BUKU ABSTRAK - Universiti Putra Malaysia

Science, Technology & Engineering
Separation of Omega-3/6 Fish Oil from Fish Waste using Pressure Swing Technique
of Supercritical Carbon Dioxide
Assoc. Prof. Dr. Md. Zaidul Islam Sarker
Sahena Ferdosh and Jinap Selamat
Faculty of Food Science and Technology, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 8536; zaidul@food.upm.edu.my
Fish industry discarded a great amount of fish wastes from processing leftovers every year. Fish wastes have a
huge unexploited potential for value adding. Fish oil especially eicosapentaenoic acid (EPA) and docosahexaenoic
acid (DHA), are highly demanded by food and pharmaceutical industries due to their potential health benefits.
The techniques currently practiced for extraction/fractionation of fish oil are fractional crystallisation, urea
complexation, countercurrent distribution, adsorption or absorption chromatography, and molecular distillation.
All these techniques are more or less cumbersome, expensive, time consuming, used organic solvents and
involved high temperature which causes loss of desired products. Supercritical fluid extraction (SFE) is a
potential alternative to the customary methods of producing fish oil. It offers the advantages of rapid, nontoxic,
environmental-friendly, residue-free and easily manipulated conditions. The objectives of this study were to
optimise the operating conditions of different technique of SFE, to extract the highest yield with least amount of
CO2 and to make the product cheaper. The results showed that pressure swing is the best technique for highest oil
recovery using least amount of carbon dioxide. The process uses CO2 as an extraction solvent and operates at 35
MPa and 60 o C with a flow rate of 2 ml min-1. Total oil was extracted in seven successive holding-extraction steps
and the yield of each step is defined as fraction. During the holding period, liquid CO2 penetrated the sample
matrix and dissolved the more readily soluble fatty acid portion which was eluted during subsequent extraction
steps. In this way seven fractions were collected separately among which the first three fractions contained
mainly saturated fatty acid (SFA) fish oil and the next four fractions predominant in polyunsaturated fatty acid
(PUFA) especially EPA and DHA. The last four fractions can be pooled together for use as value added foods or
nutraceuticals.
Keywords: Indian mackerel, fish waste, omega 3/6 fish oil, supercritical fluid extraction, pressure swing technique
A New Approach in Cryptographic Systems using Fractal Image Coding
Assoc. Prof. Dr. Mohamad Rushdan Md. Said
Nadia Al-Saidi
Institute of Mathematical Research, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 6841; mrushdan@putra.upm.edu.my
With the rapid development in the communications and information transmissions, there is a growing
demand for new approaches that increases the security of cryptographic systems. Therefore some emerging
theories, such as fractals, can be adopted to provide a contribution towards this goal. In this study, we proposed a
new cryptographic system utilising fractal theories; this approach exploited the main feature of fractals generated
by IFS techniques. Double enciphering and double deciphering methods performed to enhance the security of the
system. The encrypted data represented the attractor generated by the IFS transformation, collage theorem was
used to find the IFSM for decrypting data. The proposed method gave the possibility to hide maximum amount of
data in an image that represents the attractor of the IFS without degrading its quality and to make the hidden data
robust enough to withstand known cryptographic attacks and image processing techniques which did not change
the appearance of image.
Keywords: Iterated function system, fractal, cryptosystem, encryption, decryption
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