Diffusive transport phenomena of lactoferrin from gelatin gels crosslinked with genipin

• Published in: Food hydrocolloids 2024-01, Vol.146, p.109203, Article 109203
• Main Authors: Morrish, Courtney, Kasapis, Stefan
• Format: Article
• Language: English
• Subjects: Diffusion; Flory-Rehner theory; Gelatin; Genipin; Lactoferrin
• ISSN: 0268-005X
• DOI: 10.1016/j.foodhyd.2023.109203

In order to examine the effects of crosslinking and structure on the swelling and diffusive phenomena in a hydrogel, low-solid gelatin gels were crosslinked with a range of genipin proportions. The ninhydrin assay showed high levels of successful crosslinking within the gels whilst FTIR and WAXD showed successful entrapment of the bioactive molecule lactoferrin within the matrix. Rheological analysis further assessed the effects of crosslinking on the system with an increase in network strength at greater genipin additions. SEM illustrated the successful incorporation of lactoferrin and how the pronounced changes in gel morphology influences entrapment. Experimental evidence supported theoretical estimations of the gel morphology using the Flory-Rehner theory. Analysis of the diffusive transport of lactoferrin from each crosslinked system suggested that densely bound matrices hinder the free movement of molecules. Pairing aspects of the Flory-Rehner theory with the diffusion data allowed for the calculation of the critical molecular weight between crosslinks (M*c) for diffusion to occur and the coupling parameter (ξ) for the gelatin and lactoferrin chain segments. The apparent diffusion coefficient of lactoferrin versus the average molecular weight between two adjacent crosslinks for gelatin crosslinked with genipin based on the proposed mathematical expression by Teimouri and Kasapis to determine the coupling parameter and the critical molecular weight for diffusive transport to happen. [Display omitted] •Diffusive transport of lactoferrin from genipin crosslinked gelatin gels was studied.•Microstructural characteristics of the gels were correlated with swelling and diffusion parameters.•A new theoretical model was successfully applied to correlate diffusion kinetics to network morphology.