Preparation Of Monoacylglycerols Catalyzed By Solid Base

Monoacylglycerols (MAGs) are an important type of nonionic amphiphilicemulsifiers, which are widely used in hydrophobic food systems as well as inchemical industries. The optimal conditions for preparation of MAGswereinvestigated.(1) MAGs were produced by glycerolysis of soybean oil with catalyzed by sodiumglycerinate. Reaction temperature, reaction time, catalyst loading and mole ratio ofsubstrates have been studied. The selected conditions were listed as follows: reactiontemperature175℃, catalyst loading2.4wt%(oil mass), mole ratio of soybean oil toglycerol1:4, and reaction time2.0h. Under these conditions, the content of MAGs inthe glycerides phase after reaction reached53.1%.(2) MAGswere produced by glycerolysis of soybean oil with glycerol catalyzed byK2CO3/Al2O3.A series of single factor tests were performed to study the effect onglycerolysis efficiency.The reaction conditions were optimized by orthogonalexperiment. The optimal conditions were listed as follows: reaction temperature210℃, solid base catalyst loading0.8wt%(oil mass), mass ratio of soybean oil toglycerol1:3, and reaction time1.5h.Under the optimization condition, a content of58.3%MAGs in the acylglycerols mixture were obtained.(3) A new method to produce MAGs with high purity by glycerolysis of fullyhydrogenated palm oil (FHPO) catalyzed by hydrotalciteloaded with K2CO3(K2CO3/HT). The effects of reaction temperature, reaction time, catalysts (K2CO3/HT)loading, and mass ratio of FHPO to glycerol on glycerolysis were investigated. Theselected conditionsincluded a reaction temperature of200℃, K2CO3/HT loading at0.8wt%(FHPO mass), a5:2mass ratio ofFHPO to glycerol, and a reaction time of2.0h. Under theselected conditions, the yield of MAGs in the acylglycerol phase couldreach46.8%.(4)Some types of MAGs obtained by the glycerolysis of different partiallyhydrogenated corn oils. The melting regions of all hydrogenated samples and their MAGs shifted to higher temperatures. These data indicated that using hydrogenationto change the fatty acid composition could effectively increase the oxidation stabilityof MAGs.(5) Two-stage molecular distillation was introduced to purify the produced MAGs.The unreactedglycerol and free fatty acid in the glycerides were removed at anevaporator temperature of140℃at the first stage. MAGs with a purity of above90.0%were obtained at an evaporator temperature of190℃at the second stage.