Changes in nutritional and bio-functional compounds and antioxidant capacity during black garlic processing.

This study aimed to explore ideal processing condition for black garlic based on the change of nutritional and active components and antioxidant capacity. Fresh garlic was processed under the condition of constant temperature (65, 75 and 85 °C) and relative humidity (70, 75, 80 and 85%) for 16 days. The sensory scores, contents of nutritional and active components, and antioxidant capacity were monitored. The sensory scores reached the maximum on the 8th day at 85% humidity and 75 °C. The contents of nutritional components were significantly affected by humidity and temperature, and 85% humidity and 75 °C were appropriate. The polyphenol content increased with increase in temperature and decrease in humidity. The reducing sugars and total sugars, total acids and 5-HMF were higher at 75 °C than at 65 and 85 °C. Reducing sugar and protein contents and sensory scores decreased on the 8th day. Maintaining the temperature of 75 °C and relative humidity of 85% for 8 days were ideal for black garlic to retain antioxidant capacity and abundant nutrients.