Veeriah, Harivaindaran
(2015)
Effect Of Superheated Steam (Shs) Pre-Treatment On Quality Of Fish Oil From Catfish (C/Arias Batrachus).
Masters thesis, Perpustakaan Hamzah Sendut.
Abstract
Superheated steam (SHS), a dry steam with temperature higher than boiling
point that operates without the presence of oxygen is used to pre-treat catfish,
Clarius batrachus, before being subsequently pressed via hydraulic press to obtain
fish oil. Fish were first cleaned and reduced in size before being treated with SHS at
150°C, 200°C, 250°C, for 10, 15, 20 min for each temperature. Fish are then
transferred into a mould, pressed using a hydraulic press and the resulting aliquot is
centrifuged and oil is collected. Quality of the resulting fish oil is studied in terms of
yield, colour, oxidation, thermal analysis and fatty acid composition. Yield of the
catfish oil showed higher values when heated with higher temperatures of SHS, the
highest being the 250°C, 20 minutes pre-treatment (8.91 gram/gram fish,
significantly different at p> 0.05) which was incidentally lower than solvent
extraction and this fact has been proven in past literature. Colour analysis showed
tendency towards a darker yellow colour as treatment time and temperature
increased. In terms free fatty acids (FFA) values, solvent extracted raw catfish oil
had the highest and most significant value (2.56% oleic acid) and this reflected in
high acid value beyond that of acceptable edible oil standard. However, peroxide
values were mostly insignificantly different. The extent of oxidative damage was
obvious in the p-anisidine values whereby at 250°C, 20 minutes pre-treatment, there
was a sharp rise to 12.05 which, although significantly different, was still within
edible oil standard.
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