The proximate content; moisture, crude protein, crude ash, crude fat, crude fibre and carbohydrate, of Simarouba glauca
were determined, along with other properties to include the glucose and
amino acid contents, and the qualitative macromolecular content of the
plant. The proximate properties of the plant were determined based on
the A.O.A.C (1990) methods for moisture, crude protein and crude ash;
A.O.A.C (1984) for crude fibre and carbohydrates; and the acid base
extraction technique described by Phillips et.al. (2001). The
concentration of different amino acids were determined using the
ninhydrin, while the glucose content was determined Nelson-Simogy’s
method. The moisture contents of the
leaves and the roots were quite high,
over 60% in both. The root of the plant was also found to be rich in
fibre and low in fat, meanwhile the leaves recorded a higher fat
concentration than fibre. With the moisture and fibre content of the
roots taking a large percentage, it was found to be pretty low in crude
ash, carbohydrates, crude protein and crude fat. The leafs however was
much higher in ash, carbohydrates and protein, and a little higher in
fat. Among the essestial amino acids, methionine was the highest while
phenyl alanine was negative. The highest amino acid was cysteine, which
is a conditionally essential amino acid. From these results, it is
obvious that Simarouba glauca roots and leaf extract might not
enough nutritional supplements while being used medicinally. They can
serve as a good source of animal feed, however, proteins and fat would
need to be supplemented.
Plants undergo photosynthesis and they
constitute a primary resource of carbon, vitamins, minerals, protein,
essential fatty acids, and utilizable energy for food production (Young
and Pelett, 1994). Plants have played a significant role in maintaining
the health and improving the quality of human life for thousands of
years. (Mishra, 2010). They provide a major source of food and
nourishment for man and animal.
Nutrition is a science of food and its
relationship to health. Nutrition refers to nourishment that sustains
life. The study of nutrient requirements and the diet providing these
requirements is also known as ‘nutrition’ (Chutani, 2008). Pike and
Brown, 1984 defined it as “the science that interprets the relationship
of food to the functioning of living organism. It includes the uptake of
food, liberation of energy, elimination of wastes and all the processes
of synthesis essential for maintenance, growth and reproduction
(Chutani, 2008). Apart from maintaining normal body functioning,
nutrition is important in fighting infections and in the recuperation of
an ill person. Nutrition interacts with infections in a synergistic
manner, such that recurrent infections lead to a loss of body nitrogen
and worsen nutritional status; the resulting malnutrition, in its turn,
produces a greater susceptibility to infection (Kurpad, 2005). Aristotle
(384-322 B.C.) was the first to suggest that the composition of foods
in the normal diet might contribute to health.
In an 1897 literature on metabolic
investigations, Atwater divided food composition into five classes;
protein, fat carbohydrate, energy and water. However, today, proximate
composition is the term usually used to describe six components of food
namely; moisture, crude protein, crude ash, crude fibre, crude fat and
carbohydrate (nitrogen free extract) which are all expressed in
percentage (%) or gram per 100 grams (g/100g). The study of proximate
analysis on foods was devised over a hundred years ago by two German
scientists, Henneberg and Stohmann, and even though new techniques have
been introduced, their system of proximate still forms the basis for the
statutory declaration of the composition of foods. (Dublecz, 2011).
1.2 MOISTURE CONTENT
Water is essential for every living
organism. In the human body, water content ranges from 50-70% in
different tissues. It is present in different fluid compartments of the
human body- Intracellular (fluid inside the cells) and extra cellular.
Plasma, interstitial fluid, cerebrospinal fluid, ocular fluid, lymph,
peritoneal, pericardial, pleural and synovial fluids are part of the
extra cellular fluid (Chutani, 2008). However, the moisture content of a
feed is seldom of interest nutritionally as water is usually taken on
The active ingredients from the view of
feed nutrition are present in the part of dry matter (solid matter);
therefore the level of moisture content is an important factor in both
economy and storage. At high temperature and humidity the risk of
putrefaction is predicted due to the proliferation of molds, etc., or
self-digestion by enzymes in the feed when moisture in the feed is not
less than about 15%. As the assay for moisture in the feed measures
loss on drying by heating at normal pressure as moisture, the result
includes most of volatile substances other than H2O.
