Plant proteins as sources of bioactive peptides: Biochemical characteristics and modification by fermentation and enzymatic hydrolysis

Plant proteins have attracted increasing scientific interest due to their structural diversity and their potential as precursors of bioactive peptides released through biotechnological processing. This review examines the main biochemical characteristics of plant proteins and discusses the structural modifications induced by fermentation and enzymatic hydrolysis, with emphasis on the generation of bioactive peptides and their biological activities. A bibliometric analysis based on the Scopus database identified 154 publications between 2010 and 2025, revealing a marked increase in scientific output after 2019. Although plant proteins present certain limitations, including imbalances in essential amino acid composition and the presence of antinutritional compounds, they constitute relevant substrates for the production of peptides with diverse biological activities. Microbial fermentation and enzymatic hydrolysis promote controlled proteolysis, enhancing digestibility and facilitating the release of low-molecular-weight peptides. Fermentation is generally associated with greater peptide diversity, whereas enzymatic hydrolysis offers greater process control and reproducibility, highlighting the complementary nature of these approaches. Advances in peptidomics, high-resolution mass spectrometry, and computational tools have expanded peptide identification and structure–activity analysis. At the same time, many reported bioactivities still rely on in silico predictions, which may not accurately reflect physiological responses, underscoring the need for experimental validation. The controlled modification of plant proteins represents a promising strategy for generating functional peptide-enriched ingredients, while challenges related to standardization, scalability, and validation remain.