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Abstract
Preservation of foods and supplying essential antioxidants in vivo by natural antioxidants contained in foods is well appreciated. The study aimed at determining the effects of fermentation on the antioxidant properties maize flour. A yellow coloured QPM (TZE-POP-DT-STR-QPM) was compared with yellow coloured normal maize (SUWAN-ISR). The maize sample was divided into two; a portion was fermented and the other portion was decorticated and degermed mechanically without fermentation before milling to flour.Total antioxidant of all the samples was extracted in both aqueous and methanol medium. Total carotenoids and vitamin C contents, total phenol, flavonoids content were determined. DPPH and ABTS and Lipid peroxidation scavenging power of aqueous and methanol extracts were measured. Also, the storage stability of the antioxidant extract was carried out within 72 h of storage at refrigeration temperature. The result shows that total carotenoid of unfermented samples 35.48 and 46.85 mg/100 g for UFNM and UFQPM, respectively is lower than 50.70 and 56.69 mg/100 g obtained for fermented samples (FNM and FQPM). DPPH scavenging power of the sample ranged from 20.28 to 41.79% and 11.38–20.70% for aqueous and methanolic extracts, respectively. DPPH activities of fermented samples were more stable over a 3 days storage period compared to unfermented samples. The study established increasing effect of fermentation on total carotenoid and vitamin C with a milder reduction effect of some antioxidant capacity in aqueous medium compared to methanol extracts.