Soluble complexes between chenopodins and alginate/chitosan: Intermolecular interactions and structural-physicochemical properties. (1st January 2020)

• Record Type: Journal Article
• Authors: Romo, Isabel; Abugoch, Lilian; Tapia, Cristian
• Is Part Of: Carbohydrate polymers. Volume 227(2020)
• Publication Date: 2020-01-01
• Subjects: QP chenopodins -- Alg sodium alginate -- CH chitosan -- PS polysaccharides -- QPI quinoa protein isolate enriched in chenopodins; Chenopodins -- Sodium alginate -- Chitosan; Protein-polysaccharide complexes -- Chenopodins -- Sodium alginate -- Chitosan -- Intermolecular interactions -- Conformational changes; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2019.115334
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Hydrocolloid type and protein-hydrocolloid ratio influenced the complexes properties. Chenopodin-hydrocolloid interactions depended on the hydrocolloid nature and charge. QP-CH complexes were mainly formed by electrostatic interactions and hydrogen bonds. QP-Alg complexes were mainly formed by hydrophobic interactions and hydrogen bonds. Chenopodins interaction with both hydrocolloids caused proteins structural changes. Abstract: The research aim was to study the nature of intermolecular interactions involved in the formation of soluble complexes between chenopodins (QP) and anionic/cationic polysaccharides, sodium alginate (Alg) and chitosan (CH), above the pI of QP at different protein-polysaccharide ratios; and to evaluate their structural-physicochemical properties. The interactions and properties analysed by electrical conductivity, zeta potential, hydrodynamic particle size, intrinsic and extrinsic fluorescence spectroscopy, circular dichroism spectroscopy, differential scanning calorimetry and infrared spectroscopy. The protein-polysaccharide ratio and the type of polysaccharide influenced the complexes properties. In QP-CH complexes, the main interactions were electrostatic, while in QP-Alg complexes, hydrophobic interactions, hydrogen bonds and weak electrostatic interactions were detected. Changes in secondary and tertiary structure and increased thermal stability of chenopodins in the presence of both polysaccharides were observed. QP-Alg and QP-CH complexes seemed to have achieved the strongest interactions at 1:4, 2:3 and 3:2 ratios and at 1:4 and 2:3 ratios, respectively.