Microencapsulation of β-carotene using barley residue proteins from beer waste as coating material

This study aimed to produce and characterise microparticles produced from barley residue proteins (BRP) enriched with β-carotene. The microparticles were obtained by freeze-drying five emulsion formulations with 0.5% w/w whey protein concentrate and different concentrations of maltodextrin and BRP (0, 1.5, 3.0, 4.5 and 6.0% w/w), with the dispersed phase consisting of corn oil enriched with β-carotene. The mixtures were mechanically mixed and sonicated, the formed emulsions were freeze-drying. The microparticles obtained were tested for encapsulation efficiency, humidity, hygroscopicity, apparent density, scanning electron microscopy (SEM), accelerated stability and bioaccessibility. Microparticles produced with the emulsion containing 6% w/w BRP had lower moisture content (3.47 ± 0.05%), higher encapsulation efficiency (69.11 ± 3.36%), bioaccessibility value of 84.1% and greater β-carotene protection against thermal degradation. SEM analysis showed that microparticles had sizes ranging from 74.4 to 244.8 µm. These results show that BRP are viable for the microencapsulation of bioactive compounds by freeze-drying.

Barley Protein Properties, Extraction and Applications, with a Focus on Brewers' Spent Grain Protein

Barley is the most commonly used grain in the brewing industry for the production of beer-type beverages. This review will explore the extraction and application of proteins from barley, particularly those from brewers’ spent grain, as well as describing the variety of proteins present. As brewers’ spent grain is the most voluminous by-product of the brewing industry, the valorisation and utilisation of spent grain protein is of great interest in terms of sustainability, although at present, BSG is mainly sold cheaply for use in animal feed formulations. There is an ongoing global effort to minimise processing waste and increase up-cycling of processing side-streams. However, sustainability in the brewing industry is complex, with an innate need for a large volume of resources such as water and energy. In addition to this, large volumes of a by-product are produced at nearly every step of the process. The extraction and characterisation of proteins from BSG is of great interest due to the high protein quality and the potential for a wide variety of applications, including foods for human consumption such as bread, biscuits and snack-type products.