eChapters

Constituents of meat
i. Water- 75%
ii. Protein- 19%
iii. Soluble and non-protein substances- 3.5%
iv. Fat- 2.5%
• The muscle fibre is important unit of muscular tissue consisting of
a) Myofibrils- formed protein structures embedded in sarcoplasmic fluid
b) Sarcoplasmic reticulum- a fine system of tubules
c) Sarcolemma- a very thin membrane surrounding the myofibrils and around the exterior side of this membrane, the connective tissue is found
• 19% of protein in the muscle is muscle fibre (Table 11.1)
• α-alanine, glycine, glutamic acid and histidine are the major free amino acids present in the fresh muscle

Abstract

The conventional methods of pathogen identification have often depended on identification of disease symptoms, isolation and culturing of the organisms, and identification by morphology and biochemical tests. The major limitations of these culture based morphological approaches, however, are the reliance on the ability of the organism to be cultured, the time consuming nature and requirement of extensive taxonomic expertise. Furthermore, diagnosis of plant diseases can be even more difficult with asymptomatically infected propagative materials such as tree grafting stocks or potato tubers. The use of molecular methods can circumvent many of these shortcomings. Accordingly, there have been significant developments in the area of molecular detection of plant pathogens in the last three decades. The polymerase chain reaction (PCR) which revolutionised molecular diagnostics and biological sciences. In the last decade the range of targets that can be diagnosed using diagnostic PCR have grown tremendously. The very flexibility and application specific variations in the basic theme of the system have allowed the development of many PCR variants adapted to wide range of applications. Furthermore, diagnostic PCR has been greatly improved by the introduction of the second generation PCR, known as the Real time PCR where closed-tube fluorescence detection and quantification during PCR amplification (in real time) is possible eliminating the need for laborious post-PCR sample processing steps which greatly reduces the risk of carryover contamination. Using Real Time PCR, it is possible not only to detect the presence or absence ofthe target pathogen, but it is also possible to quantify the amount present in the sample allowing the quantitative assessment of the number of the pathogen in the sample. Enumerating the pathogen upon detection is crucial to estimate the potential risks with respect to disease development and provides a useful basis for diseases management decisions. Crops can be attacked by many pathogens which, in addition, often occur in complexes. Therefore, many disease diagnostic applications require simultaneous detection and quantification of several targets. Methodological limitations, however, are in many cases the reason for developing simplex or assays designed for only few targets. The DNA Microarray technology, originally designed to study gene expression and generate single nucleotide polymorphism (SNP) profiles, is currently a new and emerging pathogen diagnostic technology, which in theory, offers a platform for unlimited multiplexing capability. It is viewed as a technology that fundamentally alters molecular diagnostics. The fast growing databases generated by genomics and biosystematics research provides unique opportunity for the design of more versatile, high-throughput, sensitive and specific molecular assays which will address the major limitations of the current technologies and benefit plant pathology.

Abstract

Molecular markers play key role in crop improvement. There are severalmarkers such as RAPD, SSR, AFLP, SNP, DArT and many more are available for their practical uses. From the past markers like RAPD, AFLP, and SSR have been used extensively in the crop breeding. Recently new markers such as SNP and DArT have become popular among the researchers of molecular biology for use in genomics-assisted crop breeding. These markers have been applied for study of genetic diversity, germplasm management, cultivar identification, genetic mapping, gene tagging and genomics etc. Though the conventional method of breeding willcontinue to play a primary role in the crop improvement, molecular marker technology is becoming one of its integral components. Agarose-based DNA markers like ISSR, CAPS, RAPD, SCAR and AS (allele specific) have the potential for faster and accurate breeding for target traits through MAS.

