Utilization of Sunflower Oil Winterization Waxes as Functional Ingredients in Cosmetic Cream Formulations

Abstract

The present study focuses on the separation, purification, and application of waxy substances obtained as waste from the winterization of sunflower oil, with the aim of partially or completely replacing stearic acid in cosmetic cream formulations. A key challenge addressed in this research is the removal of perlite particles and the isolation of high-purity wax fractions suitable for cosmetic use. In the experimental work, a mixture of waxy substances and perlite obtained after filtration during winterization was subjected to different separation techniques. Conventional extraction with hexane was used as a control method, while aqueous solutions of sodium chloride (1–10%) were investigated as an alternative, environmentally friendly approach. The efficiency of separation was evaluated by varying solution concentration, temperature, and settling time. The isolated waxy substances were further characterized using chromatographic analysis, infrared (IR) spectroscopy, refractometry, and differential scanning calorimetry (DSC) to determine their composition and physicochemical properties. The results demonstrated that an 8% sodium chloride solution at a temperature of 20 °C and a settling duration of 10 hours provided optimal conditions for perlite removal. Under these conditions, the yield of purified waxy substances reached 98.5% relative to the conventional hexane extraction method. Importantly, the use of aqueous salt solutions significantly reduces the emission of toxic organic solvents, thereby improving environmental safety and process sustainability. The purified waxy substances were subsequently incorporated into cosmetic cream formulations as a partial or full substitute for stearic acid. It was found that replacing up to 50% of stearic acid with the recovered waxy material did not adversely affect the rheological or sensory properties of the creams. However, complete substitution led to a noticeable decline in product performance, particularly in terms of spreadability and skin absorption characteristics.