Volatile profile of industrially pre-treated soybeans defatted with ethanol

• Grant number: 22/05124-9
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: August 01, 2022
• End date: October 31, 2022
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Engineering
• Principal Investigator: Christianne Elisabete da Costa Rodrigues
• Grantee: Maria Carolina Capellini
• Supervisor: Alírio Egidio Rodrigues
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Institution abroad: Universidade do Porto (UP), Portugal
• Associated to the scholarship: 18/12713-5 - Effects of soybean pre-treatment on the performance of the alcoholic extraction process: yield, functionalities of the protein fraction and volatile fraction characterization, BP.PD

Abstract

The importance of soybean in the oilseed market is mainly due to the high nutritional and commercial value of its protein fraction, but also to its high content of polyunsaturated fatty acids and beneficial bioactive components. In this context, the extraction of soybean oil is one of the main steps involved in the process of valorization of this raw material. The solvent industrially used for the extraction of vegetable oils is a mixture of hexane isomers, derived from petroleum. Due to the potential health and environmental risks associated with the use of hexane, several alternative solvents have been studied. Among them, short-chain alcohols stand out, especially ethanol, due to their lower toxicity and superior operational safety. Regardless of the solvent used for extraction, this operation will occur more efficiently if the soybean is previously treated by lamination or expansion processes, for example, which lead to changes in the structural and surface properties of the material. In addition to the oil, large amounts of defatted solid material from the extraction process are generated, most of which consist of proteins. However, the flavor of soybean protein products has long limited the use of these materials in human food and diminished their value in the food industry, since this is often described as a characteristic beany odor and bitter taste. Studies report that "washes" of soybean protein ingredients using ethanol have been shown to be effective in removing compounds responsible for undesirable flavors in these products, which are prepared from solids defatted with hexane. Therefore, this research project intends to evaluate the impacts of industrial pre-treatments of the raw material and of the different operational conditions of the process of alcoholic extraction of soybean oil on the profile of volatiles contained in the defatted solids and in protein concentrates obtained from these solids. Also, the volatile profile will be compared to that determined for the materials obtained from the extraction of soybean oil with hexane, in order to evaluate whether, in fact, the extraction with ethanol will favor the removal of off-flavors, improving the characteristic and undesirable odor of soybean-based products. (AU)