Effect of Storage on Flavour, Colour and Other Sensory Qualities Of Sugarcane Juice (Saccharum Officinarum) Yellow Cane
A study was conducted to determine the effects of storage on the flavour and sensory attributes of sugarcane juice. Freshly extracted sugarcane juice was stored at 25 ± 20C and 5 ± 20C for IS-days. The parameters measured were colour, acidity (pH and TA), acidic phenolics and flavour. The sensor...
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| Format: | Thesis |
| Language: | English English |
| Published: |
2000
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/8426/1/FSMB_2000_17_IR.pdf |
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| Summary: | A study was conducted to determine the effects of storage on the
flavour and sensory attributes of sugarcane juice. Freshly
extracted sugarcane juice was stored at 25 ± 20C and 5 ± 20C for
IS-days. The parameters measured were colour, acidity (pH and
TA), acidic phenolics and flavour. The sensory attributes tested
were colour, viscosity, sweetness, sharpness, appearance, jaggery
and fresh flavour. Phenolic compounds were separated using solid
phase extraction technique and HPLC method was used for
isolation and identification. Major volatiles were extracted using
vacu um steam distillation (VSD) technique. Gas Chromatography
(GC) and Gas Chromatography-Mass Spectrometry (GC-MS) were
used for separation of the volatiles and identification of their
molecular weights.
Results indicated that sugarcane juice stored at 5 ± 20C retained
its colour and acidity until 10-days meanwhile, a drastic change
occurred on the colour and acidity of juice stored at 25 ± 2oC. The
sensory results showed that no remarkable changes occurred on
the quality (colour, viscosity, sweetness, sharpness, appearance,jaggery and fresh flavour) of samples stored at 5 ± 2°C up to 10-
days. There were no significant differences (P>0.05) observed
between samples stored for 5 and 10-days. However, at the end of
the IS-days, there were significant differences (P<0.05) in terms of
colour, sweetness, sharpness, jaggery and freshness compared to
the fresh, the 5 and the 10-days stored juices (except for
appearance and viscosity).
Six types of phenolic compounds were identified in sugarcane juice
namely 3,4-dihydroxybenzoic, chlorogenic, p-hydroxybenzoic,
caffeic, p-coumaric and 2 ,3-dihydroxybenzoic acids. Changes in
the phenolics contents were observed in samples stored at both
temperatures (5 ± 2°C and 25 ± 2°C). Changes in the phenolics'
concentrations were more noticeable in the juice stored at 25 ± 2°C.
This occurred despite the fact that the polyphenol oxidase (PPO)
was deactivated at the beginning before juice extraction. At the
same time, there seemed to be increases and decreases in their
concentrations. This may indicate that not only enzymatic reaction,
which consumed the phenolics but also autoxidation reaction, may
have occurred. Sugarcane juice was found to consist of about 17
major volatile compounds. Upon storage at 5 ± 2°C the major
volatiles were retained until 10-days; after that some compounds
were lost and others were evolved. After two days of storage at 25 ±
2°C the major volatiles were lost and many other new compounds
were evolved.A strong relationship (R²≥0.90) was observed between some of the
phenolics and the sensory attributes (colour, appearance, viscosity,
sweetness, sharpness, jaggery and fresh flavour) . The changes in
colour (ϪE) was also correlated well (R²=0.90) with the sensory
evaluation results.In general, sugarcane juice stored at 5 ± 2°C retained its quality
until l0-days. However, undesirable colour, flavour and the change
in taste from sweet to sour occurred after the end of the I5-days at
5 ± 2°C. Significant changes in acidity, colour, flavour and
phenolics were observed at 25 ± 2°C compared to 5 ± 2°C. In fact,
the flavour of the sample stored at 25 ± 2°C changed significantly
after 2 days. This indicated that the juice will lose its quality if kept
at 25 ± 2°C and deterioration of the juice stored at 5 ± 2°C was only
noticeable after the end of the 15-days. |
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