Vitamin C Quantification of Korean Sweet Potatoes by Cultivar and Cooking Method
2014
Hwnag, I.G., National Academy of Agricultural Science, Rural Development Administration, Jeonju, Republic of Korea | Byun, J.Y., National Academy of Agricultural Science, Rural Development Administration, Jeonju, Republic of Korea | Kim, K.M., National Academy of Agricultural Science, Rural Development Administration, Jeonju, Republic of Korea | Chung, M.N., National Insitute of Crop Science, Rural Development Administration, Jeonju, Republic of Korea | Yoo, S.M., National Insitute of Crop Science, Rural Development Administration, Jeonju, Republic of Korea
This study was carried out to investigate the amounts of vitamin C in 22 sweet potato cultivars cultivated in Korea as well as evaluate the effects of cooking methods on vitamin C contents. Methods for determining vitamin C was validated by determining linearity, specificity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy using HPLC. Results showed high linearity in the calibration curve with a coefficient of correlation (R2) of 0.9999. The LOD and LOQ values for ascorbic acid (AA) were 0.03 and 0.10 ¥�g/mL, respectively. The relative standard deviations (RSDs) for intra- and inter-day precision of AA were less than 5%. The recovery rates of AA and dehydroascorbic acid (DHA) were in the range from 98.21¢¦98.64 and 98.28¢¦100.68%, respectively. Depending on cultivar, contents of AA, DHA, and total ascorbic acid (TA) in sweet potatoes varied in the range from 37.76 (Sinyulmi)¢¦89.25 (Juhwangmin), 23.37 (Sinjami)¢¦63.94 (Sinyulmi), and 68.52 (Sinjami)¢¦115.95 (Juhwangmin) mg/100 g, respectively, and their average levels were 56.98¡¾12.53, 36.46¡¾9.03, and 93.44¡¾12.00 mg/100 g, respectively. The average TA levels were also dependent on flesh color, whish was significantly higher in general sweet potato and orange sweet potato than in purple sweet potato. Steaming, baking, and frying processes significantly reduced AA (10.61¢¦58.41%), DHA (2.57¢¦52.81%), and TA (14.54¢¦49.92%) contents in sweet potatoes. The highest reduction of AA, DHA, and TA contents was observed after baking, followed by steaming and frying. We expect that the basic information provided by this study will be useful to plant breeders and food scientists.
显示更多 [+] 显示较少 [-]