This study is aiming at determining the influence of maturing temperature and incubation time on the transformation of the natural fresh garlic into the black one. Influence of moisture, pH, concentration of phenolic, flavonoid, antioxidant activity and the organoleptic properties of the black garlic were investigated at the temperatures of 60, 70, 80 °C during the incubation period of 10, 20, 30 and 40 days. | Tạp chí Khoa học và Công nghệ 55 (1) (2017) 29-34 DOI: EFFECT OF THERMAL TREATMENT ON THE ANTIOXIDANT ABILITY OF BLACK GARLIC PRODUCED FROM PHAN RANG’S NATURAL FRESH MATERIAL Nguyen Thi Nguyen1, Phan Ngoc Hoa1, *, Le Thi Thu Thao1, Phan Dinh Tuan2 1 Hochiminh City University of Technology- VNU-HCM, 268 Ly Thuong Kiet St., District 10, Hochiminh City 2 Hochiminh City Universities of Natural Resources and Environment, 236 B Le Van Sy, Tan Binh District, Hochiminh City Received: 15 August 2016; Accepted for publication: 10 November 2016 ABSTRACT Black garlic, a product made from the natural fresh garlic, is produced by maturing in an environment of sufficient moisture for a long enough period. Black garlic contains phenolic, flavonoid and has much higher antioxidant activity than that of the natural one. This study is aiming at determining the influence of maturing temperature and incubation time on the transformation of the natural fresh garlic into the black one. Influence of moisture, pH, concentration of phenolic, flavonoid, antioxidant activity and the organoleptic properties of the black garlic were investigated at the temperatures of 60, 70, 80 °C during the incubation period of 10, 20, 30 and 40 days. It was shown that moisture and pH decrease while handling temperature increasing and prolonged incubation period. The content of amino acid, phenolic compounds and flavonoids reached their highest values of mg/g, 8534 µg GAE/g dry matter and µg GE/g dry matters, correlatively, at the temperature of 60 °C in 30 days. The antioxidant activity determined by DPPH technique as well as the reduction capacity got the highest value at the temperature of 60 °C in the incubation period of 30 days. In comparison with the raw fresh garlic, the black one incubated at 60 °C in 30 days has super high phenolic components, flavonoids as well as the antioxidant activity. The produced black garlic is of soft structure, no pungent .
