Interesterification of mafura butter and camellia oil for cosmeceutical formulations: Chemical composition and physicochemical properties of products

Abstract

Mafura butter (MB) obtained from seeds of Trichilia emetica Vahl is widely used in traditional cosmetic formulations throughout Southern Africa. It is gaining increasing popularity in the modern cosmetic industry due to growing consumer demand for natural cosmetics. However, the butter has a high melting point and low spreadability, which limits its emollient properties. In the present study, MB was chemically and enzymatically interesterified with camellia oil (CO, Camellia oleifera C.Abel) at different ratios (90:10, 80:20, 70:30, 60:40 and 50:50 w/w) to produce formulations with improved physicochemical and cosmeceutical properties. Chemical interesterification (CI) was performed using sodium methoxide catalyst, while enzymatic interesterification (EI) was carried out with three different immobilized enzymes, including Lipozyme® TL IM, Lipozyme® RM IM and Lipozyme® 435. The original and interesterified blends were examined for fatty acid (FA) and triglycerides compositions, slip melting point (SMP), solid fat content (SFC), tocopherol and sterol contents, toxic heavy metal contents, radical scavenging activity (RSA) and in vitro ultraviolet radiation protection ability. Both CI and EI reduced SMP and SFC of interesterified products, resulting in products with improved consistency. Interesterification distributed cosmeceutically relevant unsaturated FA such as oleic acid, linoleic acid and linolenic acid in the products, depending on the ratios of MB and CO. The tocopherol and phytosterol contents in MB was 495.08 ± 19.02 and 842.61 ± 35.77 μg/g, respectively, while it was 438.6 ± 20.89 and 163.57 ± 20.47 μg/g, respectively in CO. The CI dramatically reduced the tocopherol contents up to 50 % in the products, while EI did not affect its content significantly. The ICP-MS analysis revealed that MB, CO and interesterified products does not contain toxic metals such as Sn and Hg, while Cr (< 0.18 ppm) and Pb (< 0.14 ppm) were present within the acceptable limits. Interesterified products showed promising RSA (with IC50 values in the range of 10.15 ± 0.79–12.30 ± 1.15 mg/mL), however, had a low in vitro sun protection factor (SPF < 0.2).