UNIVERSITI PUTRA MALAYSIA CHARACTERIZATION OF VIRGIN ...psasir.upm.edu.my/id/eprint/27398/1/IPPH...

UNIVERSITI PUTRA MALAYSIA

CHARACTERIZATION OF VIRGIN COCONUT OIL AND MULTIPLE INSTRUMENT APPROACH FOR THE DETECTION OF LARD

ADULTERATION IN MODEL VIRGIN COCONUT OIL

TENGKU SALWANI BINTI TENGKU MANSOR

IPPH 2011 2

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CHARACTERIZATION OF VIRGIN COCONUT OIL AND MULTIPLE INSTRUMENT APPROACH FOR THE DETECTION OF LARD

ADULTERATION IN MODEL VIRGIN COCONUT OIL

By


Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia, in Fulfilment of the Requirements for the Degree of Master of Science

November 2011

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DEDICATION

I dedicate this thesis to the 4 pillars of my life:

1) Mighty God Allah, who is always there to listen to my prayers

2) My beloved husband, Dr Ahmad Syukri Jamaludin for all your patience and

love through sunshine and rain

3) My beautiful son, Ahmad Suhayl for the joy you bring

4) My parents and parents in laws for your unrelenting support

Thank you very much for everything

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Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfilment of the requirement for the degree of Masters of Science

CHARACTERIZATION OF VIRGIN COCONUT OIL AND MULTIPLE

INSTRUMENT APPROACH FOR THE DETECTION OF LARD ADULTERATION IN MODEL VIRGIN COCONUT OIL

By


November 2011

Chair: Professor Dato’ Yaakob Bin Che Man, PhD Institute: Halal Products Research Institute

The driving force for adulteration is to cut cost and to increase profit. However, in

the case of adulteration using animal oils, this would also affect in terms of

consumers beliefs and practice such as for Hindus, vegans and vegetarians, Jews and

Muslims. For Muslims, adulteration using lard (LD) or improperly slaughtered

animal oils is of significant issue. Detecting adulteration in fats and oils especially

the high-value oils such as virgin coconut oil (VCO) is indeed needed. The attempt

to find the most effective, simple, chemical-free and straightforward analysis without

compromising the sensitivity and specificity is essential. Therefore, the overall

objective of this study is to apply these three instruments, namely differential

scanning calorimeter (DSC), electronic nose/ fast gas-chromatography (fast GC) and

Fourier transform infrared (FTIR) spectroscopy to detect LD adulterations in VCO.

VCO is prepared through the ‘wet’ and ‘dry’ methods, while LD was rendered from

adipose tissue of pig using microwave oven. In the first phase, the VCO samples

were characterized and analyzed physicochemically. The results showed that in

general all VCO samples conformed to the Asian and Pacific Coconut Community

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(APCC, 2003) and does not differ strikingly from each other. Subsequently, samples

of VCO and LD were mixed in different concentration (v/v). Each sample admixtures

were subjected to analysis of fast GC, FTIR and DSC. Some chemical analyses were

performed such as iodine value (IV) and peroxide value (PV). In addition, fatty acid

(FA) and triacylglycerol (TAG) analyses were also conducted using gas

chromatography-flame ionization detector (GC-FID) and high performance liquid

chromatography (HPLC), respectively, as the control experiments. Simple linear

regression on fast GC data demonstrated that three peaks on the fast GC

chromatogram were found to fit the second order polynomial curve with R2 of

0.8121, 0.8349 and 0.9344, respectively. Partial least square (PLS) from FTIR

spectroscopy was able to predict LD adulteration in VCO with the equation y =

0.999x + 0.006. Meanwhile, DSC showed that Te A (endset peak A) in the

endothermic curve and Tr D (temperature range for peak D) in the exothermic curve

were found to have good predictor ability in determining percentage LD adulteration

in VCO with the equation from step 2 of stepwise multiple linear regression

(SMLR); % LD adulteration = 293.1 – 11.36 (Te A) – 2.17 (Tr D) and R2 adjusted of

95.82. To conclude, all three techniques were able to detect LD in VCO with ease

and without the use of chemicals.

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Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai memenuhi keperluan untuk ijazah Master Sains

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�Oleh�


November 2011

Pengerusi: Profesor Dato’ Yaakob Bin Che Man, PhD Institut: Institut Penyelidikan Produk Halal

