Effects of Germination and Fermentation the Quality Characteristics of Maize/Mushroom Based Formulation

Abstract

Maize grains were divided into four treatment groups, namely: germinated-fermented maize (GFM), germinated non-fermented maize (GNFNM), non-germinated fermented maize (NGFM) and non-germinated non-fermented maize (NGNM). Maize and mushroom (MR) based products (GFMR, GFNMR, NGFMR and NGNMR) from all four maize grains were formulated. Germination and fermentation were investigated as methods of improving the nutritional and organoleptic properties of the formulations. Inocula recycling (use of 50% fermenting mixture as starter) resulted in a pH reduction from 5.99 to 3.30 in non-germinated products and from 5.88 to 3.29 in germinated samples during fermentation. The increase in titratable acidity (expressed as g lactic acid/100g sample) from 0.14 to 0.17 in non-germinated products and from 0.14 to 0.18 in germinated samples was not significant (p< 0.05). The crude protein values ranged from 16.0g/100g for the NGFMR to 16.3g/100g for NGNFMR product. The GNFMR had the lowest carbohydrate content (60.8g/100g) while the GFMR had the highest value of 66.0g/100g. No significant difference (p< 0.05) was obtained in the variation of the ash content between 5.2g/100g for GFMR to 5.4g/100g for GNFMR and NGFMR had the highest energy value of 340KJ/100g while the NGNFMR had the lowest (336.8 KJ/100g). Germination resulted in a significant (p<0.5) increase in digestibility. A combination of germination and fermentation further improved protein digestibility (%). The PER of the germinated and fermented product (1.87) was significantly (p<0.5) higher than that of the nongerminated non-fermented product (PER=0.82). Sensory scores for flavor ranged from 3.30 out of 7 (fair) for GFMR to 4.7 (fairly good) for GNFMR. The GNFMR was characterized as having a sweet taste while the GFMR and NGFMR were characterized as having fairly sour flavors. The appearance score of 5.20 (pleasant) for NGNFMR was significantly (p<0.05) higher compared with the other products. The product made from GNFMR had the highest score of 5.50 (like very much) while NGFMR had a value of 3.70 (neither like nor dislike) for overall acceptability. Germination and/or fermentation of maize with added mushroom have been used to formulate acceptable products which could be used as a weaning food. The addition of mushroom implies that the final products have potential for improved protein quality beneficial to its consumers.