Abstract
Biopolymers derived from biological sources are safe, abundant, eco-friendly, and economical substitutes for synthetic polymers. However, intrinsic properties of biopolymer films, such as abundant hydrophilic groups, weak mechanical properties, low resistance to heat, and poor barrier properties, need to be addressed to restrict them from being used before employing them for food packaging applications. Hydrophobic modification of biopolymers is crucial to enhance their suitability for food packaging applications. Various approaches, including nanocomposites, essential oil incorporation, and chemical modifications have been investigated to address the limitations of biopolymer packaging materials. Utilizing excipients which are deemed safe for consumption effectively achieves the requisite hydrophobicity in food packaging. Opting for food-safe excipients not only upholds the safety standards of packaged food but also aligns with environmentally conscious practices. These efforts ensure that biopolymer-based films and coatings meet the health and safety standards and the mechanical, thermal, and barrier properties required for food packaging. Moreover, this transition also underscores a commitment to sustainability and addresses the escalating imperative for eco-friendly solutions within food packaging. This article explores the various strategies developed for improving the water-interactive characteristics of materials intended for food contact. Furthermore, it elaborates on techniques that can enhance the hydrophobicity of biopolymers employed for food packaging. Additionally, regulations about the use of biopolymers in food packaging have also been discussed in detail, with particular emphasis on the applications of these modifications in active and intelligent food packaging.
Highlights
- The article emphasizes the importance of developing biobased materials for food packaging.
- Biopolymer films have poor water interactive properties, may disintegrate, making them unusable.
- Methods like solvent casting, electrospinning, and cold plasma enhance biopolymer hydrophobicity.
- Food-safe additives like essential oils, waxes, fatty acids, and nanoparticles improve hydrophobicity and safety.
- Hydrophobic biopolymers in intelligent packaging monitor food freshness, enhance barriers, and extend shelf life.
Introduction
The packaging industry relies heavily on polymers derived from the fossil fuel industry. Materials such as polyethylene, polyvinyl chloride, and polyethylene terephthalate are widely used for packaging in several sectors, including food and pharmaceuticals (Joseph et al., 2024). Although employing fossil-fuel-based synthetic plastics has apparent advantages associated with cost, ease of manufacture, material properties, and durability, these materials are non-degradable and are, hence, a serious environmental concern (Singh et al., 2022). With a rise in global temperature due to climate change and calls for reducing synthetic plastic usage, greater emphasis has been imparted on developing biobased materials, especially for packaging purposes (Wei et al., 2024). Consequently, natural biopolymers have increasingly been used for packaging due to their pronounced advantages, such as biodegradability, renewability, and low cost. Most natural bio-composites are based on polysaccharides or protein fibers, making them ideal candidates for the preparation of bio-based films due to their film-forming capabilities. However, most of these films are hydrophilic restricting their use in packaging. Furthermore, these polymers tend to lose their mechanical strength over time leading to disintegration due to being comprised of either polysaccharides or proteins (Verma et al., 2020). This calls for water-resistant biopolymers for packaging spiking an interest in modifications that can make these materials hydrophobic.
Key features of good packaging include gas permeability and mass transport characteristics (e.g. diffusion, polymer permeability, and the solubility of permeant molecules) that can provide an efficient barrier against contamination and deterioration while ensuring prolonged shelf-life and freshness (Teck Kim et al., 2014). Furthermore, film properties such as polarity, high-chain stiffness, a high glass transition temperature, and cross-linking also contribute to the efficiency of a polymer as a potential food packaging systems (Miller & Krochta, 1997). Contact between moist food and packaging material can often lead to premature food spoilage (Cui et al., 2023a)Formulating food packaging films with hydrophobic biopolymers can be a strategic approach to achieving the desired barrier properties, ensuring the quality and safety of the packaged food over an extended period. However, certain challenges are associated with the implementation of hydrophobic polymers for food packaging.
Recent innovations that impart hydrophobic properties to a polymer involve the incorporation of silane compounds such as alkylsilanes, polymers like polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), epoxy and acrylic-based resins, and fluorinated compounds. However, these strategies are not a viable option from a food packaging standpoint as they are considered unfit for being in contact with food. Additionally, food packaging systems need to have adequate mechanical properties that enable them to resist abrasion and exposure to extreme temperatures that exist in food processing environments which can become a significant challenge (Youssef et al., 2018). Food packaging systems can also influence the taste and texture of food products. Maintaining the original sensory attributes of food while using these surfaces is essential for consumer acceptance and satisfaction. Hydrophobic surfaces in food processing and packaging may inadvertently affect the texture and flavor of certain food products (Bai et al., 2024). Furthermore, implementing hydrophobic surfaces in food processing and packaging may involve substantial costs, including material expenses, installation costs, and potential modifications to existing production processes. Finding the right balance between the cost and the benefits of employing hydrophobic food packaging systems is fundamental for its widespread adoption in the food packaging industry.
This review investigates state-of-the-art techniques that address all the challenges described in the earlier section spotlighting crucial elements in food packaging. The review further examines the various strategies involving the integration of diverse food-safe excipients and matrices thereby shedding light on their pivotal roles in ensuring that the packaging materials thus developed adhere to stringent safety standards. Furthermore, the review delves into the multifaceted applications of these advancements within the realm of active and intelligent packaging, emphasizing the crucial role they play in safeguarding food products, extending shelf life, and providing real-time insights into the condition of the packaged goods.
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A comprehensive review on hydrophobic modification of biopolymer composites for food packaging applications
Sneha Sabu Mathew, Amit K. Jaiswal, Swarna Jaiswal, A comprehensive review on hydrophobic modification of biopolymer composites for food packaging applications, Food Packaging and Shelf Life, Volume 48, 2025, 101464, ISSN 2214-2894,
https://doi.org/10.1016/j.fpsl.2025.101464.
