ABSTRACT
Mushroom science has gain importance mainly because of the nutritional and medicinal values. The cultivation of mushroom is seen has a profitable agricultural business. This study investigates the cultivation of Hypsizygus ulmarius using local substrates to evaluate their effect on the yield of fruit-bodies and the mycochemical constituents. The substrates used were coconut fibre (CF), maize straw (MS), sugarcane bagasse (SB), coconut fibre + maize straw (CF+MS), coconut fibre + sugarcane bagasse (CF+SB), maize straw + sugarcane bagasse (MS+SB) and coconut fibre + maize straw + sugarcane bagasse (CF+MS+SB). The result revealed that the mean stipe length ranges from 1.87 - 2.43cm, mean cap size varies from 4.43 - 5.77cm, fresh weight ranges from 2.44 - 5.10g, biological yield ranges from 41.32 - 141.72g and biological efficiency varies from 11.81 - 94.48%. The highest mean stipe length was observed in the substrate CF+MS; while the substrate MS+SB recorded highest mean cap size, fresh weight, biological yield and biological efficiency. The analyses indicated the presence of vitamins in the mushrooms cultivated on different substrates which include vitamin B1 (0.78 - 0.94mg/100g), vitamin B2 (0.29 - 0.50mg/100g), vitamin B3 (1.72 - 2.81mg/100g), vitamin A (5.77 - 8.33mg/100g) and vitamin C (7.57 - 8.64mg/100g). The mushroom harvested from different substrates had a good profile for mineral content to include calcium (198.36 - 290.51mg/100g), magnesium (72.00 - 144.44mg/100g), sodium (6.72 - 9.36mg/100g), potassium (314.41 - 395.63mg/100g) and phosphorus (152.17 - 195.23mg/100g). The fruit-bodies indicated the presence of heavy metal such as zinc (1.13 - 2.40mg/kg), iron (6.28 - 16.98mg/kg), lead (0.17 - 0.25mg/kg), cadmium (0.09 - 0.15mg/kg) and copper (0.12 - 0.21mg/kg). The proximate analyses indicated that the mushroom contained appreciable amount of protein (19.25 - 24.50%), carbohydrate (39.59 - 43.25%), fibre (14.98 - 19.73%), ash ( 7.96 - 10.50%), moisture content (4.33 - 6.28%) and fat (3.80 - 4.20%).The result also shows a varying level of bioactive compounds which include tannin (0.56 - 0.74mg/g), alkaloid (4.80 - 7.90mg/g), phenol (2.82 - 4.55mg/g), flavonoid (3.80 - 4.30mg/g), steroid (0.16 - 0.75mg/g), hydrogen cyanide (0.01 - 0.07mg/g), anthocyanin (0.22 - 0.35mg/g) and saponin (2.60 - 10.00mg/g). The mushroom contained low level of Cadmium and Lead which are considered to be highly toxic, thus making it fit for consumption. Generally, the result revealed that the mushroom is of good quality. It contained nutrients which can help to improve the micronutrients and general well-being of the people.
