Vegetable fixed oils obtained from soursop agro-industrial waste: Extraction, characterization and preliminary evaluation of the functionality as pharmaceutical ingredients

Abstract

This study was designed to evaluate the feasibility of using oils extracted from seeds of soursop industrial waste for use as pharmaceutical ingredients. For that, soursop seeds were subjected to different processes of extraction of fixed oil, by chemical and mechanical routes. After characterization of fixed oils, the feasibility of using them as pharmaceutical excipients was explored by preparing creams in which the oils were used as emollient and/or antioxidant excipient. The oil extracted from soursop seeds in a Soxhlet device and ethyl ether solvent (SFO) showed a yield of 30.72 ± 0.09 % (w w−1) and, in a domestic extruder (MFO), 23.86 ± 0.78 % (w w−1). These oils showed physicochemical attributes that indicative of good preservation. The major fatty acid was the oleic acid, with 42.94–43.73 % in relative area, followed by linoleic with 29.5%–30% in relative area. In the non-grease fraction, the SFO showed considerable levels of phenolics (194.5 ± 31.1 mg kg−1) and tocopherols (608.2 ± 36.7 mg kg−1), which gave it an antioxidant potential, confirmed by the 2,2-diphenyl-1-picrylhydrazyl test, with a concentration effective for 50% inhibition (IC50) of 2.8 mg mL−1. Finally, the evaluation of the quality parameters of the creams, suggests that the use of fixed soursop oils to replace the synthetic ingredients usually incorporated (decyl oleate, liquid petrolatum and butylhydroxytoluene), originated formulations with adequate physical and chemical stability. These findings suggest that both oils obtained are possible candidates for use as emollients and antioxidant in pharmaceutical formulas. In addition, contributing to minimize the generation of waste from the fruit agribusiness and add economic value to a by-product generated in the production of fruit pulp.