Finger millet porridges subjected to different processing conditions showed low glycemic index and variable efficacy on plasma antioxidant capacity of healthy adults

Finger millet porridges(FMP),rich in nutrient and non-nutrient compounds have been used in the traditional food cultures in Asia.The aims of the study were to determine the effect of different processing conditions of finger millet grains on glycemic response,phenolic content and the antioxidant activities of FMP and to determine the short term and long term efficacy of its consumption on plasma antioxidant levels of healthy adults.Twelve types of FMP were prepared combining different processing conditions.Phenolic content of porridges as well as antioxidant activities were determined.The glycemic index(GI)and glycemic load(GL)values of FMP were also evaluated.The long term efficacy of FMP consumption on plasma glucose(PG),total cholesterol(TC)levels and plasma antioxidant capacity(PAC)of 18 subjects were investigated using a 24 weeks randomized cross-over study.The short term efficacy of porridge consumption on AC was determined.PAC was measured by trolox equivalent antioxidant capacity(TEAC)and ferric ion reducing antioxidant power(FRAP).All FMP exhibited low GI values(<55)except the raw roasted flour which showed high and medium GI values for both particle sizes used.Parboiling of finger millet grains with 15 min steaming produced FMP with low glycemic response and possessed high PAC.Compared to baseline,PAC measured using FRAP and TEAC assays increased after 8 weeks consumption of porridge though significant changes were not observed for PG and TC levels.Furthermore,PAC was increased by 23 and 14%after 2 h of porridge consumption as measured by TEAC and FRAP,respectively.FMP consumption increased the plasma total antioxidant capacity of healthy adults.Further research on examining the potential of FMP on improving the antioxidant capacity in patients with diabetes is warranted.

Effect of processing on the antioxidant activities of porridges and Pittu prepared from finger millets (Eleusine coracana)

Finger millets are important coarse grains that exhibit high levels of phenolic compounds and antioxidant activities among other cereals. Grains are subjected to a number of thermal treatments and this could affect the contents and bioactivities of phenolic compounds. The aim of the present study was to determine the phenolic contents and antioxidant activities of finger millet flour and foods, namely porridges and Pittu subjected to several thermal treatments such as roasting, parboiling, and parboiled roasting of flour and open boiling and steaming of foods prepared using flour. The effect of the addition of spices on phenolic content and antioxidant activities to open boiled foods was determined. Antioxidant activities of phenolic extracts obtained from finger millet flour and foods were studied for their total phenolic, flavonoids and proanthocyanidins contents, radical scavenging capacities, reducing power, ferrous ion chelating capacity, and antioxidant activity in a β-carotene/linoleate emulsion. The roasted flour and foods had higher total phenolic content (TPC) than other counterparts and ranged from 21.58 to 28.63 µmol ferulic acid equivalents/g dry matter. All flour and food preparations exhibited effective inhibition of radicals, reducing power, ferrous ion chelating activity, and antioxidant activity in the β-carotene/linoleate emulsion and the degree of activity depended on the processing conditions adopted in food preparations.Foods prepared using steaming showed lower phenolic content and antioxidant activities in general than those of open-boiled counterparts. The addition of spices, namely garlic and cinnamon improved the phenolic contents and antioxidant activities of open-boiled porridges. The knowledge generated from this study may help to exploit the use of finger millets as a functional food ingredient to promote health and wellness.