Antioxidant capacity and lipid characterization of Georgia-grown underutilized fruit crops

129 Pages·2009·0.74 MB·English

by  Isidor F. Ruderfer

ANTIOXIDANT CAPACITY AND LIPID CHARACTERIZATION OF GEORGIA-GROWN
UNDERUTILIZED FRUIT CROPS

by
GARIMA PANDE

(Under the Direction of Casimir C. Akoh)
ABSTRACT
It is well known that certain bioactive compounds are involved in reducing the risk of diseases
associated with oxidative stress. Five underutilized fruit crops of Georgia were investigated
namely loquat (Eriobotrya japonica), mayhaw Crataegus sp.), fig (Ficus carica), pawpaw
(Asimina triloba), and pomegranate (Punica granatum). Both hydrophilic and lipophilic
antioxidant capacity were determined by FRAP and TEAC assays. Different fractions like seed,
pulp, peel, whole fruit, and leaves were analyzed for phenolic compounds and organic acids.
Lipid profile of seeds and fruits were also determined in terms of fatty acids, tocopherols,
phytosterols, and phospholipids. The predominant organic acid in loquat, mayhaw, pawpaw, and
fig was malic acid whereas in pomegranate it was citric acid. Among all the fruits investigated
pomegranate had the highest content of phenolic compounds and antioxidant capacity. Leaves
had the highest antioxidant capacity followed by peel in pomegranate and by seeds in other four
fruits. The highest lipid content was found in pawpaw seed (21.5%). Pomegranate seed oil had
high α and γ-tocopherols (167.3 and 84.6 mg/100 g, respectively) contents.
INDEX WORDS: antioxidant capacity; Asimina triloba; Crataegus sp.; Eriobotrya japonica;
fatty acids; Ficus carica; organic acids; phospholipids; phytosterols; polyphenols; Punica
granatum; tocopherols; underutilized fruits
ANTIOXIDANT CAPACITY AND LIPID CHARACTERIZATION OF GEORGIA-GROWN
UNDERUTILIZED FRUIT CROPS

by

GARIMA PANDE
B.Sc., G.B. Pant University of Agriculture and Technology, India, 2007

A Thesis Submitted to the Graduate Faculty of The University of Georgia in Partial Fulfillment
of the Requirements for the Degree

MASTER OF SCIENCE

ATHENS, GEORGIA
2009
© 2009
Garima Pande
All Rights Reserved
ANTIOXIDANT CAPACITY AND LIPID CHARACTERIZATION OF GEORGIA-GROWN
UNDERUTILIZED FRUIT CROPS

by

GARIMA PANDE

Major Professor: Casimir C. Akoh

Committee: Ronald R. Eitenmiller
Robert L. Shewfelt

Electronic Version Approved:

Maureen Grasso
Dean of the Graduate School
The University of Georgia
May 2009
To my mother
iv
ACKNOWLEDGEMENTS

I feel a deep sense of gratitude to all the people who contributed towards the completion
of this thesis.
I want to especially thank my major professor, Dr. Casimir C. Akoh, who not only
supported me in the accomplishment of this research but also encouraged and challenged me
throughout my academic program towards the best realization of my goals.
I express also my deep appreciation to each professor that served on my advisory
committee, Dr. Ronald R. Eitenmiller, and Dr. Robert L. Shewfelt for their guidance.
I wish to thank Drs. Gerard W. Krewer, Karina Martino, and Patrick J. Conner for their
valuable support during the selection and procurement of the samples. I would also like to thank
Dr. Dennis Phillips for his help with mass spectrometry.
I want to thank Drs. Kim, Lumor, and Ms. Brenda Jennings, Victoria Wentzel, Ashanty
Pina and Grishma Kotwal for their technical assistance.
Last but not least, thanks to the faculty and staff of the Department of Food Science &
Technology, UGA, for being part of my graduate student life and for their contributions in my
personal and professional development.
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TABLE OF CONTENTS
Page
ACKNOWLEDGEMENTS .............................................................................................................v
LIST OF TABLES ........................................................................................................................ vii
LIST OF FIGURES ....................................................................................................................... ix
CHAPTER
1 Introduction ....................................................................................................................1
2 Literature review ............................................................................................................5
3 Organic acids, phenolic content, and antioxidant capacity of Georgia-grown
underutilized fruit crops ..........................................................................................38
4 Determination of fatty acids, tocopherols, phytosterols, and phospholipids in
underutilized fruits and seeds of Georgia ................................................................64
5 Antioxidant capacity and lipid characterization of six Georgia-grown pomegranate
cultivars ..................................................................................................................84
6 Conclusion .................................................................................................................117

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LIST OF TABLES
Page
Table 2.1: The major classes of phenols. .......................................................................................32
Table 3.1: Dry matter (DM) content of fruit parts and leaves (g/g FW). ......................................54
Table 3.2: Total carotenoids content of fruit parts (mg/100 g FW) ...............................................55
Table 3.3: Major organic acids in fruit parts, whole fruit, and leaves (mg/100 g FW). ................56
Table 3.4: Individual phenolic compounds in fruit parts, whole fruit, and leaves
(mg/100 g FW).. .............................................................................................................................57
Table 3.5: Total polyphenols and antioxidant capacity of hydrophilic fractions. .........................58
Table 3.6: Total polyphenols and antioxidant capacity of lipophilic fractions..............................59
Table 3.7: Comparison of loquat, mayhaw, pawpaw, and fig with other Georgia-grown crops and
other common fruits……….. ……………………………………………………………………61
Table 4.1: Gradient elution for phospholipid determination by HPLC-ELSD. .............................77
Table 4.2: Fatty acid content of seeds and fruits (%). ...................................................................78
Table 4.3: Tocopherol, phytosterol, and phospholipid content of seeds and fruits
(mg/100 g FW). .............................................................................................................................79
Table 5.1: Gradient elution for phospholipid determination by HPLC-ELSD. ...........................105
Table 5.2: Dry matter (DM) content of cultivars (g/g FW).. .......................................................106
Table 5.3: Major organic acids in fruit parts and leaves (mg/100 g FW). ...................................107
Table 5.4: Individual phenolic compounds in fruit parts and leaves (mg/100 g FW)... ..............108
Table 5.5: Total lipid content and fatty acid compositions of pomegranate seeds (%). ..............109
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Table 5.6: Total lipid content and fatty acid compositions of pomegranate fruit (%). ................110
Table 5.7: Tocopherol, phytosterol, and phospholipid content of seeds and fruits (mg/100 g)...111
Table 5.8: Comparison of different parts of pomegranate cultivars... .........................................112
Table 5.9: Comparison of pomegranate with other Georgia-grown crops and other fruits and fruit
juices…….……………………………………………………….……………………………..113