Chemical fumigation disinfestation treatments bring more and more concerns due to its hazard to environment and human health, it is necessary to develop alternative non-chemical disinfestation treatments for agricultural products. Radio frequency (RF) and low pressure (LP) technologies have been explored as disinfestation treatments for several agricultural commodities. The aim of the current study was to develop RF and LP disinfestation treatments for legumes and fresh fruits, respectively.
Black-eyed peas and mung beans were being considered as surrogate host legumes to be infested by cowpea weevils to validate RF treatment protocol, since they are better hosts for cowpea weevil compared with target legumes (chickpeas and lentils). The resistance of cowpea weevils at different life stages was investigated under RF treatments. RF treatment with 60°C and more than 5 min holding time can completely kill insects without product quality degradation. A computer simulation model was developed and validated, which can be used to investigate RF heating process to get better heating uniformity and efficiency. Industrial scale-up tests were conducted to make RF technology available for industry application. The current studies indicated RF energy can be applied to control insects in legumes without quality degradation, industrial-scale continuous RF disinfestation treatment was effective and could be used for practical applications.
To investigate the potential of using LP technology in disinfestation study for fresh fruits, LP system stability and performance was evaluated in the first step. Results showed LP system maintained temperature, pressure and relative humidity very stable and at good levels with low chamber leakage rates. The tolerance of coding moth with different life stages was investigated as a next step. Weight loss, color, firmness, titratable acidity (TA), and soluble solid content (SSC) were selected as quality parameters to evaluate the quality changes of "Red Delicious" apples. Large larvae were found to be the most resistant life stage of codling moth in LP treatments. The insect mortality reached to 98% after 12 days LP treatment, and apple quality was maintained well after 15 days LP treatments, which indicated LP technology has the potential to be an alternative non-chemical disinfestation treatment method.
|Commitee:||Nindo, Caleb, Sablani, Shyam, Wang, Shaojin|
|School:||Washington State University|
|Department:||Biological and Agricultural Engineering|
|School Location:||United States -- Washington|
|Source:||DAI-B 73/12(E), Dissertation Abstracts International|
|Subjects:||Food Science, Agricultural engineering|
|Keywords:||Disinfestation, Fruit, Legumes, Low pressure, Postharvest treatment, Radio frequency|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be