Modulation of calcium-induced gelation of pectin by oligoguluronate as compared to alginate. (February 2019)

• Record Type: Journal Article
• Authors: Zhang, Bangheng; Hu, Bing; Nakauma, Makoto; Funami, Takahiro; Nishinari, Katsuyoshi; Draget, Kurt I.; Phillips, Glyn O.; Fang, Yapeng
• Is Part Of: Food research international. Volume 116(2019)
• Page Start: 232
• Page End: 240
• Publication Date: 2019-02
• Subjects: Pectin -- Alginate -- Oligoguluronate -- Gelation -- Modulation -- Mechanism; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2018.08.020
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: Previous studies have demonstrated that oligoguluronate (guluronate block extracted from alginate, GB) was an efficient modulator of the gelation and gelling properties of macromolecular alginate in the presence of calcium. Here we report totally different modulatory effects of the oligomer when used to modify the gelation of low methoxyl pectin (LMP). GB was found to promote the gelation of LMP in the range of R ([Ca]/[guluronate + galacturonate]) < 0.25 and could make non-gelling systems gellable. This is significantly different from the case of alginate where no gelation could be induced at all. In the range of 0.25 < R < 0.60, the addition of GB was found to inhibit the gelation of LMP, whereas it had a negligible effect on the gelation of alginate as long as a fixed R was considered. In the range of R > 0.60, GB was found to promote the gelation of LMP again, which is similar to the case of alginate. The results were in consistence with microstructural observations by AFM. The different modulatory effects of GB were thought to arise from the different gelation mechanisms of LMP and alginate, that is, a progressive dotting growth of LMP dimers vs. a critical zippering growth of alginate dimers during Ca-induced crosslinking. The mechanism of GB modulating the gelation of LMP was proposed and compared to that for alginate. Graphic abstract: Unlabelled Image Highlights: Oligoguluronate modulates efficiently the gelling properties of pectin/alginate. Pectin and alginate behave quite differently in oligoguluronate modulation. The difference is due to the presence of point-like cross-links in pectin gels.