Babassu kernel oil: Enhanced extraction and chemical characterization

Abstract

The ultrasound-assisted extraction (UAE) was applied to enhance the extraction efficiency of oil from babassu kernel (BKO) using n-hexane as solvent. For this purpose, the effects of temperature (30 to 60°C), solvent to kernel ratio (6 to 10 ml g−1), and time (10 to 30 min) on oil yield (Yo) were determined, in addition to assessing the effect of these variables in the characteristics of the obtained oil. In the condition of maximum extraction, the chemical composition of the oil was determined and the results were compared with the Soxhlet extraction. In the evaluated experimental range, the amount of solvent used in the process influenced the Yo, while time and temperature had no effect on the response variable. With this, a high oil removal of kernels (89.5% obtained by Soxhlet) was obtained in low conditions of time (10 min) and temperature (30°C), in addition to using a smaller amount of solvent (10 ml g−1) in relation to conventional technique (30 ml g−1). The lowest evaluated temperature (30°C) was also indicated to obtain an oil with higher content of phenolic compounds and antioxidant activity. BKO showed a predominance of lauric (~49.9%) and myristic acids (~15.6%), and high oxidative stability. The quality of the oil extracted by the UAE was superior in terms of phytosterols, phenolic compounds, antioxidant activity, and color parameters. Practical applications Considered an emerging technique, ultrasound-assisted extraction presents simplicity and the possibility of operational automation, lower energy and solvent consumption, in addition to the reduced complexity of the steps subsequent to extraction, composing a viable and suitable alternative for a possible industrial application. The oil obtained by the aforementioned technique resulted from mild operating conditions, presenting quality parameters that stand out and contemplate promising technological criteria in the global market demand for compounds from natural sources.