Influence of spray drying on water solubility index, apparent density, and anthocyanin content of pomegranate juice powder

Abstract

Pomegranates, originally cultivated in Iran and a valuable medicinal and nutritional fruit, could be converted into pomegranate juice powder to be accessible in other seasons and used as a valuable ingredient in other food and pharmaceutical products. In this research, pomegranate juice was spray dried at three maltodextrin levels (25, 35 and 45% w/w) and two inlet air temperatures (124 and 143°C) and physicochemical and nutritional characteristics of the powder were surveyed. The experiments were carried out to measure drying yield, water solubility index, apparent density, color values, anthocyanin content, and morphological properties of the pomegranate juice powders. Inlet air temperature just could affect density of the powder while maltodextrin level could influence anthocyanin content of the final powder as well. Higher maltodextrin levels and temperatures lowered a* values of the powder, due to the lower anthocyanin content remained in the product at these situations. SEM analysis revealed that lower maltodextrin levels and higher inlet air temperatures resulted in smaller but smoother particles. In conclusion, pomegranate juice powders produced at 25% maltodextrin level and 124°C, with high water solubility index of 95%, high density of 0.889gcm−3, and anthocyanin content of 8mgL−1, are suitable and nutritionally-rich choices for industrial production.