Ultrasound‐assisted extraction of oil from macauba pulp using alcoholic solvents

Abstract

Ultrasound‐assisted extraction (UAE) of macauba pulp oil was investigated using ethanol and isopropanol as solvents and compared with the conventional extraction technique. An experimental design was applied to evaluate the influence of the experimental variables (temperature, solvent to pulp ratio, and time) on the oil extraction and to optimize them. The optimum conditions were then evaluated in relation to the extraction kinetics and the effect of the application of ultrasound in the process was determined. For both techniques, higher yields were obtained with the use of ethanol as the solvent. The results showed that increasing the temperature, the amount of solvent used and the extraction time leads to greater oil removal from macauba pulp (p < .05), and the amount of solvent used in the process had the greatest influence. The maximum oil yields obtained by UAE were 49.2 and 38% with ethanol and isopropanol, respectively, obtained at 60 °C, with a 90‐min extraction time and solvent to pulp ratio of 10, which represent ∼86 and ∼77% of the yield obtained by conventional extraction. The UAE provided better yields when compared to the process without ultrasound. The fatty acids composition was not influenced by the extraction method and solvent used; however, UAE provides oils with higher levels of β‐carotene and flavonoids using ethanol and isopropanol, respectively. Practical applications The optimization of UAE for macauba pulp oil extraction is presented in the present study and the results demonstrate the efficiency of the method for obtaining this oil in low extraction time and solvent consumption. The oil obtained by this technique has higher levels of β‐carotene and flavonoids. Additionally, macauba pulp oil obtained using ethanol and isopropanol with solvent may be used as a food, because these solvents are considered of food grade.

Macadamia Oil Extraction With Alcoholic Solvents: Yield and Composition of Macadamia Oil and Production of Protein Concentrates From Defatted Meal

“…Oils extracted with alcoholic solvents presented typical composition of macadamia oil, predominantly of monounsaturated fatty acids (approximately 80% of palmitoleic and oleic acids), which is in agreement with results of Aquino‐Bolaños et al In fact, the fatty acid profile of oils is not influenced by the type of solvent or the extraction method …”

“…Nevertheless, hexane presents in its composition n‐hexane (approximately 52%) which is considered neurotoxic, in addition commercial hexane contributes to environmental pollution and is flammable which carries the risk of explosions in the industry. Therefore, alternative solvents have been proposed, aimed to replace it, as example ethanol and isopropanol …”

Optimized ultrasonic‐assisted extraction of papaya seed oil from Hainan/Eksotika variety

“…A literature reported by Stevanato and da Silva () evaluated the extraction of radish seed oil at 45°C and 60 min and observed that increasing the solvent‐to‐seed ratio from 4:1 to 12:1 increased the oil yield from 17.10% to 23.22%, respectively. Another study reported an increase in the yield of macauba pulp oil (28.15%–30.70%) when increasing the relative amount of solvent from 6:1 to 10:1 (Rodrigues, Mello, dos Santos Garcia, & Silva, ). Extraction time is also an important variable which has been found to have the greatest influence on the radish seed oil ( Raphubus sativus L.) yield (da Silva, dos Santos Garcia, Arroyo, & da Silva, ).…”

A Box-Behnken design for optimization of ultrasound-assisted solvent extraction of hazelnut oil

“…Besides, as the temperature increased, the density and viscosity of solvent would decrease thus resulting in the increase of mass transfer which enhanced the oil recovery (Tian et al, ). Rodrigues et al () reported that higher temperature in the range of 40–60°C could promote the solubility of oil in alcoholic solvent. Other studies by de Mello et al () and Tavares, Massa, Gonçalves, da Silva, and dos Santos () observed that increasing the temperature from 40 to 60°C increased the yield of chia seeds oil and crambe seed oil respectively.…”