Hydrates carbons (saccharides) found in nature (animals and plants) are classified into three groups based on the number of monosaccharides found or released upon acid hydrolysis. Monosaccharides the groups of carbohydrates.
3.1 Formulation of Monosaccharides
The molecular formula of any monosaccharide (mono=one and saccharide=sugar) is Cn(H2O)n or (CH2O)n. Rhamnose and Deoxyribose are exceptions to the general formula of carbohydrates. Acetic acid (C2H4O2) and formaldehyde (CH2O) are not carbohydrates but have the formula Cn(H2O)n or (CH2O)n. Fitting and Baeyer proposed the formula CHO-(CHOH)4-CH2OH, which indicates the presence of aldehyde and five hydroxyl groups.
More than one monosaccharide molecule unites to form disaccharides, oligosaccharides, and polysaccharides. Monosaccharides, being simpler units, cannot be broken down further. Generally, they have two to ten carbon atoms per molecule (dioses to decoses). The monosaccharides may have either aldehyde or ketone groups. The one possible aldodiose (CH2OH.CHO) is glycolaldehyde (2-hydroxyethanal), but ketodiose is not possible since there are only two carbons. The glucose molecular formula C6H12O6 represents the number of C, H, and O atoms but not groups. However, the proposed formula, CHO-(CHOH)4-CH2OH, indicates the presence of an aldehyde and five hydroxyl groups. These simple sugars or monosaccharides have carbon backbones linked by single bonds with hydrogen and hydroxyl groups attached in an unbranched manner.

A. Morphological Examination of Bacterial Samples
Introduction
Bacteria are most widely distributed, the simplest in morphology, the smallest in size and difficult to identify. They are prokaryotic and a few are photosynthetic. Most bacteria are only 0.5 to 2.0 μm in diameter. Bacteria are generally rod, spherical or curved shaped. Rod shaped bacteria may vary considerably in length, have square round or pointed ends and may be motile or non-motile. The spherical or coccus shaped bacteria may occur single, in pairs in tetrads, in chains or in regular masses. The helical and curved shaped bacteria exist as slender spirochetes, spirillum and bent rods (vibrios). In this exercise the ubiquitousness of these organisms will be demonstrated in the air and water, on body and in mouth etc.
Materials
1. Petri plates containing nutrient agar
2. Sterile cotton swabs
3. Sterile water blank
4. Tube of nutrient broth
5. Materials for simple staining

Bacteria are morphologically different. This characteristic is helpful in the identification of bacteria. Routine study of bacterial morphology should include examination of stained preparations. Motility should be examined by hanging drop preparation. According to the requirement, certain cell structures may be stained. Stained preparations should be made preferably from fresh agar slant cultures. Smears of Streptococcus should be made from a liquid culture. Morphology of bacteria may be described under the following terms:

1.Shape: Spherical, coccobacillary, short or long rods, filamentous, comma- shaped, curved or spiral forms.

2.Size: Spherical are measured in diameter and rod-shaped in length and breadth. Measurement is expressed in microns (µ).

3.Sides: Straight, concave, bulging, parallel or irregular.

4.Ends: Round, pointed, truncate or concave.

5.Axis: Straight or curved.

6.Arrangement: Singly, in twos, in groups of four or eight, in grape-like bunches, in long chains, or scattered irregularly, may be in bundles, angular arrangements or in Chinese letters.

7.Pleomorphism: Bacteria may differ from their typical shape. Some of the older cultures may depart greatly from their typical forms, and may show spindles, clubs, and filaments, swollen and branching forms. Variation may be both in shape and size.

8.Capsule: May or may not be present. When present, size should be noted. This requires special staining.

Life forms are composed of one of two basic cell types : Eukaryotic or Prokaryotic. Generally, eukaryotic cells are larger and more complex than the prokaryotic cells and possess a membrane-enclosed nucleus; eukaryotic means ‘true nucleus’ (eu=true; karyon = nucleus). All plants, animals, fungi, protozoa and algae are composed of eukaryotic cells. Only the microorganisms classes as bacteria and the archaea are prokaryotic cells. Prokaryotic cells have no nuclear membrane and therefore lack a true nucleus. The latin prefix pro means ‘early’ and in this instance suggests the somewhat primitive nuclear structure found in bacterial cells. Eukaryotic microorganism are sometimes simply referred to as eukaryotes, and the prokaryotic microbes as prokaryotes.

