Effects of Spray-Drying Conditions on the Functional and Physicochemical Properties of Young Barley Grass Juice Powders

Young barley leaves have been proven to distinguish themselves as highly potent in antioxidant activity, resulting from a high content of bioactive compounds. Due to their short storage time, it is crucial to prolong their shelf life. One of the methods that can be used is spray-drying, as it enables the production of powders that are highly valued in the food industry. This paper aimed to analyze the possibility of producing young barley leaf juice with improved properties. Juices were spray-dried with and without carriers at 100/60 °C inlet/outlet temperature using air of 1.5 g/m³ humidity as the drying medium. Maltodextrin (MD), Nutriose^® (N), and Arabic gum (AG) were used in a ratio 1:3 carrier/juice solids. The results proved that dehumidified air application enabled the production of young barley leaf juice powder, that was free of the carriers, of high retention coefficient (RC) of chlorophyll A and B (80.84 ± 6.56% and 87.05 ± 5.21%, respectively). No statistical difference was noted between variants with maltodextrin (chlorophyll A: 91.22 ± 5.07%, chlorophyll B: 71.72 ± 5.44%), Nutriose^® (chlorophyll A: 72.24 ± 5.32%, chlorophyll B: 67.04 ± 12.41%), and carrier-free powder; thus, the elimination of a carrier can be considered to effectively produce a "clean" label, functional product. The highest degradation among the tested bioactive compounds was noted for vitamin C.