Analysis of the volatile profile of Khao Dawk Mali 105 rice (Oryza sativa L.)

Date

4-1998

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Hidelisa P. Hernandez

Abstract

Solangon, Joseph A. Analysis of the Volatile Profile of Khao Dawk Mali Rice (Oryza sativa L.) University of the Philippines Los Banos, April 1998.

Adviser: Dr. Hidelisa P. Hernandez

The caryopsis (brown rice), milled rice and bran of Khao Dawk Mali 105 (KDM 105) were cooked using simulated household cooking conditions. The headspace volatiles were trapped in dichloromethane (DCM). Separation of the compounds was done by gas chromatography and tentative identification was done using mass spectrometry. The number of tentatively identified compounds in each sample are brown rice: 30, rice bran: 19 and milled rice: 15. From the tentatively identified compounds trans,trans-2,4-heptadienal, 2-methylcyclopentanone, cyclo-octanone, pentanal and ethylbenzene were found in all the samples. Trans, trans-2,4- heptadienal is the major component of the headspace volatile profile of milled rice and brown rice while toluene is the major component of the rice bran. The presence of some compounds in two of the samples while being absent in the other indicates that the compound's precursors may be localized in certain parts of the caryopsis.

The profile of the headspace volatiles from milled KDM 105 trapped in DCM was compared to the data from a previous study (Rodriguez, 1997) using Tenax TA. It was observed that DCM was more effective in trapping unsaturated aldehydes and alcohols. However, based on the number of compounds trapped and tentatively identified, Tenax TA was more effective than DCM.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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