Allergenicity reduction and structural modifications in soybean protein isolate through microfluidization, enzymatic treatments and their combination

Abstract

Food allergies are a growing global health problem, with soy proteins being a major allergen due to its widespread use in a variety of food products. The present work aimed at reducing the allergenicity of soy protein isolates by a physical method, microfluidization, an enzymatic treatment using papain or Flavourzyme, and by the combination of these two methods. The allergenicity of soybean protein isolates was evaluated by indirect ELISA and western blotting using two soybean-allergic patient sera. The results of enzymatic hydrolysis with papain and Flavourzyme demonstrated almost complete hydrolysis of all the major soybean allergens, leading to residual immunoreactivities ranging between 27.2 % and 41.9 % of the initial value. On the other hand, microfluidization alone has proved ineffective in reducing the allergenicity of SPI, even increasing it under specific treatment conditions. Combined with enzymatic treatments, it did not significantly enhance the obtained allergenicity reduction and degree of hydrolysis. Additionally, Fourier Transform Infrared Spectroscopy (FTIR) analysis provided insights into the secondary structure changes induced by microfluidization, contributing to a better understanding of the mechanisms by which allergenicity is altered and also of the impact of the temperature elevation during the microfluidization process.