South Dakota State University, Dairy and Food Science Department, Brookings, SD, 57006, USA.
Sci Rep. 2020 Feb 17;10(1):2730. doi: 10.1038/s41598-020-59704-x.
Lactose has become the main byproduct of many dairy products and ingredients. Current applications of lactose are insufficient to use the recovered lactose from manufacturing operations. Here we exemplified a new process for converting aqueous lactose into a sweeting syrup via one-pot synthesis. The synthesis consisted of two-steps: (1) enzymatic hydrolysis of lactose and (2) catalytic isomerization over MgO/SiO. The hydrolysis of lactose over β-galactosidase converted 95.77 ± 0.67% of lactose into glucose and galactose. The catalytic isomerization was performed over MgO/SiO with different MgO loadings (10-40 wt.%). A battery of tests was conducted to characterize the different catalysts, including surface properties, basicity, and microstructure. The one-pot synthesis, enzymatic hydrolysis and catalytic isomerization over 20%-MgO/SiO, converted 99.3% of lactose into a sweetening syrup made of glucose (30.48%), galactose (33.51%), fructose (16.92%), D-tagatose (10.54%), and lactulose (3.62%). The outcomes of this research present an opportunity for expanding the utilization of lactose.
乳糖已成为许多乳制品和成分的主要副产品。目前，乳糖的应用还不足以利用从生产操作中回收的乳糖。在这里，我们举例说明了一种将水溶液中的乳糖通过一锅合成转化为甜味糖浆的新工艺。该合成由两步组成：（1）乳糖的酶水解，（2）MgO/SiO 上的催化异构化。β-半乳糖苷酶对乳糖的水解将 95.77±0.67%的乳糖转化为葡萄糖和半乳糖。催化异构化在不同 MgO 负载量（10-40wt.%）的 MgO/SiO 上进行。进行了一系列测试来表征不同的催化剂，包括表面性质、碱性和微观结构。一锅合成、过 20%-MgO/SiO 的酶水解和催化异构化，将 99.3%的乳糖转化为由葡萄糖（30.48%）、半乳糖（33.51%）、果糖（16.92%）、D-塔格糖（10.54%）和乳果糖（3.62%）组成的甜味糖浆。这项研究的结果为扩大乳糖的利用提供了机会。
