Some Physical and Chemical Characteristics of Taşköprü and Chinese Black Garlics

Abstract

Black garlic, also called aged garlic, is a type of fermented garlic used as a food ingredient in Asian cuisine. It's made by fermenting whole bulbs of garlic at high temperature. The purpose of this study was to evaluate suitability of Taşköprü and Chinese garlic for black garlic manufacture and determine the antioxidant properties of these products. Taşköprü and Chinese garlic were harvested at 2014 in Taşköprü (Kastamonu, Turkey). They were kept to produce black garlic at 60°C and 70-90% relative humidity for 45 days. In this study, the color, dry matter, pH, penetration resistance, total phenolics and ferric reducing antioxidant power (FRAP) values of both raw and black garlics were recorded. The L∗, a∗, b∗, dry matter, pH, total phenolics and FRAP values in Taşköprü raw garlics were found as 70.71±2.80, -0.77±0.21, +23.77±0.55, 35.09±0.08%, 6.38±0.02, 294.73±11.61 mg GAE kg-1 and 640.76±86.98 μmol Fe2+ g-1, respectively, while these values in Taşköprü black garlic were found as 29.53±1.45, +1.18±0.12, +1.83±0.21, 86.52±0.52%, 4.89±0.03, 308.77±30.65 mg GAE kg-1 and 2266.75±417.62 μmol Fe2+ g-1, respectively. The parameters in Chinese raw garlics were found as 70.34±1.09, -0.30±0.05, +24.06±0.13, 36.73±0.46%, 6.43±0.03, 359.81±2.85 mg kg-1 and 678.20±77.56 μmol Fe2+ g-1, respectively, while these values in Chinese black garlics were found as 28.86±0.73, +1.43±0.26, +1.97±0.35, 83.67±0.76%, 4.64±0.10, 424.49±100.37 mg GAE kg-1 and 2304.18±162.21 μmol Fe2+ g-1, respectively. The penetration resistance of the cloves were measured by Texture Analyzer, and the results were found as 31.29±4.42 N in Taşköprü raw garlics, 22.57±11.07 N in Taşköprü black garlics, 21.03±3.90 N in Chinese raw garlics and 17.46±15.04 N in Chinese black garlics. Generally, the antioxidant power and total phenolic contents of Chinese black garlic were higher than the values of Taşköprü black garlic, but it wasn't statistically significant (P>0.05). There was no difference between the other parameters except dry matter and pH values of Taşköprü and Chinese black garlics (P>0.05).