| 摘要 |
A process of freezing sushi, boiled rice or processed food with boiled rice as the main component permits substantially the same quality offered before freezing to be obtained after natural thawing or thawing using an electric oven. When freezing nigiri-sushi at a normal temperature of about 20° C., the freezer temperature is first reduced from a preliminary cooling temperature of -10° C. to a temperature of -30° C. in about 20 min. with a temperature gradient of about 1 to 2° C./min. The freezer temperature is then reduced from -30 to -40° C. with a temperature gradient of 1° C./min. or below, preferably about 0.5° C./min., over a time of 15 to 25 min., and preferably 15 to 20 min., until a maximum ice generation temperature range of 0 to -10° C. for the rice part of the sushi, specifically -3 to -6° C., is passed. |
