Assessment of continuous and intermittent drying on antixidant activity of corn grains

Grain drying is essential for storage to preserve material quality. However, drying can affect the composition of agricultural material, as exposure to high temperatures for long periods can reduce the quality of the grain, in terms of antioxidant activity and germination power. The objective of this work was to assess the continuous and intermittent drying, in order to maximize the preservation of corn grains antioxidant potential. Experiments were conducted at 40, 55, and 70 °C with tempering periods of 5 and 10 minutes. Solvents used were methanol/water 70/30 (v/v), methanol/water 95/5 (v/v), ethanol/water 70/30 (v/v), and ethanol/water 95/5 (v/v) and extraction times of 1, 4, and 24 hours. Antioxidant activity analysis was carried by DPPH and ABTS radicals scavenging and the best results of antioxidant activity for in natura grains were obtained with methanol/water 70/30 (v/v) and 4 h. Intermittent drying of 5 and 10 minutes’ periods at 40 °C led to least reduction of antioxidant activity percentage compared to in natura corn results. This study demonstrated that intermittent drying conducted at low temperatures is an effective alternative to preserve bioactive compounds of corn.