Sunday, April 29, 2007

Monoglycerides and diglycerides synthesis in a solvent-free system by lipase-catalyzed glycerolysis

Patricia B. L. Fregolente, Leonardo V. Fregolente, Gláucia M. F. Pinto, César B. Batistella, Maria R. Wolf-Maciel, and Rubens Maciel. Department of Chemical Process, State University of Campinas (UNICAMP) - School of Chemical Engineering, CP 6066, ZIP CODE 13081-970, Campinas-SP, Brazil

Monoglycerides (MG) and diglycerides (DG) are widely used as emulsifiers in foods, cosmetics and pharmaceuticals products. Often mixtures of MG and DG are used in these applications since they are cheap and give proper performance. Industrially, the production of monoglycerides (MG) consists on the interesterification of triglycerides (TG) with glycerol (GL), in the presence of inorganic catalysts at high temperatures (above 200°C).  This reaction is known as glycerolysis and produces an approximately 50 % MG content mixture. Due to the high temperatures used, sub-products undesirable are formed. Currently, food industries present interest in production of more healthful products due to the market requirements, like products free of sub-products of the reactions of polymerization and fats in the trans configuration. The product produced by this strategy has several drawbacks, e.g., low yield, dark color and burnt taste. Thus, the substitution of the chemical synthesis of MG for the enzymatic route is presented as an attractive alternative, since in this process are used low temperatures and near neutral pH not resulting in formation of undesirable products.
Lipase-catalyzed glycerolysis of oils and fats at atmospheric pressure and lower temperature have attracted interest in both academic and industrial fields, which is believed to be a practical alternative method for the chemical methods in the production of commercial MG.
In this work, MG and DG are producing through lipase-catalyzed glycerolysis of soybean oil in a bath reactor using Thermomices lanuginose, Rhizomucor miehei and Aspergillus niger lipases, in a solvent-free system.