TABLE
OF CONTENTS
Title
Page i
Declaration ii
Certification
iii
Dedication
iv
Acknowledgements
v
Table
of Contents vi
List
of Tables ix
List
of Figures x
List
of Plates xi
Abstract xii
CHAPTER 1: INTRODUCTION
1.1 Background
to the Study 1
1.2 Statement of the Problem 4
1.3 Justification 5
1.4 Aim and Objectives 5
CHAPTER 2: LITERATURE REVIEW
2.1 Related Work 7
2.2 Elm Oyster (Hypsizygus ulmarius) 14
2.3 Spawn 15
2.4 Substrate 16
2.5 Environment 17
2.6 Mushroom Ecology 19
2.7 Importance of Mushrooms 20
2.7.1
Nutritional value 20
2.7.2 Medicinal value 21
2.7.3 Bioremediation 22
CHAPTER 3: MATERIALS AND METHODS
3.1 Description
of Study Area 23
3.2 Source of Materials 23
3.3 Preparation
of the Substrates for Cultivation 23
3.4 Inoculation and Incubation 24
3.5 Measurement
Parameters 24
3.5.1 Stipe length (height)
25
3.5.2 Cap (pileus) diameter 25
3.5.3 Fresh weights 25
3.5.4 Biological yield 25
3.5.5 Biological efficiency 25
3.6 Mycochemical
Components 25
3.7 Determination
of Vitamins 25
3.7.1 Determination of vitamin A (retinol) 25
3.7.2 Determination of vitamin B1 (thiamin) 26
3.7.3 Determination of vitamin B2 (riboflavin) 26
3.7.4 Determination of vitamin B3 (niacin) 27
3.7.5 Determination of vitamin C (ascorbic acid) 27
3.8 Determination
of Minerals 28
3.9 Determination
of Heavy Metals 28
3.10 Proximate
Analysis 29
3.10.1 Moisture content 29
3.10.2 Determination of protein content 29
3.10.3 Determination of ash contents
30
3.10.4 Determination of carbohydrate
30
3.10.5 Determination of fats and oils 30
3.10.6 Determination of crude fibre 31
3.11 Determination
of Bioactive Compounds 31
3.11.1 Determination
of alkaloids 31
3.11.2 Determination
of saponins 32
3.11.3 Determination
of phenols 32
3.11.4 Determination
of flavnoids 32
3.11.5 Determination
of tannins 33
3.11.6 Anthocyanin
determination 33
3.11.7 Hydrogen
cyanide (HCN) determination 33
3.11.8 Determination
of steroid 34
3.12 Statistical
Analysis 34
CHAPTER 4: RESULTS
AND DISCUSSION
4.1 Results
35
4.2 Discussion 55
CHAPTER
5: CONCLUSION AND
RECOMMENDATIONS
5.1 Conclusion 64
5.2 Recommendations 65
References
66
Appendix
80
LIST OF TABLES
4.1: Effect of substrates on the vitamin
composition of
Hypsizygus ulmarius (mg/100g) 42
4.2: Effect of substrates on the mineral composition
of
Hypsizygus ulmarius (mg/100g) 45
4.3 Effect of substrates on the heavy metal composition
of
Hypsizygus ulmarius (mg/kg) 48
4.4: Effect of substrates on the proximate composition
of
Hypsizygus ulmarius (%) 51
4.5: Effect of substrates on the Phytochemical
Composition of
Hypsizygus ulmarius (mg/g) 54
LIST OF FIGURES
4.1: Effect
of substrates on the stipe length of Hypsizygus
ulmarius 37
4.2: Effect
of substrates on the cap size of Hypsizygus
ulmarius 38
4.3: Effect
of substrates on the fresh weight of Hypsizygus
ulmarius 39
4.4: Effect
of substrates on the biological yield of Hypsizygus
ulmarius 40
4.5: Effect
of substrates on the biological efficiency of Hypsizygus ulmarius 41
LIST OF PLATES
4.1: Hypsizygus
ulmarius blue pinhead 57
4.2: Hypsizygus
ulmarius growing on different substrates 58
CHAPTER
1
INTRODUCTION
1.1
BACKGROUND TO THE STUDY
The quest for food sources by man has been
consistent in other to improve his biological functions, health and general
well-being. Fungi such as yeast, mushroom, and bracket fungi have been widely
utilized as food since the origin of mankind (Rahi et al., 2004). The medicinal as well as
nutritional values of edible mushrooms have a long history. Mushrooms contain
valuable biological active compounds (Rajewska et al., 2004; Manoharachary et al., 2005; Bernas et al., 2006; Deepalakshmi and
Mirunalini, 2014). In many countries, especially Europe and Asia, mushrooms are
well known and considered as favourite delicacy. Mushrooms such as the wild species
have been long used in traditional Chinese medicine. Mushrooms are usually
consumed either in the fresh or processed forms and are considered valuable
mainly due to their flavour and palatability. Edible mushrooms have the
tendency to contribute greatly to food value by supplying both macro and micro-nutrients
in the diet (Stamets, 2000 and Manzi et
al., 2001).