Abstract

Multiflash drying (MFD) process is based on the application of multiple cycles of heatingvacuum pulse to a solid food. Heat can be provided by convection (from hot air), conduction (by contact with a hot surface), microwaves, or by a combination of these methods. Due to the moderate temperatures applied to the drying food, and the sudden decompression step (vacuum pulse), MFD processes allow obtaining crispyanddried foods with very good nutritional and sensory properties. Vacuum pulses cause food texturization, which depends on the pressure drop rate during decompression. In fact, the dried products are similar to freezedried foods, but with more open structures, which result in higher crispness. The dehydration can be performed in relatively short processing times, when compared with traditional drying processes (e.g. solar drying, airdrying, vacuum drying and freezedrying). The short process time indicates clearly that this class of drying process presents a huge potential to the production of driedandcrisp foods at industrial scale.

Muscle structure
• All muscles are composed of muscle fibres which are the structural unit of muscles
• In turn, every single muscle fibre is made up of numerous smaller components called myofibrils
• Functional unit of myofibril is sarcomere
Connective tissues associated with muscle
• Whole muscle is surrounded by a sheath of connective tissue called epimysium
• Whole muscle is divided into muscle bundles by perimysium formed out of connective tissue septa originating from the interior surface of the epimysium separating the muscle fibres
• The perimysium contains the blood vessels and nerves

Mushrooms are most ancient, best known and greatly admired fleshy macrofungi. Mushrooms are delicacies, much sought after and greatly valued foods. Wild mushrooms are mostly found in forests, tree trunks, pastures, lawns and road side during winter season and appear at surprising speed. Mushroom hunting or gathering is a popular hobby in Western countries. The wild mushrooms may be edible or unpalatable or poisonous. Poisoning by wild mushrooms is common and may be fatal or produce merely mild gastrointestinal disturbance or slight allergic reaction. The term toad stool is popularly reserved for inedible or poisonous mushrooms, but this classification has no scientific basis. This alarming term keeps many people away from these foods. It is important that every mushroom intended for eating be accurately identified. Mushrooms vary in colour, size, shape, growth habit, yielding ability and other characteristics.

STRUCTURE: Mushrooms are the fleshy fungi which constitute a major group of lower plant kingdom. Mushroom is the conspicuous umbrella-shaped fruiting body (sporophore) of certain fungi of the order Agaricales in the class Basidiomycetes but also of some other groups. Popularly, the term mushroom is used to identify the edible sporophores. The edible reproductive part consists of a stem and a cap. Gills found on the underside of the cap, are arranged like spokes in a wheel. The gills bear multiple spores which start new fungi. The sporophore emerges from an extensive underground network of fine thread like white growth known as mycelium. The mushroom, fruit body produced basidiospores at the tip of club like structures, called basidia, which are arranged along the gills of the mushroom. Beneath the mushroom, in the soil, is the mold colony itself, consisting of a mat of intercoiled hyphae, sometimes several feet in diameter. The mushrooms first appear as white tiny ball consisting of short stem (stipe) and a cap (pileus) which begins to open up like an umbrella. The delicate membrane or Veil (velum) enveloping the cap tears off, if allowed to develop fully, and lamellae (gills) radiating from the stalk into the cap become visible. These gills become darkened as the basidiospores (seeds) develop into millions and fall in the ground for starting their life cycle once again for second generation of mushrooms.

