ABSTRACT
The effects of processing on nutrient composition, phytochemicals and carotenoid profile of two cultivars of Pterocarpus santalinoides were investigated. The tender leaves of Pterocarpus santalinoides was selected, washed, surface air dried, sliced at 1.5 m, then divided into four portions, raw, oven dried (500C for 1h 20 min), sautéed (500g/20ml) of fat and Blanched (1000C) for 3 min. The proximate composition, vitamins, minerals, and phytochemicals were determined according to standard methods. Carotenoid profile was determined using HPLC. The moisture content ranged from 36.84 – 76.66 %, crude protein; 12.68 – 16.42 %; Oven drying and sautéing improved the crude protein content, Ash content ranged from 1.84 to 4.15 % and was improved by oven drying. Crude fibre was moderately present in the cultivars (1.95 – 3.72 %). Oven dried Afu had high crude fibre (3.72%) than other samples (p<0.05). The Pterocarpus santalinoides cultivars are good sources of energy (81.18 – 248 K/J. Vitamin B6 (41.07 – 94.17), Afu blanched had the highest quantity of vitamin B6 (94.17 mg/100g) Pro-vitamin A content ranged from 8.95 – 243.72 µg/g and was in the highest amongst in sautéed Afu (243.72 µg/g). Vitamin C value ranged from 13.42 to 20.39 mg/100g. Raw Osw was higher in vitamin C (20.39 mg/100g), vitamin B1, B2, B3, B9 and vitamin E were in trace amount. Iodine content ranged from 45.99 to 63.33 mg/100g was significantly higher (p<0.05) in Raw Osw (63.33 mg/100g). Processing moderately reduced the iodine content. Potassium content ranged from 40.00 to 59.50 mg/100g. Osw oven dried sample had the highest iodine content (59.50 mg/100g). Magnesium content ranged from 42.12 to 44.90 mg/100g. Oven drying and sautéing improved magnesium in Osw significantly (p<0.05) (44.90 %). Iron was present in appreciable amounts (6.20 – 7.75 mg/100g). Processing did not have any significant effect on the iron content of the cultivars. Calcium (3.50 – 4.09 mg/100g) was moderately available; oven drying and sautéing significantly improved the iron content among others (4.08 and 4.09 %). Zinc (1.10 –1.29) was in trace amount. Phytochemicals analyzed were in trace amount except alkaloid (3.38 –7.73 mg/100g), oven dried and sautéed samples (4.62 and 4.52 %) respectively moderately reduced the alkaloid but blanching drastically reduced it (3.38%). The total β carotene ranged from 8.08 to 232 µg/g. Sautéing improved the total β carotene; sautéed Afu had the highest value (232.46%). Trans β carotene was present in measurable concentration (3.97 –108.15 µg/g), sautéed Afu and Osw (108.15, 102.75 µg/g) had the highest values. 13-cis β carotene was in appreciable concentration (2.58 – 86.31 µg/g). Sautéed Afu had the highest 13-cis β carotene content (86.31µg/g) significantly. - Carotene (1.66 – 23.83 µg/g) was in trace amount, but sautéing significantly improved it to 23.83, 22.53 µg/g. The chromatogram showed (4 – 7) major peaks and several minor peaks that were not identified due to lack of standard. Afu cultivar had more carotenoid than Osw cultivar. Sautéing was the best method for enhancing the carotenoid profile.