Mushrooms are large, visible
fructification of fungi which can be seen with unaided eyes. They have a
well-developed and observable spore-bearing structure called pileus (cap) and
stipe (stalk). They are referred to as macro-fungi. A mushroom can also be defined as the spore-bearing,
large fleshy fruit body of a fungus and produced on a substrate beneath or
above ground (Boa, 2004; Oei and Nieuwenhuijzen,
2005; Stevenson and Lentz, 2007). According
to Okwulehie and Odunze (2004b), mushrooms are macro-fungi with distinctive
body, which can be hypogenous or epigenous, and large enough to be seen with
the naked eye and to be picked by hand. In contrast to the vegetative
parts of the mushrooms, that are not easily seen with the unaided eye, the
mushroom fruiting bodies are large entities that can be seen with unaided eye
(Choi, 2004).
In Nigeria, fungal
fruit-bodies naturally appear in forests and farm lands during the early and
late raining season (April – June and September – November) in great diversity
and quantities (Okwulehie and Ogoke,
2013; Mmaduabuchukwu and Mbadiwe, 2013). In nature, mushrooms grow on
different substances such as logs of wood; decomposing agro-wastes, decomposing
animal wastes, and soil where they obtain their nutrients through external
digestion and absorption by the mycelium (Okwulehie and Ogoke, 2013). Similarly, mushrooms have over the
years served as an important source of protein, carbohydrates, minerals and
vitamins (Okwulehie et al., 2018). Mushrooms are fungus which has a wide range
of species. Mushrooms exhibits one or more of these lifestyles;
saprophytism, parasitism and symbiotic parasitism (Kong, 2004; Cheung, 2008 and Gwanama, 2011). They
play important roles in the ecosystem due to their ability to degrade
substrates and make use of agricultural wastes (Ouzouni et al., 2009 and Lee, 2009).
The
cultivation of mushroom has gained importance throughout the world and it is
seen as the most versatile and profitable agricultural business all over the
world (Ikeji, 2010). However, the production of mushroom
is an important tool that can be used for poverty alleviation and tackling lack
of adequate nourishment (Imtiaj and Rahman, 2008). The
world production of mushroom increased from 4.9metric tons in 1994 to 7 million
metric tons valued at $30 billion in 1997. This is an increase from the 350 metric
tons produced in 1965 (Ikeji, 2010). In Nigeria, mushrooms are consumed as food
and for medicinal purposes. Akpaja et al.
(2005) reported that, over 90% of the populace consume mushrooms as food, while
22% use some mushrooms for medicinal purposes in southern Nigeria. It has been
documented that mushrooms are commonly cultivated either for food and/or
medicinal purposes or for poverty interventions
across tropical and temperate zones (Eswaran et al., 2000). Some common mushrooms cultivated
include: (Agaricus), Shiitake (Lentinus), Oyster (Pleurotus), Straw mushroom (Volvariella),
Lion’s Head (Hericium), Jew ear (Auricularis), Ganoderma (Reishi), Maitake (Grifola frondosa), Winter mushroom (Flammulina), White jelly (Tremella),
Nameko (Pholiota), and Shaggy Mane
mushrooms (Coprinus). International
mushroom markets are dominated by Agaricus
bisporus, Lentinula edodes and Pleurotus spp, which represent three
quarters of mushrooms cultivated globally (Eswaran et al., 2000; FAO,
2002; Bhatti et al., 2007).
A major environmental problem facing the world today is the
contamination of soil, air and marine habitats by agricultural wastes, toxic
chemicals from plastics and crude oil (Lamar and White, 2007). Synthetic
polymers, such as polyethylene, are generally difficult to degrade by microorganisms.
Research on the use of biological treatment has focused on bacteria, with
fungal bioremediation (mycoremediation) attracting interest just within the
past two decades (Lamar and White, 2007).
Many researches have documented the
use of Pleurotus species in detoxifying the environment in the process
known as bioremediation. P. tuber-regium (a white-rot fungus) has
been reported to ameliorate crude oil polluted soils (Isikhuemhen et al., 2003; Adenipekun, 2008) and the
resulting soil sample supported the germination and seedling of Vigna
unguiculata. Again, heavy metal concentrations in mushroom are
considerably higher than those in agricultural crop plants, vegetables, and
fruit. This suggests that mushrooms possess a very effective mechanism that
enables them to readily take up some heavy metals from the ecosystem. Many wild
edible Mushroom species have been known to accumulate great concentrations of
heavy metals such as lead, cadmium, iron, copper, manganese, zinc, chromium,
nickel, aluminum, and mercury (Demirbas, 2000; Svoboda et al., 2000; Kalaˇc and Svoboda 2001; Falandysz et al., 2003; Dursun et al., 2006; Cocchia et al., 2006; Chen et al., 2009).
1.2 STATEMENT OF PROBLEM
Mushroom
has gained lots of interests mainly because of their taste, unique texture,
flavour, nutritional and medicinal potentials, bioremediation and fungicidal
properties. The multidimensional nature of mushrooms has led to increase in its
demand. Mushrooms occur naturally in great diversity, quantity and in different
habitats. Anthropogenic activities such as deforestation and technological
advancement which result in construction of new roads and industries are
reducing forest cover which threatens mushroom natural habitat. Similarly, the
absence of commercial cultivation of this mushroom have resulted in it
scarcity. The bulk of
mushrooms consumed especially in Nigeria are hunted for in the forest; the
practice which is often associated with some degree of negativity and fatality
since poisonous ones could be inadvertently picked and eaten. Hence,
there is need to cultivate mushroom outside their natural habitat. The major
factor in mushroom cultivation is the substrates. Unpredictable yields due to
use of unsuitable substrate has discouraged most small-scale farmers who are
often, unable to keep on with mushrooms cultivation. In view of this, there are
needs to look for the cheapest substrates that would not only give desired
qualities in terms of good taste, vigour and increase in the mycochemical
contents of the mushroom. It will ensure the existence and continuity of
mushrooms while also providing the opportunity for people to eat their desired
mushrooms with maximum assurance at season.
1.3 JUSTIFICATION
Mushroom constitutes an
integral part of the normal human diet especially in the Eastern part of
Nigeria and the amounts of consumption have been raised greatly. Mushrooms have
been documented to have food and medicinal values (Fillipie and Umek,
2002; Hu et al., 2006; Ngai et
al., 2006; Okwulehie et al., 2008; Okwulehie
et al., 2017). They are seasonal, and in
short supply; hence, absent or minimal commercial cultivation may escalate its
scarcity. In Nigeria, Hypsizygus ulmarius is a new mushroom variety which is
attractive in shape, fleshy and with excellent taste (Sumi and Geetha, 2016). Despite these attractive qualities, its
production in tropical climate has not yet been fully explored. This research stems at looking for a way of
cultivating this mushroom, through the use of easily obtainable local wastes
to find out their efficiency for the better production of H. ulmarius fruit-bodies in
great quantities and qualities.
The substrates are chosen mainly because they are cheap and readily available
for farmers. This study is also design to strengthen mushroom production
sector as it could be essential in order to enable the rural economy to keep
its vibrancy and development, increasing and diversifying business and
employment opportunities in the rural areas, and providing income opportunities
of small family farms.
1.4 AIM AND OBJECTIVES
The
aim of this study is to produce Hypsizygus ulmarius mushroom on three different
agro-wastes to determine their suitability for use by both commercial and
small-scale farmers in mushroom production with a view to increase the
awareness of people about the significance of this food item. The objectives
include:
1. To
undertake the cultivation of Hypsizygus
ulmarius to produce fruit-body in the tropical condition
2. To
examine the growth and yield performance of Hypsizygus ulmarius fruit-body
cultivated on different agro-wastes
3. To
investigate the relationship between various substrates and the vitamins, minerals,
heavy metals, proximate and bioactive composition of Hypsizygus ulmarius cultivated on
agro-wastes
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