Location: Processed Foods Research
Project Number: 5325-41000-063-08
Start Date: Apr 01, 2010
End Date: Jun 30, 2014
Popular processing tomatoes (Lycopersicon esculentum) cultivars like what we have used in our previous study will be used for the tests to optimize the processing parameters and perfect the peeling performance of the system and the quality of the peeled product (peeling throughput, peeling loss, peelability, color and texture of the peeled tomatoes). The first step of this project is to build the IR dry-peeling system for tomatoes. The system will consist of the feeding section, IR heating section, vacuum section, preskin remover section, peel eliminator section, and product inspection ramp. The mode of operation of the system is as follows: The cleaned tomato gets into the feeding line with controlled locations from a hopper. The feeding line transfers the tomato into the IR heating section, which consists of two assembled sets of tubular electric IR heaters and an automatically controlled conveyance system passing through the heating section. The IR heated tomatoes are released into vacuum chamber to induce the skin cracking, and then the tomatoes go through the pre-skin remover and a peel eliminator consisting of opposing (rotating) rollers. The opposing rotating rollers are responsible for the final phase of peel elimination. The final product is conveyed onto the peeled product inspection ramp for collection. The feeding section will have feeding lines designed to achieve specific orientation of the tomatoes as they enters the conveyor at the IR heating section. Tomato will be fed between sets of parallel emitters. The IR heating section (1m high x 0.5m wide) will have tubular electric IR emitters with corresponding reflectors assembled in parallel. The arrangement will facilitate double sided heating and is expected to achieve minimum heating time. The exposure time of tomatoes to IR heat will be regulated by the feeding and conveyor speed which will be automatically controlled. To eliminate shading (tomatoes contacting each other) during conveyance, vertical and lateral displacements are incorporated in conveyor design to allow flexible and multiple tomato vertical and lateral displacements. Peeling loss will be expressed as percentage calculated based on the difference in tomato weights before and after peeling. The color of peeled tomato will be measured and expressed in L*a*b color space. The firmness of the tomato will be measured using fruit texture analyzer. The optimal throughput and design guidelines for large scale IR peeling system will be established. The energy consumption of the system will be evaluated and compared with current processing methods. All results will be analyzed for statistical significance. Progress reports and a comprehensive final report will be developed to document the advantages and characteristics of the IR dry-peeling technology and system.