Indigenous Fermentation and Rural Livelihoods: Exploring the Functional and Cultural Value of GI-Tagged Napham in Northeast India

This study hypothesizes that microbes isolated from Napham, a traditional GI-tagged fermented food product of Assam, possess probiotic and aroma-producing properties. The dataset includes detailed morphological, microbiological, biochemical, physiological, flavor-genic, and statistical analyses of microbial strains isolated from Napham.

Key data includes:

• Sample Collection: Napham samples were collected from various households and markets in Assam.

• Isolation and Colony Morphology: Microbial strains were isolated on NAM and MRS agar and examined for colony morphology.

• Biochemical and Physiological Tests: Proteolytic and Lipolytic activity assays, carbohydrate fermentation profiling, pathogenicity assessments like hemolysis and antibiotic susceptibility tests, as well as Gram staining, IMViC tests, catalase, and oxidase assays were performed.

• Flavor-Inducing Potential: Flavor-inducing potential of the strains was evaluated based on their proteolytic, lipolytic, and carbohydrate fermentation activities, with flavor production assessed in curd and beer preparations through sensory analysis.

• Statistical and Sensory Evaluation: Sensory scoring for appearance, aroma, flavor, and mouthfeel of curd and beer confirmed the flavor-inducing potential of the strains.

• Probiotic Potential: Evaluation included NaCl tolerance, phenol tolerance, acid tolerance, in-vitro adhesion to chicken crop epithelial cells, auto-aggregation, and DNase activity tests.

• Flavor Compound Analysis (GC-MS): Gas Chromatography-Mass Spectrometry identified key volatile compounds contributing to flavor.

• 16S rRNA Identification: Molecular identification confirmed the taxonomy of the most promising strain.

Notable Findings

• Four microbial strains (NAP/1, NAP/2, NAP/3 and NAP/4) exhibited strong proteolytic, lipolytic, and carbohydrate fermentation abilities.

• Statistical analysis (p < 0.05) confirmed a significant relationship between the biochemical properties of the microbes isolated and their potential to produce flavor compounds.

• All the selected strains were non-pathogenic in nature. These strains were used for the preparation of curd and beer.

• Sensory evaluation confirmed NAP/2 as the best-performing strain, significantly improving aroma, flavor, and texture in curd and beer.

• GC-MS analysis revealed diverse flavor compounds, including esters, alcohols, ketones, and nitrogenous compounds such as L-Glutamic Acid contributing to a unique flavor profile.

• NAP/2 exhibited excellent probiotic potential, including strong acid and phenol tolerance, NaCl resilience, significant auto-aggregation, and adhesion to epithelial cells, with no DNase activity.

• Molecular characterization identified NAP/2 as Staphylococcus piscifermentans N1 with notable probiotic and flavor-enhancing potential.

• Staphylococcus piscifermentans N1 holds promise as a probiotic starter culture for flavor-rich fermented foods.