Macroalgae suspensions prepared by physical treatments: Effect of polysaccharide composition and microstructure on the rheological properties. (November 2021)

• Record Type: Journal Article
• Authors: Malafronte, Loredana; Yilmaz-Turan, Secil; Krona, Annika; Martinez-Sanz, Marta; Vilaplana, Francisco; Lopez-Sanchez, Patricia
• Is Part Of: Food hydrocolloids. Volume 120(2021)
• Publication Date: 2021-11
• Subjects: Algae -- Polysaccharides -- Suspensions -- Rheology -- Structure -- High pressure homogenisation; Hydrocolloids -- Periodicals; Food additives -- Periodicals; Colloïdes -- Périodiques; Aliments -- Additifs -- Périodiques; Colloids; Food additives; Periodicals; Electronic journals; 664.06
• DOI: 10.1016/j.foodhyd.2021.106989
• Languages: English
• ISSNs: 0268-005X

Abstract

Abstract: The use of macroalgae in food products is growing due to their techno-functionality and nutritional properties. In this context, an increased understanding of the rheological properties which are relevant for manufacturing and texture is needed. Here we investigated the impact of thermal and mechanical treatments, including high pressure homogenisation (HPH), on the polysaccharide composition, microstructure, and rheological properties of brown algae Laminaria digitata suspensions (5 wt %). Monosaccharide analysis and immunolabeling of alginate in combination with confocal laser scanning microscopy, revealed a sequential release of different polysaccharides as result of the applied shear. Results showed that thermal treatment (70 °C 1 h) and mild shear lead to suspensions of clusters of cells and release of fucoidan and laminarin into the liquid phase, conferring shear thinning properties to the suspensions. High pressure homogenisation was able to completely break the macroalgae cells, reducing particle size and releasing other soluble polysaccharides, in particular alginate, conferring gel properties (G'>G'') to the suspensions. This study contributes to the knowledge of how to design sustainable, innovative and nutritious liquid/semiliquid food products containing macroalgae biomass. Graphical abstract: Image 1 Highlights: Mild-shear in combination with heating solubilised fucoidan and laminarin. Suspensions at 70 °C were stable and shear thinning, whilst at 90 °C they sedimented. Processing at 90 °C caused a general decrease in the molar mass of polysaccharides. High Pressure Homogenisation disrupted algae cells and released alginate. High Pressure Homogenisation led to Laminaria digitata weak gels.