Heating and megasonic interventions for improvement of aqueous-based oil extraction from fresh and cold stored coconut meat

Abstract

The efficiency of oil recovery is essential for the economics of the coconut oil extraction process. This study evaluated the application of increased heat and/or megasonic steps for enhancing aqueous-based oil separation from coconut meat. Combinations of heating temperature (60 or 70 °C) and time (30 or 50 min) were studied in freshly prepared, or in 20 and 44 h cold stored (5 °C) coconut-water mixtures (1 L). The megasonic effect after heating (60 °C, 30 min) was evaluated at 2 MHz frequency and energy densities of 44–349 kJ/kg. Oil extraction from fresh coconut meat was higher when increasing heating temperature (10–13%). Net ultrasound yield in cold stored coconut meat was improved from 1.1 to 3.2% with increased sonication time from 2.5 to 20 min. Megasonic effects on mixtures heated (60 °C, 30 min) were corroborated in fresh coconut meat at a larger scale, which demonstrates the potential for megasonic to enhance aqueous-based coconut oil extraction processes.