TABLE OF CONTENTS
Cover
Page i
Title
Page ii
Declaration
iii
Certification
iv Dedication
v
Acknowledgements vi
Table
of Contents vii
List
of Tables xii
List
of Figures xiii
List
of Plates xiv
Abstract xv
CHAPTER
1: INTRODUCTION
1.1 Background of the Study 1
1.2 Statement of Problem 5
1.3 Objective of the
Study 7
1.4.1 Specific Objectives
7
1.4.2 Justification 7
CHAPTER
2: LITERATURE REVIEW
2.1 History of Nturukpa (Pterocarpus santalinoides) 9
2.1.1 Vegetables and their uses 10
2.1.2 Constituents of green leafy vegetables 11
2.1.3 Underutilized vegetables 11
2.1.4 Importance of underutilized vegetables 13
2.1.5: Uses of Pterocarpus
Santalinoides 13
2.1.6 Constraints that render a few vegetables
underutilized 14
2.2
Processing of Green Leafy Vegetables 16
2.2.1 Blanching 17
2.2.2
Drying and dehydration (oven drying) 17
2.2.3
Sauteeing 18
2.3 Vitamin 18
2.3.1 Vitamin
A 19
2.3.2 Bioavailability
of vitamin A 22
2.3.3 Vitamin
B6 23
2.3.3.1 Bioavailability
of vitamin B6 23
2.3.4. Vitamin
C 24
2.3.4.1 Bioavailability
of vitamin C 25
2.3.5 Vitamin E 26
2.3.5.1 Bioavailability of vitamin E 28
2.4 Minerals 28
2.4.1 Classification of minerals 29
2.4.1.1 Classification
of trace elements 30
2.4.1.2 Role of
trace elements 30
2.4. 1.3 Role
of major, minor and trace elements 31
2.5.1 Sodium
31
2.5.2 Potassium
32
2.5.2.1 Potassium
bioavailability 34
2.5.3 Calcium
35
2.5.3.1 Bioavailability of calcium 36
2.5.4 Magnesium 36
2.5.4.1 Bioavailability of magnesium 37
2.5.5 Zinc 38
2.5.5.1 Bioavailability of zinc 39
2.5.6 Manganese
40
2.5.7 Iodine 41
2.5.7.1 Bioavailability of iodine 41
2.5.8 Selenium 42
2.5.9 Iron 43
2.5.9.1 Bioavailability of iron 44
2.6 Anaemia 45
2.7
Phytochemicals 47
2.7.1
General functions of phytochemicals 48
2.7.2
Phenols 49
2.7.2.1
Biological function of phenols
50
2.7.2.2
Anti-Nutritional effects of
phenols 51
2.7.3
Saponins 51
2.7.3.1.
Natural functions of saponins 52
2.7.3.2
Anti-Nutritional effects of
saponins 53
2.7.4
Oxalate 53
2.7.4.1
Biological Function of Oxalate
54
2.7.4.2
Anti-Nutritional Effects of
Oxalate 54
2.7.5
Cardiac Glycosides 55
2.7.5.1
Biological function of cardiac
glycosides 55
2.7.5.2
Anti-Nutritional effects of
cardiac glycosides 56
2.7.6
Tannins 56
2.7.6.1
Biological function of tannins
57
2.7.6.2
Anti-Nutritional effects of
tannins 58
2.7.7
Phytate 58
2.7.7.1.
