Nutritional and sensory evaluation of food formulations from malted and fermented maize (Zea mays L.) fortified with defatted sesame (Sesamun indicum L.) flour

Abstract

Malting and fermentation were investigated as simple technologies for improving the nutritional and organoleptic properties of maize/sesame food formulations. Various maize flour samples were blended with defatted sesame flour, by material balancing, to give four food formulations consisting of unmalted maize + defatted sesame flour (UMS), malted maize + defatted sesame (MMS), unmalted, fermented maize + defatted sesame flour (UFMS) and malted fermented maize + defatted sesame flour (MFMS), which all contained 16g protein and 9g fat/100g food. Four diets were formulated (by material balancing with a basal diet) from the food formulations in addition to casein (milk protein), and Nutrend (a commercial complementary food produced from maize and soybeans) to give 10g protein/ 100g of each test diets, which were used for feeding trials with Wister albino rats. The protein efficiency ratio (PER), net protein ratio (NPR), apparent digestibility (AD) and amino acid profile as well as organoleptic properties of the gruels prepared from the food formulations were evaluated. The PER values of malted and fermented products (2.16 for MMS and 2.06 for MFMS) were significantly higher (p<0.05) than those of unmalted products (1.86 for UMS and 1.59 for UFMS). The NPR and AD values followed a similar trend with 3.82 and 70.50% for UMS, 4.40 and 72.10% for MMS, 4.21 and 70.00% for UFMS and 4.47 and 71.50% for MFMS respectively. Malting and fermentation significantly (p<0.05) increased lysine content from 2.16g/16gN (UFMS) to 5.46g/16gN (MFMS) and tryptophan from 1.08g/16gN (UFMS) to 1.35g/16gN (MFMS). There was significant (p < 0.05) difference in colour, taste and aroma for all the food formulations. Mean sensory scores ranged from 7.07 – 8.33 for UMS, 7.34 – 8.45 for MMS, 7.04 – 7.73 for UFMS and 6.82 – 7.74 for MFMS on a 9 – point hedonic scale. The unfermented products gave better acceptability than the fermented products in all the attributes; while the UFMS and MFMS (fermented products) did not show any significant difference in acceptability. The malted maize/sesame (MMS) blend therefore gave the best result with the highest acceptability and is therefore recommended for use as a complementary food.

Keywords:Malting, Fermentation, Formulations, Complementary, Sesame

African Journal of Food, Agriculture, Nutrition and Development, Volume 12 No. 6