Microbiological, physicochemical and sensory evaluation of "ori-ese" produced from fortified sorghum

Abstract

Sorghum is one of the important crops used for the production of different fermented foods in Africa. However, due to the fact that the nutritional quality of sorghum is poor, there is a need for fortification of these cereals with legumes or other cereals to make nutritionally rich and acceptable fermented products. “Ori ese” - a fermented thick porridge was produced from sorghum fortified with different blends: Sorghum only (SO), Sorghum-soybeans (SYBO) ratio 3:1, Sorghum-millet (MO) ratio 3:1, Sorghum-wheat (WO) ratio 3:1 and Soybeans only (WSYO). The microbial isolates during steeping and slurry fermentation consisted of lactic acid bacteria: L. plantarum, L. fermentum, Pediococcus sp., L. acidophilus, Lactococcus lactis spp cremoris, L. cellobious, L. dextranicum, coliforms ( Enterobacter aerogenes, E. coli), other bacteria (Proteus sp, Coryniformis sp, Pseudomonas pseudomalle, Streptococcus surgis, Staphylococcus aureus, Klebsiella oxytoca, Bacillus subtilis, Bacillus licheniformis, Bacillus cereus), moulds genera (Aspergillus, Penicillium, Mucor, Absidia, Monilia and Verticillum) and 2 genera of yeast (Saccharomyces and Candida). Lactic acid increased with fermentation time and this resulted in elimination of coliforms. There was a significant difference (P≤ 0.05) in pH and lactic acid production during steeping and fermentation of slurry in which the highest lactic acid concentration was recorded at 72hrs. The result of proximate analysis showed that fortification of sorghum with cereals and soybean blends resulted in an increase in protein (14. 73^e, 26. 47 ^b, 18. 79 ^c, 17. 58 ^d and 37. 69^a %) for SO, SYBO, MO, WO and WSYO respectively. There was a relative reduction in carbohydrate content and an increase in mineral content of the blends. There was a significant difference (P≤ 0.05) in proximate and mineral composition of the blends. WSYO had the highest Ca (367.25^a mg/100g) and P (726.85 ^a mg/100g) content while SO had the highest K content (86.27 ^a mg/100g), SYBO had the highest Fe content (1.86 a mg/100g) and MO had the highest Na content (57.42 ^a mg/100g). Statistical analysis of sensory evaluation showed a significant difference (P≤ 0.05) in terms of appearance, texture and palatability. There was a preference for SO in terms of appearance, for WSYO in terms of texture, SYBO in terms of flavor and taste and SYBO and SO in terms of palatability.

Key words: “Ori-ese”, sorghum, fortification, proximate, palatability