RESUMO
Three sweet potato cultivars (TNG57, TNG66, and TNG73), provided by the Taiwanese Agricultural Research Institute (TARI), were stored at either 15 °C or under ambient conditions (23.8 ~ 28.4 °C and 77.1 ~ 81.0 % of relative humidity). Sweet potato roots were randomly chosen from each replicate and evaluated for measurement of weight loss, sugar content analysis, and sprouting after 0, 14, 24, 48, 56, 70, 84, and 98 days of storage. Fresh sweet potato roots were baked at 200 °C for 60 min then samples were taken for sugar analysis. After 14 days of ambient condition storage, the sprouting percentages for TNG57, TNG66, and TNG73 were 100, 85, and 95 % respectively. When sweet potatoes were stored at 15 °C, the weight loss became less and no sweet potato root sprouted after 14 days of storage. Because manufacturers can store sweet potatoes at 15 °C for almost 2 month without other treatments, the supply capacity shortage in July and September can be reduced. The total sugar content slowly increased along with increasing the storage time. After baking, the total sugar content of sweet potatoes significantly increased due to the formation of maltose. Maltose became the major sugar of baked sweet potatoes. Raw sweet potatoes stored at 15 °C had higher total sugar contents after baking than those stored under ambient conditions. Raw sweet potatoes were recommended to be stored at 15 °C before baking.
RESUMO
The objective of this study was to evaluate the influence of sugar composition on the sensory attributes of seven baked sweet potatoes. The sugar composition was analyzed using high performance liquid chromatography. Results showed that the total sugar content of baked sweet potatoes increased significantly because of the formation of maltose. The maltose content dramatically increased after baking, and became the major sugar component of baked sweet potatoes. On the other hand, baked sweet potatoes were evaluated on a 7-point hedonic scale for sensory analysis. Overall acceptability results showed that the panelists preferred baked CYY95-26 and TNG66 over the other baked varieties. Because the correlation between overall acceptability and sweetness was the highest (r = 0.69, p < 0.01), sweetness was determined as the most important factor determining the overall acceptability of baked sweet potatoes. Although sugar composition changed on baking, the overall acceptability of baked sweet potatoes was highly associated with the sucrose content.
RESUMO
Sugar composition of seven sweet potato cultivars was successfully analyzed. Fresh CYY95-26 sweet potatoes had the highest (8.41%) total sugar content while TNG73 had the lowest (4.5%). For these fresh sweet potatoes, maltose content was very low (0 ~ 0.39%). Because 49.92 ~ 92.43% of total sugars were sucrose, sucrose was the major sugar composition of fresh sweet potatoes. After the baking treatment, the total sugar content of baked sweet potatoes was dramatically increased due to the formation of maltose. The maltose content significantly increased from 0 ~ 0.39% to 8.81 ~ 13.97% on dry weight basis. Therefore, maltose should be included in calculating the total sugar content. Electronic micrographs of fresh sweet potato samples showed that the size of starch granules was generally less than 20 µm. After the baking treatment, starch granules completely gelatinized.
RESUMO
Anthocyanins were added to a cosmetic cream to provide additional protection against UV radiation. The influence of anthocyanins on UV absorption ability was carefully evaluated. Anthocyanins were successfully extracted from TNG73 purple sweet potato using acidic ethanol and acidic water. Acidic ethanol-extracted anthocyanins had better radical scavenging ability, higher total phenolic content, and stronger reducing ability than acidic water-extracted anthocyanins. The cosmetic cream with 0.61 mg of total anthocyanins (per 100 g cream) absorbed approximately 46% of the incident UV radiation. Although the anthocyanins absorbed both UV-A and UV-B radiation, they were particularly effective against UV-B rays. This study demonstrates that the addition of anthocyanin extracts of purple sweet potato to a cosmetic cream improves the cream's UV absorption ability.
