Kinetics of thermal degradation of vitamin C in marula fruit (Sclerocarya birrea subsp. caffra) as compared to other selected tropical fruits

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• 作者：Penny Hiwilepo-van Hal ; Charlotte Bosschaart ; Charlotte van Twisk ; Ruud Verkerk ; Matthijs Dekker
• 关键词：Marula ; Vitamin C ; Degradation ; Thermal treatment ; Guava and mango
• 刊名：Lebensmittel-Wissenschaft und -Technologie
• 出版年：2012
• 出版时间：December, 2012
• 年：2012
• 卷：49
• 期：2
• 页码：188-191
• 全文大小：233 K

文摘

The kinetics of the thermal degradation of vitamin C of marula, mango and guava pulp at different heat treatments at temperature ranging from 80 to 150?¡ãC were investigated. For temperatures lower than 125?¡ãC, the ascorbic acid in marula pulp was about 15 fold more stable to heat than the ascorbic acid in mango and guava pulp. The results showed that a simple first order degradation model could not describe the vitamin C degradation as biphasic behaviour was observed. Therefore the model was transformed in a two-fraction model in which the vitamin C content is divided in relatively stable and instable fractions. Marula had a low k_d1,100¡ãC of 7.2?¡Á?10^?3?min^?1 compared to k_d1,100¡ãC of 1.2?¡Á?10^?1?min^?1 for guava and 1.3?¡Á?10^?1?min^?1 for mango. Guava had the highest activation energy, E_a of 58?kJ/mol, followed by mango with 39?kJ/mol and then marula with 29?kJ/mol.