Optimization of isoflavones extraction from soybeans using full factorial design

Abstract

This study focuses on the optimization of isoflavones extraction from soybeans cultivated in Quangnam province, Vietnam, using aqueous ethanol solvent extraction. The total isoflavone concentration was determined with six isoflavone standards including daidzin, glycitin, genistin, daidzein, glycitein, and genistein by Reversed Phase HPLC method. The effects of temperature, extraction time, and ratio of solvent to material on the extracted isoflavone content were investigated for use in the experimental planning method with full element 23 and optimization using the Box‐Wilson model. The results of the optimization showed that the optimal conditions of isoflavones extraction from soybeans using ethanol 80% was in temperature of 72.5°C, extraction time of 67.5 min, and solvent to dry soybean ratio of 26.5/1 (ml/g). The maximum amount of isoflavone content obtained from this extraction condition was 1,932.44 µg/g dry matter. Practical applications The extraction of isoflavones from soybeans involves the interaction between various factors including solvent concentration, temperature, extraction time, and ratio of solvent to material. There is a need to study the combined effect of these factors to optimize the extraction conditions within a minimum number of experiments. Hence, this work applies the full factorial design to study the effects of several factors on one or more responses to achieve the optimum extraction condition. This research work is important to obtain the most efficient extraction conditions for isoflavones production without consuming too much efforts on the experimentation. The results attain from this work can contribute to the extension of efficient isoflavones extraction in industrial scale.

Early Optimization Stages of Agave lechuguilla Bagasse Processing toward Biorefinement: Drying Procedure and Enzymatic Hydrolysis for Flavonoid Extraction

“…In the present study, the pH tested from 4 to 6 did not impact the TPC and TFC in the extracts, whereas reducing the temperature from 50 to 30 °C, and increasing the incubation time from 0.5 to 2.5 h showed a positive effect on the TPC and TFC ( Figure A4 and Figure 5 and Figure 6 ). Similarly, Viscozyme© used at 0.2% was previously found to allow higher phenolic recovery from Brassica oleracea leaves in comparison with control, and the authors reported no effect of pH (3–6) and temperature range (30–50 °C) [ 58 ]. Likewise, increasing the time enhanced the phenolic recovery from Rosmarinus officinalis leaves hydrolyzed with Viscozyme©, although longer than a 3 h incubation time was found to have a negative effect [ 76 ].…”

“…These modifications on the flavonoid profile are relevant due to the well-studied structure–activity relationship. The release of aglycone flavonols is particularly interesting for pharmaceutical applications [ 58 , 67 , 69 , 79 ]. At the same time, enhanced glycosyl flavonoids, particularly the anthocyanidin content, suggest applications in cosmetics and nutraceuticals [ 80 ].…”

“…For instance, Carmona et al [ 30 ] reported that alkaline pretreatment decreased the antioxidant capacity of the A. lechuguilla extracts. In contrast, enzymatic hydrolysis effectively degrades and disrupts the lignocellulosic matrix to release bioactive flavonoids without affecting their biological properties [ 57 , 58 ]. Thus, the integration of a hydrolysis step prior to extraction could enhance flavonoid recovery.…”

Evaluation of isoflavone extraction options at commercial scale

“…In addition, specific stages may be skipped through a bypass if the requirement has been met owing to the inherent nature of the product or process. Figure 3 illustrates our proposed stages of typical isoflavone extraction and purification based on past lab‐scale extraction studies 31,32,36,38,39 …”

“…depicts the chemical structures of the major isoflavones found in soybeans. The extraction of soy isoflavones from soybean meal is a process that has been optimized at the lab scale with little consideration for costs or the environment, as it generally involves the use of large quantities of organic solvents 30–32 . Alternative isoflavone extraction processes have been proposed, such as supercritical fluid extraction and ultrasonic‐assisted methods 33–36 .…”