352: Screening Soybean Cultivars to Identify Novel Peptides for Lipid Oxidation Inhibition

Introduction

The growing demand for natural and sustainable food preservatives has increased interest in antioxidant peptides as safer alternatives to synthetic additives like EDTA. While synthetic antioxidants effectively prevent lipid oxidation, their potential toxic effects at high concentrations raise health concerns. Soy protein, a rich source of bioactive peptides, offers a promising solution. Through enzymatic hydrolysis, antioxidant peptides can be released from soy protein, demonstrating potent lipid oxidation inhibition and shelf-life enhancement. Using soy protein cultivars to generate bioactive peptides supports the food industry's move toward clean-label additives and consumer demand for safer, eco-friendly preservatives. This study sought to create functional peptides from soy protein cultivars via enzymatic hydrolysis, aiming to prevent lipid oxidation to get natural preservative properties.

Methods

Soy flour from eight cultivars (R05-1772, R09-3789 (UA5814HP), R11-7999, R18-10491, R18-14147, R21C-02235, R21C-02304, R98-1821 (Osage)) was defatted, and proteins were isolated using isoelectric precipitation. Hydrolysis was conducted with various endo- and exo-proteases, including Alcalase from Bacillus licheniformis and protease from Aspergillus oryzae, to obtain peptide hydrolysates. Each treatment used a 5% (w/v) protein solution, a 2% enzyme/substrate ratio, and a 2-hour hydrolysis time. Functional properties, metal chelation ability, and lipid oxidation inhibition were evaluated to identify cultivars with novel preservative peptides among cultivars.

Results

The highest ferrous ion chelation activity was 84.78% for the soy cultivar R18-1049 at only 0.2 mg/ml protein concentration, achieved with 2% Alcalase treatment. The R11-7999 cultivar also showed higher metal chelation (80.1%) after two-stage hydrolysis when treated with 1-hour Alcalase and 1-hour protease treatments. The highest lipid peroxidation inhibition was 92.31% for the R98-1821 cultivar, achieved with 2% protease from A. oryzae treatment. The R98-1821 cultivar exhibited the highest lipid peroxidation inhibition across all treatments compared to other samples, indicating it will provide good storage stability for lipid-rich products over extended periods. The R98-1821 variety demonstrated improved emulsion stability, foaming capacity, and gelation properties compared to all other varieties after hydrolysis treatment.

Significance

This study confirmed that peptide cultivar differences play a key role in peptide quality. Selecting the right soybean cultivar enhances lipid oxidation prevention, supporting safer, eco-friendly food preservation and clean-label ingredient demands.

Authors: Sukanya Poddar, Nikitha Modupalli, Mahfuzur Rahman