Quality characteristics of milk jam with black garlic extract

Abstract

This study investigates the quality characteristics and antioxidant activities of milk jam with black garlic extract at levels of 0%, 7.5%, 15.0%, 22.5% and 30.0%. The quality of the black garlic milk jam was evaluated on the color, pH, total acidity, total polyphenol content, total flavonoid content, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. In color, lightness (L) and yellowness (b) of the milk jam samples decreased with increasing black garlic extract levels, whereas redness (a) increased. At higher black garlic extract levels, the pH of black garlic milk jam decreased from 6.46±0.07 to 5.44±0.01, and its total acidity increased from 0.277±0.037% to 0.399±0.026%. The total polyphenol and total flavonoid contents of black garlic milk jam ranged from 144.76±3.51 to 263.41±2.34 mg GAE/100 g and 24.29±1.31 to 44.81±0.35 mg QE/100 g, respectively. These values increased significantly (p<0.05), depending on the black garlic extract level. The DPPH radical scavenging activity was the highest the milk jam sample containing 30.0% black garlic extract. The results of this study suggest that black garlic can be used as an ingredient for functional foods.