Bioactives and extracts affect the physico-chemical properties of concentrated whey protein isolate dispersions

Abstract

Non-covalent complexation interactions are known to occur between bioactive compounds and proteins. While formulating with these components can have positive outcomes such as stabilization of colors and actives, it can also result in changes to the structures and physical properties of proteins, affecting product functionality and sensory attributes. Previous experiments reported measurable changes in the physico-chemical properties of whey protein isolate (WPI) dispersions upon formulation with Aronia berry extract, ascribing changes to protein-polyphenol (PP) interactions in the systems. Pure gallotannin, beet extract, and cranberry extract, providing a diverse variety structures and sizes, were selected for further experimentation and comparison with the effects of Aronia extract. Concentrated dispersions with varying WPI:sucrose ratios, formulated with several bioactives contents from multiple different sources were analyzed to identify the effects of different bioactives on physico-chemical properties of dispersions. Dispersions formulated with cranberry extract demonstrated the largest increases in surface tensions, viscosities, and particle sizes, while those formulated with beet extract were the least affected by the presence of bioactives, suggesting that different bioactives and extracts had varying propensities for complexation interactions with WPI, despite their relatively low levels of addition (0, 0.5, and 1%). Graphical Abstract: [Figure not available: see fulltext.]