ABSTRACT
The work involved the investigation of the effect of different substrates on the phytochemical, heavy metals and minerals var florida. The highest gross of heavy metals fruit bodies was obtained from the substrate Andropogon gayanus (351.75±0.30), followed by Pennisetum straw (342.41±0.20), while the least was found in Pannicum maximum (338.05±0.01). Similarly, the fruit bodies of substrates Andropogon gayanus weighed more than those from other substrates for both fresh and dry weight. Based on the phytochemical composition, Tannins was found to be highest (0.73±0.02) in mushroom harvested from A.gayanus followed by Pennisetum straw (0.66±0.02) while fruit-bodies harvested from P. maximum gave the lowest (0.55±0.03) phytochemical composition. Based on the mineral composition, result showed that all the fruit bodies obtained from A. gayanus substrates contained appreciable amount of calcium (1.60±0.30), potassium (2.45±0.10), magnesium (31.25±0.04), and sodium (2.30±0.30). Similarly fruit body obtained from P. ostreatus had highest (74.37±0.30) concentration of Phosphorus while significant difference in the amount of Sulphur containing fruit bodies harvesting in all substrates at p<0.05. However, the lowest (0.70+-0.10) Calcium composition was recorded in mushroom harvested from P. purpureum. Likewise P.maximum which gave the lowest of Sodium (1.60±0.20) and free Nitrogen (1.80±0.20). The result of the investigations was discussed in line of the best substrates for maximum production of Pleurotus ostreatus fruit-bodies with better qualities. The investigation concluded that growing Pluerotus ostreatus on A. gayanus straw produced the highest fruit-bodies among other substrates which will help in the wide production of mushroom for market value. In general, Pleurotus ostreatus contains nutritional properties Also, the result from the investigation revealed that A.gayanus, Pannicum maximum, and Pennisetum straw could be vital in production of P.ostreatus from fruit bodies with A. gayanus supporting the highest P.ostreatus fruit-body production.People should incorporate the habit of eating mushrooms because of their high nutritional values.
TABLE
OF CONTENT
Title
page i
Declaration ii
Certification
iii
Dedication iv
Acknowledgement v
Table
of content vi
List
of Tables ix
Abstract x
CHAPTER ONE 1
INTRODUCTION 1
1.1
Background of Study 1
1.1.1 What are
Mushrooms 1
1.1.2
The Genus Pleurotus 3
1.1.3
Importance of Mushrooms 4
1.1.3.1 Mushroom as Food 4
1.1.3.2 Nutrients
in Mushrooms 5
1.1.3.3 Vitamins 7
1.1.3.4 Minerals 7
1.1.3.5 Mushroom
are Sources of selenium 7
1.1.3.6
Ergothioneine 7
1.1.4
Therapeutic benefits of Mushroom 7
1.1.5
Justification 8
1.1.6 Aims and Objectives 9
CHAPTER TWO
LITERATURE REVIEW 10
2.1 Mycochemical Contents of Mushrooms 11
CHAPTER THREE
MATERIALS AND METHODS 14
3.1
Source of Mother Culture (SPAWN) 14
3.2
Location of Study 14
3.3 Experimental
Design 14
3.4
Spawn Multiplication 14
3.5
Substrate Preparation 15
3.6 Spawn Inoculation 15
3.7 Sample Preparation 16
3.8 Determination
of Heavy Metals 16
3.9
Determination Of Mineral Content Of
The Mushroom 17
3.10 Determination
Bioactive Compounds In The Mushroom Fruit Bodies 17
3.10.1
Determination of alkaloids 17
3.10.2 Determination of flavonoids 17
3.10.3 Determination of phenols content 18
3.10.4 Determination of Saponins 19
3.10.5 Determination of tannins 19
CHAPTER FOUR
RESULTS AND DISCUSSION 20
4.1 Results 20
4.2. Discussion 23
CHAPTER FIVE
CONCLUSION
AND RECOMMENDATION 25
5.1 Conclusion 25
5.2 Recommendation 25
References 27
Appendix I 32
Appendix II 36
LIST OF TABLES
Table 41: Effect of straw substrate on the heavy metals 20
Table 4.2: Effect of straw substrate on the minerals 21
Table 4.3: Effect of straw substrate on the phytochemicals 22
CHAPTER ONE
INTRODUCTION
1.1 Background of Study
1.1.1 What are Mushrooms?
Mushrooms
are the fleshy, spore-bearing, reproductive structures of fungi belonging
mainly to the division Basidiomycotina
and some members of Ascomycotina.
