Sonication as a Promising Technology for the Extraction of Triacylglycerols from Fruit Seeds—A Review

Fruit seeds that are by-products of the fruit processing industry are a potential, economical but neglected source of oil. The extraction of oil from waste fruit seeds is not common, and ultrasound offers an effective, green, and environment friendly alternative extraction technology that can give a higher yield (%) in less time at mild operating conditions. Although ultrasound offers significant intensification benefits, its effect on the quality of oil extracted from fruit seeds needs to be evaluated and also compared with the traditional extraction process without ultrasound. The review provides the readers with in-depth knowledge about the use of ultrasound in the extraction of fruit seed oil including the mechanism involved, the lipid profile of various fruit seed oils, interactions of ultrasound and solvent, equipment for the application of ultrasound, the effect of operating conditions, and recommendations to minimize the negative effects of ultrasound on the quality of extracted oil followed by the path ahead for this technology development. It has been elucidated that the seeds of fruits contain oil rich in polyunsaturated and essential fatty acids, thus forming an important source. Ultrasound can be effectively applied for intensified extraction of oil based on the mechanism of rupturing of the cell wall and increased rate of mass transfer. Importantly, the composition and content of fatty acids along with the antifungal/antimicrobial and antioxidant characteristics are maintained based on optimum selection of operating conditions.