

Abstract

Globally, non-dairy products are fast gaining acceptability comparable to dairy products in order to satisfy certain individuals with dietary limitations. Natural food additives such as ginger and garlic are preferable to chemically synthesized food additives and flavour enhancers. Sensory acceptability of non-dairy products is influenced by fermentation. Tigernut-milk drink was fermented using lactic starter culture isolated from ‘ogi’ for 72 h at 45°C. Surviving non-lactic bacteria in the lactic fermented drink which might not function as a probiotic in humans was identified using molecular characterization. The lactic fermented tigernut-milk drink was separately spiced with 3%, 5% ginger; 3%, 5% garlic. The products were stored at ambient (28±2°C) and refrigeration (4±2°C) temperature for 8 weeks based on a predetermined shelf life. Bacillus amyloliquefaciens strain D203 (SUB2424304 MA  KY630545), Bacillus methylotrophicus strain XJAJ2 (SUB2424304 MG KY630549), Bacillus amyloliquefaciens strain BA-07 (SUB2424304 MB  KY630546), Bacillus amyloliquefaciens strain WS-8 (SUB2424304 MD KY630547) and Acinetobacter sp. strain NC 41 (SUB2424304 MF KY630548) are non-lactic bacteria in the tigernut-milk drink. Based on sensory score, the 5% ginger spiced lactic fermented tigernut-milk drink was the most preferred drink. In this study, non-lactic bacteria was identified as being present in lactic fermented tigernut-milk drink of which storage conditions and natural spices incorporated into lactic fermented tigernut-milk drinks influenced the sensory properties of the drinks.