eChapters

Introduction

As the world population continues to grow, the global market for food products is expanding, together with an increased emphasis on food safety. Consumers have become more discerning in the type of foods they buy and how these foods affect their health and well being. Food safety is generally defined as the assurance that the food will not cause any harm to the consumer when it is prepared and/or eaten according to its intended use ( To achieve food safety, a management system has been developed which aims on preventing problems before they occur, rather than trying to detect failures through end product testing. It also places more responsibility for ensuring food safety on food manufacturers, who have to develop control and traceability of their products from ‘farm to plate’. The system requires the identification of specific hazards throughout the entire process of food production, concentrates on the points in the process that are critical to the safety of the product, and highlights measures for their control (Henson and Caswell, 1999).

Introduction

Tropical tuber crops viz., cassava (Manihot esculenta Crantz), sweet potato (Ipomoea batatas), taro (Colocasia esculenta), yams (Dioscorea sp.), Elephant foot yam (Amorphophallus paeoniifolius), arrowroot (Maranta arundinacea) etc., are the important sources of starch after cereals and are used as staple or supplementary food in many of the tropical and sub tropical countries. Being the crops with adaptability to wide range of soil, climate and environment of the tropics and sub tropics and requiring minimum agronomic input and care for growth, they can be very well fitted into the prevailing cropping systems. They are the most efficient converters of solar energy and have the ability to reserve energy in the form of carbohydrate in the bulky roots and hence tuber crops are also called as calorie density crops. Tuber crops, though branded as poor man’s crops in rural areas have considerable unrealized potential for processing into high end products for food, feed and industrial uses. They are generally consumed as vegetable after boiling it in water and eaten along with some spicy curry or by extracting starch or flour. Besides serving as an insurance crop during times of food scarcity, it can also function as an industrial raw material for a wide spectrum of products

Introduction

India, with its unique agro climatic conditions is capable of producing a wide variety of fruits and vegetables. These highly perishable produce in both fresh and processed forms are of high demand in domestic as well as international market. Nowadays farming is becoming an enterprise and shifting towards consumer driven agriculture. Produce quality measurement is of utmost importance as consumers are more quality conscious and ready to pay higher for quality. Consumer preference is moving towards healthy food, minimally processed and, fresh cut fruits and vegetables, prepared salads, ready to cook, ready to eat and ready to drink health beverages. Hence health, nutrition, convenience, quality and safety of produce should be guaranteed to the consumers. Due to globalisation of production and trade, legislations and standards for markets are strict and product quality is the necessity for competitive markets.

Quality of a produce, based on subjective and objective measurement, is defined differently by consumers, wholesalers, retailers, processors or any other who is associated with it and varies with market either national or international. Quality of foods may be defined as the composite of those characteristics that differentiate individual units of a product, and have significance in determining the degree of acceptability of that unit to the user (Kramer, 1965). According to ISO (International Organisation of Standardisation), “Food quality is the totality of features and characteristics of a product that bear on its ability to satisfy stated or implied needs” and as per CAC (2003), “Food safety is the assurance that food will not cause harm to the consumer when it is prepared and/or consumed according to its intended use”. Food safety is the most important component of quality.

Introduction

Water is not only a vital environmental factor to all forms of life, but it has also a great role to play in socio-economic development of human population. Since antiquity humans have valued the importance of clean water and have used various techniques to improve its quality. In modern times, the safe drinking water became first a public health issue and then a human rights issue. The access to safe drinkin gwater now considered as a basic human right which is an essential component of effective policy for health protection. Improving access to safe drinking-water can result in tangible as well as intangible benefits to health. It has been shown that investments in water supply and sanitation can yield a net economic benefit, because the reductions in adverse health effects and healthcare costs outweigh the costs of undertaking the interventions (WHO, 2017). Past experiences have also proved that interventions in improving access to safe water favour the poor in particular, whether in rural or urban areas, and can be an effective part of poverty alleviation strategies. The disparity in water availability, reliability, and quality between the developed world and developing countries is enormous. Unfortunately, in many developing countries people lack access to safe water and therefore waterborne diseases are still a major cause of death, especially among children under age of 5. According to a joint report by World Health Organization (WHO) and United Nations International Children’s Emergency Fund (UNICEF) (WHO/UNICEF report 2017), around 2.1 billion people worldwide lack access to safe and readily available water at home, and around 4.5 billion, lack safely managed sanitation facilities. Moreover, many of these countries that have set drinking water standards often lack the resources to implement or enforce them.

