Effects of ultrasound and hydrothermal treatment on digestible and bioactive properties of wholegrain wheat flours with different amylose conten

Abstract

The consumption of wholegrain flours contributes to an increased intake of dietary fibers and phenolic compounds beneficial to human health. However, there are some downsides to wholegrain flours, such as poor baking performance and lower technological quality. The application of ultrasound and hydrothermal treatments may provide new possibilities for the modification and improvement of the baking- and bio-functionality of flours as well as the quality of baked goods [1]. Furthermore, waxy and high-amylose wheat varieties are considered novel raw materials due to their unique properties in bread making, such as improved bread texture and increased dietary fiber content [2]. The main focus of this study was to investigate the changes in enzymatic in vitro dry matter digestibility, antioxidant capacity, and the content of total free phenolic compounds before and after the individual treatments of the whole-wheat flours with different amylose content. Hydrothermal treatment positively influenced the digestibility of the whole-wheat flours, especially in waxy genotypes compared to high amylose ones, which can be explained by the formation of resistant starch. Ultrasound positively affected the total free phenolic compounds content. Moreover, the hydrothermal treatment had an overall negative effect on the antioxidant capacity. The amylose content was in high negative correlation with digestibility after hydrothermal treatment. Starch content was negatively correlated with digestibility after ultrasound treatment. Protein content was very strongly correlated to digestibility after ultrasound treatment. These findings can provide valuable guidelines in the formulation of new wholegrain wheat foods.