Optimization of oat seed steeping and germination temperatures to maximize nutrient content and antioxidant activity

Abstract

Oats are highly nutritious and oat germination can change the concentration of nutrients and bioactive compounds in oat seeds. In order to improve the nutritional value and biological activity of oats, a central composite design was applied to optimize the steeping and germinating temperatures. The optimal steeping and germination conditions obtained were 18°C for 12 hr and 20°C for 48 hr, respectively. Under the optimized conditions, the total phenolic, flavonoid, and soluble protein contents in sprouted oats increased to 13.524 mg/g, 7.152 mg/g, and 28.103 mg/g, respectively. Furthermore, the amount of essential amino acids increased during sprouting. Compared to levels before germination, the γ-aminobutyric acid content increased by 20%. Last, oat seeds sprouted under the optimal conditions exhibited high antioxidant activity. Practical applications Through single-factor and response surface optimization experiments, the optimal temperature conditions for oat steeping and germination were 18°C and 20°C, respectively. The germinated oat showed higher nutritional content than non-germinated, including total: phenolics, flavonoids, soluble proteins, and γ-aminobutyric acid. The extracts from sprouted oats exhibited increased antioxidant activity, which can contribute to the nutritional value of oats as a commonly consumed food.