Quality Characteristics and Antioxidant Activities of Commercial Makjang

Abstract

The purpose of this research is to evaluate the quality characteristics and antioxidant activities of Makjang, Korean traditional fermented soybean paste, which has recently been disappearing, for its preservation. Six kinds of commercial Makjang from three different regions (Kang-won-do, Choong-chung-do, and Kyung-sang-do) were analysed for approximate composition, salinity, pH, total phenol contents, and DPPH and hydroxyl radical scavenging activities. Moisture content of samples was 48.30-58.93% while, crude protein was 9.42-13.67%. Crude fat was 2.45-6.50%, crude fiber was 2.08-6.45%, and ash was 6.59-14.64%. Salinity content ranged from 5.63-12.68%, and pH ranged from 4.36-5.67. Soluble solid content and reducing sugar content of samples ranged from 38.3-54.5 Brix and 22.38-31.61% respectively. The lightness, redness, and yellowness of the Hunter color system of samples were 16.58-28.19, 7.8-16.51, and 8.35-14.21, respectively. Total polyphenol contents were 0.20-0.45 mg/ml. Antioxidant activities determined by DPPH radical scavenging activity and hydroxyl radical scavenging activity (IC50 value) ranged from 45.07 mg/ml to 95.93 mg/ml and 69.81 mg/ml to 309.40 mg/ml, respectively. From these results, it was suggested that the manufacturing process of Makjang is needed to