Physicochemical Characterization of Interactions between Blueberry Polyphenols and Food Proteins from Dairy and Plant Sources

Abstract

Polyphenols are widely known for their benefits to human health; however, dietary intake of this class of compounds is low in the United States due to low intake of fruits and vegetables. Dairy foods (i.e., milk, yogurt) have been shown to increase polyphenol bioavailability via protein–polyphenol interactions, which may have important implications for human health. Increasing consumer interest in sustainability and health has led to the introduction of a variety of novel plant-based proteins and related food products as dairy alternatives. This study compared whey, a popular dairy-based food protein, to pea and hemp proteins for their abilities to form complexes with polyphenols from blueberries, which are a widely consumed fruit in the US with demonstrated health effects. Physical and chemical characteristics of each protein extract in the presence and absence of blueberry polyphenols were investigated using a variety of spectroscopic methods. The influence of polyphenol complexation on protein digestion was also assessed in vitro. While all proteins formed complexes with blueberry polyphenols, the hemp and pea proteins demonstrated greater polyphenol binding affinities than whey, which may be due to observed differences in protein secondary structure. Polyphenol addition did not affect the digestion of any protein studied. Solution pH appeared to play a role in protein–polyphenol complex formation, which suggests that the effects observed in this model food system may differ from food systems designed to mimic other food products, such as plant-based yogurts. This study provides a foundation for exploring the effects of plant-based proteins on phytochemical functionality in complex, “whole food” matrices, and supports the development of plant-based dairy analogs aimed at increasing polyphenol stability and bioavailability.

The Effect of a High-Protein Diet Supplemented with Blackthorn Flower Extract on Polyphenol Bioavailability and Antioxidant Status in the Organs of C57BL/6 Mice

“…Hydrophobic interactions mainly occur between the nonpolar aromatic rings of polyphenols and the hydroxyl groups of amino acids in proteins, while van der Waals forces act between all types of molecules and can contribute to the overall formation of protein–polyphenol complexes [ 48 , 49 ]. In a recent study by Chima et al [ 50 ], the physicochemical interactions between blueberry polyphenols and proteins from dairy and plant sources were investigated in vitro, along with the impact of polyphenol complexation on protein digestion. They compared whey proteins with pea and hemp proteins.…”

Bioactive Dairy-Fermented Products and Phenolic Compounds: Together or Apart

“…Interactions between polyphenols and proteins cause many effects, like stabilization of proteins, decrease in the antioxidant activities of proteins and polyphenols, reduction in protein digestibility, increase in thermal stability, modifying the physiochemical properties, and many others, as described in the data that has been presented in the literature [150][151][152].…”

Food Antioxidants and Their Interaction with Human Proteins

“…In general, co-ingestion of antioxidants and proteins may induce their interaction, sometimes resulting in reduced bioavailability of antioxidants (or, rarely, increased). Dairy products, for example, can increase the availability of polyphenols from berries via polyphenol/protein interaction [ 15 ].…”