Desenvolvimento de uma CBI de altos teores de StOSt / StStO/ OStSt produzida por interesterificação química seguida de fracionamentos com solvente

Abstract

Ingredients like vegetable oils and fats are constituents of several foodstuffs and add structural, sensorial and nutritional values to them. Chocolate is the classic example of food in which the characteristics of the fat used in its formulation impact directly on the quality of the final product. The effects of seasonal disturbances in the quality of cocoa butter compromise the production of chocolates. The addition of alternative fats, obtained by industrial processes able to modify, normalize or customize the chemical and physical properties of natural lipid systems enhances the standardization and commercialization of products. The chemical interesterification of fats rich in stearic acid generates high melting point lipid bases, an alternative to partial hydrogenated fats to be used in formulation of "zero-trans" products. This research considered the development of health-friendly lipid bases rich on triacylglycerols (TAGs) formed by stearic/oleic/stearic acids (StOSt/StStO/OStSt) and able to act as CBI in chocolates. These bases were obtained by chemical interesterification of a mixture of FHCO (fully hydrogenated canola oil) and HOSO (high oleic sunflower oil) at a 55:45 mass proportion, followed by a two-stages fractionation with acetone. The first fractionation stage was conducted at crystallization temperatures, Tc, of 12, 14, 26, 18, 20, 22, 25, 28 and 36ºC and the olein/stearin fractions were quantified in terms of TAG's composition (gas chromatography), solid fat profile (NMR), thermal behavior (DSC) and consistency (penetrometer). The olein fraction obtained at 25ºC showed the highest concentration in disaturated TAGs (approximately 48%) and lesser in trisaturated (less than 2%) and was selected for the second fractionation. The temperatures Tc of the second fractionation were 8, 10 and 12ºC and the olein/stearin fraction were submitted to the same types of analyses as in the first fractionation, as well as the determination of the melting profile (via DSC), the composition in fatty acids and calculations of the Iodine and the Saponification Indexes. All three stearin fractions obtained by the second fractionation were suitable to function as CBE (cocoa butter equivalent) and the stearin formed at Tc of 12ºC showed characteristics of a CBI (cocoa butter equivalent), containing approximately 74% of disaturated.