Dietary proteins as excipient ingredients for improving the solubility, stability, and bioaccessibility of quercetin: Role of intermolecular interactions. (November 2022)

• Record Type: Journal Article
• Authors: Liao, Li; Julian McClements, David; Chen, Xing; Zhu, Yuqing; Liu, Yikun; Liang, Ruihong; Zou, Liqiang; Liu, Wei
• Is Part Of: Food research international. Volume 161(2022)
• Publication Date: 2022-11
• Subjects: Quercetin -- Protein -- Solubility -- Stability -- Bioaccessibility -- Plant proteins; 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.2022.111806
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: Hydrophobic forces dominated quercetin's interactions with casein, whey, and soy proteins. Quercetin-protein nanoparticles (50 to 208 nm) were formed after the interactions. Quercetin had the highest water-solubility, thermal and digestive stability in whey protein nanoparticles. Quercetin had the highest bioaccessibility in casein nanoparticles. Casein and whey protein can be used as excipient ingredients to enhance quercetin bioaccessibility. Abstract: Soy protein isolate (SPI), whey protein isolate (WPI) and sodium caseinate (CS) were used as excipient ingredients to improve the water-solubility, chemical stability, and in vitro bioaccessibility of quercetin. Quercetin powder was dispersed in the protein solutions (pH 7.0) and then the mixtures were held at 30 °C for 24 h or 100 °C for 60 min. The mean particle diameter of the colloidal dispersions formed ranged from around 53 to 208 nm, whereas the zeta-potential values ranged from around –23 to −27 mV. The high-temperature treatment (100 °C) of the quercetin-protein mixtures led to a higher quercetin solubility than the low-temperature treatment (30 °C). When held at 100 °C, the solubility of quercetin increased first but then decreased over time when quercetin mixed with WPI, CS and SPI respectively. A simulated gastrointestinal tract study showed that the in vitro bioaccessibility of quercetin increased after being mixed with the protein solutions: from 13.5 % for free quercetin to 20.3 %, 26.5 %, and 36.3 % for SPI, WPI, and CS respectively. Fluorescent spectroscopy analysis indicated that there was about one quercetin molecule bound per protein molecule, with the dominant force being hydrophobic attraction. Per unit mass of protein, the total number of quercetin binding sites available was greater for CS and WPI than for SPI. This phenomenon may account for the greater enhancement in quercetin solubility, stability, and bioaccessibility for CS and WPI than SPI.