Effect of spray drying conditions and feed composition on the physical properties of black mulberry juice powder

• Published in: Food and bioproducts processing 2012-10, Vol.90 (4), p.667-675
• Main Authors: Fazaeli, Mahboubeh, Emam-Djomeh, Zahra, Kalbasi Ashtari, Ahmad, Omid, Mahmoud
• Format: Article
• Language: English
• Subjects: air flow; air temperature; Biological and medical sciences; Black mulberry; Bulk density; Feed and pet food industries; feed composition; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Glass transition temperature; glucose; gum arabic; juices; microstructure; Morus nigra; porosity; powders; Solubility; Spray drying; water activity; water content; Yield
• ISSN: 0960-3085; 1744-3571
• DOI: 10.1016/j.fbp.2012.04.006

► Effects of spray drying conditions on the powder properties were investigated. ► Decreasing maltodextrin DE causes an increase in drying yield and solubility. ► Higher inlet air temperature causes a decrease in moisture content. ► Increasing the compressed air flow rate has a positive effect on bulk density. ► Blend of maltodextrin 6DE and gum Arabic shows the best effect on powder property. In this study, the effects of some processing parameters on moisture content, water activity, drying yield, bulk density, solubility, glass transition temperature (Tg), and microstructure of spray dried black mulberry (Morus nigra) juice powders were investigated. A pilot-scale spray dryer was employed for the spray drying process and maltodextrin with different dextrose equivalent (6, 9, and 20DE) and gum Arabic were used as carrier agent. Independent variables were inlet air temperature (110, 130, and 150°C), compressed air flow rate (400, 600, and 800L/h), concentration of drying aids (8, 12, and 16%) and percent replacement of maltodextrin (6 and 9DE) by gum Arabic and maltodextrin 20DE (25, 50, and 75%). Between the different drying aids, maltodextrin 6DE shows the best effect on the properties of black mulberry juice powders. The process drying yield ranges from 45 to 82%. The highest drying yield (82%) and solubility (87%) refer to the blend of maltodextrin 6DE and gum Arabic. The lowest moisture content powders (1.5%) produced at the compressed air flow rate of 800L/h. Inlet air temperature negatively influenced the bulk density due to the increase of powder's porosity. The lower the bulk density, the higher the solubility of powder is. With regard to morphology, powders produced with maltodextrin and gum Arabic presented the smallest size.