Natural functions of phytic acid 59
2.7.7.2
Anti-Nutritional effects of
phytic acid 60
2.7.8
Alkaloids 60
2.7.8.1 Biological function of alkaloids 61
2.7.8.2
Anti-Nutritional effects of
alkaloids 62
2.7.9 Flavonoids 62
2.7.9.1
Biological function of
flavonoids 64
2.7.9.2
Anti-Nutritional effects of
flavonoids 64
2.7.10
Haemagglutinin 65
2.7.10.1
Biological function of plant haemaglutinin 65
2.7.10.2
Anti-Nutritional effects of plant haemaglutin 66
2.8 Carotenoids and its sources 66
2.8.1 Classification of carotenoids 68
2.8.2 Types of carotenoids 69
2.8.2.1 Carotenes 73
2.8.2.2 Lycopene 74
2.8.2.3 Uses and application of carotenoids
in food and nutraceutical industry 75
2.8.3 Factors implicated in the cardiovascular
disease 76
2.8.4 Biosynthesis of carotenoids and its pathway 76
2.8.5: The role of carotenoid as an antioxidant,
pro-vitamin A, and it’s
Mechanism of action. 79
2.8.6 The relevance of carotenoids in food
industry 83
CHAPTER 3: MATERIALS AND METHODS
3.1 Sample Source 85
3.2 Sample
Preparation 85
3.3 Determination of Proximate Composition 89
3.3.1 Determination
of moisture content 89
3.3.2 Determination
of crude protein 89
3.3.3 Determination of ash content 90
3.3.4 Crude fat content
determination 90
3.3.5 Determination of crude fibre 91
3.3.6 Determination of
carbohydrate content 92
3.3.7 Determination
of energy value
92
3.4. Determination
of Vitamin Composition 92
3.4.1 Determination
of vitamin B1 92
3.4.2 Determination of riboflavin content (B2) 92
3.4.3 Determination of vitamin B3 93
3.4.4 Determination of B6 94
3.4.5 Vitamin C content determination. 94
3.4.6 Determination of vitamin E content 95
3.5. Determination
of Minerals 95
3.5.1 Determination of calcium and
magnesium 95
3.5.2 Determination of trace element 96
3.5.3 Determination of iodine value 97
3.6. Determination of phytochemicals 98
3.6.1 Determination of tannin content 98
3.6.2 Determination of alkaloid content 99
3.6.3 Determination of flavonoid content 99
3.6.4 Determination of phytate content 100
3.6.5 Determination of oxalate content 101
3.6.6 Hydrogen cyanide determination 102
3.7. Protocol for Carotenoid Analysis of
Vegetables 102
3.7.1 Sample extraction 103
3.7.2 Identification of the carotenoid 104
3.8 Statistical
Analysis
CHAPTER
4: RESULT AND DISCUSSION
4.1 Morphological and Description of Pterocarpus santalinoides Leaves 105
4.2 Effect of Processing Methods on the
Proximate Composition of Two
Cultivars
of Pterocarpus santalinoides 107
4.2.1 Moisture
content 110
4.2.2 Crude protein 111
4.2.3 Crude fat 111
4.2.4 Fibre content 112
4.2.5 Ash 113
4.2.6 Carbohydrate 114
4.2.7 Energy value 115
4.3 Effect of Processing Methods on the
Vitamin Content of Two
Cultivars
of Pterocarpus santalinoides. 116
4.3.1 Vitamin B1 118
4.3.2 Vitamin B2 119
4.3.3 Vitamin B3 120
4.3.4 Vitamin B6 121
4.3.5 Vitamin B9 121
4.3.6 Pro-vitamin
A 122
4.3.7 Vitamin
C 122
4.3.8 Vitamin E 124
4.4 Effect
of Processing Methods on Mineral Content of Two Cultivars of
Pterocarpus
santalinoides. 127
4.4.1 Iron 129
4.4.2 Magnesium 130
4.4.3 Zinc 131
4.4.4 Calcium 132
4.4.5 Selenium 133
4.4.6 Potassium 134
4.4.7 Iodine 135
4.5 Effect of Processing on the Phytochemical Content of Pterocarpus
santalinoides 137
4.5.1 Steriod 139
4.5.2 Phenol 139
4.5.3 Saponin 140
4.5.4 Oxalate 140
4.5.5 Cyangenic glycosides 141
4.5.6 Anthocyanin 142
4.5.7 Tannin 142
4.5.8 Phytate 144
4.5.9 Alkaloid 144
4.5.10 Flavonoid 146
4.6 Effect of Processing on the Carotenoid
Profile of Two Cultivars of
Pterocarpus santalinoides 148
4.6.1 α-carotene 150
4.6.2 13-cis-β-carotene 151
4.6.3: Trans
β-carotene 152
4.6.4: 9-cis-β
carotene
153
4.6.5: Total
β-carotene 154
CHAPTER 5: CONCLUSION
AND RECOMMENDATION
5.1 Conclusion 161
5.2 Recommendation 162
References 163
Appendices
LIST OF TABLES
2.1 The
Medicinal Value of Some Alkaloid 61
2.2 Carotenoid
Types, Examples, Sources and Medicinal Properties 68
4.1 Effect of Processing on the
Proximate Composition of Two
Cultivars of Pterocarpus santalinoides 109
4.2 Effect of Processing Methods
on the Vitamin Composition of
