Non-Thermal Food Processing for Plant Protein Allergenicity Reduction: A Systematic Review

The global incidence of food allergies has increased in the last decade. Compared with thermal processing techniques, non-thermal food processing poses an effective solution for reducing allergenicity while preserving the nutrient content of the food. This study aims to compile the latest advances in modifying plant allergens through non-thermal technologies. The information presented provides useful references for the potential production of hypoallergenic foods. We searched for original articles and reviews in databases published in English from January 2019 to August 2024. The databases used were ProQuest Central, ASC Journals, SAGE Journals, EBSCO Academic Search Ultimate, ScienceDirect, Web of Science, Springer Link, LILACS, Scopus, Cambridge University Press, and WIPO. Targeted allergen reduction and general protein structural modification were considered eligible for inclusion. Articles that did not determine structural or allergenicity modifications were excluded. Thirty-five original research articles and three patents were included for review. No risk of bias assessment was performed. Results were synthesized manually in tables highlighting the principal results and confidence intervals for quantitative results. Findings indicate that non-thermal processing technologies have the potential to effectively reduce plant protein's immunoreactivity by more than 50% compared to untreated plants when adequate conditions are selected. Allergenicity reduction is most probably achieved through protein structural modifications. Therefore, evidence of changes in secondary and tertiary structures produced after non-thermal processing could represent the potential to use these techniques for future research on producing hypoallergenic foods. However, there are limitations in this relation as the structural changes could still not be sufficient to destroy protein epitopes or generate new antigenic sites. Treatments should be optimized for maximum immunoreactivity reduction while maintaining the plant's nutritional value and organoleptic properties.