The use of Spray Drying and Agglomeration Methods to Obtain Vegetable Juice Powder and Agglomerates
Project no. 353 · Status: Kapanmış · 2018
Summary
In this study, agglomeration was applied to spray dried vegetable juice powders and the obtained agglomerates were stored at 3 different temperatures for 6 months. The spray drying was carried out at a feed rate of 1.00±0.20kg/h, at the air inlet/outlet temperature of 160/100°C; agglomeration was carried out in a fluid bed dryer at 60°C. 1.6 m/sec (with water, maltodextrin, whey protein isolate and gum arabic as drying agents). The moisture content and water activity values of the spinach and black carrot juice agglomerates were; 6.44% -11.68% and 11.35% -12.8% and 0.254-0.412 and 0.256-0.379 respectively. The agglomeration process showed that wettability and solubility times decreased, and stickiness, flowability and hygroscopicity were improved compared to the powder products. The friability values of spinach and black carrot agglomerates were 5.02- 95.4% and 37.21- 77.04% respectively. The glass transition temperature of the spinach and black carrot powders was 110.72°C and 18.81°C, and increased to 117.32 ° C-127.38°C and -5.42°C-20.47°C respectively. SEM analysis showed the increase in particle size with agglomeration. During storage, the moisture content of spinach and black carrot agglomerates changed between 4-11% and 7.45%-12.28%; 0.31-0.61 and 0.25-0.50. For the agglomerates, (L*) values increased, (a*) and (b*) values decreased as the temperature increased. The wettability and solubility times of the stored spinach and black carrot agglomerates were respectively 29.50-320.00sec and 12.50-157.00sec; 435.50-1790.00sec and 125.00-675.00 sec depending on the binder solution. The bulk and tapped density values for spinach and black carrot agglomerates were, 289.90-452.80 kg/m3 and 329.40-590.44 kg/m3 ; and 253.55-396.00 kg/m3 and 306.74-558.24 kg/m3 respectively. The Tg values of the agglomerates were found to vary depending on the storage time, temperature and binding solution. Key words: black carrot, spinach, spray drying, agglomeration, fluid bed agglomeration