Adsorption of Quercetin on Brown Rice and Almond Protein Matrices: Effect of Quercetin Concentration.

Ivana Buljeta,Mirela Kopjar,Josip Šimunović,Anita Pichler,Ina Ćorković

doi:10.3390/foods11060793

Ivana Buljeta, Mirela Kopjar + Show 3 more

Open Access

https://doi.org/10.3390/foods11060793

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Abstract

Plant-based proteins are very often used as carriers of different phenolic compounds. For that purpose, complexation of quercetin with almond and brown rice protein matrices was investigated. The amount of protein matrices was constant, while the concentration of quercetin varied (1 mM, 2 mM or 5 mM) during complexation. Dried complexes were investigated for quercetin amount (HPLC analysis) and antioxidant activity (DPPH, FRAP and CUPRAC methods). Additionally, complexation was proven by DSC and FTIR-ATR screening. An increase in the concentration of quercetin in the initial complexation mixture resulted in the increase in the adsorption of quercetin onto protein matrices. For the brown rice protein matrices, this increase was proportional to the initial quercetin concentration. Adsorption of quercetin caused the change in thermal stability of microparticles in comparison to corresponding protein matrices that have been proven by DSC. FTIR-ATR analysis revealed structural changes on microparticles upon adsorption of quercetin.

Highlights

IntroductionA growing area of interest in the field of polyphenols is their interactions with other components present in the food matrix, including proteins, carbohydrates and lipids [1]
Effect of Quercetin Concentration.A growing area of interest in the field of polyphenols is their interactions with other components present in the food matrix, including proteins, carbohydrates and lipids [1].Proteins as building blocks have both nutritional and functional properties and are an important dietary source of amino acids [2]
Comparison of almond protein/quercetin (AP/Q) microparticles and brown rice/quercetin (RP/Q) microparticles showed that RP/Q microparticles had a higher amount of quercetin than AP/Q microparticles prepared with the same initial concentration of quercetin, indicating that the brown rice protein matrix had a higher affinity towards quercetin

Summary

Introduction

A growing area of interest in the field of polyphenols is their interactions with other components present in the food matrix, including proteins, carbohydrates and lipids [1]. Proteins as building blocks have both nutritional and functional properties and are an important dietary source of amino acids [2]. As an outcome of interactions between polyphenols and proteins, various complexes can be formed, which cause changes in antioxidant properties of polyphenols and affect the functional, structural and nutritional properties of proteins [3]. The application of an adequate delivery system is one way to achieve stabilization and improvement of the health benefits of quercetin. Possibilities for the application of delivery systems can be various from food, agrochemical, pharmaceutical, cosmetic to personal care industries [10]

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