Undergraduate Thesis Or Project

 

Development of a colorimetric test kit to determine enzymatically produced pyruvic acid in sweet onions Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/undergraduate_thesis_or_projects/f7623f34v

Descriptions

Attribute NameValues
Creator
Abstract
  • Sweet onions are valued for their unique flavor and praised for their health and dietary character. Onion sweetness is perceived as the degree of pungency decreases. Pungency can be quantitatively determined in onions by measuring enzymatically produced pyruvic acid. The onion industry quantifies a sweet onion as one having a pyruvic acid concentration of 1 – 4 μmol/g. Identification of pyruvic acid is accomplished by reacting onion extract with 2, 4-dinitrophenylhydrazine (DNPH) to produce a colored adduct that is measured spectrophotometrically. Currently, onion processors outsource pungency analysis to a laboratory in Texas. The cost and turn around time are both high. Satisfying the need for a modified method, where samples can be analyzed quickly on site, is the goal of this research. The laboratory method produced data qualifying sweet onions. Averages of 15 samples resulted in 4.05 ± 0.48 with a percent recovery by over-spiked samples of 104% ± 10.4%. Check standards reveal a percent recovery of 98% ± 0.78%. This method is reproducible and adaptable for a quick, field test kit for onion breeders. The test kit identifies pyruvic acid with the use of the DNPH color indicator, and qualifies sweet onions by comparing samples to a provided color chart. The test kit proposed reduces the cost of sweet onion analysis significantly and decreases the overall turn around time for pungency analysis.
Contributor
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Replaces
Additional Information
  • description.provenance : Approved for entry into archive by Linda Kathman(linda.kathman@oregonstate.edu) on 2009-12-16T14:21:45Z (GMT) No. of bitstreams: 2Thesis Presentation.ppt: 4984320 bytes, checksum: c94c24677c9ca7f8cc95c058ac86f177 (MD5)Merrill, D. Thesis.doc: 1711616 bytes, checksum: 1b382f425044efbe0da3c58577a7c94b (MD5)
  • description.provenance : Submitted by Wanda Crannell (crannelw@hort.oregonstate.edu) on 2009-12-15T23:07:08ZNo. of bitstreams: 2Thesis Presentation.ppt: 4984320 bytes, checksum: c94c24677c9ca7f8cc95c058ac86f177 (MD5)Merrill, D. Thesis.doc: 1711616 bytes, checksum: 1b382f425044efbe0da3c58577a7c94b (MD5)
  • description.provenance : Made available in DSpace on 2009-12-16T14:21:45Z (GMT). No. of bitstreams: 2Thesis Presentation.ppt: 4984320 bytes, checksum: c94c24677c9ca7f8cc95c058ac86f177 (MD5)Merrill, D. Thesis.doc: 1711616 bytes, checksum: 1b382f425044efbe0da3c58577a7c94b (MD5)

Relationships

Parents:

This work has no parents.

Items