Improved Food-Processing Techniques to Reduce Isoflavones in Soy-Based Foodstuffs

Area of Science:

• Food Science and Technology
• Nutritional Biochemistry
• Chemical Engineering

Background:

• Soy is a significant protein source, but its isoflavone content raises health concerns due to estrogenic activity.
• Exceeding toxicological limits of isoflavones in soy products necessitates methods for concentration reduction.
• Maintaining nutritional quality during isoflavone reduction is crucial for public health.

Purpose of the Study:

• To develop and demonstrate a feasible and efficient pilot-scale process for isoflavone extraction from soybeans.
• To optimize laboratory-proven extraction factors for pilot-scale application.
• To address technical challenges encountered at pilot scale, including drenching and granulometry.

Main Methods:

• Optimization of laboratory treatment factors and their transposition to pilot scale.
• Adjustment of the process to pilot-scale constraints, incorporating drenching and granulometry analysis.
• Validation using ELISA and Folin-Ciocalteu assays to monitor genistein and daidzein levels.
• Isoflavone recovery from process water via filtration, centrifugation, and resin adsorption.

Main Results:

• The most effective pilot treatment involved soybean dehulling, drenching, washing, and drying.
• This process nearly halved isoflavone concentrations while preserving key nutritional characteristics.
• A multi-technique approach achieved near-complete recovery of isoflavones from treatment water.

Conclusions:

• A pilot-scale process effectively reduces isoflavones in soybeans, addressing public health concerns.
• The developed method balances isoflavone reduction with the preservation of soy's nutritional value.
• Isoflavone recovery from wastewater offers potential for valorization and environmental benefits.