Comparison of Nanopowdered and Powdered Ginseng-added Yogurt on Its Physicochemical and Sensory Properties during Storage

This study was conducted to compare the physicochemical and sensory properties of yogurt added with nanopowdered ginseng (NPG) and powdered ginseng (PG) of different concentrations (0.1, 0.3, 0.5, and 0.7%) (w/v) during the storage at $7^{\circ}C$ for 20 d. The pH and viscosity values of yogurt added NPG or PG decreased during the storage. The pH values of the yogurt samples were ranged from 4.0 to 4.6 as a reflective of the fresh state. Viscosity values of yogurt with NPG at lower concentrations 0.1 and 0.3% (w/v) showed higher values during increased storage time. DPPH radical scavenging activity was significantly higher in the NPG-added yogurt than in the PG during the storage period (p<0.05). The lactic acid bacteria (LAB) counts ranged from $3.0{\times}10^9$ to $1.3{\times}10^9$ and $2.2{\times}10^9$ to $1.1{\times}10^9CFU/mL$ in 0.3% NPG and PG-added yogurts, respectively. Increased storage period showed decrease in LAB counts irrespective of the type of ginseng powder and storage period. In sensory test, 0.1 and 0.3% NPG-added yogurt showed similar results to control in yellowness, viscosity, and bitterness. Based on the data obtained from the present study, it was concluded that the concentrations 0.1 and 0.3% (w/v) of NPG could be used to produce NPG-added yogurt without significant adverse effects on physicochemical and sensory properties, and enhance functional value of yogurt.