Development of dispersive solvent extraction method to determine the chemical composition of apple peel wax. (February 2019) - Klein, Bruna
Abstract: A method to extract apple peel wax was developed using the dispersive solvent extraction technique and applied to four apple cultivars (Royal Gala, Pink Lady®, Red Delicious, and Granny Smith). Different variables of the method were optimized, namely type and volume of extraction and dispersive solvents, ionic strength, and use of ultrasound. Extracts were evaluated as gravimetric yield of wax and composition as determined by gas chromatography. Optimized conditions provided yields higher than 95%. In a repeatability assay, the relative standard deviation for the extracted wax content was <3%. Thirty-one wax compounds were identified, among them fatty acids, hydrocarbons, sterols, and terpenes. Fatty acids were the major constituents in the analyzed extracts. N-alkane, nonacosane, and triterpene ursolic acid were also significant constituents. The method allows the determination of the total peel wax content and the different constituents of this fraction from distinct apple cultivars. Graphical abstract: Unlabelled Image Highlights: A novel extraction method was developed for apple peel wax characterization. High efficiency and reduced solvent volume were found in proposed method. The method provided a detailed cuticle profile for Malus domestica Borkh. Peel wax composition of four different apple cultivars were characterized.