Pendorong utama terhadap pencemaran dalam makanan adalah untuk mengurangkan

kos dan meningkatkan keuntungan. Namun begitu, pencemaran lemak haiwan akan

menjejaskan amalan kepercayaan sesetengah penganut beragama Hindu, vegan dan

‘vegetarian’, penganut agama Yahudi dan juga Muslim. Bagi penganut Islam,

penggunaan lemak khinzir (LK) ataupun penggunaan lemak haiwan yang tidak

disembelih secara sah merupakan isu yang penting. Pengesanan pencemaran di

dalam lemak dan minyak terutamanya minyak yang bernilai tinggi seperti Minyak

Kelapa Dara (MKD) memang diperlukan. Percubaan untuk menemui teknik yang

paling efektif, mudah dan tidak menggunakan bahan kimia tanpa mengurangkan

sensitiviti dan spesifisiti adalah sangat-sangat diperlukan. Oleh itu, objektif

keseluruhan kajian ini adalah untuk menggunakan Pembezaan Pengimbasan

Kalorimeter (PPK), hidung elektronik/ Kromatografi-gas pantas (KG pantas) dan

Pengubah Fourier Inframerah (PFIM) spektroskopi untuk mengesan kehadiran LK di

dalam MKD. MKD telah disediakan melalui proses ‘kering’ dan ‘basah’, manakala

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LK dihasilkan daripada ketuhar gelombang mikro. Pada fasa pertama, sampel-

sampel MKD ini dianalisa sifat fizikal dan kimianya dan didapati bahawa secara

keseluruhannya semua MKD yang dihasilkan adalah mengikut kriteria yang

diberikan oleh Persatuan Kelapa Asian dan Pasifik (APCC, 2003) dan tidak berbeza

antara satu sama lain secara keterlaluan. Sampel-sampel MKD dan LK kemudiannya

dicampur dalam pelbagai kepekatan (v/v). Setiap sampel dianalisa oleh GK pantas,

PFIM dan PPK. Analisis kimia juga telah dijalankan ke atas sampel-sampel ini

seperti nilai iodin dan nilai peroksida. Analisis asid lemak (AL) dan triasilgliserol

(TAG) juga dilakukan menggunakan kromatografi gas-pengesan pengionan nyala

(KG-PPN) dan juga Kromatografi Cecair Berprestasi Tinggi (KCBT) sebagai

eksperimen kawalan. Analisa Regresi Linear Mudah pada data KG pantas

menunjukkan bahawa tiga puncak di kromatogram KG pantas serasi dengan

lengkungan polinomial aturan kedua dengan R2 0.8121, 0.8349 dan 0.9344. Statistik

Persegi Separa Terkecil (PST) daripada PFIM juga dapat meramalkan LK di dalam

MKD dengan persamaan matematik y = 0.999x + 0.006. Disamping itu, PPK

menunjukkan bahawa Te A (suhu akhiran puncak A) dan Tr D (perbezaan suhu

puncak D) pada keluk eksoterma dapat mengesan peratus LK di dalam MKD dengan

persamaan matematik daripada langkah kedua statistik Regresi Linear Berbilang

Langkah (RLBL); yakni % percampuran LK = 293.1 – 11.36 (Te A) – 2.17 (Tr D) dan

penyesuaian R2 = 95.82. Sebagai kesimpulan, ketiga-tiga teknik ini berjaya untuk

mengsan kehadiran LK di dalam MKD dengan mudah dan tanpa menggunakan

bahan kimia.

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ACKNOWLEDGEMENTS

I would like to express my deepest appreciations and immense thanks to my

Supervisor, Professor Dato’ Dr Yaakob Bin Che Man, whose support and guidance

from the initial phase till the end has enabled me to learn something new and

valuable, as well as giving me insight to the understanding of the subject.

I am also greatly indebt to my Co-Supervisor, Associate Prof Dr Shuhaimi

Mustafa for his unremitting assistance, considerations and thoughtfulness towards

myself.

Special thank to my colleagues especially Abdul Rohman for sharing your

knowledge and expertise with me. Same goes to Nasyrah, Aisyah, Akasyah,

Sarafhana, Wan Farizan, Yanti, Aina, Nina, Azira, Irmie, Hanif, Shariena, Nadiha,

Wan, Farihah, Ilyia, Dr Zuledham, Hazim and Ali, who would always be mentors to

me and for being there with me, be it rain or sunshine.

Lastly, I greatly appreciate Universiti Putra Malaysia for providing the funds

for the study and to give me the chance to study here.

Thank you all.

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I certify that a Thesis Examination Committee has met on 29th November 2011 to conduct the final examination of Tengku Salwani Binti Tengku Mansor on her thesis entitled “�� ” in accordance with the Universities and University Colleges Act 1971 and the Constitution of the Universiti Putra Malaysia [P.U.(A) 106] 15 March 1998. The Committee recommends that the student be awarded the Masters of Science degree. Members of the Thesis Examination Committee were as follows: �� Professor Faculty of Food Science and Technology Universiti Putra Malaysia (Chairman) Amin Ismail, PhD Professor Faculty of Medicine and Health Sciences Universiti Putra Malaysia (Internal Examiner) Tan Chin Ping, PhD Associate Professor Faculty of Food Science and Technology Universiti Putra Malaysia (Internal Examiner) Bahruddin Saad, PhD Professor School of Chemical Sciences Universiti Sains Malaysia 11800, Minden, Pulau Pinang Malaysia (External Examiner) ______________________ �� Professor and Deputy Dean School of Graduate Studies Universiti Putra Malaysia Date:

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This thesis was submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfillment of the requirement for the degree of Masters of Science. The members of the Supervisory Committee were as follows: Yaakob Bin Che Man, PhD Professor Halal Products Research Institute Universiti Putra Malaysia (Chairman) Shuhaimi Bin Mustafa, PhD Associate Professor Halal Products Research Institute Universiti Putra Malaysia (Member) ______________________ BUJANG BIN KIM HUAT, PhD Professor and Dean School of Graduate Studies Universiti Putra Malaysia Date:

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DECLARATION

I declare that the thesis is my original work except for quotations and citations which have been duly acknowledged. I also declare that it has not been previously, and is not concurrently, submitted for any other degree at Universiti Putra Malaysia or at any other institution.

