Influence of Heating on Antinutritional Factors on Maize and Rice Cereals

Abstract

Antinutritional factors are secondary metabolites synthesized in plants, which tend to antagonize nutrition either by causing toxicity or secondary nutritional deficiency of some important nutrients necessary for animal nutrition. Effect of heating regimes on the antinutritional contents of two varieties of rice and maize was determined; boiled for 30, 60, 90 and 120 minutes. The samples were sun-dried and levels of the antinutrients were determined using reported procedures. Rice (foreign): phytate – 8.92 ± 1.24, Oxalate – 3.15 ± 0.45, Tannins – 4.44 ± 0.89, For rice (Local): Phytate – 6.03 ± 1.07, Oxalate – 2.05 ± 0.26, Tannins – 2.49 ± 0.36, Maize (White): Phytate – 7.23 ± 0.26, Oxalate – 6.45 ± 1.13, Tannins –  4.66 ± 0.17 and Maize (Red): Phytate – 6.90 ± 0.71, Oxalate – 4.05 ± 0.45 and Tannins–8.58±0.13. Heating for 120 minutes decreases the levels of antinutrients to; Rice (Foreign): Phyate – 5.59. ± 0.16, Oxalate – 1.36 ± 0.19, Tannins – 1.57 ± 0.13, Rice (Local): Phytate – 0.29 ± 0.07, Oxalate – 0.33 ± 0.09, Tannins – 0.52 ± 0.31,  Maize (White): Phyate – 3.00 ± 0.08, Oxalate – 1.37 ± 0.31, Tannins – 1.92 ± 0.09 and Maize (red): Phytate – 3.01 ± 0.08, Oxalate – 1.27 ± 0.60 and Tannins 3.19 ± 0.23.  The data were analyzed by analysis of variance using SPSS 20. For the analysis,   there was significant difference (P˂0.05) between rice and maize cereals, but no significant difference (P˂0.05) between both the cultivars of rice and maize. Similarly, there was significant difference (P˂0.05) in the effect of heating on the two cereals, but no significant difference (P˂0.05) in the effect of heat between the red and white maize as well as local and foreign rice.  The results showed that decrease in the levels of antinutritional contents is proportional to the heating time in rice and maize samples.