Many objective chemical tests have attempted to correlate with organoleptic evaluation of oxidative rancidity. Major chemical tests used to detect oxidative rancidity of lipids measure nonvolatile high molecular weight carbonylic substances which make no considerable contribution to rancid flavors. High molecular weight carbonyls are present at much greater concentrations than volatile low molecular weight carbonyls. Peroxides and other unknown substances also react in these chemical tests to give at best an empirical evaluation. A 3-methyl-2-benzothiazolinone hydrazone chemical test is proposed which corrected some deficiencies of earlier procedures, and was correlated with organoleptic evaluation of rancid turkey samples. The proposed test measures oxidative rancidity in terms of milligrams of acetaldehyde per kilogram of sample.
A comparison of the 3-methyl-2-benzothiazolinone hydrazone method with a widely used chemical test was conducted. The thiobarbituric acid test was selected because it is used most often as an indicator of rancidity. The thiobarbituric acid test values increased followed by a definite leveling off as formation of malonaldehyde reached a maximum even though rancid flavor continued to increase. The 3-methyl-2-benzothiazolinone hydrazone test measured a continuing increase of volatile aliphatic aldehydes as rancid flavor increased .
| Identifer | oai:union.ndltd.org:UTAHS/oai:digitalcommons.usu.edu:etd-6223 |
| Date | 01 May 1976 |
| Creators | Andrews, Stanley J. |
| Publisher | DigitalCommons@USU |
| Source Sets | Utah State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | All Graduate Theses and Dissertations |
| Rights | Copyright for this work is held by the author. Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user. For more information contact digitalcommons@usu.edu. |
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