• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.205-212
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• 1988

The effect of physicochemical characteristics on the freezing point depression of garlic bulb was studied to examine the reasons of cryoprotectivity in garlic bulb stored at subzero temperature. The composition of fresh garlic was characterized by having high soluble solids($40^{\circ}$ Brix; 90% on dry basis), comparing with $10^{\circ}$ Brix in case of other fruits and vegetables. Soluble solids were composed of 70% sugars, 20% protein, and 10% insoluble solids(including 3% of ash, 3% of crude fiber, and 4% of fat). The main component of sugars in garlic was fructosan with 1-29 degree of polymerization(D.P) and the fructosan of 4-5 D.P was over 50% of total fructosan. Freezing point of garlic bulb, which is a parameter of cryoprotectivity, was depressed as the concentration of soluble solids increased, and as the D.P value decreased in the same concentration of soluble solids.

• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.200-204
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• 1988

Cryoprotectivity of garlic bulb caused by the freezing point depression was studied to establish the possibility of preserving the garlic at subzero temperature. Freezing point of fresh garlic tissue showed almost consistency, ranged from $-4^{\circ}C\;to\;-5^{\circ}C$ regardless of the cultivation area. However, the freezing point was varied with the postharvest treatment and storage conditions, so that freezing point of fresh garlic was $-3.5^{\circ}C$ before predrying, $-4.5^{\circ}C$ after predrying, $-5.5^{\circ}C$ after 5 months of storage and that of dead tissue was $-2.5^{\circ}C$. Freezing lethality of fresh garlic bulb preserved at -4, -6.5 and $-15.5^{\circ}C$ were 0, 10 and 70%, respectively. From these results, it was concluded that critical lethal temperature might be $-5{\sim}-6^{\circ}C$. The respiration rate of garlic bulb decreased with lowering the storage temperature down to $-4^{\circ}C$. $Q_{10}$ value was 2 at the temperature range of $-4{\sim}-5^{\circ}C$, 3 at $5{\sim}15^{\circ}C$ and 1.2 at $15{\sim}37^{\circ}C$. In conclusion, optimal temperature for garlic storage was $-4^{\circ}C$ when considering the cryoprotectivity of garlic bulb at subzero temperature.