Strategies for Exploiting Milk Protein Properties in Making Films and Coatings for Food Packaging: A Review

Abstract

Biopolymers of different natures (carbohydrates, proteins, etc.) recovered from by-products of industrial processes are increasingly being studied to obtain biomaterials as alternatives to conventional plastics, thus contributing to the implementation of a circular economy. The food industry generates huge amounts of by-products and waste, including unsold food products that reach the end of their shelf life and are no longer usable in the food chain. Milk proteins can be easily separated from dairy waste and adapted into effective bio-based polymeric materials. Firstly, this review describes the relevant properties of milk proteins and the approaches to modifying them for subsequent use. Then, we provide an overview of recent studies on the development of films and coatings based on milk proteins and, where available, their applications in food packaging. Comparisons among published studies were made based on the formulation as well as production conditions and technologies. The role of different additives and modifiers tested for the performances of films and coatings, such as water vapor permeability, tensile strength, and elongation at break, were reviewed. This review also outlines the limitations of milk-protein-based materials, such as moisture sensitivity and brittleness. Overall, milk proteins hold great potential as a sustainable alternative to petroleum-based polymers. However, their use in food packaging materials at an industrial level remains problematic.

Protein‐based active films: Raw materials, functions, and food applications

“…The addition of plasticizers to proteins can lead to changes in their three-dimensional structure, where plasticizers enter between protein molecular chains and join proteins through physical interactions and chemical reactions, resulting in increased ductility, flexibility, and elasticity and decreased mechanical properties, cohesion, and stiffness (Ananey-Obiri et al, 2018). Currently, plasticizers, such as those made from soy protein isolate (Zhu et al, 2023), corn protein (Baloyi et al, 2023), milk protein (Stefano et al, 2023), and whey protein isolate (Mariana et al, 2022), have been used in protein-based packaging films, and good results have been obtained. Water is the most used best-performing plasticizer in the preparation of protein films.…”

Production and Characterization of Active Pectin Films with Olive or Guava Leaf Extract Used as Soluble Sachets for Chicken Stock Powder

“…Several researchers have worked to find the best combination between low-price film-based materials and their activation with different plant extracts or additives that potentially have antioxidant, antimicrobial, and anti-biofilm activities [5], to enhance the food's shelf-life or other functionality for food applications [6][7][8][9]. As a result of short shelf-life and inadequate packaging, food waste remains a significant global challenge, emphasizing the need for innovative and sustainable packaging solutions [10][11][12][13][14][15][16]. Edible films and coatings are prepared mainly from hydrocolloidal materials (e.g., carbohydrates and proteins, or a combination of both sources).…”