Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai 400 019, India.
Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai 400 019, India.
Ultrason Sonochem. 2017 Jul;37:9-15. doi: 10.1016/j.ultsonch.2016.12.029. Epub 2016 Dec 23.
The current work deals with the value addition of lactose by transforming into hydrolyzed lactose syrup containing glucose and galactose in major proportion using the novel approach of ultrasound assisted acid catalyzed lactose hydrolysis. The hydrolysis of lactose was performed in ultrasonic bath (33kHz) at 50% duty cycle at different temperatures as 65°C and 70°C and two different hydrochloric acid (HCl) concentrations as 2.5N and 3N. It was observed that acid concentration, temperature and ultrasonic treatment were the major factors in deciding the time required to achieve ∼90% hydrolysis. The ultrasonic assisted approach resulted in reduction in the reaction time and the extent of intensification was established to be dependent on the temperature, acid concentration and time of ultrasonic exposure. It was observed that the maximum process intensification obtained by introduction of ultrasound in the lactose hydrolysis process performed at 70°C and 3N HCl was reduction in the required time for ∼90% hydrolysis from 4h (without the presence of ultrasound) to 3h. The scale-up study was also performed using an ultrasonic bath with longitudinal horn (36kHz as operating frequency) at 50% duty cycle, optimized temperature of 70°C and acid concentration of 3N. It was observed that the reaction was faster in the presence of ultrasound and stirring by axial impeller at rpm of 225±25. The time required to complete ∼90% of hydrolysis remained almost the same as observed for small scale study on ultrasonic bath (33kHz) at 50% duty cycle. The use of recovered lactose from whey samples instead of pure lactose did not result in any significant changes in the progress of hydrolysis, confirming the efficacy of the selected approach. Overall, the work has presented a novel ultrasound assisted approach for intensified lactose hydrolysis.
目前的工作涉及通过使用超声辅助酸催化乳糖水解的新方法将乳糖转化为主要含有葡萄糖和半乳糖的水解乳糖糖浆来实现乳糖的增值。在不同温度下（65°C 和 70°C）和两种不同盐酸（HCl）浓度下（2.5N 和 3N），在超声浴（33kHz）中以 50%占空比进行乳糖水解。结果表明，酸浓度、温度和超声处理是决定达到约 90%水解所需时间的主要因素。超声辅助方法缩短了反应时间，并且强化程度被确定取决于温度、酸浓度和超声暴露时间。结果表明，在 70°C 和 3N HCl 下进行的乳糖水解过程中引入超声时，最大的过程强化是将约 90%水解所需的时间从 4 小时（无超声存在）缩短至 3 小时。还使用具有纵向号角（36kHz 作为工作频率）的超声浴在 50%占空比、优化温度为 70°C 和酸浓度为 3N 的条件下进行了放大研究。结果表明，在超声和轴向叶轮以 225±25rpm 搅拌存在下，反应更快。完成约 90%水解所需的时间与在 50%占空比的超声浴（33kHz）上进行小规模研究观察到的时间几乎相同。使用乳清样品回收的乳糖而不是纯乳糖不会导致水解进展发生任何显著变化，这证实了所选方法的有效性。总的来说，这项工作提出了一种新的超声辅助强化乳糖水解方法。
