A critical review of Metata Ayib and its potential for food innovation

Abstract

Metata Ayib is a traditional Ethiopian spiced fermented hard cheese produced through spontaneous anaerobic fermentation of cottage cheese ( Ayib ) with various spices. This critical review, the first comprehensive synthesis of research on Metata Ayib , critically evaluates the available literature to assess its microbiological, physicochemical, and functional properties. This critical review was conducted by searching PubMed, Scopus, Web of Science, Google Scholar, and African Journals Online for all available studies on Metata Ayib published up to February 2025. Existing literature, comprising 12 primary research works were found to be relevant to the synthesis and were critically evaluated for microbiological, physicochemical, and functional data. Analysis confirms a fermentation-driven microbial succession wherein lactic acid bacteria (LAB) predominantly Lactobacillus, Lactococcus, Pediococcus, and Weissella species become the dominant microbiota, while coliforms, Salmonella, and Staphylococcus aureus are eliminated. Documented LAB strains exhibit broad-spectrum antimicrobial activity against foodborne pathogens, including drug-resistant clinical isolates, with inhibition zones reaching 25.33 mm. The spice matrix (garlic, ginger, rue, basil, black mustard seed, among others) acts synergistically with LAB metabolites (organic acids, bacteriocins, hydrogen peroxide) to create a multi-hurdle preservation system. Fermentation significantly enhances nutritional density: protein content increases from 14.6% in fresh Ayib to 37.8–47.4% in Metata Ayib , while mineral concentrations (calcium, magnesium, phosphorus) rise 2- to 5-fold. Despite these documented qualities, critical knowledge gaps persist: no molecular characterization of microbial communities, absence of strain-level identification, insufficient functional validation of probiotic claims, and lack of standardized production parameters. This review identifies priority research directions metagenomic profiling, metabolomic analysis, starter culture development, and safety assessment to transform Metata Ayib from a culturally significant traditional food into a validated resource for global food innovation.