Formation and Characterization of β-Lactoglobulin and Gum Arabic Complexes: the Role of pH

Abstract

Protein–polysaccharide complexes have received increasing attention as delivery systems to improve the stability and bioavailability of multiple bioactive compounds. However, deep and comprehensive understanding of the interactions between proteins and polysaccharides is still required for enhancing their loading efficiency and facilitating targeted delivery. In this study, we fabricated a type of protein–polysaccharide complexes using food-grade materials of β-lactoglobulin (β-Lg) and gum arabic (GA). The formation and characteristics of β-Lg–GA complexes were investigated by determining the influence of pH and other factors on their turbidity, zeta-potential, particle size and rheology. Results demonstrated that the β-Lg and GA suspension experienced four regimes including co-soluble polymers, soluble complexes, insoluble complexes and co-soluble polymers when the pH ranged from 1.2 to 7 and that β-Lg–GA complexes formed in large quantities at pH 4.2. An increased ratio of β-Lg in the mixtures was found to promote the formation of β-Lg and GA complexes, and the optimal β-Lg/GA ratio was found to be 2:1. The electrostatic interactions between the NH3+ group in β-Lg and the COO− group in GA were confirmed to be the main driving forces for the formation of β-Lg/GA complexes. The formed structure also resulted in enhanced thermal stability and viscosity. These findings provide critical implications for the application of β-lactoglobulin and gum arabic complexes in food research and industry.

Complexation of β‐lactoglobulin with gum arabic: Effect of heat treatment and enhanced encapsulation efficiency

“…In recent years, GA has been combined to a variety of proteins, such as milk, egg, wheat, rice, and soybean proteins (Li et al., 2019; Niu et al., 2017; Wei & Huang, 2019). The latest research showed that the electrostatic interactions were the main driven force for the formation of the β‐Lg‐GA nanoparticles (Wang et al., 2020). Schmitt et al (2000) studied the effect of protein aggregates on the complex coacervation between β‐Lg and GA at pH 4.2, which showed that the pH can affect β‐Lg aggregation and thus the formation of β‐Lg‐GA nanoparticles.…”

Microencapsulation of Carvacrol by Complex Coacervation of Walnut Meal Protein Isolate and Gum Arabic: Preparation, Characterization and Bio-Functional Activity

“…The above typical peaks indicated the presence of a large fraction of protein [ 32 ]. GA is a heteropolysaccharide that consists of galactose and glycoproteins [ 33 ]. The FTIR spectrum of GA showed a broad peak at 3389 cm −1 , which was attributed to the amino groups (Amide A).…”

“…The FTIR spectrum of GA showed a broad peak at 3389 cm −1 , which was attributed to the amino groups (Amide A). The peaks at 1606 cm −1 and 1420 cm −1 corresponded to the asymmetrical and symmetrical stretching vibrations of –COOH groups with the negative charge [ 33 ].…”

Rheological Characteristics of Soluble Cress Seed Mucilage and β-Lactoglobulin Complexes with Salts Addition: Rheological Evidence of Structural Rearrangement

“…Near the isoelectric point (pI = 5.1), it, however, starts to aggregates and form a different structure depending on the ionic strength and pH of the solution [ 7 ]. There is a possibility to impress the aggregation, thereby generating functional properties of Blg when it enters complexation with other biopolymers such as acacia gum [ 8 ], pectin [ 9 ], and κ-carrageenan [ 10 ].…”