Two Cultivars of Pterocarpus
santalinoides 117
4.3 Effect
of Processing Methods on Mineral Composition of Two
Cultivars of Pterocarpus santalinoides 128
4.4 Effects of Processing on
Phytochemical Composition of Two
Cultivars
of Pterocarpus santalinoides 138
4.5 Effect of Processing on
Carotenoid Profile of Two Cultivars
of
Pterocarpus santalinoides 149
LIST OF FIGURES
2.1 Pterocarpus santalinoides (Nturukpa
leaves). 9
2.2 Phenols Other Names: Carbolic
Acid, Benzenol,
Phenylic Acid 50
2.3
Chemical Structure of
the Saponin 52
2.4 The Structure of the Oxalate
Anion. 53
2.5
The
Chemical Structure of Oleandrin, Toxic Cardiac Glycosides 55
2.6
Tannic Acid 57
2.7
Molecular Structure of
Phytic Acid 59
2.8 The Nicotine Molecule 61
2.9
Molecular Structure of
the Flavone Backbone. 63
2.10
Chemical Structure of all
Major Carotenoids 72
2.11
Biosynthetic Pathway of
Carotenoids in Plants 78
2.12 Biosynthetic Contents of Biosynthesis 79
3.1a
Pterocarpus santalinoide, (Avuo
leaves) 86
3.1b Pterocarpus santalinoides (Oselukwu
leaves). 87
3.2 Preparation
of Pterocarpus santalinoides Samples 88
4.2.a Carotenoid
Profile of Raw Pterocarpus
santalinoides
(Afu cultivar). 155
4.2.b Carotenoid
Profile of Sautéed Pterocarpus
santalinoides
(Afu cultivar) 156
4.2.c Carotenoid
profile of Raw Pterocarpus
santalinoides
(Osw
cultivar). 157
4.2.d Carotenoid
Profile of Sautéed Pterocarpus
santalinoides
(Osw cultivar). 158
LIST
OF PLATES
1 Avuo
(Oven drying) 106
2 Oselukwu
(Oven drying) 106
3 Avuo
(Blanching) 106
4 Oselukwu
(Blanching) 106
5 Avuo (Sautéing) 107
6 Oselukwu (Sautéing) 107
CHAPTER
1
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
The
role of diets and sustenance as determinants of persistent sicknesses is all
around recorded (Thiam et al., 2006).
The expense of these illnesses has brought about friendly pain, loss of
efficiency and financial weight on wellbeing. The variables adding to the quick
change in sickness design incorporate urbanization, change in diets and
reception of a more westernized way of life because of monetary turn of events
and market globalization (WHO/FAO, 2003). This has brought about the
relinquishment of native food sources that are wealthy in supplements and
wellbeing ensuring parts. Vegetables are agrarian items which are significant
wellsprings of defensive food varieties that are profoundly valuable for the
support of good wellbeing and avoidance of illnesses. Verdant vegetables
address a reasonable however excellent supplement source particularly for the
helpless portion of the populace where hunger is wide spread (Ezeife, 2010).
Albeit a few vegetables can be
raised nearly at lower the executive’s costs and on poor minimal soil, they
have remained underutilized because of absence of consciousness of their
healthy benefits, and somewhat because of the planning strategies, for
fascinating vegetables. Vegetables are considered as significant supporters of
a sound eating routine and their admission is of central need to decrease the
danger of explicit infections like malignant growths, cardiovascular illnesses,
neural cylinder deformities, and waterfalls. They are the chief wellspring of
carotenoids as a result of their significant role in diet as sources to
Pro-vitamin A carotenoids (Haskell, 2013). Bioactive constituents from
vegetables, like carotenoids, folic corrosive and dietary fiber will in general
assume significant parts in the anticipation of these infections. Lacking food
and supplement consumption, helpless sustenance schooling, unseemly homegrown
handling procedures and food planning strategies are among the significant
reasons for ailing health (Ifesan et al.,
2014). The ideal wellbeing and sustenance of people reliant upon an ordinary
and adjusted inventory of food and water, and when diets are problematic, a
person's ability for work and accomplishments is enormously diminished; roughly
30 % of ladies devour not exactly their day by day prerequisites of energy and
something like 40 % of ladies’ overall experience the ill effects of
iron-inadequacy weakness, (FAO, 2012).
