胡萝卜中类胡萝卜素的提取动力学

Kinetic Studies on Extraction of Carotenoids from Carrot Powder

使用抗坏血酸和2,6-二叔丁基-4-甲基苯酚保护剂,以石油醚-丙酮（体积比4∶1）混合液为提取剂,分别用水浴直接提取法、超声辅助提取法和微波辅助提取法从胡萝卜粉中提取类胡萝卜素。采用不同温度和原料粒度进行从胡萝卜粉中提取类胡萝卜素的提取动力学实验。结果表明,水浴法和超声辅助法是符合反应-内扩散控制的动力学模型,所得提取动力学方程分别为：1）水浴法：y=0.009 9t＋0.110 7（R2=0.920 9,30℃）、y=0.018 6t＋0.096 1（R2=0.893 7,40℃）、y=0.018 2t＋0.088 6（R2=0.965 7,45℃）;2）超声辅助法：y=0.001 1t＋0.080 9（R2=0.917 9,30℃）、y=0.001 6t＋0.043 9（R2=0.978 8,40℃）、y=0.001 8t＋0.039（R2=0.964 2,45℃）。表观活化能分别为Ea（水浴）=-26.825 1 k J/mol和Ea（超声）=-35.196 5 k J/mol。而微波辅助法则是符合混合控制的动力学模型,其方程为y=0.027 5t＋0.344 6（R2=0.972 3,30℃）、y=0.031 9t＋0.426 5（R2=0.868 9,40℃）、y=0.058 7t＋0.275 1（R2=0.973 4,45℃）,表观活化能为E a（微波）=-36.105 2 k J/mol。通过水浴法考察原料粒度对提取动力学的影响,结果表明原料粒度对提取速率和提取率的影响程度是60~80目〉40~60目〉20~40目,即粒度越细越有利于类胡萝卜素的提取。

In this paper, kinetic studies were carried out to investigate the extraction of carotenoids from carrot powders of different particle sizes by three different methods, namely water bath, ultrasonic-assisted and microwave-assisted extraction, at different temperatures respectively, using vitamin C and BHT as antioxidants and petroleum：acetone（4：1, V/V） as extractant. The results showed that the kinetic models for water bath and ultrasonic-assisted extraction conformed to the internal diffusion-controlled chemical kinetic models, which were as follows： y = 0.009 9t ＋ 0.110 7（R2 = 0.920 9, 30 ℃）, y = 0.018 6t ＋ 0.096 1（R2 = 0.893 7, 40 ℃）, y = 0.018 2t ＋ 0.088 6（R2 = 0.965 7, 45 ℃） for water bath extraction; y = 0.001 1t ＋ 0.080 9（R2 = 0.917 9, 30 ℃）, y = 0.001 6t ＋ 0.043 9（R2 = 0.978 8, 40 ℃）, y = 0.001 8t ＋ 0.039（R2 = 0.964 2, 45 ℃） for ultrasonic-assisted extraction. In addition, the values of activation energy were Ea（water bath extraction） =-26.825 1 k J/mol and Ea（ultrasonic-assisted extraction） =-35.196 5 k J/mol. However, the kinetic model for microwave-assisted extraction conformed to the hybrid-controlled kinetic model and the fitted equations were as follows： y = 0.027 5t ＋ 0.344 6（R2 = 0.972 3, 30 ℃）, y = 0.031 9t ＋ 0.426 5（R2 = 0.868 9, 40 ℃）, y = 0.058 7t ＋ 0.275 1（R2 = 0.973 4, 45 ℃）; the value of activation energy, Ea（microwave-assisted extraction）, was-36.105 2 k J/mol. The extraction efficiency and rate with water bath was affected by raw material particle size in the decreasing order of 60–80 mesh 〉40–60 mesh 〉20–40 mesh. Therefore, small particle size is beneficial for the extraction of caroteinoids.