Correlation between Physico-Chemical Characteristics of Particulated β-Lactoglobulin and Its Behavior at Air/Water and Oil/Water Interfaces.

Franziska Kurz,Claudia Hengst,Christine Bilke-Krause,Jannika Dombrowski,Vera Reitberger,Ulrich Kulozik

doi:10.3390/foods10061426

Franziska Kurz, Claudia Hengst + Show 4 more

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https://doi.org/10.3390/foods10061426

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Abstract

It is widely accepted that protein-based particles can efficiently stabilize foams and emulsions. However, it is not fully elucidated which particle properties are decisive for the stabilization of air/water and oil/water interfaces. To unravel this correlation, selected properties of nano-sized soluble β-lactoglobulin particles were changed one at a time. Therefore, particles of (1) variable size but similar zeta potential and degree of cross-linking and (2) similar size but different further properties were produced by heat treatment under a specific combination of pH value and NaCl concentration and then analyzed for their interfacial behavior as well as foaming and emulsifying properties. On the one hand, it was found that the initial phase of protein adsorption at both the air/water and the oil/water interface was mainly influenced by the zeta potential, independent of the particle size. On the other hand, foam stability as resolved from the time-dependent evolution of mean bubble area negatively correlated with disulfide cross-linking, whereas emulsion stability in terms of oil droplet flocculation showed a positive correlation with disulfide cross-linking. In addition, flocculation was more pronounced for larger particles. Concluding from this, foam and emulsion stability are not linked to the same particle properties and, thus, explanatory approaches cannot be used interchangeably.

Highlights

IntroductionBased on the current state of the literature, the correlation between specific particle properties and high foam as well as emulsion stability has still not been fully elucidated, i.e., knowledge of decisive particle properties for different applications as well as interface types is lacking
Protein particles have attracted considerable attention during the last few years, in the context of stabilizing foams and emulsions as they are deemed to provide high product stability and offer novel opportunities for the food industry [1,2,3].based on the current state of the literature, the correlation between specific particle properties and high foam as well as emulsion stability has still not been fully elucidated, i.e., knowledge of decisive particle properties for different applications as well as interface types is lacking
A mechanistic understanding of how those particles act at both air/water and oil/water interfaces is crucial for their design and applicability

Summary

Introduction

Based on the current state of the literature, the correlation between specific particle properties and high foam as well as emulsion stability has still not been fully elucidated, i.e., knowledge of decisive particle properties for different applications as well as interface types is lacking. In this regard, a mechanistic understanding of how those particles act at both air/water and oil/water interfaces is crucial for their design and applicability. To better understand and explain their functionality in contrast to inorganic particles or to proteins in their native state, in depth knowledge about their behavior at air/water and oil/water interfaces is required. Due to the deformable and porous structure of protein particles, a transfer of the classical contact angle-based ‘Pickering concept’ is not considered reasonable [4,5,6].

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