The
micro-nutrient content of green verdant vegetables might possibly resolve the
issue of micronutrient inadequacy among the rustic inhabitants in Nigeria.
Comparable to wellbeing, sensible measure of vegetable admission has been
accounted for to decrease the danger of degenerative illnesses like malignancy,
diabetes mellitus and cardiovascular infections (Ukom and Obi, 2018). By and by,
there has been an expanding mindfulness on the requirement for remembering more
vegetables for our eating routine to keep a solid body. To this date, a few
specialists have disentangled various reasons why the pace of delivering
vegetables and organic product should increment tremendously. There is a need
to remember more leafy foods for our eating regimen and the advantages of
eating more products of the soil consistently are various. Carotenoids are plant shades labile for
radiant red, yellow and orange tones in many products of the soil. Carotenoids
and their subsidiaries are flexible isoprenoids and they assume an imperative
part in plants and creatures (Ramesh et
al., 2015). Individuals who eat food sources containing carotenoids get
defensive medical advantages also. Carotenoids are lipophilic regular plant
colors, which are processed by plants, green growth, and photosynthetic
microscopic organisms (Ramesh et al.,
2015). They are classes of natural mixtures made out of at least two units of
hydrocarbons, with every unit comprising of five carbon particles masterminded
in a particular example (regular isoprenoid shades). They are labile for the
yellow, orange, and red tones in different leafy foods (Namitha and Negi,
2010). Carotenoids serve two key roles in plants and green growth: they retain
light energy for use in photosynthesis, and they shield chlorophyll from
photograph harm. The main part of carotenoids in our eating regimen is the cell
reinforcement and supportive of pro-vitamin A action, and furthermore the
shading that they grant to our food, (Skibsted, 2012). The most widely
recognized ones in the western eating regimen, and the most contemplated, are
alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, lycopene and
zeaxanthin.
There are two expansive
characterizations of carotenoids: carotenes and xanthophylls. Carotenoids can
be characterized dependent on useful gatherings; xanthophylls, containing
oxygen as utilitarian gathering, including lutein and zeaxanthin, and carotenes,
which contain just parent hydrocarbon chain with no practical gathering, for
example, α-carotene, β-carotene and lycopene, (Ramesh et al.,
2015). Expansion of polar gatherings (epoxy, hydroxyl and keto) changes the
extremity of carotenoids and influences organic capacities (Britton, 2008).
Carotenoids assist plants with engrossing energy for use in photosynthesis.
They additionally have a significant cancer prevention agent capacity of
deactivating free revolutionaries’ single oxygen iotas that can harm cells by
responding with different atoms (Ramesh et al., 2015). A few carotenoids are
forerunners of pro-vitamin A, which is vital for vision and ordinary
development and improvement. Carotenoids likewise have calming and resistant
framework benefits. Epidemiological examinations showed that the utilization of
diets wealthy in carotenoids is related with a lower frequency of malignant
growth, cardiovascular sicknesses, age related macular degeneration and
waterfall development (Sharoni et al., 2012 Meyers et al.,
2014). Inadequacy of carotenoids brings about clinical indications of
conjunctiva and corneal abnormalities including, xerophthalmia, night visual
deficiency, keratomalacia, corneal ulceration, scarring, and resultant
irreversible visual impairment (Sommer, 2008). Lycopene is the amazing cell
reinforcement carotenoid however it needs Pro-vitamin A movement yet its strong
cell reinforcement action is liable for the insurance of cell framework from an
assortment of receptive oxygen and responsive nitrogen species and furthermore
helps in forestalling cardiovascular sicknesses in human (Muller et al.,
2016). Because of carotenoids adaptable use in food sources, beauty care
products and drug businesses, it makes them possible for improvement and
control (Ramesh et al.,
2015).