_______________________________

TENGKU SALWANI BINTI TENGKU MANSOR Date: 29 November 2011

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TABLE OF CONTENTS

� � � � � � � � � � �� !"�DEDICATION iiii ABSTRACT iv ABSTRAK vi APPROVAL ix DECLARATION xi LIST OF TABLES xv LIST OF FIGURES xvii LIST OF ABBREVIATIONS xviii �

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CHAPTER

1 GENERAL INTRODUCTION 1

2 LITERATURE REVIEW 5 2.1 Virgin Coconut Oil 5

2.1.1 Methods of VCO extraction 6 2.1.2 Physicochemical characteristics 9 2.1.3 Benefits and uses 9

2.2 Lard 12 2.2.1 Physicochemical characteristics 13 2.2.2 Uses 16

2.3 Adulteration of Foods 17 2.3.1 Implications 18 2.3.2 Methods of detecting adulterations in food products 19 2.3.3 Lard adulterations 23

2.4 Electronic Nose/Fast Gas Chromatography (Fast GC) 26

2.4.1 Working steps 29 2.4.2 Fast GC – surface acoustic wave (SAW) sensor 29 2.4.3 Practical uses 31 2.4.4 Advantages and disadvantages 32

2.5 FTIR 32 2.5.1 Instrumentation and sample handling techniques. 33 2.5.2 IR spectra of oil 34 2.5.3 Advantages and disadvantages 36

2.6 DSC 36 2.6.1 DSC in fats and oils 38 2.6.2 Advantages and disadvantages 40

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3 PHYSICOCHEMICAL PROPERTIES OF VIRGIN

COCONUT OIL EXTRACTED FROM DIFFERENT PROCESSING METHODS 41 3.1 Introduction 41 3.2 Materials and Methods 42

3.2.1 Materials 42 3.2.2 Extraction methods 42 3.2.3 Oil recovery 44 3.2.4 Physicochemical analyses 45 3.2.5 Fatty acid methyl esters (FAME) compositional analysis 46 3.2.6 Triacylglycerol (TAG) analysis by HPLC 47 3.2.7 Tocopherol analysis 47 3.2.8 Statistical analysis 48

3.3 Results and discussion 48 3.3.1 Oil Recovery 48 3.3.2 Physicochemical Analysis 51 3.3.3 Color 54 3.3.4 Fatty acid methyl esters (FAME) compositional analysis 55 3.3.5 TAG Analysis By Reverse Phase HPLC 58 3.3.6 Tocopherol Analysis by HPLC 60

3.4 Conclusions 63 �

4 APPLICATION OF FAST GAS CHROMATOGRAPHY AND FOURIER TRANSFORM INFRARED SPECTROSCOPY FOR ANALYSIS OF LARD ADULTERATION IN VIRGIN COCONUT OIL 64 4.1 Introduction 64 4.2 Materials and Methods 66

4.2.1 Blends 67 4.2.2 Chemical analyses 67 4.2.3 Fast gas chromatography-surface acoustic wave

(GC-SAW) detector system analysis 67 4.2.4 FTIR Spectroscopic analysis 68 4.2.5 Statistical Analysis 69

4.3 Results and Discussion 69 4.3.1 Chemical analysis 69 4.3.2 Fast gas chromatography-surface acoustic wave

(GC-SAW) detector system analysis 71 4.3.3 FTIR analysis 77


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5 EMPLOYMENT OF DIFFERENTIAL SCANNING

CALORIMETER IN DETECTING LARD ADULTERATION IN VIRGIN COCONUT OIL 82 5.1 Introduction 82 5.2 Materials and Methods 83

5.2.1 Preparation of Blends 84 5.2.2 Chemical analyses 84 5.2.3 Fatty acid (FA) compositional analysis 84 5.2.4 Triacylglycerol (TAG) compositional analysis

by HPLC 84 5.2.5 Thermal analysis by DSC 85 5.2.6 Statistical analysis 85

5.3 Results and Discussion 86 5.3.1 Chemical analysis 86 5.3.2 Fatty acid (FA) compositional analysis 87 5.3.3 TAG analysis by reverse-phase HPLC 91 5.3.4 Thermal analysis by DSC 98


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�6 SUMMARY, GENERAL CONCLUSION AND

RECOMMENDATION FOR FUTURE RESEARCH 112 6.1 Summary 112 6.2 General Conclusion 113 6.3 Recommendation for Future Research 113

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�REFERENCES 115 BIODATA OF STUDENT 128 LIST OF PUBLICATIONS 129 �

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