A new approach for the purification of soybean acid extract: Simultaneous production of an isoflavone aglycone-rich fraction and a furfural derivative-rich by-product

作者：Nemitz Marina Cardoso; Teixeira Helder Ferreira; von Poser Gilsane Lino^*

来源：Industrial Crops and Products, 2015, 67: 414-421.

DOI：10.1016/j.indcrop.2015.01.074

• Defatted soybean
• Acid hydrolysis
• Isoflavone aglycones
• 5-Hydroxymethylfurfural
• 5-Ethoxymethyl-2-furfural

Isoflavones are found mostly in legumes, such as soybeans. These compounds have several therapeutic potentials, largely attributed to their aglycone forms. The soybean extraction followed by acid hydrolysis is the usual process for coverting isoflavone glucosides into their bioactive compounds. However, under extreme pH, different compounds, characterized as contaminants or even having important properties, can be obtained. In this context, this paper aimed to produce an isoflavone aglycone-rich fraction (IAF) from a soybean rich cultivar, as well as isolate and identify other compounds formed during the IAF production. The extraction of defatted soybean seeds was performed with ethanol-water (80:20, v/v) in a Soxhlet apparatus, followed by acid hydrolysis with 1.3 M HCl, under reflux at 80 degrees C at different times (0-360 min). During the hydrolysis procedure, besides the isoflavones, two unknown compounds were produced in high amounts. These compounds were isolated by column chromatography and identified as 5-hydroxymethylfurfural (HMF) and 5-ethoxymethyl-2-furfural (EMF), both isolated for the first time from soybeans. These substances are derived from sugars, classified as furanic derivatives, possibly toxic for medicinal uses, but with significant importance in the biofuel field. In order to produce an IAF intended for a future food or pharmaceuticals use, the soybean acid extract was submitted to liquid-liquid partition, solid phase extraction, and antisolvent precipitation processes, resulting in a fraction with high isoflavone aglycones purity (92%). From this process, the removed impurities originated a furfural derivative- rich solution, which can be an attractive by-product for the biofuel field.

• 出版日期2015-5