Development of a Solar Thermal Drum Dryer for Specialty Crop Purees and Pomaces

Goals / Objectives
Specialty crop processors would benefit from an environmentally-friendly technology for quickly drying purees and pomaces. Drum drying is a well-established food processing unit operation that can dry large amounts of product in a matter of seconds; however, current drum dryer designs require high-pressure steam and are thus not well-suited for smaller processors or field use. In theory, solar thermal technology can provide the heat required for drum drying, but the combination of these two technologies has never before been explored. Thus, the objective of this project is to develop a processor-friendly solar thermal drum dryer that can be used to quickly dry specialty crop products such as apple, pear, berry, and vegetable purees and pomaces from tomatoes, grapes, olives, and carrots.

Project Methods
In Year 1, we will perform experiments to determine how best to interface a drum dryer and a solar thermal heating system. Purees and pomaces from crops such as apples, pears, grapes, plums, olives, tomatoes, and carrots will be the focus of these experiments. By the end of Year 1, a prototype system will be constructed. The availability of the prototype system for testing with various pomaces and purees will be advertised via email newsletters and events of relevant trade groups. In Year 2, we will collect processor feedback on the prototype system and refine its design to make it as useful as possible to the California specialty crop industry. The final version of the design will be completed the end of Year 2. Scientific manuscripts detailing the development of the tool will be published in scholarly journals and presented at meetings of the Institute of Food Technologists.