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

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their seed coat. These anti-nutrients includes phytin lectin trypsin inhibitor

activity tannin and cyanide. In addition they also contain minerals such as

sodium potassiumcalciummagnesiumphosphoruszincmanganeseironselenium

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

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lowering effect on blood cholesterol.Additionallysome phytoestrogens may have

antioxidant properties(Goldberg 2003).

In Britain oilseeds are usually consumed following processingas 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

soybeanolive and sunflower oilwhile 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).

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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.

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