Ozonation of Adzuki beans (Vigna angularis): effect on the hydration kinetics, phenolic compounds and antioxidant capacity

Ozone is used in grains to guarantee mycotoxin degradation, microbial inactivation, and insect disinfestation. However, its oxidizing properties can promote changes in the grain constituents, affecting both product properties and process behavior. Even so, the effect of ozone processing on quality properties of grains and their process, was rarely studied. Consequently, this work studied the impact of ozonation processing on the hydration kinetics and selected nutritional properties of Adzuki beans (Vigna angularis). As the ozone reactiveness increases at high moistures, three different levels of grain moisture were evaluated. The bean nutritional quality was evaluated considering the total phenolic content and antioxidant capacity (both radicals ABTS and DPPH). The results showed that there was neither significant difference in the hydration kinetics nor in the phenolic compounds and antioxidant capacity after the processing with ozone. Consequently, ozonation is proposed as an alternative in the control of grain contaminants without affecting its quality. Practical applications: Grains are important raw materials worldwide, since they are used as food, feed or for extracting different components. Ozone, a safe and green technology, is used for microorganism inactivation and insect disinfestation, as well as for mycotoxins degradation in grains. However, although ozone can be used to guarantee safety, its oxidizing properties can promote changes in the grain constituents. These changes can negatively impact the nutritional properties, as well as alter the grain behaviour during processing. However, these evaluations are rarely carried out, questioning the ozone practical application. Therefore, the present work was developed to conduct this evaluation. It was demonstrated that the ozone processing did not alter neither the grain hydration kinetics nor the phenolic compounds and antioxidant capacity. Consequently, ozonation is proposed as a viable alternative in grain processing.