DYNAMIC CHANGES IN POLYPHENOLS, FREE CARBOHYDRATES, AND ANTIOXIDANT ACTIVITY DURING GERMINATION OF WHEAT AND BARLEY FOR PREPARATION OF MALT FLOUR

Abstract

The study aimed to determine the free sugar and total phenolic contents (TPC), and in vitro antioxidant activity in different wheat and barley malt flour. Thirty malt flour samples were prepared from wheat cultivars Lorena and Snaša, and malting barley Tristan, feed barley Zlatko, hull-less barley Osvit, and Mandatar, during different periods of germination from 1 to 4 days. The identified sugars in the samples were maltose, glucose (Glc), and sucrose, but fructose (Fru) and isomaltose were found in trace amounts. The maltose content was the highest, reaching up to 8.6 % among the detected sugars. The Glc content ranged between 1.0 % and 4.4 %, and sucrose was from 0.6 to 4.3 %. The samples Tristan (14.9 %) and Osvit (13.5 %) were characterized by the highest total free sugar content. Snaša flour contained high comparable amounts of soluble sugars (11.6 - 8.1 %) at 0 - 96 h of germination. The TPC and in vitro DPPH radical scavenging activity increased during germination, as they were higher in barley varieties than in wheat ones. Wheat and barley malt flour can be combined to increase the amounts of fermentable sugars and antioxidants to create bakery products, sourdoughs, craft beers, functional and dietary foods, and fermented drinks.

Keywords

• аntioxidant activity
• barley
• malt flour
• polyphenols
• sugars
• wheat