The Effect of Non-Thermal Energy Exposure on the Unfolding and Gelation of Local Fish Protein: A Biochemical Approach: A Systematic Literature Review

Abstract

Myofibrillar proteins play an essential role in determining the texture and gel properties of fish-based products. Non-thermal technologies, particularly ultrasound and High Pressure Processing (HPP), offer alternatives for modifying protein structures without intensive heating. This study aims to analyze the effects of these technologies on protein unfolding, conformational changes, sulfhydryl group exposure, and gelation properties. A Systematic Literature Review (SLR) was conducted using ScienceDirect, Scopus, and Google Scholar, focusing on empirical studies published within the last ten years. The selected literature was analyzed based on treatment mechanisms, structural changes, and functional properties. The findings indicate that ultrasound induces protein unfolding through acoustic cavitation, generating shear forces and shock waves, whereas HPP promotes conformational changes through hydrostatic pressure. Both treatments can expose hydrophobic and sulfhydryl groups, facilitating intermolecular interactions and disulfide bond formation that support gel network development. Controlled structural modification has the potential to improve gel strength, water-holding capacity (WHC), and emulsifying properties. However, excessive treatment may cause protein aggregation and reduce functional quality. Therefore, optimizing treatment intensity and duration is essential to achieving desirable protein functionality.