Pea protein isolate characteristics modulate functional properties of pea protein–cranberry polyphenol particles

Abstract

Plant polyphenols have a natural binding affinity for proteins, and their interaction can be exploited to form diverse aggregate particles. Protein–polyphenol particles utilized as food ingredients allow consumers to incorporate more health‐benefiting plant bioactives into their diets. The functional properties of the protein–polyphenol particles can be influenced by many factors, including complexation conditions and starting material properties. Here, cranberry polyphenols extracted from pomace were complexed with nine pea protein isolate starting materials with different physical (particle size and protein content) and chemical (hydrolyzed and oxidized) properties to investigate the impact of protein characteristics on particle functionality. Chemical differences between proteins affected polyphenol binding; oxidized protein isolate (specifically, VegOtein N) bound 12%–27% more polyphenols than other isolates. Polyphenol binding to proteins decreased digestion rates in vitro, averaging 25% slower gastric (pepsin) digestion and a 35% slower intestinal (pancreatin) digestion. Physical differences in protein starting materials affected digestibility; isolate with the largest particle size (specifically, Nutralys F85G) produced particles with the lowest digestion rate. Solubility was impacted by both the process of forming particles and by polyphenol binding; control particles were 56% less soluble, and protein–polyphenol particles up to 75% less soluble, than unmodified proteins. The solubility of unmodified protein isolate starting materials varied widely according to the manufacturing process, but, after complexation, protein–polyphenol particles produced from all protein sources exhibited a similar depressed level of solubility. The desired functional properties of the protein–polyphenol particle food ingredients will be considerably influenced by the properties of the protein isolate starting material.

Cranberry: Chemical Composition, Antioxidant Activity and Impact on Human Health: Overview

“…Polyphenols naturally bind to proteins to form insoluble, stable colloidal protein-polyphenol particles, which when used as food ingredients provide more health benefits to consumers from additional bioactives [ 99 ]. Strauch and Lila [ 99 ] examined the effect of protein processing on the physiochemical properties of the pea protein-cranberry polyphenol system and found that chemical differences between proteins affected polyphenol binding and influenced digestibility. It was demonstrated that solubility was affected by both the process of forming particles and the protein-cranberry polyphenol binding [ 99 ].…”

“…Strauch and Lila [ 99 ] examined the effect of protein processing on the physiochemical properties of the pea protein-cranberry polyphenol system and found that chemical differences between proteins affected polyphenol binding and influenced digestibility. It was demonstrated that solubility was affected by both the process of forming particles and the protein-cranberry polyphenol binding [ 99 ]. Since it has been determined that the functional properties of the protein-cranberry polyphenol particles are impacted by the properties of the protein isolate raw material, more studies need to be performed on the selection of protein isolate starting material for the desirable functional food [ 99 ].…”

“…It was demonstrated that solubility was affected by both the process of forming particles and the protein-cranberry polyphenol binding [ 99 ]. Since it has been determined that the functional properties of the protein-cranberry polyphenol particles are impacted by the properties of the protein isolate raw material, more studies need to be performed on the selection of protein isolate starting material for the desirable functional food [ 99 ].…”

Effect of Fractionation and Processing Conditions on the Digestibility of Plant Proteins as Food Ingredients

“…Forming protein complexes with other proteins or other compounds can be an unintended consequence of combining materials in one matrix or can be intentionally induced to achieve certain functions, such as colon-targeted drug delivery [ 80 ] or to confer an added nutritional benefit [ 81 ].…”

“…In contrast to the positive effects of anthocyanins and hydroxycinnamic acids, protein–polyphenol complexes reduce the digestibility of pea and soybean PI. Nine commercial pea PI with different physical and chemical characteristics were used to form complexes with polyphenols from cranberry pomace [ 81 ]. For some PI, no significant differences were found in the pepsin digestion of non-complexed and complexed proteins; however, all complexed isolates were less extensively hydrolysed by pancreatin digestion.…”