Effect of spray-drying or freeze-drying on the physicochemical parameters, antioxidant activity, and volatile components of craft beer

Summary Converting craft beer to a powder form allows the concentration of phenolic and volatile compounds. In this study, craft beer was brewed in laboratory brewing equipment and converted to a powder using freeze-drying and spray-drying processes. When the freeze-dried powder was dissolved in water, its physicochemical properties were identical to those of craft beer. Freeze-drying effectively encapsulated the bioactive compounds in craft beer, with an encapsulation rate of 99.6%, which was 27.6% higher than that of spray-drying. Headspace solid-phase microextraction coupled to gas chromatography–mass spectrometry analysis revealed that the esters were effectively retained after freeze-drying and had the highest retention of 90% for ethyl hexanoate, whereas spray-drying resulted in the loss of most of the esters. Spray-dried particles were all spherical, whereas lyophilized particles were irregularly shaped. The particle size ranged from 6.28 μm to 12.15 μm for spray-dried powders and from 14.19 μm to 50.97 μm for lyophilized powders. The findings indicate that both encapsulation methods are effective for the preparation of craft beer powder. However, freeze-drying can encapsulate the bioactive and volatile compounds in craft beer more effectively than spray-drying and aid in the better retention of craft beer characteristics.