Chemical Engineering Department, Federal University of Rio Grande do Sul (UFRGS), Rua Engenheiro Luiz Englert s/n, Porto Alegre/RS 90040-040, Brazil.
Food Chem. 2013 Jan 15;136(2):853-7. doi: 10.1016/j.foodchem.2012.08.024. Epub 2012 Aug 30.
Degradation kinetics of monomeric anthocyanins in acerola pulp during thermal treatment by ohmic and conventional heating was evaluated at different temperatures (75-90°C). Anthocyanin degradation fitted a first-order reaction model and the rate constants ranged from 5.9 to 19.7 × 10(-3)min(-1). There were no significant differences between the rate constants of the ohmic and the conventional heating processes at all evaluated temperatures. D-Values ranged from 116.7 to 374.5 for ohmic heating and from 134.9 to 390.4 for conventional heating. Values of the free energy of inactivation were within the range of 100.19 and 101.35 kJ mol(-1). The enthalpy of activation presented values between 71.79 and 71.94 kJ mol(-1) and the entropy of activation ranged from -80.15 to -82.63 J mol(-1)K(-1). Both heating technologies showed activation energy of 74.8 kJ mol(-1) and close values for all thermodynamic parameters, indicating similar mechanisms of degradation.
在不同温度（75-90°C）下，通过欧姆加热和常规加热评估了单体花色苷在酸樱桃浆热处理过程中的降解动力学。花色苷降解符合一级反应模型，速率常数范围为 5.9 至 19.7×10(-3)min(-1)。在所有评估的温度下，欧姆加热和常规加热过程的速率常数之间没有显着差异。对于欧姆加热，D 值范围为 116.7 至 374.5，对于常规加热，D 值范围为 134.9 至 390.4。失活自由能的值在 100.19 和 101.35 kJ mol(-1)之间。活化焓值在 71.79 和 71.94 kJ mol(-1)之间，活化熵值范围为-80.15 至-82.63 J mol(-1)K(-1)。这两种加热技术的活化能均为 74.8 kJ mol(-1)，所有热力学参数值相近，表明降解机制相似。