Introduction

Food grains have been the key component of the human diet for thousands of years and have played a vital role in framing human civilization. Rice, wheat, and maize, and to a lesser extent, coarse grains are major staples, crucial to the daily endurance of billions of people around the world. Cereal grains are consumed by more than 50% of world population to meet daily calorie requirements. Most grains undergo a milling process that ideally removes the outer bran (pericarp) and germ layers; catering to consumer market requirements. To a farmer, yield is the most prominent aspect. As the grain moves along the supply chain, and as the product reaches the market, quality becomes the key determinant of its sale-ability and economic value. Grain quality is defined by a range of physical and compositional properties where threshold necessities are set according to end consumer use requirements. Most industries and consumer markets have become habituated over the years to demand grain with specific attributes. Where consumers are close to the source of grain production (e.g. in local markets), their own preferences and the laws of supply and demand control the grain quality. However, where grain is traded over large distances, particularly internationally, consumers almost have no direct influence on quality, requiring regulatory standards to be established and imposed to protect consumer rights. Therefore in the grain supply chain, all points have effects with respect to grain quality.

Introduction

The world does not function without mathematics. In our day-today life we come across many problems which are solved mathematically. The mathematical logical system follows “Yes” or “No”, “True” or “False”, “1” or “0” which are precise outputs for the precise inputs. There are several ambiguous or vague problems which cannot be given with accurate precise value with the conventional logical operators. Beyond this Boolean logic operator the logical system which mimics the human brain and gives precise solutions for the imprecise linguistic variables is the Fuzzy logic system. Fuzzy logic is a novel approach that intends to imitate human reasoning using calculations and operations with fuzzy systems and linguistic variables. The problems with vague imprecise data which we come across in our day today life cannot be solved by conventional binary logical method. The fuzzy logic solution spontaneously splits a complex problem into its component parts. This reduces the solution to its component parts. Compilers may re-assemble the code for effective execution on some target, but at the programmer level the problem is a number of simple tasks.

Fuzzy sets theory was introduced by Zadehin the year 1965, and it allows uncertain phenomena to be treated mathematically.

Introduction

The food that we consume should not only contain all essential nutrients like carbohydrate, protein, fat, vitamins, minerals, fibre etc but also should be hygienic and safe. Safety and quality of food is to be ensured not only during food production but also should be continuously monitored till it reaches the consumer (Coles and Frewer, 2013). The characteristics of food are altered during every processing operations viz., cleaning, sorting, transportation, thermal processing, packaging, storage, distribution etc which may be desirable or undesirable. Persistent physical, chemical and microbiological analyses have to be done at all levels of supply chain to ensure the quality of food. Traditional methods of food safety analysis are spectrophotometry, aerobic plate count method, microscopic plate count, titrations, chromatography etc. Though these techniques provide accurate results, the analysis demand cumbersome extraction steps, trained technical staff and are time consuming (Di-Natale et al., 2000). Hence, steady, sensitive and rapid monitoring of food analysis technique is a need of the hour in the present era. Biosensors can effectively replace the conventional techniques owing to its reliability, rapidity, economic and field applicability (Prasad et al., 2014). Biosensors are an attractive diagnostic alternative owing to their in situ detection ability and comparatively reduced detection time from several days to hours, or even minutes (Ruiz et al., 2017). Rapid food analysis can also minimise spoilage, especially in freshly harvested agricultural commodities, such as fruits and vegetables, meat, fish etc. In addition, the portable detection devices provide in-situ detection capabilities without extensive training and assist in integrating real time analysis in food processing centres.