Underutilized vegetables
are those vegetables that have under-took advantage of possibilities for adding
to food security, wholesome, therapeutic and pay age (Anil et al.,
2018). They may not be generally known outside of a particular region or
locale, and there is discernment that they are filled for the most part in
rustic regions (Anil et al.,
2018). In certain spots utilization of these plants isn't socially adequate by
certain networks since they are viewed as nourishment for poor people. They
have likely advantages however need public or worldwide acknowledgment and
appreciation (Anil et al.,
2018). They can possibly add to neediness end through business openings and pay
age and furthermore through further developed effectiveness and productivity of
ranch family work use in both country and metropolitan conditions (Anil et al.,
2018). With the utilization of underutilized vegetable yields, there is an
approach to decrease the danger of over-dependence on extremely set number of
significant harvests. They can add to supportable occupations through family
food security as they can broaden the food edibility choices (Anil et al.,
2018). They add supplements to the eating regimen and are here and there
comfort food varieties for low pay metropolitan individuals (Anil et al.,
2018). For instance, numerous underutilized vegetables contain more vitamin C
and supportive of Pro-vitamin A than generally accessible business species and
assortments. Concentrating on underutilized vegetables is a powerful method to
assist with keeping a different and solid eating routine and to battle
micronutrient lacks, the alleged 'covered up hunger', and other dietary
inadequacies especially among the country poor and the weaker gatherings of
people in non-industrial nations (Anil et al., 2018).
Age-related macular degeneration is a
significant reason for irreversible visual impairment among the older in the
Western world and affects
the macula lutea (yellow spot) of the retina, the space of maximal visual
action (Stahl and Sies, 2005). Vitamin A is a fundamental micronutrient for the
typical working of the visual and resistant frameworks, development and
advancement, support of epithelial cell uprightness, and for multiplication.
Vitamin A lack is the main source of preventable visual impairment in kids and
builds the danger of sickness and passing from serious diseases (Ceballos et al.,
2017). In pregnant ladies, Vitamin A lack causes night visual impairment and
may expand the danger of maternal mortality. It is a general medical condition
in the greater part, all things considered, particularly in Africa and
South-East Asia. An expected 250,000 to 500,000 Vitamin A inadequate kids
become visually impaired each year, a big part of them passing on inside a year
of losing their sight (Ceballos et al., 2017).
1.2 STATEMENT OF PROBLEM
In
spite of the abundance of green leafy vegetables in our environment and their
utilization in the preparation of customary soups and dishes, data on Pterocarpus santalinoides, carotenoid is
lacking. The need to expand the use of these vegetables cannot be over
stressed. Micronutrient deficiency is a common place among the populace. In
non-industrial nations, similar to Nigeria, vitamin A (retinol) deficiency is
predominant amongst preschool children, pregnant women, lactating mothers and
even all adults. This can cause visual deficiency, poor development, and death
(World Health Organization, 2002, Gurmu et
al., 2014). Pro-vitamin A, iron, zinc etc are micronutrients that contribute
immensely to human wellbeing and deficiencies lead to paleness and low serum
retinol (Underwood, 1998; Ortiz, 2011) and furthermore iodine helps in memory
improvement. In any case, food diversity with vegetables high in micronutrients
and carotenoids can be a panacea to wellbeing challenges presented by
micronutrient inadequacy among the populace (Anil et al., 2018). Some underutilized vegetables like Pterocarpus santalinoides (Nturukpa leaves) are accepted to be rich
sources of micronutrients: iron, zinc, B6, B9, vitamin C,
Pro-vitamin A, carotenoid, even iodine (Underwood, 1998). Pro-vitamin A, close
by iron and iodine, is among the main micronutrients whose insufficiency
involves general wellbeing concern (Underwood, 1998).
