ABSTRACT
Elemental analysis is the qualitative detection and quantitative determination of
chemical elements(atoms,ions)in a sample(Fritz Pregl 1923). To detect an
element, one should fix an appearance of an analytical signal. The formation of
precipitate or characteristic crystals, colour change, an isolation of gaseous
products, an appearance of a definite lines in spectrum, luminescence, etc. To
determine elements quantity, it is necessary to measure a value of an analytical
signal; a precipitate mass, intensity of a current, solution absorption, spectrum line,
luminescence or radioactivity, a reaction rate and so on.(www.intechopen.com).
This study was undertaken to analse the elements present in grounded Pterocarpus
mildbreadii (Oha seed) using Atomic Absorption Spectrometer(AAS MODELAA320N).The
seed was found to contain these essential macro minerals/elements
sodium(Na),Potassium(K),calcium(Ca),magnesium(Mg),and the trace elements
iron(Fe),copper(Cu),zinc(Zn), and selenium(Se)(Duffus,2002).
The study established that Pterocarpus mildbreadii(oha seed) does not contain
manganese and has high content of potassium which is necessary for good health.
CHAPTER ONE
1.1 INTRODUCTION, AIMS AND OBJECTIVES
A seed or mature ovule is a miniature plant with a protective cover in a
suspended state of development. Most seeds contain a built-in food supply called
endosperm, orchid is an exception. The endosperm can be made up of proteins,
carbohydrates and fats.
Seed can also be defined as a small embryonic plant enclosed in a covering called
the seed coat, usually with some stored food. It is the product of the ripened ovule
of gymnosperm and angiosperm plants which occurs after fertilization and some
growth within the mother plant(Wikipedia).Seed protects a plant embryo so that it
can grow into a new plant. Many seeds are edible, such as sunflower seeds, tomato
seeds, corn and peas.
Seeds contain three distinct structures. The inside of a seed contains an embryo,
which is a baby plant with a shoot and a tiny root. The two halves of a seed are
stored food that provides the nourishment necessary for seeds to germinate, or
begin growing. Surrounding the seed is a hard, tough seed coat, which protects the
seed during dormancy(Anville 2007).
Most seeds contain a built-in food supply called endosperm. The endosperm can
be made up of proteins, carbohydrates and fats. Seeds also contain anti-nutrients in
their seed coat. These anti-nutrients includes phytin, lectin, trypsin inhibitor
activity, tannin and cyanide. In addition, they also contain minerals such as
sodium, potassium,calcium,magnesium,phosphorus,zinc,manganese,iron,selenium
and copper.(Balogun 2000)
Oilseeds are energy dense foods; for example, sesame seeds provide 600kcal or
2470kj/1000g.Although oilseeds contain protein(|14-32g/100g)and
carbohydrate(ranging from less than 1g/100g to more than 34g/100g),most of the
food energy they provide is as fat(which provides 9kcal or 37kj/g).Oilseeds vary
widely in their fatty acid composition but tend to be rich in MUFA(e.g peanut)r
PUFA(e.g sunflower seeds).Some seed oils contain significant amounts of EFA,
ALNA, an n-3 fatty acid, and linoleic acid(LA),an n-6 fatty acid. from these two
fatty acids, the body can make all the fatty acids it needs. From LA, arachidonic
acid can be produced, and from ALNA the long chain n-3 eicosapentaenoic
acid(EPA)and docosahexanoic acid(DHA)can be made.(BNF 1999).
Generally, whole oilseeds are a source of fibre, phosphorus, iron and magnesium;
many oilseeds are a source of vitamin E(an antioxidant),niacin and folate. Whole
oilseeds also contain phytoestrogens, a group of substances including lignans and
isoflavones. Phytoestrogens have a structure similar to the oestrogen hormone
oestradiol and can bind to oestrogen receptors.Phytoestrogens may provide a
protective effect against coronary heart disease as they have been shown to have a
lowering effect on blood cholesterol.Additionally,some phytoestrogens may have
antioxidant properties(Goldberg 2003).
In Britain, oilseeds are usually consumed, following processing,as oils and
margarines. The fatty acid composition of oils produced from oilseeds varies
widely. Vegetable oils do not contain the same levels of macronutrients, vitamins
and minerals as whole oilseeds. In fact, apart from fat itself, vitamin E is the only
nutrient present in appreciable amounts. Vegetable oils do, however, contain a
range of phytochemicals, e.g they are the main source of natural plant sterols in
the diet. Plant sterols have a structure similar to cholesterol and hence reduce
cholesterol absorption, therefore reducing the circulating levels of total and low
density lipoprotein(LDL)cholesterol. Plant sterols can be present as free or
esterified forms and the proportions vary, e.g free sterols dominate in
soybean,olive and sunflower oil,while in rapeseed and corn oil, free sterols account
for only 30% of the plant sterols.Refining vegetable oils decreases the content of
sterols(from 10-70% depending on the oil and processing conditions used),thus
decreasing their potential to lower serum cholesterol(Goldberg 2003).
1.2 AIM OF STUDY
To determine the elements present in grinded oha seed(Pterocarpus
mildbreadii)
1.3 RESEARCH OBJECTIVE;
This study was primarily designed to use grinded oha seed(Pterocarpus
mildbreadii) extract for elemental analysis.