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There is a variety of yeast components that can both achieve a greater commercial value than the brewer’s yeast itself and maximize the total profitability of the process of beer production. One such compound is β-D-glucan, a yeast cell wall polysaccharide that can be used in several ways. Therefore, spent brewer’s yeast can be a good raw material for its production. Yeast β-glucan possesses many interesting properties and it is a high-value product which can improve human and animal health and immune system. Its applications in food production, pharmaceutics, chemical industry, and cosmetics are also described. Water-insoluble (particulate) β-glucans were previously isolated from spent brewer’s yeast from a Croatian brewery. Average particle dimensions of 6.56 – 9.61 μm, obtained after sonication and spray-drying, were still higher than those regarded as optimal for binding to macrophage receptors. This study focused on optimization of ultrasonic treatment and parameters of spray-drying (type of dispersion medium, concentration of β-glucans suspension, duration of ultrasonic treatment), in order to obtain smaller β-glucan particles with a higher biological activity and better immunopotentiation ability. Optimization experiments were performed using wet β-glucan preparations, isolated using two different isolation procedures: alkaline (A) and alkaline-acidic with mannoprotein removal (AAM). The obtained average particle dimensions of 1.54 – 2.05 μm could be more favorable for exerting biological activity. The yield of spray-drying was increased by ethanol as dispersion medium. All spray-dried β-glucans showed ability of swelling shortly after being resuspended in water. |