A greater part of people in the
underdeveloped nations can't fulfill their wholesome necessities for
development and advancement. This prompts lack of healthy sustenance, which is
one of the significant reasons for death, especially in babies and little youngsters.
Hunger can show as protein-energy, lack of healthy sustenance and micronutrient
inadequacy. Micronutrients are engaged with digestion of energy supplements and
their insufficiency might accelerate. It is just as their particular
insufficiency sicknesses (Onoja, 2014). Paleness establishes a genuine medical
condition in numerous tropical nations including Nigeria in view of the
pervasiveness of jungle fever and other parasitic diseases which conceivably
prompts lessening of hemoglobin (Toma et
al., 2015). Pterocarpus santalinoides
(Nturukpa leaves) are wealthy in
iron which assumes a part in the fix of pallor. Handling techniques,
notwithstanding, can lessen or improve the micro-vitamin content of food
sources. In addition, supplement accessibility in food varieties is better
considered at the prepared conditions before utilization. It is subsequently
critical to think about the impacts of handling on the phytochemical pieces,
supplement arrangements, carotenoid profile of underutilized vegetables in
maximum usage, for example, Pterocarpus
santalinoides (Nturukpa leaves).
1.3 OBJECTIVE
OF THE STUDY
The
main objective of this study was to determine the effects of processing methods
on the nutrient composition, phytochemicals and carotenoid profile of two
cultivars of Pterocarpus santalinoides (Nturukpa leaves).
1.4 SPECIFIC OBJECTIVES OF THE STUDY
v The
specific objectives of this study were: To determine the proximate, vitamin and
mineral composition of two cultivars of Pterocarpus
santalinoides leaves.
v To
evaluate some of the phytochemicals present in the two cultivars of Pterocarpus
santalinoides leaves.
v To
determine the carotenoid profile of two cultivars of Pterocarpus santalinoides
leaves.
v To
evaluate the effects of processing on the nutrient and phytochemical composition of the two cultivars of Pterocarpus santalinoides leaves.
v
To evaluate the effects of
processing on the carotenoid profile of the two cultivars of Pterocarpus santalinoides leaves.
1.5 JUSTIFICATION
Cataract
as a deficiency disease of Pro-vitamin A, cancer cells and malnutrition has
affected many ageing and aged people. There is an urgent need to diversify
means of combating eye defects which is caused by cataract since many people
cannot have access to surgery and many does not want to attempt surgery because
of its risk factors (most especially the rural dwellers). Also, there is an
urgent need to know the carotenoid content of the leaves under study and to
ascertain if they are good sources of β-carotene, hence could reduce the
risk of cancer. Numerous cases of anaemia
could be reduced by increasing blood level of individuals through optimal
utilization of our locally available underutilized vegetables- Pterocarpus santalinoides. Some underutilized vegetables have been
reported to be very good in blood building (Toma et al., 2015). It has been established that green
vegetables contribute significantly to the daily dietary requirements of calcium
(Ca) and iron (Fe) among children within the ages 2 to 5 years and even older
adults (Ogbuji et al., 2016). Heat treatment can lead to a change
in the chemical structures of vegetables, leading to the breakdown of cells and
the degradation of some phenolic compounds from biological structures, the
release of phenolics from the food matrix, and the conversion of insoluble
phenolics to more soluble forms. In addition, the phenolic compounds are
soluble in water; thus, water-based cooking techniques often lead to loss of
phenolics by leaking (Kamalaja et
al., 2018). It is therefore envisaged that
results from this study will enlighten the public mostly, the rural and
vulnerable population of the nation, on the processing methods with better
carotenoid profile and nutients availability in Pterocarpus santalinoides (Nturukpa
leaves) which are commonly consumed in South East Nigeria.
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