Interactions between different forms of bovine lactoferrin and sodium alginate affect the properties of their mixtures

Abstract

1The interactions between different forms (apo-, native-and holo-) of lactoferrin (Lf) and 2 sodium alginate at different ratios in aqueous solution in the pH range of 4-7 were evaluated. 3Fourier transform infra-red (FTIR) spectra of freeze dried mixtures showed shifts only in the 4 bands arising from the carboxylate groups of alginate relative to physical mixtures; indicating 5 intermolecular interactions involving COO¯ moieties of alginate. Circular dichroism (CD) 6 spectroscopy showed that Lf retained its tertiary structure in the Lf-alginate mixtures. In the 7 pH range of 4 -7, the zeta-potential of Lf-alginate solutions was significantly less negative

In-vitro digestion of different forms of bovine lactoferrin encapsulated in alginate micro-gel particles

“…Thus we limited the encapsulation study to the mixing ratio of 1:1 and total solids content of 2%. In addition, from our previous study (Bokkhim et al, 2015), within the 2% total solids content of Lf-alginate mixture, changing the mixing ratio alone was not able to increase the viscosity of the mixtures with apo-and holo-Lf to the required level for improved encapsulation. Increasing the concentration of calcium in the crosslinking solution to 0.2 M improved the micro-gel particle formation process for Lf-alginate mixtures containing apo-and holo-Lf however, the Lf entrapment efficiency was affected concomitantly as discussed below.…”

“…The difference in behaviour of the different forms of Lf might be due to the differences in the viscosity of the mixtures. The viscosities of Lf-alginate mixtures with apo-(721 ± 38 mPa s) and holo-Lf (514 ± 14 mPa s) were significantly lower than that with native-Lf (1297 ± 36 mPa s) (Bokkhim et al, 2015). In order to be able to compare the micro-gel particles with different forms of Lf, the same composition has to be used for all Lf-alginate mixtures.…”

“…This showed that encapsulating Lf, especially apo-and native-Lf, in alginate micro-gel particles delays the action of pepsin by limiting its access to Lf thereby leading to lower Lf degradation. The intermolecular interactions which occur between Lf and alginate (Bokkhim et al, 2015;David-Birman, Mackie, & Lesmes, 2013;Peinado et al, 2010) could have played a role in making Lf less available for pepsin degradation. It should be noted that during the gastric digestion, an increase in pH from 2.0 to 3.5 was observed for all types of micro-gel particles.…”

“…cationic proteins such as Lf) leading to a sustained release of macromolecules from the gel particles Wells & Sheardown, 2007). Research has shown that electrostatic as well as other intermolecular interactions occur between Lf and alginate and that the extent of interactions is affected by the form of Lf (Bokkhim, Bansal, Grøndahl, & Bhandari, 2015;Peinado, Lesmes, Andr es, & McClements, 2010). These interactions minimize the loss of entrapped Lf by diffusion, lower at pH 4 compared to pH 7 for native-and holo-Lf, thus ensuring the stability of Lf within the alginate gel matrix .…”

Solubility, structural properties, and immunomodulatory activities of rice dreg protein modified with sodium alginate under microwave heating

“…Therefore, improved RDP modification technologies should be developed for functional foods. Sodium alginate, an important cell wall component isolated from brown marine algae ( Phaeophyceae ), is composed of polymeric sequences of (1–4) linked β‐D‐mannuronate (M) and α‐L‐guluronate (G) residues and has a high affinity for cationic protein molecules (Bokkhim, Bansal, Grøndahl, & Bhandari, ; Fioramonti, Perez, Aríngoli, Rubiolo, & Santiago, ). Sodium alginate has been extensively used to improve water holding, gelling, and emulsifying properties of food proteins based on the interactions between protein and polysaccharide (Yao et al, ).…”