Abstract
Laboratory tests, comparing microbial, enzymic, and chemical deterioration of sucrose in factory cane juice, were undertaken.
Heat (boiling temperature) and biocide treated juice, as well as untreated juice, were deteriorated at 27
C (to simulate factory
ambient temperature) in an incubator over 71 h. The biocide-treated juice retained its dark brown colour, fresh odour, initial pH
and
Brix levels over 71 h. In strong contrast, after 71 h the untreated juice was light brown, had a strong alcohol odour and
markedly lower pH and
Brix levels. The colour of the heated juice decreased only after 23 h, and the juice was viscous after 71 h
and had neither a fresh nor alcoholic odour. Sucrose, glucose, and fructose were analyzed using gas chromatography. Over the first
14 h of deterioration, 93.0% of sucrose losses were microbial, 5.7% enzymic and 1.3% were chemical (acid degradation). Ion
chromatography with integrated pulsed amperometric detection (IC–IPAD) was used to simultaneously determine ethanol, man-
nitol, and oligosaccharides in deteriorated cane juice. The rate of formation of mannitol, produced from the reduction of fructose
by mannitol dehydrogenase in dextran forming Leuconostoc bacteria, was much higher than associated oligosaccharides or ethanol
formation. A further investigation of the use of mannitol as a sensitive indicator of future dextran-related processing problems at
the cane factory is warranted. Ethanol was shown not to be very useful as an indicator of Leuconostoc bacterial cane deterioration.
# 2002 Published by Elsevier Science Ltd.
Abstract
Laboratory tests, comparing microbial, enzymic, and chemical deterioration of sucrose in factory cane juice, were undertaken.
Heat (boiling temperature) and biocide treated juice, as well as untreated juice, were deteriorated at 27
C (to simulate factory
ambient temperature) in an incubator over 71 h. The biocide-treated juice retained its dark brown colour, fresh odour, initial pH
and
Brix levels over 71 h. In strong contrast, after 71 h the untreated juice was light brown, had a strong alcohol odour and
markedly lower pH and
Brix levels. The colour of the heated juice decreased only after 23 h, and the juice was viscous after 71 h
and had neither a fresh nor alcoholic odour. Sucrose, glucose, and fructose were analyzed using gas chromatography. Over the first
14 h of deterioration, 93.0% of sucrose losses were microbial, 5.7% enzymic and 1.3% were chemical (acid degradation). Ion
chromatography with integrated pulsed amperometric detection (IC–IPAD) was used to simultaneously determine ethanol, man-
nitol, and oligosaccharides in deteriorated cane juice. The rate of formation of mannitol, produced from the reduction of fructose
by mannitol dehydrogenase in dextran forming Leuconostoc bacteria, was much higher than associated oligosaccharides or ethanol
formation. A further investigation of the use of mannitol as a sensitive indicator of future dextran-related processing problems at
the cane factory is warranted. Ethanol was shown not to be very useful as an indicator of Leuconostoc bacterial cane deterioration.
# 2002 Published by Elsevier Science Ltd.
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