DEVELOPMENT OF CEREAL-BASED FUNCTIONAL FOOD PRODUCTS USING PROBIOTIC POTENTIAL LACTIC ACID BACTERIA ISOLATED FROM KENOKO
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The global demand and interest for non-dairy beverages with potential health benefits continue to increase. Development of probiotic strains from fermented cereal and legumes with the ability to grow well and adapt to gastrointestinal conditions at the same time possess high therapeutic ability is considered a great achievement. The food industry is interested in the development of food products that meet high quality, are safe and in addition can boost the health status of an individual. Kenoko is a spontaneously fermented cereal-legume product common among the indigenous Maragoli community of Western Kenya. This study aimed at isolating potential probiotic lactic acid bacteria from kenoko, which were characterized then screened for probiotic attributes and safety. The screened lactic acid bacteria kenoko isolates were then used for development of functional cereal-legume based food products. Lactic acid bacteria were isolated using MRS and M17 media followed by biochemical characterization. Eleven (11) isolates that met the preliminary attributes of probiotic bacteria were selected for further investigation on safety and probiotic attributes. Effect of low acid conditions and bile salt concentration on growth rate of the isolates was assessed. Findings from this study revealed that the presumptive lactic acid bacteria isolated from kenoko of legumes and cereals survive well at low pH, high temperature of up to 45℃ and high salt concentration. From a safety point of view, the enzymes DNase and gelatinase used to test pathogenicity of a microorganism were not produced by all the isolates in this study. The isolates recorded a high susceptibility to eight (8) antibiotics used. This research also revealed that the tested isolates have the ability to grow well at minimum tested pH of 1.0 for 1 and 2 hours of incubation. All the 11 isolates grew well at low pH and high bile salt. Most isolates were resistant to 0.3% bile concentration with over 84% survival. Five lactic acid bacteria (MPU1, MPU2, FPU1, FPU2 and SPU2) from cereals and six isolates (RC0PU2E, SB0PU3E, RC0PU2m, SB0PU2m, CP0PU2m and CP0PU1E) from legumes were confirmed to have probiotic potential. Four functional cereal-legume drinks (BPS1, BPS2, BPS3 and BPS4) were developed using the 11 probiotic potential lactic acid bacterial isolates with varied ratios of cereal and legume flour mixtures. Physicochemical properties, viable cell count on storage, shelf life and sensory evaluation were carried out using a nine-point hedonic scale. Viable count numbers for probiotic lactic acid bacteria in the products remained reasonably high in all samples throughout the period of storage of 28 days (more than107cfu/mL). The performance of products on sensory evaluation was generally above average on most parameters. The overall consumer acceptability for product sample BPS1 and BPS2 was relatively high with a sensory evaluation score of 6.85 and 6.45 respectively. Findings from this study concluded that kenoko is a potential source of probiotics with unique characteristics which can produce starter cultures for industrial application. The lactic acid bacteria strains possed probiotic attributes and are safe for use in Food industry for development of functional foods.