The Role of Methionine in the Formation of Key Aroma Compounds in Microwaved Walnuts

Given the growing consumer preference for plant-based proteins, improving their flavor profiles is essential for market success. Despite their nutritional benefits, plant proteins, such as walnut proteins, often suffer from weaker and less appealing flavors than those of animal proteins. This study investigated the pivotal role of amino acids in walnut aroma development during microwave treatment. Through gas chromatography mass spectrometry analysis of five walnut varieties, considerable differences in the aroma compound composition were identified with 13 key aroma components highlighted via relative odor activity value analysis. The present results demonstrated that methionine played a predominant role in pyrazine and heterocyclic compound production, underscoring its importance in walnut aroma formation. Thus, heat treatments, particularly microwave processing, show potential for enhancing flavor under the conditions investigated. These findings suggest a possible approach for improving flavor profiles in plant protein–based systems.