Articles
Characterization of mucilage proteins and carbohydrates responsible for capacity and stability of foam food systems
Article number
1343_59
Pages
473 – 480
Language
English
Abstract
Polysaccharides and proteins have a synergistic effect on foam stability in food systems.
The coherent elastic absorbed layer at the air/water interface brought about by the conformational rearrangement of a protein and its hydrophobicity is what determined the success of bubble formation and stability.
The nature of many polysaccharides is known to be hydrophilic therefore, it adds a thickening and gelling effect to the liquid, which further stabilizes the bubbles formed by the proteins.
The aim of this investigation was to evaluate how mucilage affects the overall formation and stability of food foam systems by quantifying and characterizing the proteins and carbohydrates thereof to understand their effectiveness in reducing surface tension in foams.
Mucilage was extracted and freeze-dried from 42 cactus pear cultivars obtained from an experimental orchard on the University of the Free State campus.
The total sugar concentration, monosaccharide profile, free amino acid content, protein concentration and protein size as well as viscosity, were determined using phenol-sulfuric acid, HPLC, cadmium-ninhydrin, the Bradford assay, SDS-PAGE and a rheometer, respectively.
The Leco and Bradford assays did not identify the same cultivars in selection of the highest protein concentrations; therefore, foam capacity and stability tests were performed to identify the five best foam-formation capacity cultivars. Zastron had the highest total sugar molecular weight, and the highest viscosity. Gymno-Carpo had the biggest protein size and the most stable foam.
Cultivars with equal total sugar molecular weight (Van As and Robusta) behaved differently during rheology tests.
The explanation might be due to the different sugar constituents (monosaccharides). Zastron had highest sugar molecular weight, no protein band, yet had stable foam.
The coherent elastic absorbed layer at the air/water interface brought about by the conformational rearrangement of a protein and its hydrophobicity is what determined the success of bubble formation and stability.
The nature of many polysaccharides is known to be hydrophilic therefore, it adds a thickening and gelling effect to the liquid, which further stabilizes the bubbles formed by the proteins.
The aim of this investigation was to evaluate how mucilage affects the overall formation and stability of food foam systems by quantifying and characterizing the proteins and carbohydrates thereof to understand their effectiveness in reducing surface tension in foams.
Mucilage was extracted and freeze-dried from 42 cactus pear cultivars obtained from an experimental orchard on the University of the Free State campus.
The total sugar concentration, monosaccharide profile, free amino acid content, protein concentration and protein size as well as viscosity, were determined using phenol-sulfuric acid, HPLC, cadmium-ninhydrin, the Bradford assay, SDS-PAGE and a rheometer, respectively.
The Leco and Bradford assays did not identify the same cultivars in selection of the highest protein concentrations; therefore, foam capacity and stability tests were performed to identify the five best foam-formation capacity cultivars. Zastron had the highest total sugar molecular weight, and the highest viscosity. Gymno-Carpo had the biggest protein size and the most stable foam.
Cultivars with equal total sugar molecular weight (Van As and Robusta) behaved differently during rheology tests.
The explanation might be due to the different sugar constituents (monosaccharides). Zastron had highest sugar molecular weight, no protein band, yet had stable foam.
Publication
Authors
S. Miya, M. de Wit, A. van Biljon, S.L. Venter, E. Amonsou
Keywords
capacity, carbohydrates, foam, free amino acids, protein, stability
Groups involved
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