Review on improvement of physicochemical properties of sodium alginate-based edible films

Abstract

Sodium alginate (SA) is favored for its film-forming ability, biodegradability, and non-toxicity, often serving as a substrate for edible films. However, the application of SA-based edible films in the food industry is limited due to their inherent strong hydrophilicity and high brittleness. To enhance their physical and chemical properties, various exogenous compounds are frequently incorporated. This review summarizes the advancements in the physicochemical properties (mechanical, optical, thermal, hydrophobic, and barrier properties) of SA-based edible films over the past decade. It discusses the types of exogenous additives used and their effects on the properties of these films. Additionally, it highlights the applications of SA-based edible films enriched with functional compounds in areas such as food freshness detection, antioxidation, and antibacterial activity. It has been observed that the characteristics of SA-based edible films vary depending on the properties and structures of the exogenous compounds used, as well as their interactions with the SA matrix. SA-based edible films with functional additives demonstrate significant potential for extending food shelf life and enhancing freshness detection. However, challenges such as scalability, high production costs, and limited application scope still need to be addressed in future research.