Influence of Fermentation Time on the Nutritional and Antioxidant Properties of Black Garlic

Black garlic (BG) is a nutritive food produced by subjecting fresh garlic (FG) to controlled thermal processing and humidity conditions for at least 4 weeks. To date, the effect of the fermentation period on the nutritional values of black garlic remains vague in Brunei Darussalam. Therefore, this study aimed to evaluate the nutritional compositions of BG fermented for 4, 6 and 8 weeks at 65 °C and relative humidity of around 70%. The salt, sugar, alcohol, protein, lipid content and antioxidant activity of BG were examined and compared with FG. The study showed that different fermentation periods demonstrated a significant effect (p < 0.05) on the salt, sugar, protein and lipid content of the garlic samples. No alcohol content was detected in all garlic samples. The present study also revealed that BG exhibited higher antioxidant properties, about 5-7 times higher as compared to FG. Our study indicated that the best treatment is black garlic fermented for 4 weeks (BG4) owing to its high protein content and antioxidant properties. Overall, BG is a promising high-value product that can be exploited by the food or nutraceutical industries.