Miguel A. Bootello

Evaluation of high oleic-high stearic sunflower hard stearins for cocoa butter equivalent formulation

Cocoa butter equivalents (CBEs) are produced from vegetable fats by blending palm mid fraction (PMF) and tropical butters coming from shea, mango kernel or kokum fat. In this regard, high oleic-high stearic (HOHS) sunflower hard stearins from solvent fractionation can be used in CBE production since their compositions and physical properties are similar to those found in the above-mentioned tropical butters. In this work, three sunflower hard stearins (SHS) ranging from 65% to 95% of disaturated triacylglycerols and a shea stearin (used as reference) were blended with PMF to evaluate their potential use in CBEs formulation. Isosolid phase diagrams of mixtures of PMF/SHS showed eutectic formation for SHS 65 and SHS 80, but monotectic behaviour with softening effect for SHS 95. Three CBEs from SHS and shea stearin were formulated according to phase behaviour diagrams and solid fat content data at 25 °C. Isosolid phase diagrams of mixtures of these CBEs with cocoa butter showed no eutectic behaviour. Therefore, CBEs elaborated from SHS exhibited full compatibility with cocoa butter.

Food Uses of Sunflower Oils

Publisher Summary The seeds of sunflower are produced within an achene and consist of a shell, composed mainly of lignin and cellulose material, and the kernel, which accounts for 80% of the total weight of the seeds and is rich in oil. Sunflower oil is one of the most desirable oils in the world, and in some countries, it is preferred over other vegetable oils such as soybean, cottonseed, and rapeseed oils. Sunflower produces oil rich in linoleic acid and vitamin E that is very appreciated by consumers all over the world. Thus, it has typically been one of the oils most used for retailing and for domestic consumption. In industry, regular sunflower has been used for frying, showing similar performance to other oilseeds such as soybean and canola; for the production of emulsions and sauces; and in margarine formulations. The high stearic–high oleic sunflower oils can be fractionated to produce fractions with high levels of solids and different melting profiles that can be used in broad variety of food formulations, including fillings, spreads, coatings, and confectionary products.

Effect of solvents on the fractionation of high oleic–high stearic sunflower oil

Solvent fractionation of high oleic-high stearic (HOHS) sunflower oil was studied to determine the best solvent to use (hexane or acetone) in terms of the operational parameters and properties of the final stearins. Acetone fractionation on two types of HOHS sunflower oils (N17 and N20) was carried out at temperatures from 5 to 10 °C using micelles with different oil/solvent ratios. Acetone was more suitable than hexane as a solvent for HSHO sunflower oil fractionation because it allowed the oil to be fractionated at higher temperatures and at lower supercooling degrees. Likewise, a sunflower soft stearin obtained by dry fractionation of HOHS sunflower oil was also used to produce high-melting point stearins by acetone or hexane fractionation. The fractionation of these stearins could be performed at higher temperatures and gave higher yields. The combination of dry and solvent fractionation to obtain tailor-made stearins is discussed.

Comparing Sunflower Stearins with Cocoa Butter

High-oleic high-stearic sunflower mutant is one of the new commercial varieties of this oil crop that have been developed by breeding and mutagenesis from common sunflower lines. The oil extracted from this line contains high levels of stearic acid in a high-oleic background and could be a source of stearate-rich fats in the future. Dry fractionation is a process by which the triacylglycerols with a high degree of saturation of an oil or fat are selectively crystallized and separated from the liquid matrix without the addition of any solvent to yield a solid fraction enriched in saturated fatty acids and a liquid fraction richer in unsaturated fatty acids. This method is used for palm oil fractionation. Solvent fractionation involves the addition of solvent to oil as a step previous to its fractionation. The resulting micelle is fractionated by crystallization of the species of triacylglycerols with higher levels of saturated fatty acids. The resulting solid phase is separated from the liquid one and washed with fresh solvent. This method is more efficient than dry fractionation, although it requires higher operation costs. It is often used to obtain highly valuable stearate-rich butters from tropical fats. Stearin is the name given to the solid fraction obtained in the fractionation of an oil or fat. It contains higher levels of saturated fatty acids than the initial oil. Its characteristics and composition will depend on the composition of the initial oil and the method and conditions of fractionation. A cocoa butter equivalent is a vegetable fat or a mixture of vegetable fats with similar physical and chemical properties to those of cocoa butter. It has to be compatible in mixtures with cocoa butter and display similar polymorphism. Cocoa butter equivalents are produced by mixing stearate-rich tropical butters and fractions resulting from palm oil fractionation.