Total phenolic content and antioxidant activity of cryo-milled buckwheat hulls treated with cellulase and hemicellulase

Heljda pripada skupini pseudožitarica te se zbog svoje iznimne nutritivne vrijednosti sve više koristi u različitim oblicima u ljudskoj prehrani. Jedna od njenih glavnih karakteristika je visoka antioksidativna aktivnost koja je ponajprije vezana uz vanjski dio zrna. Heljdine ljuske su nusproizvodi pa se u pravilu ne koriste u ljudskoj prehrani, već kao hrana za životinje te u nekim drugim industrijama. U ovom radu određivana je antioksidativna aktivnost, DPPH i FRAP metodom te udio fenolnih spojeva u kriomljevenim ljuskama heljde tretiranim hemicelulazom i celulazom pri različitoj koncentraciji enzima (0,1 % i 1 %) i vremenu tretmana (1 h, 4 h i 8 h). U odnosu na netretirane ljuske heljde, u enzimski tretiranim ljuskama nije utvrđena promjena antioksidativne aktivnosti. Najveći udio fenolnih spojeva utvrđen je u ljuskama tretiranim s dodatkom 1 % enzima tijekom 1 h.Buckwheat belongs to a group of pseudocereals and because of its exceptional nutritional value, it is increasingly used in different forms in the human diet. One of its main features is the high antioxidant activity, which is primarily related to the outer layer of the grain. Buckwheat hulls are by-product and they are not typically used in the human diet. They have been used as feed and in some other industries. The main goal of this study was to determine antioxidant activity by DPPH and FRAP method and the total phenolic content in cryo-milled buckwheat hulls treated with enzymes at different concentrations (0.1 % and 1 %) and treatment time (1 h, 4 h and 8 h). Compared to untreated buckwheat hulls, change in antioxidant activity in enzymatically treated buckwheat hulls was not observed. The highest content of the phenolic compounds was determined in buckwheat hulls treated for 1 h with the addition of 1% of enzyme