PHYSICAL PROPERTIES OF MICROENCAPSULATED STRAWBERRY JUICE

Abstract

Microencapsulated strawberry juice powders were obtained by freeze-drying using maltodextrin and inulin as encapsulating materials at different concentrations (10–25%). The aim of the study was to evaluate the physical properties of microencapsulated strawberry juice powders (bulk density, yield, rehydration ratio, and color characteristics) and to determine the effect of the type and concentration of encapsulating materials on these parameters. The data were analyzed using analysis of variance (ANOVA), and statistically significant differences were determined at p ≤ 0.05. The results showed that no statistically significant differences in bulk density were observed between different concentrations of maltodextrin and inulin, while the bulk density of strawberry juice powder without encapsulating materials could not be determined due to pronounced hygroscopicity and stickiness after freeze-drying. Powder yield increased with increasing concentrations of encapsulating materials, with the highest values (approximately 24–25%) obtained in samples containing 25% maltodextrin or inulin. In contrast, the rehydration ratio decreased as the concentration of encapsulating materials increased, which may be associated with higher total solids content and reduced powder solubility. Color analysis using the CIE Lab* system showed that increasing the concentration of encapsulating materials resulted in a statistically significant increase in lightness (L*) values, while redness (a*) and yellowness (b*) values decreased. The highest L* values were observed in samples containing 25% encapsulating materials, particularly when inulin was used, producing lighter powders compared to maltodextrin. The results indicate that both the type and concentration of encapsulating materials significantly influence the physical properties and technological applicability of microencapsulated strawberry juice powders.