According to Okwuliehie and Ogoke (2013) the fruit-bodies of mushrooms appear
spontaneously in the forest and farm- lands in great quantities after the
rains. The word “mushroom” is most often applied to those fungi (Basidiomycota and Ascomycete) that have a stem (Stipe), a cap (Pileus), and gills
(lamellae, sing. Lamella) on the underside of the cap. Although they are plants
they do not produce chlorophyll like green plants. They consist of stipe (Stem)
that arises from underground mycelium and a Pileus or cap, with lower surface
for spore development (Chang and Miles, 2000). They therefore do not manufacture
their own food, but rely on substances such as litter, sawdust, decaying tree
logs, wooden plugs, straw, and wood chips, or soil for nourishment. They
require preformed food like smaller broken down molecules of cellulose and
starch (Banjo, 1998).Mushroom can be found growing anywhere and on any natural
material. They also grow on grassy ground, rotten leaf litter, dung, and other
favorable substrates. They are widely distributed and have a wide range of
shape taste and colour. Usually, the fruiting–bodies of mushrooms are umbrella
shaped structures which produce spore in large numbers. These spores are
minutes or microscopic and are dispersed by wind; under favorable condition
they germinate to form a mass of branched hyphae or mycelia with colonies in
substrates. This represents the vegetative stage of its growth. When a given
substrate is fully colonized, the vegetative growth ceases.
These
fruit-bodies which are known today as mushrooms appear white and have a short
life span.
In
Nigeria, rural dwellers consume mushrooms as delicacies in soups and as
ingredients for seasoning or part of the local melon cake (usu) in Igbo nation.
Edible mushrooms are found in the wild especially with the onset tropical
rainfall. In nature, a number of species of mushrooms are found mainly during
the rainy season, on almost all type of soil, on decaying organic matter.
Mushrooms have profound biological, ecological, and economic impact in the
Nigeria and the world in general. The wild mushrooms which are edible,
collected from the forests, gardens and other suitable substrates and are sold
in the market of remote areas and also in the supermarkets of site life areas.
Many
people have learnt since ages, (by trials and error) to identify the edible and
inedible mushrooms. In many cases poisonous mushrooms are look-alikes of the
edible ones and are often eaten without adverse effects (Bao, 2004).
Edible
mushroom is a microfungus with a distinctive fruiting-body, which can be
hypogeous or epigeous, large enough to be seen with unaided eyes. These
mushrooms are grouped under Basidiomycetes
but these are still some species of Ascomycetes
that belongs to mushroom. As a whole, mushrooms constitute at least 14,000 and
as many as 22,000 known species. However, the number of mushroom species in
earth is estimated to be 140,000 suggesting that only 10% are known
(Lindequisite et al., 2005).
Edible
mushrooms have long and rich history of use. More than 2,000years ago,
Paleolithic people knew and used mushrooms as powerful medicines to flight
illness. In the world of pre-world Shaman, spirits caused disease and medicinal
compounds were administered to appease or threat them. Mushroom was used as
same tool as a practical treatment for microbial infection.
The
medicinal use of mushroom has a very long tradition in the Asian countries,
where as their use in West hemisphere has been slightly increasing only since
last decades (Lindequisite et al.,
2005). In Asia, mushroom in traditional Chinese medicine have been summation of
more than 3,000years of use for the prevention and treatment of diseases
(Chang, 2006). Historically, medicinal mushroom species harvested from the
forest where they grew on dead or living trees and forest litter.
Edible
mushroom have been considered to have medicinal value and to be devoid of
undesirable effect. They may be eaten as meat substitutes and used as
flavorings in foods, soups, and sauces. They also contain large amount of
vitamins and minerals. (Oie, 2003, Okwulehie et al.,2007). In developing countries like India with rich
biodiversity mushrooms are the bone for progress in the field of food, medicine
and unemployment because of several nutriceuticals and medicinal mushrooms that
have been found to be useful towards human health development as food, medicines,
minerals and drugs among others (Wani et
al., 2010).
1.1.2 The Genus Pleurotus
Pleurotus
is a genus of gilled mushrooms which includes one of the widely edible mushroom
species. Pleurotus is also called
oyster, mushrooms comprises some of the commonly cultivated mushrooms in the
world (chang, 2004). Pleurotus means
“side ear”. The cap maybe laterally attached (with no stem), if there is a
stem, it is normally eccentric and gills decurrently along it. The spores are
smooth and elongated where hyphae meet. They are joined by clamp connections.
