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Masters Theses 1911 - February 2014
2008
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Jean Alamed
University of Massachusetts Amherst
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Alamed, Jean, "Impact of Chemical and Physical Properties on the Ability of Antioxidants to Inhibit Lipid
Oxidation in Foods" (2008). Masters Theses 1911 - February 2014. 187.
Retrieved from https://scholarworks.umass.edu/theses/187
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IMPACT OF CHEMICAL AND PHYSICAL PROPERTIES ON THE ABILITY
OF ANTIOXIDANTS TO INHIBIT LIPID OXIDATION IN FOODS
A Thesis Presented
by
JEAN ALAMED
Submitted to the Graduate School of the
University of Massachusetts Amherst in fulfillment
of the requirements for the degree of
MASTER OF SCIENCE
September 2008
Food Science
© Copyright by Jean Alamed 2008
All Rights Reserved
IMPACT OF CHEMICAL AND PHYSICAL PROPERTIES ON THE ABILITY OF
ANTIOXIDANTS TO INHIBIT LIPID OXIDATION IN FOODS
A Thesis Presented
by
JEAN ALAMED
Approved as to style and content by:
__________________________________________
Eric A. Decker, Chair
__________________________________________
D. Julian McClements, Member
__________________________________________
Yeonhwa Park, Member
________________________________________
Lynne McLandsborough, Interim Department Head
Food Science
ACKNOWLEDGMENTS
I would like to thank Dr. Eric Decker for his guidance and support on this
research and in my pursuit of a master degree. I would like to equally thank Dr. Julian
McClements for his support on this research and in my pursuit of a master degree.
Also, I would like to extend thanks to Dr. Yeonhwa Park for her support and for being a
member of my committee and Dr. Fergus Clydesdale for his continuous efforts in
making this the best Food Science Department in the country.
Many, many thanks to Tuk, Ratjika (Noi), Ryan, Faraji, Pom, Dao and Tang for
their ongoing and unconditional friendship and support over the years – I could not have
done this without them! I’d also like to thank all current and previous faculty, staff and
lab members with special thanks to Dr. Nawar, Brian, Rob, Daka, Mariana, Lauren,
Jeab, Saori, Young-Hee, Carla, Mary, Fran and Dan. In addition, I’d like to thank my
friends outside of the University who continue to support my endeavors.
Most importantly, I’d like to thank my family; especially Mom, Dad, Andy,
Christina and Brady; for their endless love, support and encouragement!
iv
ABSTRACT
IMPACT OF CHEMICAL AND PHYSICAL PROPERTIES ON THE ABILITY OF
ANTIOXIDANTS TO INHIBIT LIPID OXIDATION IN FOODS
SEPTEMBER 2008
JEAN ALAMED, B.A., WESTFIELD STATE COLLEGE
M.S., UNIVERSITY OF MASSACHUSETTS AMHERST
Directed by: Professor Eric A. Decker
Lipid oxidation is a major problem in foods resulting in alteration of texture,
appearance, off flavors, aroma and decreased nutritional quality. The ability of
compounds to inhibit lipid oxidation in foods is dependent on both physical and
chemical properties. The effects of heating (50-90°C), ethylenediaminetetraacetic acid
(EDTA), and calcium on the oxidative and physical stability of salmon oil-in-water
emlusions were investigated in the first study. Oil-in-water emulsions were prepared
with 2% salmon oil, stabilized by 0.2% Brij 35 at pH 7. Above 2.5 µM, EDTA
dramatically decreased lipid oxidation in all samples. Addition of calcium to emulsions
containing 7.5 µM EDTA significantly increased both thiobarbituric acid reactive
substances (TBARS) and hydroperoxide formation when calcium concentrations were
2-fold greater than EDTA concentrations. These results indicate that heat processed
salmon oil-in-water emulsions with high physical and oxidative stability could be
produced in the presence of EDTA. The objective of the second study was to compare
how the free radical scavenging activity of various compounds relates to their ability to
inhibit lipid oxidation in cooked ground beef and oil-in-water emulsion. The order of
v
free radical scavenging activity of the polar compounds was: ferulic acid > coumaric
acid > propyl gallate > gallic acid > ascorbic acid as determined by oxygen radical
absorbance capacity (ORAC). The free radical scavenging activity of the nonpolar
compounds was rosmarinic acid > BHT ≥ TBHQ > α-tocopherol as determined by 2, 2-
diphenyl-1-picrylhydrazyl (DPPH•). Of these compounds only propyl gallate and
TBHQ were found to inhibit the formation of TBARS in cooked ground beef while
propyl gallate, TBHQ, gallic acid and rosmarinic acid were able to decrease lipid
hydroperoxides and hexanal in the oil-in-water emulsion. These data indicate that a
compound’s free radical scavenging activity did not directly correlate with their ability
to inhibit lipid oxidation in cooked ground beef and emulsion suggesting that free
radical scavenging assays have limited value in predicting the ability of a compound to
act as an antioxidant in complex foods.
