APPLICATION OF THE AGGLOMERATION PROCESS ON VEGETABLE JUICE POWDERS OBTAINED BY SPRAY DRYING METHOD
Project no. 1369 · Status: Kapanmış · 2018
Summary
In this study, agglomeration process was applied in order to improve the functional properties of the vegetable powders produced by spray drying technique. The drying was performed in a spray dryer at 160/100 ° C air inlet/outlet temperature at 1.00 ± 0.20 kg /h feed flow rate, 392kPa atomizer pressure and 1.54 m3 / min air flow rate and the agglomeration was performed in a fluidized bed dryer at 60 ° C and 1.6 m/s air velocity. Distilled water, maltodextrin, whey and gum arabic solutions were used as binding agents. The moisture content of the obtained spinach juice agglomerates was measured in the range of %6.44-%11.68 while the moisture content of the carrot juice agglomerates was in the range of 11.35% -12.8%. Water activity values for spinach and black carrot agglomerates are between 0.254-0.412 and 0.256-0.379 respectively. According to the results of the color analysis, with the agglomeration process a decrease in brightness (L *) values was observed and an increase in yellowness/ blueness (b *) values was observed. It has been observed that agglomeration of vegetable powders increases the mean particle diameters and wettability and solubility times. The calculated bulk and tapped density values for spinach and black carrot agglomerates are respectively; 380-510 kg/m3 and 490-618 kg/m3, 328-445 kg/m3 and 430-565 kg/m3. The cohesiveness and flowability properties of agglomerates were improved compared to powder products. Due to the agglomeration process, particle density and porosity values increased and hygroscopic properties were improved due to the increase of particle size. The friability values for spinach and black carrot agglomerates are respectively 5.02-95.4% and 37.21-77.04%; and the solubility (%) values ranged from 99.17% to 99.41% and from 99.17% to 99.6%. When the results of SEM and DSC analysis are examined; the glass transition temperature of the obtained spinach and black carrot powders were 110.72°C and 18.81°C respectively while for the agglomerates these values changed between 117.32°C-127.38°C and -5.42°C-20.47°C. As a result, agglomeration of the spinach and black carrot juice powders obtained by the spray drier can be successfully carried out in the fluidized bed. Key words: black carrot, spinach, spray drying, agglomeration, fluid bed agglomeration, reconstitution properties