Valorisation of brewers’ spent grain in different particle size in yogurt production

¹ Department of Functional Food Products Development, Faculty of Biotechnology and Food Science, Wroclaw University of Environmental and Life Sciences, 51-630, Wroclaw, Poland
² Department of Chemistry, Faculty of Natural Sciences and Mathematics, University of Tetova, 1200 Tetovo, North Macedonia
³ Department of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb 10000, Croatia
⁴ Institute of Agricultural Engineering, Wroclaw University of Environmental and Life Sciences, 51-630, Wroclaw, Poland
⁵ Food Chemistry and Food Development, Department of Life Technologies, University of Turku, 20014 Turku, Finland
⁶ Fraunhofer Institute for Process Engineering and Packaging IVV, 85354 Freising, Germany
⁷ Center of Food and Fermentation Technologies, TFTAK, 12618 Tallim, Estonia

^* Corresponding author: joncer.naibaho@upwr.edu.pl

Abstract

The potential of brewers’ spent grain (BSG) as a functional food ingredient has been investigated for having high nutritional value. A high amount of dietary fiber of BSG shows a high ability to bind water; thus, it tends to solidify food mixture. This characteristic has a beneficial effect in the utilization of BSG as a filler and texturizer in yogurt. The study aims to evaluate the impact of the BSG addition in yogurt production and its quality. BSG was prepared in three different particle sizes, and an amount of 10% was added for yogurt fermentation. The impact of BSG addition was evaluated after 24 h of storage. The result shows that different particle sizes of BSG had no significant impact on pH and syneresis, while it significantly affected the amount of lactic acid and countable S. thermophilus. However, BSG increased the fermentation rate of yogurt, and had a positive impact on water holding capacity. A lower particle size had a higher amount of lactic acid and a lower S. thermophilus. The lower particle size lowered the lightness of the yogurt. Rheological analysis showed that a higher particle size of BSG increased the shear stress and viscosity of yogurt.