Techno-functional changes in proteins from plant-based agro-industrial by-products induced by enzymatic hydrolysis: a review.
This review explores the potential of plant-based agro-industrial by-products as sustainable protein sources. It examines how enzymatic hydrolysis can modify and enhance their techno-functional properties for food applications. A literature search (2020-2025) in major databases identified experimental studies using protein-rich by-products (≥10 g/100 g protein) processed into protein ingredients, concentrates, isolates, and, especially, hydrolysates. These by-products generally exhibit favorable amino acid profiles and notable bioactive properties, including antioxidant and enzyme-inhibitory activities. Hydrolysis, often combined with greener extraction and pretreatment technologies, improves key techno-functional properties. Reported surfactant-related effects include increased solubility, emulsifying, foaming, and oil-holding capacities. Moisturizing properties such as water-holding capacity, gelation, and texture are enhanced, while hydrodynamic behavior is tailored to improve colloidal stability. These functionalities have been successfully exploited in breads, cakes, yogurts, emulsified meat products, confectionery, encapsulated systems, and other model foods, enabling partial replacement of conventional ingredients such as eggs, milk solids, or synthetic surfactants. Despite these advances, most applications remain concentrated in bakery and dairy products, underscoring the need for broader exploration in other food matrices and for studies addressing scale-up, regulatory considerations, and consumer acceptance. Overall, plant protein hydrolysates derived from agro-industrial by-products are promising, sustainable ingredients for the development of functional, cleaner-label foods.