| 摘要 |
PURPOSE:Boiled noodle is subjected to freeze and vacuum drying where the temperature is lowered from 4 deg.C to 0 deg.C within 30min and from 0 deg.C to -20--30 deg.C for 3-4hr then drying is started, thus producing good-quality instant noodle with high restoration rate. CONSTITUTION:Boiled noodle of about 75% water content is cooled to 30 deg.C and stored in a refrigerator where the noodle is cooled so that the time taken while noodle's temperature drops from 4 deg.C to 0 deg.C becomes within 30min by sending cooling air. Further, cooling is continued and 3-4hr is taken for cooling to -30- -40 deg.C, then rapidly cooled to about -50 deg.C with liquid nitrogen or dry ice and subjected to vacuum drying until the water content becomes about 12%. The resultant instant noodle can completely be restored within 5min, because, under the freezing conditions, the temperature range of 4-0 deg.C at which the conversion rate of starch from alpha form to beta one becomes maximum is passed in a short time and the water in noodles becomes ice particles with appropriate sizes to give proper porous structure. |
