Phytosterols Content in Vegetable Oils of Brazil: Coconut, Safflower, Linseed and Evening Primrose

Abstract In the last years phytosterols, natural components of plants, have received more attention due to association of their consumption with reducing risk of cardiovascular diseases and cancer. There are several scientific studies about phytosterols in vegetable oils, but they are scarce in unconventional oils. The objective of this research was evaluating the content of phytosterols (β-sitosterol, stigmasterol and campesterol) in vegetable oils sold in São Paulo city, in Brazil. The analysis included cold alkaline saponification, derivatization with hexamethyldisilazane and trimethylchlorosilane reagents, and quantification by gas chromatography using flame ionization detection and internal standardization. The quality control parameters indicated that the method was suitable for analysis. Total sterols were between 272.3 mg kg-1 (coconut oil) to 6169.7 mg kg-1 (evening primrose oil). β-sitosterol was the component found in higher concentrations and evening primrose oil was the most representative in quantity of phytosterols.

Production and characterization of alginate-starch-chitosan microparticles containing stigmasterol through the external ionic gelation technique

Stigmasterol - a plant sterol with several pharmacological activities - is susceptible to oxidation when exposed to air, a process enhanced by heat and humidity. In this context, microencapsulation is a way of preventing oxidation, allowing stigmasterol to be incorporated into various pharmaceutical forms while increasing its absorption. Microparticles were obtained using a blend of polymers of sodium alginate, starch and chitosan as the coating material through a one-stage process using the external gelation technique. Resultant microparticles were spherical, averaging 1.4 mm in size. Encapsulation efficiency was 90.42% and method yield 94.87%. The amount of stigmasterol in the oil recovered from microparticles was 9.97 mg/g. This technique proved feasible for the microencapsulation of stigmasterol.

O estigmasterol, um fitoesterol com diversas atividades farmacológicas, é suscetível à oxidação quando exposto ao ar, calor e umidade. Neste contexto, a microencapsulação é uma forma de proteção contra oxidação, permitindo a incorporação do estigmasterol em diversas formas farmacêuticas e aumentar sua absorção. As micropartículas foram obtidas por gelificação iônica externa, em uma etapa, utilizando como revestimento polímeros naturais de alginato de sódio, amido de milho e quitosana. As micropartículas apresentaram formato esférico com tamanho aproximado de 1,4 mm. O rendimento foi de 94,87% e a eficiência média de encapsulação de 90,42%. A quantidade de estigmasterol no óleo recuperado das micropartículas foi de 9,97 mg/g. O método mostrou-se viável para a microencapsulação do estigmasterol.