Changes in Sugar Content of Sweet Potatoes with Changes in Curing and Storage Conditions

Abstract

This study examined the effect of storage conditions on the improvement in the sugar content of processed sweet potatoes (Jeungmi variety and overseas collected species (OCS)). Total sugar, reducing sugar, and free sugar contents were high when the sweet potatoes were stored at 9°C in all the treatment methodologies used. The total sugar content of the Jeungmi variety stored at 9°C increased from 13.75∼138.42 mg/g sample on day zero to 42.30∼ 376.57 mg/g after 10 days of storage and then decreased thereafter. The reducing sugar and free sugar content also showed the same tendencies as total sugar. The sugar content in sweet potatoes after the curing and steaming treatment was higher than that of untreated sweet potatoes. Specifically, maltose was not detected before the steaming treatment, but steaming increased levels to 108.76 mg/g sample in the Jeungmi variety and 79.36 mg/g sample in the OCS. From the above results, to increase the sugar content of stored sweet potatoes, a storage temperature of 9°C and a storage period of 10 days are most appropriate, and the quality of sweet potatoes can be improved through curing after harvest.

Fermentation and Quality Characteristics of Yogurt Treated with Bifidobacterium longum

“…The total sugar content of the yogurt was measured using the phenol-sulfuric acid method [11]. The sample was diluted to an appropriate ratio, 0.5 mL of a 5% phenol (Shinyo Pure Chemicals Co., Ltd., Osaka, Japan) solution was added to 1 mL of the diluent, 2.5 mL of 95% sulfuric acid (Daejung Chemicals and Metals Co., Ltd., Siheung, Republic of Korea) was added, and the mixture was left at room temperature for 30 min.…”