• Korean journal of food and cookery science
• /
• v.14 no.4
• /
• pp.394-399
• /
• 1998

The juice of garlic (Euichun variety) was extracted and concentrated by heating at 90$^{\circ}C$, by using a rotary vacuum evaporator at 45$^{\circ}C$, or by freezing at -50$^{\circ}C$ until the volume was reduced to 70% of the original's. The concentrated garlic juice was packed into 15 ml test tubes wrapped with aluminum foil and kept at 4$^{\circ}C$ or 25$^{\circ}C$ for 60 days. Changes of browning, microbiological and sensory characteristics of the concentrated garlic juices were monitored every 10 days. The specific gravity and viscosity of the prepared juices decreased in the juices concentrated at 90$^{\circ}C$, 45$^{\circ}C$ and -50$^{\circ}C$ in order. Browning of the concentrated garlic juices was slower during the storage at 4$^{\circ}C$ than at 25$^{\circ}C$. Browning occurred rapidly in the juice concentrated at 45$^{\circ}C$ during the storage, especially at 25$^{\circ}C$. The numbers of mesophilic and psychrotrophic bacteria in the juices did not increase significantly during the storage, which means the garlic juices had good shelf-life. The CFUs/ml of garlic juice concentrated at 90$^{\circ}C$ were lower about 1 to 2 log cycles than those in other concentrated juices. The juice concentrated at 90$^{\circ}C$ showed the weakest garlic odor and the strongest cooked odor among the juices. The juice concentrated at -50$^{\circ}C$ had the freshest odor, especially stored at 4$^{\circ}C$, but the juice concentrated at 90$^{\circ}C$ had lowest score in fresh odor. Brown color was dark in the juice concentrated at 45$^{\circ}C$ and green color of all the juices did not change significantly during the storage.