Mathematical modeling of the release of food active compounds from viscoelastic matrices

Assessment of calcium alginate gels as wall materials for encapsulation systems

BACKGROUND

Calcium alginate gels are widely used to encapsulate active compounds. Some characteristic parameters of these gels are necessary to describe the release of active compounds through mechanistic mathematical models. In this work, transport and kinetics properties of calcium alginate gels were determined through simple experimental techniques.

RESULTS

The weight-average molecular weight (M ¯ w  = 192 × 103  Da) and the fraction of residues of α-l-guluronic acid (F G  = 0.356) of sodium alginate were determined by capillary viscometry and 1 H-nuclear magnetic resonance at 25 °C, respectively. Considering the half egg-box model, both values were used to estimate the molecular weight of calcium alginate asM g  = 2.02 × 105  Da. An effective diffusion coefficient of water (D eff , w  = 2.256 × 10-9  m2  s-1 ) in calcium alginate was determined using a diffusion cell at 37 °C. Finally, a kinetics constant of depolymerization (k m  = 9.72 × 10-9  m3  mol-1  s-1 ) of calcium alginate was obtained considering dissolution of calcium to a medium under intestinal conditions.

CONCLUSION

The experimental techniques used are simple and easily reproducible. The obtained values may be useful in the design, production, and optimization of the alginate-based delivery systems that require specific release kinetics of the encapsulated active compounds. © 2023 Society of Chemical Industry.

Recent Advances in Sustainable Antimicrobial Food Packaging: Insights into Release Mechanisms, Design Strategies, and Applications in the Food Industry

In response to the issues of foodborne microbial contamination and carbon neutrality goals, sustainable antimicrobial food packaging (SAFP) composed of renewable or biodegradable biopolymer matrices with ecofriendly antimicrobial agents has emerged. SAFP offers longer effectiveness, wider coverage, more controllability, and better environmental performance. Analyzing SAFP information, including the release profile of each antimicrobial agent for each food, the interaction of each biomass matrix with each food, the material size, form, and preparation methods, and its service quality in real foods, is crucial. While encouraging reports exist, a comprehensive review summarizing these developments is lacking. Therefore, this review critically examines recent release-antimicrobial mechanisms, kinetics models, preparation methods, and key regulatory parameters for SAFPs based on slow- or controlled-release theory. Furthermore, it discusses fundamental physicochemical characteristics, effective concentrations, advantages, release approaches, and antimicrobial and preservative effects of various materials in food simulants or actual food. Lastly, inadequacies and future trends are explored, providing practical references to regulate the movement of active substances in different media, reduce the reliance on petrochemical-based materials, and advance food packaging and preservation technologies.