Therefore, it may be more appropriate to be referred to as volatile
matter rather than moisture for accuracy. Organic acids such as acetic
acid and butyric acid in silage as well as ammonia and flavor components
in feed materials are also vaporized and thus measured as moisture.
Because the content of these in most feed is extremely low, there has
hardly been a need to consider their influence on the measured value.
Photosynthesis is a process used by
plants and other organisms to convert light energy from the sun, into
chemical energy that can be later released to fuel the organisms'
activities. The light energy harnessed from the sun drives the reduction
of carbon from CO2 to produce O2 and fixed carbon in form of carbohydrate.
Early in the twentieth century, it was mistakenly thought that light absorbed by photosynthetic pigments directly reduced CO2
which then combined with water to form carbohydrate. In fact,
photosynthesis in plants is a two stage process in which light energy is
harnessed to oxidise H2O:
2H2O ? O2 + 4 [H+]
The electrons thereby obtained subsequently reduce CO2:
4H+ + CO2 ? (CH2O)n + H2O
The two stages of photosynthesis are traditionally referred to as the light reactions and the dark reactions:
- In the light reactions, specialised pigment molecules capture light
energy and are thereby oxidized. A series of electron- transfer
reactions which culminate with the reduction of NADP+ to NADPH, generate ATP from ADP + Pi. The oxidised pigment molecules are reduced to H2O, thereby generating O2.
- The dark reactions use NADPH and ATP to reduce CO2 and incorporate it into the three-carbon precursors of carbohydrate.
The light reactions takes place in the
thylakoid membrane of chloroplasts in leaves and green parts of plants.
The inside of the thylakoid is referred to as the lumen. The light
reactions are catalysed by enzymes located in the thylakoid membrane,
whereas the dark reactions take place in the stroma. The principal
photoreceptor of light is chlorophyll. These chlorophyll molecules do
not participate directly in photochemical reactions but function to act
as light harvesting antennas. The absorbed photons are transferred from
molecule to molecule until it reaches the photosynthetic reaction
In the respiratory chain, electrons flow from NADH + H+ to O2, with the production of water and energy. However in photosynthesis, electrons are taken up from water and transferred to NADP+,
with an expenditure of energy. Photosynthetic electron transport is
therefore energetically “uphill work.” To make this possible, the
transport is stimulated at two points by the absorption of light energy.
This occurs through two photo systems protein complexes that contain
large numbers of chlorophyll molecules and other pigments Another
component of the transport chain is the cytochrome bf
complex, an aggregate of integral membrane proteins that includes two
cytochromes (b563 and f). Plastoquinone, which is comparable to
ubiquinone, and two soluble proteins, the copper containing plastocyanin
and ferredoxin, function as mobile electron carriers. At the end of the
chain, there is an enzyme that transfers the electrons to NADP+.
Because photosystem II and the cytochrome b/f complex release protons
from reduced plastoquinone into the lumen, photosynthetic electron
transport establishes an electrochemical gradient across the thylakoid
membrane, which is used for ATP synthesis by an ATP synthase.
ATP and NADPH + H+, which are both needed for the dark reactions, are formed in the stroma. (Voet et al., 2013).
The actual CO2 fixation i.e., the incorporation of CO2
into an organic compound is catalysed by ribulosebisphosphate
carboxylase/oxygenase (“rubisco”). Rubisco, the most abundant enzyme on
Earth, converts ribulose 1,5-bis-phosphate, CO2 and water
into two molecules of 3-phosphoglycerate. These are then converted, via
1,3-bisphosphoglycerate and 3-phosphoglycerate, into glyceraldehyde
3-phosphate. In this way, 1,2-glyceraldehyde 3-phosphates are
synthesized from six CO2. Two molecules of this intermediate
are used by gluconeogenesis reactions to synthesize glucose 6-phosphate.
