eChapters

Physicochemical parameters of meat
1. Moisture, ash and fat content
• Meat samples are dried at 105 °C for 24 h for determining the moisture content and for ash content analysis, samples are burned at 525 °C
• Fat determination is done by acidic hydrolysis of the sample
• Sample is boiled initially and then cooled and later, it is filtered, washed and dried
• Thereafter, petroleum ether is used to extract the fat
• Ether is evaporated and the remnant is dried and weighed
2. Protein content
• Often, protein in meat sample is estimated using Kjeldahl method
• The protein content is determined by multiplying the nitrogen content in the meat sample by an appropriate conversion factor
• Strong acid is used to digest the meat sample and the released nitrogen is measured by proper titration technique
• Then, the protein quantity of the sample is determined from the nitrogen concentration of the meat
• Kjeldahl method does not determine the protein content in straightway manner; a conversion factor (F) is required to convert the nitrogen content to protein content
• Usually, a conversion factor of 6.25 (corresponding to 0.16 g nitrogen/g of protein) is used for several food samples

Soil texture and mechanical analysis: The chemistry of the mineral framework was explained in Chapter II. Its physical properties are quite as important- When all the extraneous matter is removed from the soil we are left with a collection of particles of various sizes. These particles are not spherical in shape, but most of them are nearly so. At any rate the discussion is very much simplified if we suppose that they are spherical and the arguments advanced are equally applicable if the shape deviates from the spherical.

Ultrasound is important tool for diagnosis and research that can be compared with other tools like radio-immunoassays. This has become an important tool applicable to farm and pet animals. Ultrasound uses high-frequency sound waves to produce images of soft tissues and internal organs. Electric current is applied to crystals in the transducer, producing vibrations characteristic of the crystals and resulting in sound waves. The sound beams that pass through the tissues are quite thin and a thin “slice” of tissue is sampled. The two dimensional image produced by ultrasound resemble to histological section. The sound waves are propagated or reflected by various tissues in different ways depending on their thickness and composition. The transducer receives those reflections and converts into electric signals and produces an echo on the ultrasound screen. Grey - scale is the term used for monochrome monitors on which a number of grey shades are distinguishable between black and white and constitute the image of reflected portion of tissue. Non-ecogenic (non echoic) tissues like fluids do not reflect sound waves and appear black on the screen. The echogenic tissues, having dense consistency, appear white as they reflect most portion of sound beam. Sometimes the artifacts create problem in the real image of the organ. These artifacts are created by certain tissues that cause bending or back and forth bouncing or blocking of sound beams. For imaging the reproductive tract of the domestic animals, B-mode (brightness modality), real time scanners are used. The amplitude of returning beams is reflected in the brightness of the dots on the screen. B-mode modulates brightness of the dots or pixels on the screen of echo displayer. The echo signals are presented as brightness of pixel corresponding to the amplitude of signal. The picture should be adjusted for clear display. In B-mode display the time-base brightness should be reduced just below the threshold of visibility so that even the smallest echoes could be visible.

The physio-chemical properties of ice cream strongly influence its processing behaviour, texture, stability, and consumer acceptance. This chapter examines ice cream as a complex multiphase system and discusses important properties including overrun, density, viscosity, freezing behaviour, hardness, scoopability, meltdown, and fat destabilization. It explains how formulation and processing conditions influence these properties and how they relate to sensory quality. The chapter also considers quality-control tests used in industrial ice cream plants and identifies defects associated with physio-chemical imbalance. Understanding these relationships enables manufacturers to establish suitable product targets, diagnose quality problems, optimize formulations, and maintain consistency across different ice cream products.

Introduction

Drought is the most important abiotic factor that adversely affect growth and crop production. Drought stress can altered the normal physiological processes that influence one or a combination of biological factors for yield and yield attributing traits (Ashraf, 2010). The abnormal metabolism due to stress may reduce plant growth (Claves et al., 2002). Production is limited by environmental stresses, according to different scholar estimates, only 10 per cent of the world’s arable land is free from stress, in general, a major factor in the difference between yield and potential performance, environmental stresses. Drought is one of the most common environmental stresses that almost 25 per cent of agricultural lands for agricultural farm products in the world are limited (Loresto, 1976; Chaves, 2002). Drought occurrence in India is also very frequent. Drought occurred in past 1967, 1968, 1969, 1972, 1974, 1979, 1987, 2002, 2009 and had considerable impact on food grain production. For example, the drought of 1966-67 reduced overall food grains production by 19%. The drought of 1972-73 reduced the food grains production from 108.95 million tonnes to 95 million tonnes, causing a loss of about $ 400 million $. The 1987 drought in India damaged 58.6 million ha of cropped area affecting 285 million people (Ray et al., 2015). Drought in 2002 has reduced food grains production to 174 million tonnes from 212 million tonnes resulting in decline of 3.2% GDP (Rathore et al., 2009; Ray et al., 2015).

