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Rapid determination of chlorophylls in vegetable oils by laser‐based fluorometry
Author(s) -
Tan Y A,
Low K S,
Chong C L
Publication year - 1994
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740660409
Subject(s) - fluorescence spectroscopy , chemistry , fluorescence , laser , rapeseed , chromatography , vegetable oil , analytical chemistry (journal) , optics , food science , physics
The presence of chlorophylls in vegetable oils is considered undesirable due to their adverse effects on oxidative deterioration, bleachability and hydrogenation. The usual methods for determination of chlorophylls in vegetable oils are absorption spectrophotometry, fluorometry and liquid chromatography using fluorescence detectors. This paper outlines a fluorometric method using a laser as the excitation source. The chlorophylls in crude palm oil, rapeseed oil, soya bean oil and olive oil were determined directly by laser‐based fluorometry using (a) a helium‐neon laser (632‐8 nm, 5 mW) as the excitation source and an optical‐multichannel analyser (OMA) with an intensified diode array as the detector, and (b) a helium‐neon laser and a photomultiplier tube as the detector. The method is especially suitable for the detection of chlorophylls in crude palm oil since no pre‐extraction step is required. The levels of chlorophylls measured in vegetable oils using the laser technique was also compared against values obtained by conventional spectrophotometric methods. The simplicity and rapid quantification of laser based fluorometry suggest that this technique can be readily applied to the detection or a wide variety of fluorescing species in vegetable oils.