An improved sample preparation method for quantification of ascorbic acid and dehydroascorbic acid by HPLC

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• 作者：Kranthi K. Chebrolu<sup>asup> ; G.K. Jayaprakasha<sup>asup> ; Kil Sun Yoo<sup>asup> ; John L. Jifon<sup>asup><sup> ; sup><sup>bsup><sup> ; sup><sup>jljifon@ag.tamu.edusup> ; Bhimanagouda S. Patil<sup>asup><sup> ; sup><sup>b-patil@tamu.edusup>
• 关键词：Vitamin C ; Total ascorbic acid ; Grapefruit ; Optimization
• 刊名：Lebensmittel-Wissenschaft und -Technologie
• 出版年：2012
• 期刊代码：121_00236438
• 类别：abs
• 出版时间：July, 2012
• 卷：47
• 期：2
• 页码：443-449
• 文件大小：853 K

摘要

Ascorbic acid (AA) and dehydroascorbic acid (DHA) are reduced and oxidized forms of vitamin C, which are ubiquitously found in various fruits and vegetables. The present study has evaluated and optimized various factors responsible for AA and DHA stability in grapefruit samples. Furthermore, the optimized method was used to quantify these compounds in different fruits and vegetables. The AA stability in the samples was evaluated by extracting grapefruit juice using 1, 3 and 5聽g/100聽mL metaphosphoric acid (MPA) and trichloro聽acetic acid (TCA). The AA levels were stable in grapefruit samples extracted with 1, 3 and 5聽g/100聽mL MPA, whereas TCA extracts showed degradation in 48聽h. Among the three reducing agents studied, tris(2-carboxy ethyl) phosphine hydrochloride (TCEP) has efficiently converted DHA at all concentrations and the samples were stable for 48聽h at 2.5聽mmol/L TCEP. Lower pH favored complete conversion of DHA by TCEP than dithiothreitol. Among various fruits and vegetables analyzed, the highest levels of AA (260.1聽mg/100聽g) were observed in guava and DHA (58.6聽mg/100聽g) in parsley samples. The current optimized method prevents the degradation of AA and DHA from fruit and vegetable samples stored at room temperature for two days.