GARCIA Daniela Celeste
congresos y reuniones científicas
EFFECT OF DRYING TEMPERATURE ON THE NUTRITIONAL AND FUNCTIONAL PROPERTIES OF BEER SPENT GRAINS FOR THE PREPARATION OF FUNCTIONAL FOODS
GARCIA, DANIELA CELESTE; I VILLALBA; N SAVINO; G FRAGOLA; C GUPTA
Congreso; International Conference on Food Sustainability: Challenges and Oportunities for the Future; 2022
Beer is one of the most popular and widely consumed beverages all over the world. The brewing process produces significant amounts of an insoluble residue, known locally as brewer´s spent grain (BSG). The sustainable use of organic waste and by-products generated in the food industry has lately attracted great attention due to increased environmental awareness. Besides, BSG may be used as raw material for the development of new food products that can provide higher nutritional and functional value. Most of the BSG contains a high degree of moisture (70-80%), which must be dried and processed to storage to avoid rapid microbiological deterioration. The objective of this work was to evaluate the drying conditions of lager beer BSG and the characterization of BSG powder extracts. The BSG after being collected from breweries was dried at room temperature by natural aeration and in drying ovens at 45, 60, and 100°C. Subsequently, dried BSG was processed in an electric grinder to powder. BSG powder were extracted assisted by ultrasound using hydroalcoholic solvents. Phenolic compound contents were measured by the Folin-Ciocalteu method. Besides, melanoidin, soluble sugars, tannins, and soluble protein concentrations were also determined. Antioxidant activity were analyzed using ABTS radical bleaching method. Lipid oxidative status was measured as TBARS. Results indicate that when drying BSG at high temperatures, significant increases in phenolic compound contents were observed. Significant increases were also observed in the antioxidant activity of the extracts and their melanoidin contents. Parallelly, BSG drying at 100 °C increased oxidative deterioration markers. BSG from lager beer dried at high temperatures leads to a material rich in antioxidants and phenolic compounds although increased lipid oxidation. Drying by natural aeration would allow obtaining extracts rich in bioactive compounds and lower oxidative status; besides, it reduces energy consumption.