|Lin, Yaling - UC DAVIS, DAVIS, CA|
|Li, Shujun - CHINESE ACADEMY, CHINA|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2005
Publication Date: N/A
Interpretive Summary: Infrared dry-blanching and dehydration methods for fruits and vegetables have been recently developed. However, the processing performances of the infrared blanching and dehydration are related to the processing parameters (such as infrared radiation intensity), chemical, physical and optical properties of the fruits and vegetables. This research used a predictive mathematical modeling method to study the processing performances and provide optimum design and operational parameters for achieving high quality processed products.
Technical Abstract: Blanching and dehydration are two essential processing steps used to extend their shelf-lives of fruits and vegetables by inactivating enzymes and lowering water activity of the products, respectively. A recently developed medium-far infrared simultaneous dry-blanching (IDB) and dehydration technology has many advantages over the existing processing methods. The objective of this study was to develop predictive heat and mass transfer models to predict the temperature distribution and moisture removal of apple slabs under simultaneous IDB and dehydration process. The apple slabs were heated with continuous heating to reach a preset temperature at the apple slab surface and then the preset temperature was maintained by using intermittent heating. To study the effectiveness of the blanching method, the enzymatic activities of polyphenol oxidase (PPO) and peroxidase (POD) were calculated based on the predicted temperature under different heating conditions. The heat and mass transfer models were coupled with enzyme inactivation model and solved with the finite element method. The predicted temperature, moisture removal, and enzymatic activities were validated. The mathematical models can be used to provide the necessary information for designing infrared equipment, and determining and optimizing processing parameters for the infrared blanching and dehydration processes.