Simultaneous extraction of the oil from the kernel and pulp of macauba fruit using a green solvent

Abstract

The objective of this study was to evaluate the effect of temperature, solvent (ethanol):sample ratio, and time on the extraction of oil, carotenoids, and phytosterols from a mixture of different macauba fruit parts (kernel and pulp). To achieve this aim, a Box–Behnken experimental design and ultrasound-assisted extraction (UAE) were used. The quality and yield of the oil obtained were compared to the data for by Soxhlet extraction of the mixture and the individual parts. Principal component analysis (PCA) was performed on the results. Based on the observed effects of the variables (linear, quadratic, and interaction), the maximum values for the evaluated response variables were obtained at 70ºC. Oil and carotenoids are rapidly extracted (15 min), while phytosterols require a longer extraction time (45 min). A low amount of ethanol was sufficient for β-carotene extraction, but for the extraction of the oil and phytosterols the volume required increased by a factor of 3. The oils obtained with the two techniques presented predominance of lauric and oleic acids. The extraction of oil from the mixture of macauba parts yielded an oil that aggregated carotenoids and oleic acid from the pulp and phytosterols and lauric acid from kernel. In addition, the use of UAE provides the highest concentration of active compounds in the oil. PCA confirmed the differences between the performance of the methods in relation to the variables evaluated. It also allowed a better discrimination and interpretation of the data obtained under the experimental conditions investigated in the UAE. Practical applications The use of UAE to obtain oils from the mixture of different macauba fruit parts (kernel and pulp) presented higher values of carotenoids and phytosterols than the oils obtained individually, aggregating the high concentrations of each part of the fruit. In addition, oils rich in active compounds may be used in the food industry due to the solvent employed in the extraction.