Ultrasound-Assisted Germination of Buckwheat: Impact on Anti-nutritional and Antioxidant Content

Buckwheat is a highly nutritious grain that contains macro and micronutrients with antioxidant potential. However, some anti-nutritional components in buckwheat, such as phytic acid and condensed tannins, reduce its bioavailability. Germination is an ancient and natural method to improve the nutritional value of cereal grains. Controlled germination processes increase the nutritional value of pseudocereals by reducing the amount of antinutrients. Thus, the bioavailability of nutrients improved. Ultrasound-assisted germination can be a good alternative for increasing nutritional and bioactive values and mitigating the anti-nutritional properties of buckwheat by accelerating enzyme activity and biochemical changes by affecting the cell membrane structure. This study investigated the changes in chemical composition, phenolic content, antioxidant activity, color, and anti-nutrient content of buckwheat grains (Fagopyrum esculentum Moench. cv. Aktaş) germinated for 72 hours by traditional and ultrasound-assisted methods. The highest total phenolic content (498.572.93 mg GAE 100 g-1) and antioxidant activity (10.911.62 mol TEAC g-1) of buckwheat were measured in the germinated sample using the ultrasound-assisted method. However, the color changes were not notable during 72 h of germination. The lipid (3.06 – 3.39%) and protein contents (12.56 – 15.05%) were increased after germination. The starch content was 58.58% in ungerminated buckwheat and decreased (52.36%) after 72 h of germination using the ultrasound-assisted method. In germinated samples, tannin content was reduced by 43 – 54%, whereas a slight reduction was observed in phytic acid concentrations. Ultrasound-assisted germination can be a valuable alternative to improve the chemical composition and bioactive potential and mitigate the anti-nutritional properties of buckwheat grains. Germinated grain, flour, or processed products might be good alternatives to traditional cereal consumption because of their improved functional properties.