EFFECT OF GINGER EXTRACT ON SHELF LIFE AND MICROBIOLOGICAL QUALITY OF TIGER NUT MILK

ABSTRACT This study effect of ginger (Zingiber officinale) extract on the shelf life and microbiological quality of tiger nut milk (Cyperus esculentus). The objective was to determine whether varying concentrations of ginger extract could inhibit microbial growth, enhance preservation, and extend the milk’s usability period. The research was carried out in the microbiology laboratory of the Federal Polytechnic Bauchi using a laboratory experimental design. Fresh tiger nuts were processed into milk and treated with different concentrations of ginger extract (0%, 2%, 4%, 6%, and 8%). The treated samples were stored under ambient and refrigerated conditions, and microbiological analyses including total viable bacterial count, fungal count, and coliform count were conducted using standard pour-plate techniques. Phytochemical screening confirmed the presence of bioactive compounds such as flavonoids, tannins, alkaloids, phenols, and saponins, which contributed to the extract’s antimicrobial potency. The findings revealed that ginger extract significantly inhibited microbial proliferation, with higher concentrations (6%–8%) showing the most pronounced effect. The treated samples maintained lower microbial loads, higher pH stability, and improved sensory qualities compared to the untreated control. The theoretical framework of the study was based on the natural antimicrobial theory, which emphasizes the role of plant bioactives in controlling spoilage organisms. It was recommended that ginger extract be adopted as a natural preservative in tiger nut milk production and that storage under refrigeration (4°C) be prioritized to ensure safety and quality. Further studies should isolate and quantify the specific bioactive constituents responsible for the observed antimicrobial effects Keywords: Tiger nut milk, Ginger extract, Shelf life, Microbiological quality