Evaluation of oxidative stability of emulsifiers of acylglicerol origin

Most food emulsifiers E471 do not contain polyunsaturated fatty acids and are mono-, diacylglycerols of saturated fatty acids, which in industry are produced by glycerolysis of palm oil. Obtaining new harmless to human health and the environment emulsifiers of acylglycerol origin based on sunflower oil with essential unsaturated fatty acids is relevant. The authors of this study obtained such emulsifiers under mild conditions (35–40°C) by the transesterification reaction of triacylglycerols of sunflower oil. The process was carried out in a binary system of solvents with an alkaline catalyst by activating the reacting components by mechanical stirring. This ensured the preservation of the essential nutrients (59.7% w-6 polyunsaturated linoleic acid) in resulting emulsifiers. To assess the oxidative stability of new emulsifiers we studied the kinetics of accumulating oxidation products in them and in the sunflower oil from which they were obtained. Changes in the UV spectra of 0.02% solutions in isooctane were studied in the range from 200 to 285 nm, as well as at 232 nm, 268 nm depending on the storage duration (up to 100 days) and storage temperature (20°C, 50°C, 100°C) of emulsifiers and oils. The results showed that in the process of starage emulsifiers of acylglycerol origin showed higher resistance to oxidation compared to oil. The maximum content of peroxides in them after 100 days at (20±1)°C was 5.01 mmol 1/2O/kg, in oil – 6.56 mmol 1/2O/kg, at (50±1)°C – 5.12 mmol1/2O/kg and 6.98 mmol 1/2O/kg, respectively. The results of spectroscopic studies have shown the ability of acylglycerol emulsifiers obtained under mild conditions from sunflower oil to stabilize the oxidative degradation of lipids. They also confirmed the feasibility and prospects of their use as a perfectly compatible with lipids and a completely safe ingredient for stabilizing the quality of fats and products with them.