Submitted to: Proceedings for CIGR World Congress Meetings
Publication Type: Proceedings
Publication Acceptance Date: 6/15/2006
Publication Date: 9/3/2006
Publication URL: www.cigr.com
Citation: Pan, Z., Shih, C., Mc Hugh, T.H., Hirschberg, E. 2006. Study of Banana Dehydration Using Sequential Infrared Radiation and Freeze-Drying. Proceedings of XVI CIGR World Congress, 9/3-9/7/06, Bonn, Germany. Paper 1-16. Interpretive Summary: This research studied the drying and quality characteristics of bananas dried with a sequential infrared radiation and freeze-drying method.
Technical Abstract: The drying and quality characteristics of banana slices processed with a sequential infrared radiation and freeze-drying (SIRFD) method were investigated. To study the drying characteristics of bananas during the infrared (IR) and hot air predehydration, Cavendish bananas slices with 5 mm thickness were pre-dehydrated using IR heating at each one of three radiation intensities, 3000, 4000, and 5000 W/m2 or hot air at 62.8°C. The pre-dehydrated samples with 20% and 40% weight reductions obtained using 4000 W/m2 IR intensity were then further dried using freeze-drying for various times to determine the effect of pre-dehydration on the drying rate during freeze-drying. To improve the quality of dried banana chips, the banana slices were also treated with a dipping solution containing 1% ascorbic acid and 1% citric acid before the IR pre-dehydration. Control samples were produced using regular freeze-drying without the pre-dehydration. The quality characteristics of dried banana chips, including color, thickness shrinkage and crispness were evaluated. The pre-dehydration results showed that the drying rate of IR heating was significantly higher than the hot air drying and increased with the increase of IR intensity. However, the banana slices with IR pre-dehydration dried slower during freeze-drying compared to the samples without pre-dehydration, which was due to texture changes that occurred during predehydration. The acid dipping treatment improved the drying rate during freeze-drying and effectively minimized the browning of banana chips. It is recommended to use acid dipping and IR pre-dehydration treatments for producing crispy banana chips.