Sponsor
Portland State University. Department of Physics
First Advisor
Raj Solanki
Term of Graduation
Spring 2019
Date of Publication
Spring 6-10-2019
Document Type
Dissertation
Degree Name
Doctor of Philosophy (Ph.D.) in Applied Physics
Department
Physics
Language
English
Subjects
Electrochemical sensors, Fruit -- Postharvest technology, Ethylene, Food spoilage -- Prevention
DOI
10.15760/etd.6870
Physical Description
1 online resource (viii, 147 pages)
Abstract
The sensing needs for the fresh produce industry can be split into two primary stages: during maturation in the field, also referred to as Precision Farming, and during storage and transport of the produce, or Postharvest Storage. This work seeks to improve the accuracy and reliability of commercially available electrochemical and spectroscopic sensors tailored to the sensing needs of the fresh produce industry. For electrochemical sensing, this study proposes the use of an inline filter to remove polar organic compounds, which can interfere with the readings of a platinum-based electrochemical sensor. A 50% improvement in measurement accuracy was achieved when monitoring the storage headspace of a container of apples. For portable spectroscopy instruments, this study suggests improvements for the alignment of the optical bench and the spectral collect protocol. Methods to reduce the influence of environmental noise, such as variability of background light (sunlight in the field) and thermal effects on hardware performance, are presented. This study also presents the first report of the calibration transfer of spectral regressions developed with Karl Norris's Derivative Quotient Method. The motivation for this aspect of research was to develop methods to collect stable and accurate data in the field, which can be used to improve the quality of fresh produce reaching the customer and reduce premature food spoilage.
Rights
In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
Persistent Identifier
https://archives.pdx.edu/ds/psu/28992
Recommended Citation
Lerud, Ryan M., "Sensors and Portable Instruments for Postharvest Agriculture" (2019). Dissertations and Theses. Paper 4994.
https://doi.org/10.15760/etd.6870