Composition Of Corn Cob And Functional Properties Of Corn Cob Ash:- Onyebuchi, Chidimma J

ABSTRACT

This study evaluated the valorization of corn cob through its conversion to ash, with the aim of assessing the proximate composition of the corn cob, the mineral content ofthe ash, and the functional properties of the ash extract in food applications. A traditional emulsion-based dish (African salad) was prepared using the corn cob ash, which was further subjected to sensory evaluation by a panel. The proximate composition analysis ofthe corn cob revealed high moisture (65.44%), moderate crude fibre (20.92%), and low ash (1.62%), resulting in an energy value of 63.92 kcal/100 g. Functional property analysis showed that the emulsification capacity and stability of corn cob ash with palm oil (26.32-43.35% and 42.52-53.16%) were comparable to those obtained with vegetable oil (38.73-45.71% and 46.48-49.36%). Foam capacity (10.52%) and stability (7.18%) were found to be low. Mineral analysis of the ash indicated appreciable amounts of phosphorus (0.83%), calcium (1.28%), magnesium (0.51%), and potassium (6.74%), which were sufficient to meet or exceed daily requirements. However, sodium (0.0001%) and nitrogen (0.20%) were far below recommended levels, indicating limited contribution to daily intake. Trace elements such as manganese (377.56 ppm), iron (265.00 ppm), copper (46.14 ppm), and zinc (352.63 ppm) were present in amounts exceeding daily requirements, while chromium (0.02 ppm) and nickel (0.01 ppm) were very low, and selenium was below detectable levels. Heavy metals such as cadmium (0.08 ppm) and barium (0.22 ppm) remained within safe consumption limits, but lead (11.05 ppm) exceeded safe levels, posing a potential toxicity risk if not treated before use. Sensory evaluation revealed that African salad prepared with corn cob ash (APA) scored higher than that prepared with potash (APP) in appearance (7.73 vs. 7.23), aroma (6.04 vs. 5.88), texture (7.69 vs. 7.35), taste (7.73 vs. 7.31), and general acceptability (7.96 vs. 7.50). However, in mouthfeel, APP (7.50) was rated higher than APA (7.19). These findings suggest that fresh corn cob is a fibrous, low-calorie agricultural by-product suitable for incorporation into complementary food formulations and traditional culinary practices. It is recommended that corn cobs be dried prior to storage and that further studies be conducted to ensure safe treatment ofthe ash before use.