ABSTRACT
The interactions between proteins and chlorogenic acid (CGA) have gained significant attention in recent years, not only as a promising approach to modify the structural and techno-functional properties of proteins but also to enhance their bioactive potential in food systems. These interactions can be divided into covalent (chemical or irreversible) and non-covalent (physical or reversible) linkages. Mechanistically, CGA forms covalent bonds with nucleophilic amino acid residues of proteins by alkaline, free radical, and enzymatic approaches, leading to changes in protein structure and functionality, such as solubility, emulsification properties, and antioxidant activity. In addition, the protein-CGA complexes can be obtained by hydrogen bonds, hydrophobic and electrostatic interactions, and van der Waals forces, each offering unique advantages and outcomes. This review highlights the mechanism of these interactions and their importance in modifying the structural, functional, nutritional, and physiological attributes of animal- and plant-based proteins. Moreover, the potential applications of these protein-CGA conjugates/complexes are explored in various food systems, such as beverages, films and coatings, emulsion-based delivery systems, and so on. Overall, this literature review provides an in-depth overview of protein-CGA interactions, offering valuable insights for future research to develop novel protein-based food and non-food products with improved nutritional and functional characteristics.
ABSTRACT
The rise in the global population, which is projected to reach 9.7 billion by 2050, has resulted in an increased demand for proteins in the human diet. The green leaves of many plants are an affordable, abundant, and sustainable source of proteins suitable for human consumption. This article reviews the various sources of green leaf proteins that may play an important role in alleviating global malnutrition, including those from alfalfa, amaranth, cabbage, cassava, duckweed, moringa, olive, radish, spinach, sugar beet, and tea. The structure of green leaves and the location of the proteins within these leaves are described, as well as methods for extracting and purifying these proteins. The composition, nutritional profile, and functional attributes of green leaf proteins are then discussed. The potential advantages and disadvantages of using green leaf proteins as functional food ingredients are highlighted. The importance of obtaining a better understanding of the composition and structure of different green leaves and the proteins extracted from them is highlighted. This includes an assessment of non-protein nitrogen and anti-nutritional compounds that may be present. Furthermore, the impact of isolation and purification techniques on the functionality of the plant protein ingredients obtained must be carefully evaluated.