Green Ultrasound-Assisted Extraction of Carotenoids from Peach Wastes Using Vegetable Oils

Abstract The aim of this work was to study a novel method for utilizing peach peels in the food industry through ultrasound-assisted extraction of carotenoids, after phenolics extraction, employing various vegetable oils as solvents. This approach results in the production of an oil enriched with antioxidants. Soybean oil and rice bran oil were selected as alternative solvents. The factors analyzed included extraction temperature, solid-to-oil ratio, and amplitude level. Comparative analyses between ultrasound-assisted extraction and traditional solvent extraction were conducted. The optimum conditions were: extraction temperature of 55 °C; peels-to-solvent ratio of 0.30; amplitude level of 80%; and use of soy bean oil. The optimum extraction yield was 0.672 mg/100 g of dry peels, whereas the obtained value for conventional extraction with n-hexane was 0.677 mg per 100 g of dry peels. To assess the quality of the enriched oils, acidity, peroxide levels, and the presence of conjugated dienes were evaluated, whereas the identification of carotenoids was conducted to evaluate their stability during ultrasound extraction. The quality of the enriched oils was preserved, showing no signs of oxidation. These oils exhibited a high level of unsaturated fatty acids, in contrast to a markedly reduced total content of saturated fatty acids.