Pleurotus
is not considered to be a bracket fungus and most of the species are monomitic
(with a soft consistency). However, it can sometimes be dimitic, meaning that it has additional skeletal hyphae which give
it a tougher consistency like bracket fungi (Knuden, 2008). Pleurotus fungi are found both in
tropical and temperate climate throughout the world (Chang, 2004).
Classification
of the species within the genus Pleurotus
is difficult due to high phenotypic variability across wide geographic ranges,
geographic overlap of species and ongoing evolution and speciation.More
recently, molecular phylogeny has been tied to determine genetic and evolution
relationship between groups within the genus, delineating discrete clades
(Gonzalez, 2000, Zervakis, 2004). Pleurotus
species are morphologically varied and are described as having convex or flat,
fan shaped, kidney-shaped, asymmetric, appolaritic or sometimes funnel-shaped
pileus with in volute margin (Rembelli and Menini, 1983). The size of the
pileus ranges from 4.15cm in diameter, whitish, grey- white, violet grey,
brownish grey, pink or violet black. (Rambelli and Menini, 1983). The gills are
dense, unequal decurrent and light in colour. The oyster mushroom is commercially
cultivated around the world for food, oyster mushroom can also be used
industrially for mycoremediation purposes (Chang, 2004).it is one of the more
commonly sought wild mushroom, it can be cultivated on straw and other media
1.1.3 Importance of
Mushrooms
1.1.3.1 Mushroom as Food
The
food and agricultural organization recognized mushroom as food containing
protein nutrition to the countries depending largely on cereals (FAO, 2011).
Mushroom with their flavour, texture and high productivity per unit have been
identifies as an excellent food source (Eswaran and Rambadran, 2000). The
desirability of a food product does not necessarily bear any correlation to its
nutritional value. Instead, its appearance, taste and aroma, sometimes can
stimulate one’s appetite ( ).Mushroom showcase the qualities expressed by the
above statement. Mushroom has major unique colour, taste aroma and texture
characteristics which attract their consumption by humans (Sh-ting, 2004).
Mushroom
have been considered as source of rich food because they contain protein,
sugar, glycogen, lipids, vitamins, amino acids and crude fibres (Okwulehie and
Odunze, 2004a, Okwulehie et al., 2007,
Okwulehie et al., 2009, Okwulehie and
Ogoke, 2013). The protein of mushrooms is twice that of Asparagus and potatoes,
four times that of tomatoes and carrot and six times that of oranges (Adejumo
and Awosanya, 2005, Jonathan et al., 2006, Okwulehie, et al., 2014a). Apart from being a relatively rich source of
protein compared to animal’s protein, mushroom could also hold special
attraction and maybe recommended or people with cholesterol- related ailment
(Adejumo and Awosanya, 2005).
1.1.3.2 Nutrients in
Mushrooms
Mushrooms
has been in consumption in the past centuries, but the discovery of the full
nutritional values and other benefits from mushrooms is recent.Mushrooms have
been found to contain all the essential amino acids that form the
proteins.
Falade
et al., 2008 observed that some
mushroom species in Nigeria contain 81.4% and 93.2% moisture and also have some
plant nutrients like tannin and trypsin inhibitor. In addition, mushrooms have
been reported to accumulate several trace elements at greatly exceeding
contents than in other plant food (Kelac et
al., 2004). The protein content of mushrooms is about twice that of
vegetables and four times that of oranges and more over the essential amino
acids are present in mushroom. Crude protein was found in Pleurotus Ostreatus 27.3% and minimum P. djmor 24. 83% and P. sajor-
Cajus 25.25% (Jawad et al.,
2010). Sadiq et al., 2008 reported the protein content of wild 24.66% in P.
Ostreatus. Similarly Okwulehie (2004)
gave the protein content of 4 Nigeria mushrooms Auricularia auricular, Pleurotus Squarrosulus, P. tuber-regium and Russula
spp range from 15.0 - 24.96g/100g on dry matter basis.
Mushroom
is very rich in vitamins, they provide several types of vitamins, particularly
thiamine (Mohan and Singh, 2011), Ekpo and Aluko, (2002). Riboflavin, Niacin,
Biotin, Ascorbic acid, vitamin D and vitamin K, (Okwulehie 2004a).