The water deficit reduces crop yield due to decrease in photosynthetic area, decreased radiation use efficiency and harvest index (Earl and Davis, 2003). Drought stress affect the water balance and plant metabolisms. Plants under drought conditions use various changes to tolerate stress conditions and increase drought tolerance which includes changes in whole plant, tissue, at physiological and molecular levels. Appearance of a single or a combination of inherent changes determines the ability of the plant to stand under aridity conditions. Tolerant plant adjusts its water balance by osmotic adjustment, deep root systems and by transient leaf rolling.

The seed yield, along with the rate of application and uptake of nutrients, is used to determine the following parameters for nitrogen or other nutrients:

Partial Factor Productivity (PFP) (kg seed/kg N applied): Partial Factor Productivity (PFP) is a measure used in agriculture to assess the efficiency of nutrient use, particularly nitrogen or other essential nutrients, in crop production. It is calculated as the ratio of the seed yield to the rate of nutrient application. The formula for PFP is:

*A higher PFP value indicates greater efficiency, meaning that more crop yield is produced per unit of nutrient applied. This is desirable as it implies that the nutrient is being used more effectively by the crop.

Agronomic Efficiency (AE) (kg seed/kg N applied): Agronomic Efficiency is a measure used to evaluate the effectiveness of nutrient application in increasing crop yield. It specifically assesses the yield gain per unit of nutrient applied. The formula for AE is:

Plants are frequently subjected to environmental stresses such as water deficit, freezing, heat and salt stress. Soil salinity is a major problem in arid and semi- arid regions, where rainfall is insufficient to leach salt and excess of sodium ion down and out of root zone. In Asia, around 21.5 million ha of cultivable land was affected by salinity. India had 8.6 million ha of salinity affected cultivable land. It is observed that the area of salinity has been increasing in India. In Tamil Nadu, the area affected by salinity is around 6 lakh ha. Salinity affected areas are Chengalpattu, Salem, Thanjavur, Trichy, Tirunelveli, Dharmapuri and Ramanathapuram. Salinity is the most serious threats to the agriculture especially in the arid and semi-arid region. The presence of salts in the soil and their effects on the plant physiological mechanisms was major restrictive factor for agricultural productivity. Investigations on such soils have revealed that they were charged with high and abnormal soluble salt concentrations that lowered agricultural yield, limited crop distribution and even lead to extinction of certain species.

Salinity adversely affects plant growth and development, hindering seed germination, seedling growth, enzyme activity, DNA, RNA, protein synthesis and mitosis. There has been a variation in the response of plants to salinity with its growth stages according to quantity and period of exposure to salt. Salinity by competing in nutrition element absorption causes growth reduction. Primary salt injuries include metabolic disturbance and inhibition of growth and development. Secondary salt effects include nutrient deficiency and osmotic dehydration. Excessive amounts of salts, especially sodium chloride (NaCl), in the soil induce osmotic effects, leading to changes in plant metabolism. General symptoms of damage by salt stress are growth inhibition, accelerated development and senescence and death during prolonged exposure. Salt stress causes the reduction of rice yield and severe salt stress may even threaten survival.

Introduction

Phenolic compounds have been shown to be of importance in regulation of plant growth, development and metabolism, therefore now they are not considered as passive by products of any catabolic or anabolic processes. Salicylic acid is one of them and it is a naturally occurring phenolic which has received much attention due to its association with economically important plant responses to disease and other stresses (Raskin, 1992; Borsani et al., 2001; Clarke et al., 2004). Centuries before medical scientists had identified numerous therapeutic effects of salicylates. Leaves and barks of willow tree were used by women as a pain reliever during child birth in 4th century B.C. It also cured aches and fevers. Due to a number of curative properties of willow bark, in 1828 Jahann Buchner, a scientist from Munich had isolated a small amount of silicin - a salicylic alcohol glucoside, the major salicylate in willow bark. In 1838, Rafaela Piria had given the name salicylic acid (SA), from the Latin salix, a willow tree. Further during 19th century SA and other salicylates, mainly methyl esters and glucosides easily convert to SA, isolated from a number of plants. Salicylic acid has an aromatic ring which bears a hydroxyl group or its functional derivative (Fig. 1).

INTRODUCTION

Iron in the terrain’s crust is more oxidized now than it was when life evolved. It has been hypothesized that dissolved ferrous iron could have been a convenient oxygen acceptor and that deposition of oxidized iron in sediments must have taken place before oxygen could have entered the atmosphere in significant quantities. Obviously, during early evolution on this planet, the essential elements are present only in reduced form. Today a number of elements are present only in a highly oxidized form and considerable energy must be expanded to reduce them to a form similar to that on early earth which plants can utilize.

Iron represents essential elements which are usually available in oxidized form but must be reduced, often using metabolic energy, before they can be utilized. For the first time, Gris (1844) observed yellowing of grapevine leaves in absence of iron in the nutrient solution in which these plants were growing. Later, iron was reported to be essential for diverse group of plants. Due to a great variation in iron requirement by different plant species, it is difficult to decide whether iron is a macro or micronutrient.

