Changes in physicochemical characteristics and nutritional values of soybean, meju, and doenjang by varying sowing periods

The purpose of this study was to determine how seeding time changes the properties of soybean products meju and doenjang. Soybeans were seeded on the last day of May (5L), on the mid day of June (6M), and on the last day of June (6L), respectively. The 5L soybeans experienced a distinguishing hot and humid climate at the ripening stage, and these climate conditions resulted in smaller seed sizes. Fermentation briskly progressed in all doenjang until 120 days, and the 5L doenjang exhibited the lowest fermentation efficiency. The 5L soybeans showed the highest GABA, polyphenol contents, and ACE inhibitory activity, and the 6M soybeans showed the highest radical scavenging activity among the groups tested. In doenjang, the functional properties generally increased as the aging time approached the 120 th day, and the 6M doenjang showed the highest functional properties at the 120 th day. Therefore, 6M soybeans had the most appropriate characteristics when producing doenjang.