Barbary,, O. (2000). KEEPING ONION QUALITY USING TREHALOSE PRIOR TO DRYING. Journal of Food and Dairy Sciences, 25(1), 305-317. doi: 10.21608/jfds.2000.258310
O. M. Barbary,. "KEEPING ONION QUALITY USING TREHALOSE PRIOR TO DRYING". Journal of Food and Dairy Sciences, 25, 1, 2000, 305-317. doi: 10.21608/jfds.2000.258310
Barbary,, O. (2000). 'KEEPING ONION QUALITY USING TREHALOSE PRIOR TO DRYING', Journal of Food and Dairy Sciences, 25(1), pp. 305-317. doi: 10.21608/jfds.2000.258310
Barbary,, O. KEEPING ONION QUALITY USING TREHALOSE PRIOR TO DRYING. Journal of Food and Dairy Sciences, 2000; 25(1): 305-317. doi: 10.21608/jfds.2000.258310
KEEPING ONION QUALITY USING TREHALOSE PRIOR TO DRYING
Dept. of Food Sci., Fac. of Agric. (Saba Basha), Univ. of Alexandria.
Abstract
Onion samples were immersed in different trehalose solutions (1.00; 0.50; 0.25 and 0.00 g/L) for 5; 10; 15; 25 and 30 min. at room temperature, then oven dried at 60°C. Sensory attributes (colour, flavour by mouth and odour); dry matters; total sulphur and pyruvic acid contents of fresh and dried onions were investigated. Sensory attributes scores revealed that trehalose concentration had remarkable effects on the colour; flavour by mouth and odour of the dried onions. Using trehalose solution at 1.0 g/L for 5 min prior to drying of onions showed the best sensory results as well as the highest total sulphur and pyruvic acid contents as compared to the other concentrations used. The dry matter contents of onions were neither affected by trehalose concentrations nor by the time of soaking. Dried onions that soaked in trehalose solutions (1.0 g/L for 5 min; 0.50 g/L for 15 min and 0.25 g/L for 30 min.) were stored in glass bottles at room temperature up to 6 months. Results revealed that the concentration and the time of storage affected the quality of dried onions. Onions soaked in trehalose solution at 1.0 g/L for 5 min greatly retained both flavour by mouth and odour of fresh onions with acceptable colour for 6 months. The total sulphur and pyruvic acid contents obtained supported the sensory results. Meanwhile, samples soaked in trehalose solutions at 0.50 or 0.25 g/L for 15 and 30 min prior to drying could be stored for 4 and 2 months, respectively, with acceptable sensory and chemically qualities. Using trehalose solutions prior to drying of foods opens a new era in food drying process as it is very cheap, simple and keeps the freshness characteristics of the food after rehaydration.