Environmentally friendly process for phytosterols recovery from residues of biodiesel production

Abstract

Phytosterols are naturally occurring plant sterols found in various foods of plant origin, such as fruits, vegetables, nuts, and whole grains. Phytosterols have been shown to have potential beneficial effects on human health, particularly in reducing the risk of cardiovascular disease. Insoluble tank precipitates, predominantly composed of sterylglucosides (SG), are recognized as a by-product of biodiesel production. These SG glucosides can be hydrolyzed using mineral acids to yield valuable phytosterols. In this study, we developed an efficient method for preparing phytosterols from SG recovered from soybean biodiesel insoluble precipitates. Instead of traditional mineral acids, we employed aqueous solutions of Methanesulphonic acid (MSA), which is an environmentally friendly alternative. By optimizing temperature, reaction time, and MSA concentration using a Central Composite design, we accurately predicted the phytosterol yield with a resulting model. Validation experiments confirmed the model´s accuracy, demonstrating the effectiveness of the optimized method in preparing phytosterols. Notably, this developed and optimized method offers a greener approach in terms of E factor and energy consumption, as well as improved safety. The development of a simple and efficient method for producing phytosterols from a biodiesel by-product has important implications for the food and nutraceutical industries, which are increasingly focused on using renewable and eco-friendly sources.