Extraction of soybean oil using mixtures of alcohols and triacetin

• Grant number: 19/14778-0
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): September 01, 2019
• Effective date (End): November 30, 2021
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Engineering
• Principal researcher: Christianne Elisabete da Costa Rodrigues
• Grantee: Leticia Ayres de Oliveira
• Home Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated research grant: 14/21252-0 - Equilibrium and production processes of biofuels and bioproducts, AP.TEM

Abstract

The solvent industrially employed for extraction of vegetable oils, a mixture of isomers of the hexane, presents high stability and capacity of extraction, however this solvent presents as main disadvantages the high toxicity, flammability and great polluting capacity when not recovered in the proper way . Due to the potential health and environmental hazards associated with the use of hexane, several alternative solvents have been studied, especially ethanol, because of its lower toxicity, since it has the GRAS (Generally Recognized As Safe) label, superior operational safety and high productivity at low cost in Brazil. Because of their higher polarity, alcoholic solvents are capable of extracting more unsaponifiable matter from the solid matrix, thus increasing the nutritional value of the oils. However, ethanol is partially miscible with vegetable oils at room temperature, which implies using more ethanol when compared to hexane to extract the same amount of vegetable oil from a solid matrix. The use of ethanol flow around 280% higher than the hexane flow rate can compromise the viability of the oil extraction process with the alternative renewable solvent, in this way, several authors have proposed intensification of the process, such as the addition of co-solvents to ethanol. This scientific initiation project aims to evaluate the use of short chain triacylglycerols, such as triacetin, as co-solvent of ethanol in the soybean oil extraction process. The impact of the addition of triacetin to ethanol on the extraction yield, oil partition coefficient and on the defatted protein fraction functionalities will be evaluated from the determination of the nitrogen solubility index.