Graduate Thesis Or Dissertation
 

Sub-threshold effects on the perceived intensity of recognizable odorants : the roles of functional groups and carbon chain lengths

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/bn999932h

Descriptions

Attribute NameValues
Creator
Abstract
  • Sub-threshold effects were studied in binary and tertiary mixtures comprising a panel-recognition-concentration odorant and sub-threshold odorant(s). Sub-threshold condition was maintained by controlling the sub-threshold concentration as percentages of subjects' individual detection threshold. The perceived intensities (overall intensity and several descriptors) of recognizable odorants were rated using magnitude estimation. Sub-threshold suppression was common and concentration independent in mixtures comprising odorants with different functional groups. Suppression was observed at the lowest sub-threshold concentration tested (30% level). At sub-threshold concentrations, acetic acid suppressed the perceived intensity of acetaldehyde and ethanol but not vice versa. Acetaldehyde and ethanol, however, suppressed each other when one was at sub-threshold concentrations in binary mixtures. Enhancement was observed in tertiary mixtures containing acetaldehyde at panel recognition concentration and was dependent on sub-threshold concentrations of acetic acid and ethanol. In mixtures that contained aliphatic acids with different carbon chain lengths (acetic acid, propanoic acid and n-butanoic acid), sub-threshold enhancement and suppression depended on concentrations and molecular similarity of mixture components. Sub-threshold effects were not observed when the acids were two carbon-atoms different. 50% and 70% sub-threshold levels caused sub-threshold enhancement; however, higher concentrations caused decrease in intensity. Sub-threshold suppression was observed in mixtures containing n-butanoic acid as a recognizable odorants with propanoic acid at a 10% level in a binary mixture and acetic acid and propanoic acid in a 30%-30% combination in the tertiary mixture.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Scamax Scan+ V.1.0.32.10766 on a Scanmax 412CD by InoTec inPDF format. LuraDocument PDF Compressor V.5.8.71.50 used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details LEPETCHARATKANNAPON2002.pdf 2017-08-08 Public Download