TABLE OF CONTENT
Title page
Approval page
Dedication
Acknowlegdement
Abstract
Table of contents
List of tables
List of figures
Abbreviations
CHAPTER ONE
1.0
Introduction
1.1
Objectives of the Study
CHAPTER TWO
2.0 Literature
Review
3.0 2.1
Importance of Phytochemicals
2.1.1
Mechanism of Action of Tomato Phytochemicals
2.1.2
Importance of Tomatoes
2.2
Structure of Vitamin C and its Activity
2.2.1
Biosynthesis and species-synthetic ability
2.2.2
Absorption, Transport and Disposal
2.2.3
Deficiency
2.2.4
Physiological functions in mammals
2.2.5
Daily requirement
2.2.6
Therapeutic uses
2.2.7
Adverse effects
2.3
Structure of Beta Carotene and its Activity
2.3.1
Previtamin A activity
2.3.2
Symmetric and Asymmetric Cleavage
2.3.3
Sources in Diet
2.3.4
Side Effects
2.3.5
Beta Carotene and lung cancer in smokers
2.3.6 Uses based on
Scientific Evidence
2.4
Structure of Lycopene and Its Chemical Activity
2.4.1
Bioavailability of Lycopene
2.4.2
Digestion and absorption of Lycopene
2.4.3
Roles of Lycopene in Human Health
2.5 Structure of
Polyphenol and its activity
2.5.1
Classification and Nomenclature
2.5.2Potential Health
Benefits
CHAPTER THREE
3.0
Materials and Methods
3.1
Equipments/Apparatus
3.2
Procurement of Raw Materials
3.3 Study
Design
3.4 Sample
Processing
3.5 Chemical
Analysis of Samples
3.5.1Vitamin C content
determination
3.5.2Beta-carotene
content Determination
3.5.3
Lycopene Content Determination
CHAPTER FOUR
4.0 Results
and discussion
CHAPTER FIVE
5.0
Conclusion
Reference
CHAPTER ONE
1.0 INTRODUCTION
Intake of tomato and
tomato based-products contributes to the absorption of a wide range of
carotenoids in human serum and tissues. The prominent carotenoid in tomatoes is
lycopene, a pigment principally responsible for the deep-red colour of tomato
fruits and tomato products. Fruits and vegetables contain in excess of 40
carotenoids that are routinely absorbed and metabolized by humans (Khachik,
1992).
Tomatoes and tomato
products are now being investigated for their potential role in prostate cancer
prevention and therapy. This review summarizes the in vitro and invivo evidence
as well as the molecular data that show the anticarcinogenic potential of
tomatoes. Raw and processed tomatoes are among the most commonly
consumed vegetables. They are rich in the phytochemicals, carotenoids and
polyphenols. Lycopene and quercetin are the most abundant carotenoids and
flavonols respectively. Canned tomato sauce is the primary source of lycopene whereas
the tomato skin is enriched with flavonols. Most epidemiological studies
suggest that the consumption of tomatoes and the products in associated with a
reduced prostate cancer risk. The health professionals follows-up study found
that men who consumed 2 to 4 servings of raw tomatoes per week had a more than
20% reduction in prostate cancer risk compared to men who did not consume
tomatoes. High lycopene plasma concentrations were associated with a low
incidence of prostate cancer and aggressive prostate cancer in rested
case-control study with the physician’s health study. Invitro data show that
the compounds found in tomatoes are potent anticarcinogens. Cancer cell growth
is inhibited by the polyphenols quercetin, kaempferol and naringerin in a dose
dependent manner. These compounds do not have cytotoxic effect. In a rat model
of prostate cancer, tomato powder into but not lycopene intake by itself
reduced prostate cancer related mortality. This suggests that the compounds in
tomatoes have an additive influence on prostate cancer. Lycopenes exist as
either the cis or trans isomer. The half-life of lycopene is approximately 10
to 14 days, so it remains in the body during washout period. The trans isomer
dominates in tomatoes, between the cis isomer dominates in serum and tissues
and during a washout period. Thus, recent intake of lycopenes is reflected in
blood concentrations whereas long-term exposure is determined in the
tissues.
Lycopene is a bioactive
carotenoid found in many red fruits and vegetables, such as tomatoes,
watermelon, pink grapefruits etc. Different fruits, vegetable and their
products contain different concentrations of lycopene. This natural red pigment
is synthesized exclusive by plants and microorganisms (fungi, bacteria and
algae). It facilitates the absorption of light during photosynthesis and also
provides protection against photosensitization (Adam et al., 1996) Animals
including human being, cannot synthesize lycopene therefore, they obtain
lycopene exclusively from diet (Tapiero et al. 2004; Omoni and Aluko, 2005).
Although, tomato contain
a lower concentration of nutrients compared to other commercially grow fruits
species, they are a major source of lycopene. Lycopene comprises 83% of the
total pigment present in tomatoes (Shi et al., 1990). Therefore, the amount of
lycopene present in tomatoes other fruits and vegetables vary with variety,
degree of ripeness and other dimatic conditions and agricultural practices.
The fraction of vitamin
C in the diet that is absorbed and the rate at which the excess is eliminated
from the body vary strongly with the dose. Large, randomized clinical trials on
the effects of high doses on the general population have not been conducted.
Venturi suggested that the antioxidant action of ascorbic acid developed first
in the plant kingdom when, about 500 million years ago (mya), plants began to
adapt to antioxidant mineral deficient fresh waters of estuaries. Ascorbic acid
or vitamin C is a common enzymatic cofactor in mammals used in the synthesis of
collagen. Ascorbate is a powerful reducing agent capable of rapidly scavenging
a number of reactive oxygen species (ROS). Freshwater fishes also require
dietary vitamin C in their diet or they will get scurvy. The most widely
recognized symptoms of vitamin C deficiency in fishes are scoliosis, lordosis
and dark skin coloration.
The name “carotene” was
first coined in the early 19th century by the scientist
Wachenroder after he crystallized this compound from carrot roots.
Beta-carotene is a member of the carotenoids, which are highly pigmented (red,
orange, yellow), fat-soluble compounds naturally present in many fruits,
grains, oils and vegetables (green plants, carrots, sweet potatoes, squash,
spinach, apricots, and green peppers). Alpha, beta and gamma carotene are
considered provitamins because they can be converted to active vitamin A. The
carotenes possess antioxidant properties. Vitamin A serves several biological
functions including involvement in the synthesis of certain glycoproteins.
Commercially available beta-carotene produced synthetically or from palm oil,
algae, or fungi. Beta-carotene is converted to retinol, which is essential for
vision and is subsequently converted to retinoic acid, which is used for
processes involving growth and cell differentiation.
1.1
Objectives of the study
The main objective of
this project is to do a comparative analysis (quantitative analysis) on
phytochemicals present in tomatoes and some selected tomato products (canned
tomato) sold in any common market in Nigeria.
Department | Bio-Chemistry |
Project ID Code | BCH0019 |
Chapters | 5 Chapters |
No of Pages | 79 pages |
Methodology | Null |
Reference | YES |
Format | Microsoft Word |
Price | ₦5000, $15 |
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