|Pekke, Milly - UC DAVIS, DAVIS, CA|
|Smith, Gary - UC DAVIS, DAVIS, CA|
|Thompson, James - UC DAVIS, DAVIS, CA|
Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: May 20, 2008
Publication Date: June 29, 2008
Citation: Pekke, M., Pan, Z., Smith, G., Thompson, J. 2008. Banana Dehydration Utilizing Infrared Radiation. Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE). Paper No. 084163. 1-20. Interpretive Summary: This research studied the quality and enzymatic activity of bananas under infrared heating. The processing conditions for achieving high quality products are recommended.
Technical Abstract: The enzyme of polyphenol oxidase (PPO) has been found to be the main cause of browning in bananas. Infrared radiation (IR) drying could be used to minimize biochemical degradation hence eliminating the need for pre-treatments. This study was to investigate quality characteristics of bananas dried using IR as compared to conventional hot air (HA) drying. Cavendish banana slices of 5 mm thickness were dried with IR and HA dryer at 60 degrees C, 70 degrees C, and 80 degrees C product temperatures. Changes in residual PPO, color, moisture content (MC) and water activity were measured. PPO was completely inactivated with IR at all temperatures but only 32% reduction compared to fresh bananas with HA at 60 degree C. The enzyme’s D values with IR are 4 to 20 fold lower than those with HA. Using IR at 60 degrees C and 70 degrees C, can offset overall color change ( delta E) by 23% and 37% respectively, compared to IR use at 80 degrees C. The MC decreased more rapidly in early drying stage with IR than with HA, which resulted in high drying rates at the beginning of the drying and at high temperature. The final MC of the products from both HA and IR were almost the same at similar drying conditions and time. It is concluded that IR can be used to produce dried banana products without active enzymes.