Obtention and characterization of a byproduct from ethanolic extraction of soybean oil

OTERO NOELY; BAÜMLER, ERICA; CARELLI, AMALIA; CARRIN, M.E.

Córdoba

Congreso; VI Congreso Internacional de Ciencia y Tecnología de los Alimentos; 2016

Ministerio de Ciencia y Tecnología de la provincia de Córdoba

After the conventional soybean oil extraction with hexane, the obtained meal, commonly used asanimal feed, is considered an important product due to its high protein content. However, its use asa protein replacement in the food industry is limited because of the residual amounts of neutral andpolar lipids. The carbohydrates, which have previously been considered to be undesirablecomponents causing flatulence, are the other major constituents of defatted flour. Nevertheless,nowadays they have been found to be probiotic materials, therefore, it would be of great interest torecover them. On the other hand, ethanolic extraction is interesting not only due to its effectivenessin the oil extraction but also its capability to remove other compounds. So, the resulting meal ismore concentrated in proteins that the one obtained using hexane and at the same time could beobtained a byproduct with a possible added value. The aim of this work was to obtain experimentaldata of the extraction kinetics of the extracted material, different to the oil, during ethanolicextraction process and evaluate its added value. The extraction assays were carried out in a batchsystem at 60ºC using a solid (soybean collets):solvent ratio of 1:10 (w/v). The miscella obtainedafter each extraction, containing the total extracted material, was fractionated in oil (hexane-solublefraction) and other compounds (hexane-insoluble fraction). The hexane-insoluble fraction was called?defatted extract?. Phospholipids, sugars, protein and fiber were analyzed to evaluate its composition.The results obtained indicate that the defatted extract is composed by sugars and phospholipids, beingsugars the major component, representing 92.37 ±1.79% d.b. at 960 min. Sucrose and stachyosewere the predominant sugars, 86.22 ±1.06% at 960 min. Their profiles did not show significantdifferences over time (p>0.1). The amount of sugars extracted at 960 min signified a 23% of totalsugars presents in soybean collets. In the case of phospholipids, phosphatidylinositol,phosphatidylethanolamine, phosphatidylcholine and phosphatidic acid were detected. Although themajor phospholipid in soybean oil was phosphatidylcholine, the highest percentage in the case ofdefatted extract corresponded to phosphatidylinositol, 66.67 ± 8.51%. In order to evaluate thephospholipid distribution between the two phases obtained after phase separation of miscella with nhexane,the amounts recovered in each fraction were compared. As result, a tendency of phospholipidsto go to the oily phase was observed. Protein and fiber contents of soybean collets were not affectedby ethanolic extraction. Results obtained demonstrated the ability of ethanol to remove sugars andphospholipids, allowing obtaining both a soybean meal more concentrated in proteins and a byproductconcentrated in sugars.Keywords: ethanol, hexane, solvent extraction, sugars, phospholipids