Preparation of a mirin-like sweetening made from potato (potato mirin)

A mirin-like sweetener for seasoning (potato mirin) was prepared from potat o produced in Hokkaido. Peeled and crushed potato (200 g) after cooked at 1 21 degreesC for 30 min, rice koji (40 g) and syocyu (100 g) containing 35% (v/v)-ethanol were mixed and incubated at 30 degreesC for 60 days. Effect o f the addition of alpha -amylase (Amylase AD [AMANO] 1) and neutral proteas e (Denatyme AP) was examined. There were little differences on a yield, tot al sugar (as glucose) and ethanol content between potato mirin prepared wit hout and with 0.03%, 0.07% and 0.15% (w/w) of the enzymes. But the nitrogen content of the product increased of the remarkably when 0.15% (w/w) of the enzymes was added, indicating that 0.15% enzyme concentration was most sui table. In potato mirin prepared by the addition of 0.15% enzymes, yield rat io, total sugar (as glucose), ethanol and total nitrogen were 72% (w/w), 22 .4 (w/v), 8.5 (w/v) and 0.27% (w/v), respectively. Its major sugar componen ts were glucose 18.3% (w/v) and isomaltose 2.3% (w/v). And the total free a mino acid content in this potato and commercial mirin was 0.92% (w/v) and 0 .23% (w/v), respectively. Recovery ratios of glucose and total nitrogen wei ght were about 70% and 65%, respectively. For mass balance of potato mirin preparation, when 100 g of fresh potato was used, peeled and crushed potato , total materials for incubation and recovered potato mirin were 87.4 g, 14 9.0 g and 107.3 g, respectively.