1985 Volume 32 Issue 2 Pages 133-137
It was demonstrated that an effective way of softening the texture of Imo-karinto, deep-fat fried and sugar-coated sweet potato product, was to pre-treat strips of sweet potatoes by blanching followed by freezing. The period of blanching in boiling water depended on the size of sweet potato strips. Adequate period of blanching strip whose size was 3×3mm, 5×5mm, 7×7mm and 10×10mm thick (length, about 5cm) each was in the range of 25-30, 30-40, 40-60 and 60-90sec, respectively. The hardness and oil content of Imo-karinto were not affected by the temperature and the period of freezing. The deep-fat fried products with a certain pre-treatment had a good texture, and their hardness decreased to approximately one-half of those without the pre-treatment, and their oil content increased by about 15-20%. Adequate deep-fat frying temperature for blanched and frozen strips was about 140°C. "Clean-up-to" (commercial food additive) effectively prevented discoloration caused by oxidation of polyphenols when sweet potatoes were cut into strips. Moreover, the appearance of Imo-karinto was improved by blanching in a boiling solution of disodium dihydrogen pyrophosphate.
