The Effect of Carrier Quantity and Drying Method on the Physical Properties of Apple Juice Powders

Abstract

Abstract:The study aimed at the evaluation of the physical properties of apple juice powders mixed with different concentration of maltodextrin obtained by freeze-, vacuum and spray drying methods. Due to the chemical composition of apple juice there was a possibility to obtain apple juice powders by freeze-, spray and vacuum drying, excluding vacuum drying at 40 • C when 15% and 20% of maltodextrin were added. The moisture content of powders was more dependent on the drying method than on the quantity of maltodextrin added. The spray drying process in the context of an increase in maltodextrin quantity resulted in a decrease in the water activity of apple powders, whereas low temperature processes increased its values. Lower values of true density were observed after spray drying in comparison to freeze-and vacuum drying processes. The application of selected drying methods resulted in the formation of different particles' size of apple powders influencing the bulk density of the products. The highest values of bulk density were indicated for powders obtained by vacuum drying due to the bigger size of the particles (crystalized structure). The porosity of apple juice powders was strictly related to the bulk density. Colour parameters of powders were more influenced by drying techniques than the quantity of maltodextrin (15% up to 35%) added.

The Influence of Maltodextrin and Inulin on the Physico-Chemical Properties of Cranberry Juice Powders

“…In general, the spray-drying process resulted in a lower moisture content (approximately 87%) in comparison to powders gained after the freeze-drying process, regardless of the type of carrier and the concentration used for the preparation of feed solutions. A similar observation was made in case of apple powders [31]. Likewise, in the studies on the watermelon, Gac, and ginger juice [14,[32][33][34], it was observed that a higher content of carrier in the feed solution resulted in a lower moisture content of the powders obtained, pointing to a strong influence of the carrier concertation on the powders' final properties.…”

“…In the powders obtained after freeze-drying, lower water activity and lighter color were noticed, whereas, after spray-drying, higher water activity and a darker color of powders were indicated. In the studies performed by Michalska and Lech [31], powders of the apple juice containing maltodextrin were lighter after the freeze-drying process when compared to spray-drying. When the coordinate a* was concerned, the increase in the concentration of the carrier caused a decrease in the a* values.…”

“…Similarly to watermelon and apple juice powders, the average a w of the cranberry powders obtained after the freeze-drying process was approximately 3.9 times higher when compared to powders obtained after the spray-drying process, regardless of the type of carrier used and the concentration applied for feed preparation [14,31]. In general, among the powders gained after the freeze-drying process, the increased concentration of carriers lowered the water activity of the products, which was also observed in case of Cagaita powders [38].…”

“…At the same time, inulin protected the red pigments (coordinate a*) and b* values to the highest extent, even when compared to freeze-dried powders. Thus, the type of carrier and the drying method applied had a strong influence on the coordinated L*, a*, and b* values [31]. Table 2.…”

Process optimization of polyphenol‐rich milk powder using bee pollen based on physicochemical and functional properties

“…The bulk density for present study (Table ) varied from 0.37 to 0.63 g cm −3 which falls within the limit for food powders, however, crossed the lower limit of skim milk powders due to the higher fat content (12.38%) in the rapeseed bee pollen (when added at a rate of 15% rather than 5%). Moreover, the vacuum drying causes the bigger size of particles (crystallized structure) thus resulting in the higher bulk density of powders than the freeze and spray drying (Michalska & Lech, ). The linear effects of pollen ( x 1 ) and temperature ( x 2 ) were strongly significant ( p < .0001) for bulk density showing the increase in bulk density on reducing the pollen and temperature (Figure ).…”