Physical, chemical and quality properties of agglomerates and their beverages from fluidised bed drying of calamansi, pineapple and starfruit juice

Abstract

Calamansi, pineapple and starfruit juice can be converted into powder or agglomerate through the process of fluidised bed d rying and agglomeration. One kilogramme of ground sugar was used as a carrier for the fluidised bed drying and agglomeration process. Essential minor additives i.e. anhydrous citric acid, flavour and permitted food colour were used to boost up flavour, sugar-acid balance and eye appeal of the product. Suitable process variables used were 40°C as the pro c e s s t e m p e r a t u re, 20 m /h as the volumetric airflow rate which resulted in an air velocity of 1.5 m/s, an atomisation pre s s u re of 3 bar and a pump flow rate of 8 g/min. Fresh juice was used as a binder for the agglomeration process in the fluidized bed dryer which was sprayed at the beginning of the drying process. Moisture content and juice re c o v e ry of the fruits were determined. The c o l o u r, TTA, pH and viscosity of the juice were obtained and compared to that of the beverage. Organoleptic evaluation based on five sensory attributes of the juice was compared to the beverage. The particle size distribution of the agglomerates was determined by sieving. From the cumulative distribution plot, the median diameter for the carrier and agglomerates were determined. The colour, bulk density, moisture content and nutrient compositions of the agglomerates were analysed. Sorption isotherm of the agglomerates at the beginning of the storage period was analysed by determining the initial moisture content and water activity. Thus, the critical moisture content and the equilibrium relative humidity of the agglomerates were obtained fro m the graph. Microbiological quality remained the same throughout the 12 months of storage. Storage of the agglomerates for a period of 12 months at room temperature using laminated OPP/PE/AL/PP (with thickness 20µ:15µ:7µ:25µ) pouches did not change the physical, chemical and quality pro p e rties of the agglomerate.