1a.Objectives (from AD-416)
1. Determine the processing and energy efficiencies and product quality of infrared dry-blanching with selected fruits and vegetables using a pilot scale infrared dryer/blancher.
2. Develop alternative processing methods for producing infused blueberry products.
1b.Approach (from AD-416)
For the infrared dry-blanching study, two types of selected vegetables, including baby carrots and cut potatoes will be used in the study. The research is aimed at determining processing characteristics, such as processing time, energy consumption, product temperature profiles and quality (color and moisture change). A pilot scale infrared dryer/blancher equipped with catalytic infrared emitters will be used. The catalytic infrared emitters will be able to provide uniform heating across the surface of the products on the sample tray. The temperature profiles of product during heating will be measured and recorded with thermocouples and a computer. The retention time in the blancher will also be measured. The effectiveness of enzyme inactivation will be determined by using polyphenol oxidase as an indicator. The quality of finished products will be evaluated based on color and moisture change. The color of products before and after processing will be measured using colorimeter. The obtained data will be able to quantify the advantages of the infrared dry-blanching supporting the commercialization of the infrared dry-blanching.
For developing new infused blueberry products and processing methods, cultivated blueberries will be used. The research will focused on determining appropriate heating conditions and moisture removal levels for achieving high quality infused products. Selected humectants will also be tested for producing different infused products. To determine the appropriate infrared heating conditions, selected infrared intensities and product temperatures will be studied in the tests to remove different levels of moisture both before and after the infusion process. The color and appearance of partially dehydrated products will be evaluated visually or using instruments. The dehydrated products will be infused with syrup or sucrose solution with selected concentrations for different times to determine the infusion rates. The infused products will be dried to desired moisture contents or water activities. The color, appearance, sensory quality of the finished products will be evaluated again. To determine the feasibility of alternative humectants and improve the infusion rate, selected fruit concentrates (two or three types) and surfactants will be tested for the infusion of blueberries. The product quality will be evaluated against the products infused with syrup or sucrose solution. It is expected that the research will develop new infusion processing methods for producing infused blueberries. Documents CRADA. Log 27827.
The dry-blanching test results of using pilot scale infrared heating system showed that dry-blanching can be achieved with high product quality.