Degree Type

Dissertation

Date of Award

2010

Degree Name

Doctor of Philosophy

Department

Food Science and Human Nutrition

First Advisor

Pamela J. White

Second Advisor

Lawrence A. Johnson

Abstract

The impact of polydimethylsiloxane (PDMS) on oxidation of soybean oil at frying temperatures was investigated. At concentrations of PDMS greater than that calculated to be necessary for a compact monolayer on the oil surface, the rates of degradation of linoleate (18:2) and gamma- and delta-tocopherols were slower than in untreated oil. Degradation rates of 18:2 increased after a certain time at frying temperatures, likely caused by a reduction of the tocopherols and/or the PDMS to levels at which they were no longer protective. PDMS decreased oxygen transfer to the oil at temperatures close to frying temperatures. The concentration of 4-hydroxynonenal (HNE), a toxic product of 18:2 oxidation, was affected by PDMS concentration. In general, PDMS retarded HNE formation when used at concentrations greater than the monolayer concentration. PDMS concentrations capable of forming multilayers were more effective than a monolayer, and the protective effect lasted for a longer time. The results strongly suggest that PDMS decreases the oxygen transfer rate into the oil, thus decreasing the degradation of 18:2, tocopherols, and the formation of oxidation products, such as HNE.

Copyright Owner

Jose Arnaldo Gerde

Language

en

Date Available

2012-04-30

File Format

application/pdf

File Size

109 pages

Included in

Nutrition Commons

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