1. Introduction

Mushrooms represent a highly specialized group of fungi, mostly basidiomycetes, with production of fruiting bodies bearing the spores for continued propogation. The fruiting bodies vary greatly in shape, size, color, texture, structure and aroma (Rajarathnam et al., 1998). They are endowed with the unique ability to biodegrade cellulosic wastes, including lignin, and biotransform into edible fruiting bodies (Rajarathnam et al., 1992, 1998, Rajarathnam and Zakia Bano, 1990). Their chemistry is also varied comprising characteristic polysaccharides, phenolics, proteins, amino acids, peptides, lectins, fatty acids, minerals, and so on (Rajarathnam et al., 1998). The wide spectrum of compounds have endowed the mushroom species with a spectrum of biofunctional activities of medicinal importance and accordingly their role in human health are implicated through studies on chemical, cell culture and animal feeding experiments. Vast literature available on this subject is condensed for presentation here.
Fifty nine medicinal species are reported from Diaoluoshan Nature Reserve in Hainan Province, China (Li et al., 2003). A health food made from luminescent mushrooms (Mycena chlorophos) is described. The luminescent parts that emit light in the carpophore of the mushrooms are dried without thermal decomposition and pulverized (Sugimoto, 2006). Consideration is given to the health promoting properties of 3 types of Asian fungi, namely, shiitake (Lentinus edodes), reishi (Ganoderma lucidum) and maitake (Grifola frondosa). Properties considered include beneficial components (e.g polysaccharides, vitamins, amino acids) and effects on the immune system (Anon, 1997). Auricularia auricula (kikurage or tree-ear) and Tremella fuciformis (shirokikurage or white jelly-leaf) are widely used in Chinese cuisine. Chemical structures of some of the polysaccharides from A. auricula and T. fuciformis, in relation to their medicinal and nutritional effects are described (Misaki and Kakuta, 1995).

1. INTRODUCTION

Mushrooms are edible fungi of commercial importance and their cultivation has emerged as a promising agro-based land-independent enterprise. There are about 20 varieties of mushrooms being cultivated throughout the world for food. In India, only white button mushroom (Agaricus bisporus J.E. Lange Imbach), oyster mushroom (Pleurotus spp. [Fr.] P. Kumm) and paddy straw mushroom (Volvariella volvacea [Bul.] Singer) are grown commercially. Of these, white button mushroom contributes ~90% of the total production. Mushrooms have been recognized as an alternate source of good quality protein and produce the highest quantity of protein per unit area from agro-wastes. Besides, they provide potentiality for generating employment, improving economic status of growers, help in checking pollution and earn foreign exchange.

Out of the total production about 45% of mushrooms produced are consumed in the fresh form while the other 55% are processed, with 5% in dehydrated form and 50% in canned form. This is because their shelf-life in the fresh form is very short and hence mushrooms are traded in the world market mostly in the processed form. Fruiting bodies (reproductive phase) of Agaricus are appreciated not only for texture and flavour but also for their chemical and nutritional characteristics.

Abstract

Mycotoxins are naturally occurring chemicals produced by fungi growing on grain, feed or food. The fungi that produce mycotoxins in grains commonly include Fusarium, Aspergillus and Penicillium species. The toxins can accumulate in maturing corns, cereals, soybeans, sorghum, peanuts and other food and feed crops in the field and in grain during transportation. The toxins may occur in storage under conditions favorable for the growth of the toxin producing fungi. Diseases in animals and human beings resulting from the consumption of mycotoxins are called Mycotoxicoses. These fungal metabolites are detrimental to the health of both animals and human. Toxicity ranges from acute death to chronic diseases, cancer and reproductive malfunction. Mycotoxin contamination of food and feed grains is a serious economic problem for grain producers and processors because grain contamination impacts market 

Fungi cause diseases in plants and animals and in such diseases, the fungi actively grow and invade the body of their hosts. There is another means by which fungi can cause harm is growing on stored food material that we consume and produce toxic metabolites referred to as mycotoxins (means fungus poisons). Food is particularly susceptible to fungal infections at almost every stage of storage or production. Mycotoxin is toxic substance produced by a fungus. The term is restricted to toxins produced by fungi growing in human foods or animal feeds. The growth of the fungi in food grains leading to physical spoilage of grains and toxin production is a serious problem in developing countries. Their occurrence in food and feed has both economic and health implications, as the toxic effects in human beings, animals and other living systems were well established. The effects of poisoning by mycotoxin are referred to as mycotoxicoses.

Naïve panel: It refers to the sensory evaluation panel that has not been trained specifically regarding the product evaluation being undertaken in the study. It is untrained panel of sensory evaluation.

Nano technology: It is the art of manipulating materials on an atomic or molecular scale to build microscopic devices. The word “nano’ meaning ‘dwarf” in Greek language refers to dimension / magnitude of the material / particle in the order of 10-9. Nanotechnology is nothing but manipulating of particles into very small particles called nano-particles. These particles have dimensions in the scale of nano-meter and used to design / build materials and devices. Nanotechnology has been provisionally defined as relating to materials, systems and processes which operate at a scale of 100 nanometers (nm) or less. It will allow many things to be manufactured at low cost and with no pollution. The concept of nanotechnology was first given by Nobel Laureate physicist Richard P. Feynman in Southern California in 1959.