From the remaining 10 molecules, six molecules of
ribulose-1,5-bisphosphate are regenerated, and the cycle then starts
over again. In the Calvin cycle, ATP is required for phosphorylation of
3-phosphoglycerate and ribulose-5-phosphate. NADPH + H+, the
second product of the light reaction, is consumed in the reduction of
1,3-bisphosphoglycerate to glyceraldehyde-3- phosphate.
Carbohydrates are the most abundant
biomolecules produced on earth; photosynthetic plants and algae convert
over 100 billion metric tons of CO2 and water into sugars,
starches, and cellulose like substance. Carbohydrates supply energy for
the human body to function. They are the most abundant bulk nutrients
and form the major source of biological energy through their oxidation
in the tissues. They also furnish organic precursors for the
biosynthesis of many cell components. Carbohydrates are not essential in
the human diet, but because carbohydrate rich foods are abundant and
cheap, compared with fats and protein, they naturally form a major part
of the diet in most of the world. (Voet et al., 2013).
The requirements for total protein, at
various stages during the life cycle of humans, were reviewed and
evaluated by a joint panel of the Food and Agriculture Organization, the
World Health Organization, and the United Nations University (FAO/
The requirement for dietary protein consists of two components:
1) the requirement for the
nutritionally indispensable amino acids (histidine, isoleucine, leucine,
lysine, methionine, phenylalanine, threonine, tryptophan, and valine)
under all conditions and for conditionally indispensable amino acids
(cysteine, tyrosine, taurine, glycine, arginine, glutamine, proline)
under specific physiological and pathological conditions and
2) the requirement for nonspecific
nitrogen for the synthesis of the nutritionally dispensable amino acids
(aspartic acid, asparagine, glutamic acid, alanine, serine) and other
physiologically important nitrogen-containing compounds such as nucleic
acids, creatine, and porphyrins.
With respect to the first component, it
is usually accepted that the nutritive values of various food protein
sources are to a large extent determined by the concentration and
availability of the individual indispensable amino acids. Hence, the
efficiency with which a given source of food protein is utilized in
support of an adequate state of nutritional health depends both on the
physiological requirements for the indispensable amino acids and total
nitrogen and on the concentration of specific amino acids in the source
of interest (Young and Pelett, 1994).
Proteins, are synthesized from a complex
series of steps which involves the transcription of DNA already present
in each cell of an organism, and its consequent transcription into a
polypeptide chain. This chain is modified by other inherent mechanisms
in the cell to yield protein.
1.5 CRUDE ASH
Ash is the inorganic residue remaining
after the water and organic matter have been removed by heating in the
presence of oxidizing agents, which provides a measure of the total
amount of minerals within a food. The ash content is a measure of the
total amount of minerals present within a food. Minerals are required
for many purposes like forming the frame and rigid structure of the
body, as part of the body/cell fluids and for number of cellular and sub
cellular physiological functions (Chutani, 2008). The mineral content
includes specific inorganic components present within a food, such as
Ca, Na, K and Cl. Determination of the ash and mineral content of foods
is important for a number of reasons. The most important reason in
regards a plant like S. glauca is the nutritional importance. Some minerals are essential to a healthy diet (e.g. calcium, phosphorous, potassium and sodium) whereas others can be toxic (e.g. lead, mercury, cadmium and aluminum).
1.6 FAT AND FIBRE
The importance of fat and fibre in
nutrition cannot be underestimated. Crude fat contains fat, complex
lipid, sterols, fatty acids and fat soluble dyes; while crude fibre
contains cellulose, hemicellulose, and lignin.
1.7 AIM OF THE RESEARCH WORK
This study is designed to screen the proximate constituents of the leaf extracts of Simarouba glauca which includes moisture, protein, carbohydrates, ash fibre and lipid content of Simarouba glauca. In addition to this, to determine the quantitative carbohydrate and amino acid constituents of Simarouba glauca.
Thus, the nutritional value of Simarouba roots and leaves with some
emphasis on their possible use both as a medicinal and nutritional food
for the sick or convalescent.