How does ultrasound‐assisted ionic liquid treatment affect protein? A comprehensive review of their potential mechanisms, safety evaluation, and physicochemical and functional properties

Abstract

Proteins are essential to human health with enormous food applications. Despite their advantages, plant and animal proteins often exhibit limited molecular flexibility and poor solubility due to hydrogen bonds, hydrophobic interactions, and ionic interactions within their molecular structures. Thus, there is an urgent need to modify the rigid structure of proteins to enhance their stability and functional properties. Ultrasound‐assisted ionic liquid (UA‐IL) treatment for developing compound modification and producing proteins with excellent functional properties has received interest. However, no review specifically addresses the interactions between UA‐ILs and proteins. Hence, this review focused on recent research advancements concerning the effects and potential reaction mechanisms of UA‐ILs on the physicochemical properties (including particle size; primary, secondary, and tertiary structure; and surface morphology) as well as the functionality (such as solubility, emulsifying properties, and foaming ability) of proteins. Moreover, the safety evaluation of modified proteins was also discussed from various perspectives, such as acute and chronic toxicity, genotoxicity, cytotoxicity, and environmental and microbial toxicity. This review demonstrated that UA‐IL treatment‐induced protein structural changes significantly impact the functional characteristics of proteins. This treatment approach efficiently promotes protein structure stretching and spatial rearrangement through cavitation, thermal effects, and ionic interactions. As a result, the functional properties of modified proteins exhibited an obvious enhancement, thereby bringing more opportunities to utilize modified protein products in the food industry. Potential future directions for protein modification using UA‐ILs were also proposed.

Proteins from Legumes, Cereals, and Pseudo-Cereals: Composition, Modification, Bioactivities, and Applications

“…Protein modification pertains to the alteration of amino acid residues and polypeptide chains, leading to changes in protein spatial structure and properties to enhance their functionalities [3]. The techniques are broadly classified into physical, chemical, enzymatic, combined, and bioengineering methods (Figure 2) [45].…”

“…It necessitates a change in both the quantity and variety of dietary foods [2]. Proteins, essential for human health due to their multifaceted functions, including catalyzing biochemical reactions, transporting essential substances, maintaining metabolic processes, providing energy, and facilitating cellular communication [3], are at the forefront of this demand shift. The global protein demand is expected to double by 2050, underscoring the need to evaluate food proteins.…”