Molecular characterisation of hot moulded alginate gels as a delivery vehicle for the release of entrapped caffeine

Competitive Biosynthesis of Bacterial Alginate Using Azotobacter vinelandii 12 for Tissue Engineering Applications

“…Although high molecular weight capsular bacterial alginate produces the densest gels, there was no linear correlation with algal and low molecular weight capsular alginate. A non-linear relationship between gel strength and calcium addition arose as a result of the crosslinking mode between the alginate chains [ 76 ]. At low counterion addition levels, there is a limited replacement of sodium with calcium ions, which leads to a low crosslink density [ 77 ].…”

Alginate‐based delivery systems for food bioactive ingredients: An overview of recent advances and future trends

“…According to reports in the literature, alginate exhibits antimicrobial, antioxidant, anti-inflammatory activities and immunomodulatory effects (Hamedi et al, 2017). In addition, alginate possesses some unique functional prop-erties, such as ionic crosslinking, pH sensitiveness, biocompatibility and biodegradability (Morrish et al, 2020).…”

“…Since the crosslinking of polyvalent cations with alginate is expeditious and irreversible, it is pivotal to control the dripping rate and way of crosslinked ions. There are two primary methods of alginate gelation, namely, internal gelation method and external gelation method (Morrish et al, 2020). It is important to mention that the method of manufacturing gel determines the gel strength, stiffness, pore size as well as permeability and all these parameters can impact both the physicochemical stability and encapsulation efficiency of bioactive ingredients (Morales et al, 2017).…”

“…Apart from ionic crosslinking, pH sensitiveness is another peculiarity of alginate (Figure 2b). pH plays an unparalleled role in the design and manufacture of alginate-based delivery system because it can influence the swelling degree of alginate gel and release rate of bioactive compounds in the gastrointestinal tract (Morrish et al, 2020). As a result of the existence of carboxylic groups in the alginate structure, the alginate polymer has significant sensitivity to the change of external pH (Ramdhan et al, 2019).…”

“…Furthermore, numerous studies have reported alginate gels shrinking in the stomach (acidic environment) owing to a decline in repulsion between protonated carboxylic groups. On the contrary, alginate gels swell in the intestine (alkaline environment) due to electrostatic repulsion engendered by dissociation of the carboxylic acid, which leads to the increase of swelling rate and the expansion of polymer chain (Apoorva et al, 2020;Morrish et al, 2020;Ramdhan et al, 2019). Consequently, the pH sensitiveness of alginate is considered to be an excellent functional property because it allows bioactive ingredients encapsulated in the alginate-based delivery system to reach the small intestine and be absorbed by the human body more easily.…”