NaNO2 : Pink colour of cured meat is preserved by NaNO2 . It is effective against Cl. Botulinosm

Nanogram: It is one billionth of a gram.

Nano-materials: Nano material have been defined as having one or more dimensions measuring 100 nm or less, or having at least one dimension at this scale which affects the materials behavior and properties (Plate 438).

The term nanotechnology was coined by Prof Taniguchi, Japan in 1974 during conference of the Japanese Society of Precision Engineering. Nano technology is a domain of scientific activity oriented on synthesis, characterization, application of devices and materials and technical systems which functions at nano structures having 1 to 100 nm size. Prof R. Feynman American Physicist and Nobel Prize winner was the first person pointed out the importance and promising outlook for nano particles during his lecture entitled “There’s Plenty of Room at the Bottom. An Invitation to Enter a New Field of Physics,” delivered on December 29th 1959 at the California Institute of Technology. He pointed out that “... when we have some control of the arrangement of things on a small scale we will get an enormously greater range of possible properties that substances can have, and of different things that we can do ... The problems of chemistry and biologycan be greatly helped if our ability to see what we are doing, and to do things on an atomic level, is ultimately developed”. Later scientists realized the potential of nano particulate materials during the last decade has tremendous advancement in nano research. Governments and private sectors of the world invested huge sums to reap the benefits from novel applications of nano materials.

Nanotechnology: The principle of nano technology is that the material with known properties and functions at normal size exhibit different behaviour and functions at nano scale. By decreasing the size of the material the surface area per unit material will increase enormously and this helps greater interactions with reactive sites. Nano technology implied that the process of fabricating and/ or controlling the material sized between 1 to 100nm.

Fundamentals of Nanotechnology in Packaging • Overview of Nanotechnology in Packaging: Nanotechnology in packaging refers to using materials manipulated at an extremely small scale (1-100 nanometers) to boost the performance and capabilities of packaging. Techniques like nanoparticles, nanofibers, and nanocomposites are integrated into packaging materials to improve their physical properties, prolong shelf life, and introduce new functions like antimicrobial features. Mechanisms and Key Materials • Nanoparticles: Small particles added to packaging to enhance strength, f lexibility, and barrier properties. Common types include silver, titanium dioxide, and zinc oxide nanoparticles. • Nanofibers: Made from substances such as chitosan, cellulose, or polymers, these fibers increase strength and are useful in active packaging coatings. • Nanoclays: Dispersed in polymers, these increase resistance to gases and moisture, enhancing barrier performance

Fruits and vegetables are perishables and the post-harvest losses from the point of production at the farm gate till it reaches the consumers is estimated as 30-35 per cent which constitute a major economic drain of more than 33 billion USD equivalent to Rs 2,40,000 crores annually. In order to reduce the losses at various stages, nanotechnologies have come as potential strategies to minimize the losses while improving the marketability and profitability of perishables. One of the plants derived natural compounds “hexanal” which is known to extend the shelf-life of fruits when it is used as a pre-harvest spray or post-harvest dip as a nano-emulsion. Since, it is a highly volatile compound, efforts were undertaken to entrap the compound in the polymer-based nano f ibres (as nano stickers) or as a cyclodextrin inclusion complex (as nano pellets) in order to preserve the perishables. Further, hexanal vapour was also evaluated to preserve fruits. In this book chapter, various nanotechnologies tested, evaluated and technologies developed over the years are elucidated. Overall, the literature review suggests that use of any of the nanotechnologies delivered as pre-harvest spray, post-harvest dip, nano-stickers, nano-pellets and vapour singly or in combination found to reduce the infestation of post harvest diseases, minimize the losses and extended shelf-life by 2-3 weeks that help the farmers to get lucrative prices due to the late arrival in the market besides significantly improve the productivity and profitability of orchards.