Providing Stability to High Internal Phase Emulsion Gels Using Brewery Industry By-Products as Stabilizers.

Adrián López-García,Gemma Moraga,Isabel Hernando,Amparo Quiles

doi:10.3390/gels7040245

Adrián López-García, Gemma Moraga + Show 2 more

Open Access

https://doi.org/10.3390/gels7040245

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Journal: Gels	Publication Date: Dec 1, 2021
Citations: 2	License type: CC BY 4.0

Affiliation: Universitat Politècnica de València

Abstract

The modern brewing industry generates high amounts of solid wastes containing biopolymers—proteins and polysaccharides—with interesting technological and functional properties. The novelty of this study was to use raw by-product from the brewing industry in the development of high internal phase emulsion (HIPE) gels. Thus, the influence of the emulsion’s aqueous phase pH and the by-product’s concentration on structural and physical stability of the emulsions was studied. The microstructure was analyzed using cryo-field emission scanning electron microscopy. To evaluate the rheological behavior, oscillatory tests (amplitude and frequency) and flow curves were conducted. Moreover, the physical stability of the emulsions and the color were also studied. The increase in by-product concentration and the pH of the aqueous phase allowed development of HIPE gels with homogeneously distributed oil droplets of regular size and polyhedral structure. The data from the rheology tests showed a more stable structure at higher pH and higher by-product concentration. This study widens the possibilities of valorizing the brewing industry’s by-products as stabilizers when designing emulsions.

Highlights

Food and by-product management is one of the main challenges that the agroindustrial sector faces in the 21st century
This study aimed to structure sunflower oil to obtain high internal phase emulsion (HIPE) gels using brewing industry by-products as stabilizers
Samples 9H, 12L, and 12H were observed using the Cryo-FESEM technique to study the effect of pH and by-product concentration in the microstructure of the emulsions (Figure 1)

Summary

Introduction

Food and by-product management is one of the main challenges that the agroindustrial sector faces in the 21st century. Modern brewing is an industry producing high amounts of by-products, including solid and liquids. Throughout the process, diverse solid wastes are produced, mainly spent grains, trub, and spent yeast [1]. Trub is an effluent mainly composed of hop particles, colloidal proteins, and residual beer liquor. Spent yeast comprises excess yeast recovered from sedimentation in the tank. Trub and spent yeast generation can reach 0.4 and 3 kg per hL of beer, respectively [2]

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