The safety of the food supply suitably remains a high main concern for industry stakeholders, regulatory agencies and patrons. With the surfacing of new safety challenges and issues, companies are establishing and upgrading programs to reduce risk factors. These programs are constantly monitored for reliability, repeatability, reproducibility and effectiveness. Due to the health and safety risks posed by chemical, microbiological and environmental contaminants, analytical methods are progressively more becoming a pride and joy of food safety programs. Innovative analytical approaches are being developed in response to budding food safety issues. To monitor for known issues only the established and officially approved methods are used often. Oftentimes, new analytical methods are developed, improved or modified quickly in response to issues, such as melamine contamination, which are unforeseen. In such instances, accurate data derived from sound, validated analytical methods are required to facilitate industry stakeholders and regulators to make sound methodical decisions.

Through research, industry has improved a host of analytical methods in recent years, resulting in higher sensitivity and accuracy for difficult-to-detect contaminants, detection of contaminants in new matrix classes for grades. These advances have been made in the face of changing set of laws, more painstaking method-validation standards and end user demands for safe, quality products. Further to this, this spirit of innovation will continue to be fundamental in industry’s efforts to ensure the safety of the comprehensive food chain.

Introduction

For the year 2016-17, as per the FAO global estimate, the food grain production has crossed over 2.6 trillion metric tons, while the steadily increasing the demand is anticipated to be approximately 3.3 trillion metric tons for 2016-17. Similarly,the global production of all horticultural commodities has crossed over 1.8 trillion metric tons. The global trade of these commodities is purely based on their quality, the demand for good quality produces increases day by day. The term “quality” is a broad terminology used to explain many parameters and differs from commodity to commodity. Usually, the term ‘quality’ is classified into internal and external quality. The external quality refers the external colour, size, shape appearance, uniformity, external damage, cracks and bruishness etc. These parameters may be common for both perishables and durables.

But, in case of internal quality, each and every parameter vary from commodity to commodity, product to product. For food grains, the internal quality refers to moisture content and other nutritional parameters like carbohydrate, protein content etc. But in fruits, the internal quality refers to internal pulp colour, TSS, pH, acidity, juice content, ripeness, other biochemical and nutritional quality parameters. 

Introduction

Food safety and quality assumes paramount significance in any food industry. Globalization has driven both the food and agricultural firms to adopt systems that functions in a way to interlink food standards and international trade so as to achieve superior food quality and safety. Food industries follow several regional and international food safety procedures to procure certification from the government and other agencies in order to survive in both domestic and international markets (Ryan, 2014). The essential components in the food safety include handling, preparation and storing of the food products to ensure the food quality and to avoid food-borne diseases. The unwanted substances in a food product included by an accident is known as contaminants and the unwanted substance added to the food product to reduce the cost or to improve the other properties are known as adulterants. Contaminants and adulterants may lead to pathogens and toxins that pose serious concerns over the health of the consumer (Jha, 2016). The adulterants and contaminants are classified as physical adulterants and contaminants, chemical adulterants and residues, microbiological and pathogenic contaminants and toxins.

Hazards in food can be categorized into physical, chemical and biological.

Physical Hazards: Physical hazards are foreign organic or inorganic objects or extraneous materials in the food products. Hard and sharp physical hazards are of particular concern. Examples of physical hazards are broken glass, plastics, metal pieces, wood pieces, stones etc.

An electron impringing on a solid surface may be scattered once, several times, or never. When an incident electron beam bombard atoms of the sample, secondary electrons (SEs) and backscattered electrons (BSEs) emerge from the sample surface. Multiple scatterings occur if the dimension of the material is greater than approximately twice the mean free path of the electrons. This scattering may be elastic or inelastic. A pear shaped volume (interaction volume) is formed as shown in Fig. 1 and this volume of excitation increases with increase in the beam voltage (electron energy) and decreases with the increasing specimen density (ion atomic number).

