EFFECTS OF DIFFERENT ORGANIC WASTES ON THE GROWTH YIELD MARKET QUALITY AND PROTEIN CONTENT OF LENTINUS SQUARROSULUS (MONT.) SINGER AN EDIBLE NIGERIAN MUSHROOM

ABSTRACT

Four organic wastes; mahogany (Khaya ivorensis) sawdust (MSD), Gmelina aborea sawdust (GSD), oil palm fruit fibre (OPFF) and oil palm empty fruit bunch (OPEFB) were evaluated for  their  effects  on  growth,  yield,  quality  and  protein  content  of  Lentinus  squarrosulus (Mont.) Singer. Plastic bag technology was used with  treatments  replicated  ten times and arranged using a completely randomized design. The quality of the harvested mushrooms was evaluated on the basis of four pileus diameter size groups (>7 cm, 5-7 cm, 3-5 cm, <3 cm) and a deformed group; while their protein analyses were carried out using Kjeldahl’s method. Results on mushroom growth showed that oil palm fruit fibre (OPFF) took the least time for full  mycelial  colonization  and  the  longest  time  occurred  on  Gmelina  sawdust  (GSD). Analysis of variance showed  that there were significant differences (P < 0.05) in the time required  for  primordia  initiation  of  mushrooms  grown  on  oil  palm  empty  fruit  bunch (OPEFB), oil palm fruit fibre (OPFF) and Gmelina sawdust (GSD). Results on mushroom yield revealed that mean fresh weights of harvested mushrooms varied from 4.12 ± 0.16 g on oil palm empty fruit bunch (OPEFB) to 16.05 ± 0.68 g on mahogany sawdust (MSD). There were significant differences (P < 0.05) in the biological efficiency of mushrooms grown on mahogany  sawdust  (MSD),  Gmelina  sawdust  (GSD)  and  oil  palm  empty  fruit  bunch (OPEFB). Mahogany sawdust produced the highest quality mushrooms, with 26% in the >7 cm group while Gmelina sawdust (GSD) and oil palm empty fruit bunch (OPEFB) had none in the same quality group. The percentage protein content of harvested mushrooms ranged from 13.27% for mushrooms produced from mahogany sawdust (MSD) to 27.42% for those grown  on  oil  palm  fruit  fibre  (OPFF).  The   above  findings  reveal  the  possibility  of commercial production of high quality L.  squarrosulus on oil palm fruit fibre (OPFF) and mahogany sawdust (MSD) while oil  palm fruit fibre (OPFF) is recommended  as the best substrate for spawn production among the various organic wastes used in this study.

INTRODUCTION

CHAPTER ONE

1.1 BACKGROUND

Chang and Miles (1992) defined  mushroom  as a macrofungus  with a distinctive  fruiting body,  which  can  be  either  epigenous  (growing  on  or  close  to  ground)  or  hypogenous (growing under the ground) and large enough to be visible to the naked eye and to be picked up by hand. Thus, mushrooms need not be only basidiomycetes, or aerial or fleshy, or edible. Mushrooms can be ascomycetes, grow underground, have a non-fleshy texture and need not be edible (Chang, 2008).

Mushrooms  are  widespread  in  nature  and  since  earliest  recorded  history;  humans  have viewed them as a special kind of food, savoring the delicious flavours and acknowledging the nutritional value of this special group of fungi (Chang and Buswell, 1996). Mushrooms have long  been  appreciated  for  their  flavour  and  texture,  and  some  for  medicinal  and  tonic attributes.   However,   recognition   that   they  are   nutritionally   a  very   good   food   and physiologically an important potential source of biologically active compounds of medicinal value is much more recent (Chang, 1996). It is now known that mushrooms are rich in high quality protein, contain a high proportion of unsaturated fatty acids and have a nucleic acid content  low enough to allow daily  use as a form of vegetable  (Chang,  1996). Moreover, latter-day application of modern analytical techniques has, in a number of cases, provided a scientific basis for assigning medicinal value through the identification of various mushroom- derived       compounds       including       anti-cancer,       anti-viral,       immunopotentiating, hypocholesterolaemic  and  hepatoprotective  agents  (Liu  et  al.,  1995).  For  example,  the pharmacological activities of Ganoderma lucidum have been attributed mainly to triterpenes and polysaccharides produced by the mushroom. Several polysaccharides and protein-bound polysaccharides with immune-modulating and anti-tumour activities have also been isolated from a variety of mushrooms (Chang, 1996).

Agricultural production and the agro-food  industry furnish large volumes of solid  wastes, residues and by-products, produced either in the primary agro-forestry sector (crop-based) or by   secondary   processing   industries   (processing-based)    with   the   major   part   being lignocellulosic biomass (Philippoussis and Diamantopoulou, 2011). Recently, Zhang (2008), reviewing  the  global  world  information  about  lignocellulose  availability  estimated  the

production of lignocellulosic biomass to be more than 200×109  tonnes per year. The amount

of crop residues produced annually in the world from 27 food crops is estimated at  about

4×109   tonnes  (Lal,  2008).  The  majority  of  this  organic  matter  poses  an  environmental pollution problem.

In nature, mushrooms have not only been a source of food for man and other animals, but also have played an important role in the cycling of carbon and other elements through the breakdown of lignocellulosic plant residues and animal dung, which serve as the substrates for these saprophytic fungi (Chang, 1996). In this way, mushroom species, as agents of decay help keep the environment from being overwhelmed by the dead organic debris of plants and animals.   Mushroom   forming   fungi   are   therefore   amongst   nature’s   most   powerful decomposers,  secreting  strong  extracellular  enzymes  due  to  their  aggressive  growth  and biomass production (Adenipekun, 2009). They have the capability to produce a wide range of enzymes that can break down complex substrates into simpler soluble substances and absorb them for their growth and development (Oei, 1991).

Strong consumer demands and threats of depletion of mushrooms have stimulated increased worldwide  production  in  the  past  few  decades  (Chang  and  Miles,  2004).  The  increased demand for mushrooms is due to their unique culinary and medicinal properties (Yan et al.,

2003). Commercial cultivation of mushrooms as a source of food, nutriceutical and medicine is now a worldwide industry with over 120 countries contributing to a crop which, in 1999 totalled 4.3 million tonnes (Chang and Miles, 1991). Several reports indicate that commercial production of fresh edible mushrooms is a rapidly growing industrial activity. In 2002, world production of cultivated mushrooms was estimated to  be 12,250 thousand tonnes and was valued  at  about  US$  32  billion,  whereas  mushroom  products  used  mainly  for  dietary supplements  were  assessed  to  have   generated  about  US$  11  billion  (Chang,  2006). Mushroom cultivation is an efficient and relatively short biological process of food protein recovery from  lignocellulosic  materials (Martinez-Carrera  et al., 2000). The cultivation of edible mushrooms has become an increasingly important practice in modern society due to the biotechnological process of bioconversion of various residues into edible mushrooms or in dietary supplements of high nutritional value, enabling a more efficient utilization of waste materials. Interestingly, the spent compost that remains after harvesting mushrooms may still be recycled for use as animal feeds and soil conditioner. Earlier studies have demonstrated that spent compost of both Volvariella  and Pleurotus had increased  crude  protein content compared with raw straw (Quimio, 2004).

Mushroom production can be a lucrative cottage industry for low-income rural households in developing countries (Ferchak and Croucher, 1996). The activity is labour intensive and can provide  full  or  part-time  employment.  A  small  mushroom  production  business  can  be

established  with  low  capital  investment  and  with  minimal  requirements  for  space  and equipment.

Mushroom   production   represents   an  important   opportunity   for  developing   countries, particularly  Nigeria,  since  innovations  in  cultivation  and  post-harvest  processing  make possible new opportunities (Ferchak and Croucher, 1996).

1.2 Problem Statement

Nigeria by virtue of her population size generates several tonnes of agricultural,  industrial, municipal and domestic wastes that overwhelms the nation’s waste disposal machinery and pose an environmental  pollution problem (Okhuoya  et al., 2010).  These  so called wastes constitute  a  negative  factor  both  in  the  economic  evaluation  of  existing  industrial  and agricultural operations and because of the adverse environmental effects resulting from their disposal.   Sadly, much of this waste is either  burned, shredded or used as landfill or for improvement  of  soil  quality,  even  though  these  wastes  constitute  a potentially  valuable resource and can be recycled for the production of edible food for man (Chang, 1996).

Much of the cellulose in nature is bound physicochemically with lignin. Because  lignin is highly resistant, it protects cellulose against attack by most microbes, and it must be degraded by chemical or biological means before the cellulose can be utilized (Salvagi and Kaulkarnis,

2001). The use of the polysaccharides in the lignocellulosic complex is also limited due to their high lignin content (Hadar et al., 1992). Zadrazil and Grabbe (1983) reported that about one-half  the  total  production  of plant  residues  from  agriculture  and  industrial  processes remains unused and burdens the environment. Chang (1989) also noted that all agricultural production  from  crop  plants  generated  enormous  waste,  because  little  of each crop  was actually used; typically 80-90% of the total biomass of agricultural production is discarded as waste and this is because only part of the organic matter synthesized through photosynthesis every year is directly edible in the form of fruits, vegetables and food grains.

The handling and disposal of these lignocellulosic residues are often problematic due to their chemical  structure  and  decomposition  properties  (Philippoussis  et  al.,  2001).  However, various problems associated with the practical utilization of these materials have not yet been solved (Taniguchi et al., 2005). One of the key problems hindering the effective utilization of these renewable resources as raw materials for the production of food and feeds is the low susceptibility of lignocellulose to hydrolysis, which is attributable to the crystalline structure of cellulose fibrils surrounded by hemicellulose  and the presence of the lignin seal which prevents penetration by degrading enzymes (Chahal and Chahal, 1999).

Although physical and chemical technologies may, in some cases, play important associated roles for handling these wastes. Biotechnological approaches are essential for the emergence of practical conversion processes which can be applied to situations in developing countries throughout the world where large scale capital intensive operations are inappropriate. Adequate food-intake is one of the fundamental human requirements, but there is no denying the fact that millions of people especially in the developing  countries of Africa, Asia and Latin America are beset with danger of their very survival due to its non-availability.  The greatest difficulty in feeding humans is to supply a sufficient quantity of the body building protein (Chang, 2008). In Africa, the  gap between the increasing population and supply of protein is somewhat wide since  the traditional sources of protein have not kept pace with population  growth.  In view  of the  general  shortage  of animal protein  in the  developing countries,  the  need  to  explore  vegetable  protein  as an alternative  source  has  been  duly recognized.

An FAO/WHO joint expert group on protein requirement reviewed evidence on the effects of protein malnutrition  on the predisposition  of adults and children to  infection, on reduced stature and retarded  psychomotor  developments  in adults  malnourished  in younger  years. They also observed reduced birth weight and difficulty in recovering from surgery trauma and other pathological states (Chang, 2008).

Foodstuffs  of plant origin such as cereals,  vegetables,  potatoes and cassava constitute  an important dietary source of protein for many segments of the world’s population particularly where animal protein is not only in short supply but have become costly and beyond the reach of middle and poor classes. One of the major disadvantages of these types of foodstuffs is their  low protein  contents.  As the  shortage  of high quality  protein  is at  its peak  in the developing   countries   like   Nigeria,   there   is   need   to   supplement   these   diets   with unconventional sources of protein.

1.3 Justification

Huge  quantities  of a wide variety of organic  wastes  are  generated  annually through  the activities of the agricultural, forest and processing industries. Therefore, there is considerable pressure nowadays to develop biotechnological  processes for the rational  treatment and/or disposal  of  these  vast  quantities  of  waste  lignocellulosic  materials  generated  annually (Buswell et al., 1996). Of the various approaches adopted, one of  the most significant  in terms  of  producing  a  higher  value  product  from  the  wastes  is  the  cultivation  of  edible mushrooms by solid state fermentation (Chang and Miles,  1991). Reports have shown that

various  lignocellulosic  residues  from  agro-industrial  sector,  such as oil palm  and  timber wastes among others, can provide the mushroom with nutrients required for spawn run and fructification which under controlled conditions and procedures result in an optimum product yield (Fung et al., 2005).

Mushrooms are a nutritious food source being rich in protein, vitamins and minerals. Earlier reports have shown that mushrooms are rich in ascorbic and amino acids, and protein is their most abundant nutrient (Fasidi and Kadiri, 1990; Aletor, 1995). The  food and agricultural organization (FAO) recognizes mushrooms as food contributing to the protein nutrition of the countries which depend largely on cereals because of their high protein quantity and quality (Kuforiji and Fasidi, 2009). They are also known to  contain substances  that enhance the immune system, fight infectious diseases, and  lower blood pressure and cholesterol levels. The fact that mushrooms,  a novel source  of protein offer a promising way of alleviating protein malnutrition in developing countries in the nearest future cannot be denied.

In addition, Nigeria by virtue of its vantage tropical location is one of the world’s potential hotspots for various forms of biological resources including mushroom (Akpaja et al., 2003). Currently, the exploitation of indigenous Nigerian mycoresources is still over-shadowed by the preponderance  of green plants (Okhuoya  et al., 2010).  Vigorous  researches  on these easily over looked forest members might evolve an accidental source of drugs that would resolve the world’s cancer, AIDS and leukemia problems (Okhuoya et al., 2010).

1.4 Objectives of the Study

      To determine the effects of different local organic wastes on the growth and yield of Lentinus squarrosulus.

      To evaluate the market quality of Lentinus squarrosulus cultivated on the different organic wastes.

      To estimate the protein content of the mushrooms grown on different local organic wastes.

₦5,000.00 – DOWNLOAD FULL PROJECT DOWNLOAD FULL PROJECT Added to cart

---

---

---

---

Related Project Topics :