On
dry weight basis, Pleurotus Species 30-144mg/100g
ascorbic acid, 1.16-4.8mg/100g thiamine, 109mg/100g niacin, and 4.7mg/ 100g
riboflavin. Volvariella volvacea
contain 206.27mg/100g of ascorbic acid while Nigeria Auricularia auricular, P. squarrosulus, P. tuber-regium and Russula
species contains 5.46-9.86mg/100mg, 0.49-0.67mg/100mg riboflavin and
0.08-0.17mg/100g thiamin (Okwulehie and Odunze, 2004a, Okwulehie et al., 2009). Randive (2012) reported that oyster mushrooms are rich in vitamin C, B complex required by
the human body.
Compared
to cereals, pulses, fruits and vegetables the protein content of mushroom is
much lighter on dry weight basis. Usually protein content of cultivated
mushroom range from 2-5.3%, on fresh weight basis and 20-35%.On dry quality and
of high die stability (70-83% properties). Cereals are deficient in two amino
acids Lysine and tryptophan. But mushroom core rich in these two amino acids
apart from most of the essential amino acid like leucine, isoleucine, valine,
threonine, tyrosine and phenylamine. The order two essential amino acids,
methionine and cysteine are however less in mushroom but in cereals (Tasvina et al., 2013).
1.1.3.3 Vitamins
Mushrooms
are rich source of vitamins B complex (Thiamine, Riboflavin and Niacin) and
VitaminC (ascorbic and acid) they also contain folic acid and Vitamin B12,
which are not found in green vegetables.
1.1.3.4 Minerals
The
minerals like potassium, sodium and phosphorus are abundantly found in
mushroom. Which make it ideally suitable for hypertensive patients (Tasvina et al., 2013).
1.1.3.5 Mushroom are
Sources of selenium
It
is a mineral that works as an antioxidant to protect body cells from damage
that might lead to heart disease, some concerns and other diseases of aging. It
has also been found to be important for the immune system and fertility in men
(Fresh – mushroom, 2014).
1.1.3.6 Ergothioneine
It
is a naturally occurring antioxidant that also may help protect the body’s
cell.Mushroom provides 2.8-49mg of ergothionine per serving of white,
portabella or criminal mushrooms (fresh- mushroom, 2014). It is a mineral that
works as an antioxidant to protect body cells from damage that might lead to
heart disease, some concerns and other diseases of aging.
1.1.4 Therapeutic
benefits of Mushroom
- Mushroom
are referred to as “vegetarian
meat” as it is rich in protein 35%
- Mushroom
are suitable for diabetic patients
low carbohydrate content and low
starch
- Mushrooms
are suitable diet for obsess person as these are low in calories (32
kcal/100g) fresh mushroom.
- They
contain ergosterol which converts into vitamin D in the human body. The
deadly cholesterol is absent.
- It
is high fibre content
- Mushrooms
are beneficial for acidity gastritis problem due to presence of more than
7% alkaline ash.
1.1.5 Justification
According
to Okwulehie, and Odunze, (2014a), the importance if mushrooms cannot be over
emphasized. They are consumed on daily basis and are regarded as healthy
additives to diets because they contain relatively high concentration of
protein, fiber minerals and vitamins. Availability of suitable substrate for
commercial production of Pleurotus
ostreatus within Umudike in Abia
state has remained a relative problem, especially in the availability of substrate such as rice straw which is best suitable for the culture of P. ostreatus with the confirmation of Andropogon a yet another suitable substrate as stated by Okwulehie
and Okwujiako (2008). Andropogon is
one of the major grass plants in Umudike, it is not eaten as food but most
times are cleared and burnt to ash either during farming or clean up exercises.
It is however justifiable to exploit such agro waste for food production,
especially in the era of food insecurity and move to actualize millennium
development goals. Nutritional value of food around Umudike and Africa are
posed with low vitamin capacity, which has resulted to vitamin deficiency
issues among children. Since supplementation of mushroom has shown good
correlation with high yield and nutritional richness (Okwulehie and Okoro,
2014), it therefore pertinent to try enriching the mushrooms with vitamins.
This
fact i resulted to fortifying the substrates with vitamins since it has been
established that the richness of mushrooms fruit bodies is a subject of the
type of substrates on which they are grown.
1.1.6 Aims and
Objectives
The objective of this research work is:-
-
To determine the effect
of straw substrates on the heavy metals composition of P. ostreatus
-
To determine the effect
of straw substrates on the minerals
composition of P. ostreatus
-
To determine the effect
of straw substrate on the phytochemical composition of P. ostreatus
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