Micro wet milling and spray drying of whole mandarin powder and its characterization

Abstract

A study was conducted using micro wet milling and spray drying to produce whole mandarin juice (WMJ) powders using maltodextrin as a carrier agent. Micro wet milling (MWM) was successfully produced concentrated whole fruit Mandarin slurry with smaller particle sizes of 43.15 µm and enhanced the physico chemical and antioxidant properties. Spray dried WMJ powders were analyzed for moisture, glass transition temperature, water activity, solubility, flowability, particle size, surface morphological and total polyphenol content. Results demonstrated that WMJ powders with higher maltodextrin solids exhibited better physical properties. The usage of 40 to 70% maltodextrin resulted in hygroscopic powders with lower moisture content, reduced water activity and increased solubility. The WMJ powders yield were also increased as maltodextrin levels in powders increased but the total phenolic compounds were decreased. Surface morphological characterization using SEM revealed that all WMJ powders are irregular spherical shapes, smoothed surfaces, agglomerated and no shrinkage observed. The study was also attempted to quantify the four major carotenoids (α-carotene, β-cryptoxanthin, lutein, violaxanthin) presents in the WMJ powders by HPLC. The results demonstrated that all WMJ powders retained carotenoids except violaxanthin in the order of β-cryptoxanthin > lutein > α-carotene.