vi
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS...............................................................................................iv
ABSTRACT......................................................................................................................v
LIST OF TABLES............................................................................................................x
LIST OF FIGURES..........................................................................................................xi
CHAPTER
1. INTRODUCTION.................................................................................................1
2. LITERATURE REVIEW......................................................................................6
2.1 Lipid oxidation................................................................................................6
2.1.1 Mechanisms of lipid oxidation........................................................7
2.1.2 Lipid oxidation decomposition products.........................................8
2.1.3 Factors influencing oxidative stability.............................................8
2.1.3.1 Fatty acid composition......................................................9
2.1.3.2 Oxygen concentration.......................................................9
2.1.3.3 Temperature......................................................................9
2.1.3.4 Surface area.....................................................................10
2.1.3.5 Transition metals.............................................................10
2.1.3.6 Enzymes and singlet oxygen...........................................12
2.2 Antioxidants..................................................................................................12
2.2.1 Free radical scavengers and chain breaking antioxidants..............13
2.2.2 Metal inactivators and chelators....................................................17
2.2.3 Singlet oxygen quenchers..............................................................18
2.2.4 Multiple antioxidant functions.......................................................19
2.3 Measurement of antioxidant capacity...........................................................19
2.3.1 HAT methods.................................................................................21
2.3.1.1 ORAC.............................................................................22
2.3.1.2 TRAP..............................................................................23
2.3.2 ET methods....................................................................................25
vii
2.3.2.1 TEAC..............................................................................25
2.3.2.2 FRAP...............................................................................27
2.3.2.3 DPPH•.............................................................................28
2.4 Measurement of lipid oxidation....................................................................29
2.4.1 Lipid hydroperoxides.....................................................................30
2.4.2 Thiobarbituric acid reactive substances.........................................31
2.4.3 Chromatographic method...............................................................31
2.5 Omega-3 fatty acids......................................................................................32
2.6 Lipid oxidation in food systems....................................................................34
2.6.1 Emulsions.......................................................................................34
2.6.2 Edible (bulk) oils............................................................................38
2.6.3 Muscle foods..................................................................................40
3. INFLUENCE OF HEAT PROCESSING AND CALCIUM
IONS ON THE ABILITY OF EDTA TO INHIBIT LIPID OXIDATION IN
OIL-IN-WATER EMULSIONS CONTAINING OMEGA-3 FATTY ACIDS..43
3.1 Abstract.........................................................................................................43
3.2 Introduction...................................................................................................44
3.3 Materials and Methods..................................................................................46
3.3.1 Materials........................................................................................46
3.3.2 Methods..........................................................................................47
3.3.2.1 Preparation of salmon oil................................................47
3.3.2.2 Preparation of emulsion..................................................47
3.3.2.3 Preparation of EDTA containing samples......................48
3.3.2.4 Preparation of calcium components................................48
3.3.2.5 Lipid oxidation measurements........................................48
3.3.2.6 Statistics..........................................................................49
3.4 Results and Discussion.................................................................................50
3.4.1 Heat processing and holding time..................................................50
3.4.2 Influence of EDTA.........................................................................51
3.4.3 Influence of adding EDTA before or after heating........................54
3.4.4 Influence of calcium on antioxidant effects of EDTA...................56
3.5 Conclusions...................................................................................................58
viii
4. THE RELATIONSHIP BETWEEN A COMOUNDS FREE RADICAL
SCAVENGING ACTIVITY AND ITS ABILITY TO INHIBIT LIPID
OXIDATION IN FOODS...................................................................................59
4.1 Abstract.........................................................................................................59
4.2 Introduction...................................................................................................60
4.3 Materials and Methods..................................................................................63
4.3.1 Materials........................................................................................63
4.3.2 Methods..........................................................................................63
4.3.2.1 Free Radical Scavenging Assays.....................................63
4.3.2.2 Lipid Oxidation in Cooked Ground Beef........................68
4.3.2.3 Lipid Oxidation in Oil-in-Water Emulsion.....................69
4.3.2.4 Statistics..........................................................................71
4.4 Results...........................................................................................................71
4.4.1 Free Radical Scavenging Capacity Assays....................................71
4.4.2 Inhibition of Lipid Oxidation in Foods..........................................75
4.5 Discussion.....................................................................................................82
4.6 Conclusions...................................................................................................87
5. OVERALL CONCLUSIONS.............................................................................89
6. FUTURE WORK................................................................................................92
BIBLIOGRAPHY...........................................................................................................95
ix
Description:Structures of non-polar test compounds . 67. 4.3. Changes in the relative fluorescence intensity of 45 nM fluorescein. (λEM 493 nm, λEX 515 nm) in the presence of 20 mM 2,2′- azobis(2-amidinopropane hydrochloride) (AAPH) and 5 uM ferulic acid (FA), propyl gallate (PG)