X-ray diffraction (XRD) is an important experimental tool used in determining crustal structure of material system in bulk and nanoregimes. Therefore, it is important to understand the basic concepts of XRD.

Characterization Tools: Microscopy

Chemical Synthesis Methods

Several methods can be used for the production of these nanoparticles, namely: (i) top-down methods (Li et al., 2006) such as vacuum sputtering (Kuhn et al., 2002) or the decomposition of iron penta carbonyl (Fe(CO)5) in organic solvents (Karlsson et al., 2005); and (ii) bottom-up methods that promote the ‘growth’ of the nanostructures via chemical synthesis, for example through the reaction of iron(II) or iron(III) salts with sodium borohydride (Wang and Zhang, 1997). However, these methods present several limitations and problems; the top-down methods are generally expensive and require specific and costly equipment while the drawbacks of the bottom-up approaches are related to safety issues due to the toxicity of sodium borohydride, the production of flammable hydrogen gas during the process (Li et al., 2006), and the tendency to form large agglomerates, very fast and at a high extent, and therefore have a reduced reactivity and degradation efficiency.

Aim

To synthesize Zero valent (Fe) (nZVIs) iron using tea leaf extract.

Introduction

In this approach extracts of natural products (in most cases green tea leaves) with high antioxidant capacities are used. The compounds present in these extracts react with Fe (III) in solution to form nZVIs (Nadagouda et al., 2010).

Aim

Phytosynthesis of silver (Ag) nanoparticles using Cassia roxburghii aqueous leaf extract.

Introduction

The Ag nanoparticles constantly exhibit adverse effects on microbes such as inhibition and inactivation (Nasrollahi et al., 2011). The Ag nanoparticles synthesized by using various biological sources such as herbs, plants and biological organisms display excellent properties in various fields i.e., non-linear optics and intercalation materials for electrical batteries as optical receptors, catalysts in chemical reactions biolabelling and as antibacterials (Sanghi and Verma, 2009).

Aim

To synthesize gold (Au) nanoparticle using fungal mycelium.

Introduction

Biosynthesis of nanoparticles is a kind of bottom up approach where the main reaction occurring is reduction/oxidation. The fungal enzymes are usually responsible for reduction of metal compounds into their respective nanoparticles.

Aim

To synthesize phosphorus (P) nanoparticles from tricalcium phosphate using fungal mycelium.

Introduction

Green nanotechnology includes a range of processes that reduce or eliminate toxic substances to restore environment. Microorganisms like fungi and bacteria having naturally bestowed property of reducing and oxidizing nanoparticles, are used for synthesis.

Biological synthesis of Zinc Oxide (ZnO) nanoparticles

Aim

To synthesize nano ZnO particles using fungal isolates.

Introduction

The ZnO nanoparticle are effective anti-bacterial and antiodur agent. Biological synthesis of ZnO nanoparticle is a new approach for environmentally benign protocol in context to green nanotechnology, (Raliya and Tarafdar, 2013).

Polymer Clay Nanocomposites

Polymer clay nanocomposites has been used as to affect permeability of the maternal to gases and vapours. Majority of papers on nanocomposites have been focused on the use of smectitic type clays as nanoparticles. They are a group of swelling type of clay minerals including montmorilonite, nontronite, saponite, sauconite and hectorite.

A number of polymer-layered silicates (PLS) preparation methods has been reported in literature. The three most common methods to synthesize PLS nanocomposite are intercalation of suitable monomer and subsequent in situ polymerization, intercalation of polymer from solution and polymer melt intercalation.

In general, layered silicates have layer thickness on the order of 1 nm and a very high aspect ratio (e.g. 10–1000). A few weight percent of layered silicates that are properly dispersed throughout the polymer matrix thus create much higher surface area for polymer/filler interaction as compared to conventional composites. Depending on the strength of interfacial interactions between the polymer matrix and layered silicate (modified or not), three different types of PLS nanocomposites are thermodynamically achievable (Fig. 1 and 2 ) as outlined by Sinha Ray and Okamoto (2003). They are as follows: