Monoacylglycerols(MAGs) and diacylglycerols(DAGs) are partial glycerides widely used in food industry. They are safe and non-toxic food emulsifiers, especially for MAGs. MAGs account for approximately 75% of the total...Monoacylglycerols(MAGs) and diacylglycerols(DAGs) are partial glycerides widely used in food industry. They are safe and non-toxic food emulsifiers, especially for MAGs. MAGs account for approximately 75% of the total emulsifiers in food industry worldwide. DAGs are recognized as functional cooking oils, they can suppress body fat accumulation and postprandial serum triacylglycerols(TAGs) level. The traditional production of MAGs and DAGs is based on the chemical method, which requires high reaction temperature usually up to 200–260 ℃. Such high temperature is not suitable for oil containing heat sensitive polyunsaturated fatty acids. Enzymatic approach has been received increasing attentions. Enzymatic production of partial glycerides to replace chemical processes has been in industry, particularly for DAGs production as the products have been claimed as a functional and nutritional oil. Enzyme technology for the processing of oils and fats has been moved to industry step by step and case by case during the last 20 years. More and more applications are particularly moving into bulky oils and fats processing. At the same time, the cost of enzymes as a commercial product is reducing steadily. This review summarized the recent 15 years advances on the the enzymatic preparation of MAGs and DAGs. The critical process parameters under different reaction routes were presented and emphasized. The reaction media not only increased the homogeneity of the reaction system, but also shifted the reaction equilibrium towards the target product generation, and this part was stated in detail. In addition, the patent evaluation was included, and the application of MAGs and DAGs was covered.展开更多
采用NaOH和NaAlO2溶液相结合的处理方法对Hβ沸石进行脱硅补铝处理,制备了一系列不同硅/铝比的Hβ沸石催化剂。采用ICP、XRD、NH3-TPD、FT-IR和27Al MAS NMR等手段,对几种补铝Hβ沸石催化剂的物化性质进行了表征,并在100 ml间歇式不锈...采用NaOH和NaAlO2溶液相结合的处理方法对Hβ沸石进行脱硅补铝处理,制备了一系列不同硅/铝比的Hβ沸石催化剂。采用ICP、XRD、NH3-TPD、FT-IR和27Al MAS NMR等手段,对几种补铝Hβ沸石催化剂的物化性质进行了表征,并在100 ml间歇式不锈钢高压反应釜中考察了其在甲苯与叔丁醇烷基化反应中的催化性能。结果表明,铝原子可以有效地进入Hβ沸石骨架;随着NaAlO2浓度的增加,Hβ沸石的硅/铝比下降,相对结晶度下降,催化剂酸强度呈下降趋势;当NaAlO2浓度为0.15 mol/l时,制备的Hβ3沸石的酸量最大,其对应的催化活性最好。采用Hβ3作为催化剂,研究了各种反应条件对催化剂性能的影响。实验结果发现,在适宜的反应条件下,即反应温度180℃、反应时间4 h、叔丁醇/甲苯摩尔比为4、甲苯/催化剂质量比为5,甲苯的转化率49.6%,对叔丁基甲苯的选择性72.9%。催化剂的再生能力良好,重复使用4次后,甲苯转化率仍达到41.0%。展开更多
基金supported by the National Natural Science Foundation of China(31772000).
文摘Monoacylglycerols(MAGs) and diacylglycerols(DAGs) are partial glycerides widely used in food industry. They are safe and non-toxic food emulsifiers, especially for MAGs. MAGs account for approximately 75% of the total emulsifiers in food industry worldwide. DAGs are recognized as functional cooking oils, they can suppress body fat accumulation and postprandial serum triacylglycerols(TAGs) level. The traditional production of MAGs and DAGs is based on the chemical method, which requires high reaction temperature usually up to 200–260 ℃. Such high temperature is not suitable for oil containing heat sensitive polyunsaturated fatty acids. Enzymatic approach has been received increasing attentions. Enzymatic production of partial glycerides to replace chemical processes has been in industry, particularly for DAGs production as the products have been claimed as a functional and nutritional oil. Enzyme technology for the processing of oils and fats has been moved to industry step by step and case by case during the last 20 years. More and more applications are particularly moving into bulky oils and fats processing. At the same time, the cost of enzymes as a commercial product is reducing steadily. This review summarized the recent 15 years advances on the the enzymatic preparation of MAGs and DAGs. The critical process parameters under different reaction routes were presented and emphasized. The reaction media not only increased the homogeneity of the reaction system, but also shifted the reaction equilibrium towards the target product generation, and this part was stated in detail. In addition, the patent evaluation was included, and the application of MAGs and DAGs was covered.