Abstract

Nitrate uptake from the soil is the first step in nitrate acquisition and utilization by plants. Nitrate uptake and its release into cells is mediated by nitrate transporter(s) located into the plasma membrane of the root. Three transporters have been identified by kinetic measurements in plant roots. These are constitutive high affinity nitrate transporter (cHATS), inducible high affinity nitrate transporter (iHATS) and low affinity nitrate transporter (LATS). Two of these display saturable kinetics; a low capacity constitutive system and a high capacity inducible system. In addition, a non-saturating low affinity, high capacity system becomes apparent only at higher external NO^-₃ concentration. Genes that encode representatives of each class of transport system have been identified and fall into two families: NRT1 and NRT2. Members of these families are induced in response to nitrate in the environment and are regulated by internal signals including nitrogen metabolites and shoot demand for nitrogen. This chapter deals with the physiology and molecular biology of nitrate transporters in higher plants.

Through green revolution, we have developed high yielding varieties albeit with high nutrient requirements putting much more reliance on chemical fertilizers. The major challenge facing plant biology right now is to improve crop production and to feed an expanding world population. This is against a background of pressure on agricultural land use and climate change having negative impacts on growing conditions. The adverse effects of agriculture, and specifically fertilizer use, include damage to the environment, a large carbon footprint for the manufacture and use of agrochemicals, and the utilization of non-renewable resources. One solution is to increase the area of land for agriculture, as well as increasing production while maintaining the current rate of inputs; however, this is predicted to have substantial negative impacts on the environment (Tilman et al., 2002), is unsustainable in terms of phosphate use, and would have a huge economic footprint in terms of energy demands for nitrogenous fertilizer production. The challenge is to increase yield, decrease inputs, and improve resistance to abiotic and biotic stresses. Improving crop nutrient use efficiency ideally requires an understanding of the whole system, from the macro (agro-ecosystem) to the molecular level.

Fruits, the vivid and delightful offerings of the nature, undergo remarkable transformations as they travel from the orchard to our dining tables. These changes indicate the significance of post-harvest physiology, which is the scientific study that reveals the secrets of how fruits behave after they are picked, including the mechanisms that affect fruit quality and how long it may be stored. The next section provides definitions of the various stages and key players involved in the processes of fruit maturity, ripening, and post harvest physiology. These topics will be further explored in the subsequent sub-sections of this chapter.

Fruit developmental physiology

The life cycle of horticultural commodities (fruits and vegetables) can be effectively categorized into three primary physiological stages after fruit set or initiation, namely growth, maturation, and senescence. Still, a lack of obvious differentiation exists among the several stages. Growth encompasses the process of cell division followed by cell enlargement, which determines the ultimate size of the product. Maturation typically begins prior to the cessation of growth and involves various activities across different commodities. The stages of growth and maturity are commonly denoted as the developmental phase. Senescence can be described as the phase in which anabolic biochemical processes transition into catabolic processes, resulting in the ageing and eventual demise of the tissue. Ripening, a term specifically used for fruit, is typically regarded as the initial phase of senescence that occurs during the later phases of development. Defining the transition from growth to senescence is rather straightforward.

Physiological disorders refer to non-parasitic or inanimate disease of fruit crops, or it is the breakdown of tissue that is not caused by either invasion by pathogens or by mechanical damage. They may develop in response to an adverse environment, especially temperature or to a nutritional deficiency during growth and development. Physiological disorder is broadly classified into two broad categories. They are:

Aonla

1. Fruit necrosis

• Fruit necrosis is especially a problem in ‘Francis’
• Boron deficiency / Borax at 0.6%, September-October.

2. Fruit drop

i) First wave: 70% lack of pollination

ii) Second wave: Dormancy break

iii) Third-wave:

Dry spell, number of developing fruits. Imbalance of hormones and improper nutrition.

Fluctuation in temperature, variety and age of the tree.

Apple

1. Scald

4.1. Physiological disorders in field crops

Identification of physiological disorders in agricultural crops

Leaves in the centres appear bleached and may have brown edges. Shade should be provided to reduce the light level to 1800-2500-foot candles to control this problem.

Internal necrosis has been observed in Aonla (Emblica officinalis Gaertn.) fruits. Francis cultivar, preceded by Banarsi, is highly susceptible. The symptoms begin with browning of the inner majority of the mesocarpic tissue in the 2nd or 3rd week of September at the time of endocarp hardening, which later spreads to the epicarp, resulting in brownish black flesh appearance. Internal fruit necrosis is associated with boron deficiency during the fruit development.

In the flesh of the fruit, tiny, 2-10 mm (depending on the cultivar) brown blemishes form. Below the surface, the tissue gets black and corky. At harvest or after cold storage, the skin develops depressed patches on the surface. These tend to develop as water-soaked patches on the skin around the calyx. Overall, these patches became darker and sunken than the skin around and developed entirely after one to two months in storage.

Smaller leaves are produced and finally a rosette is formed. Internodal length reduction and apex-tapering of the stem. Most of the nuts are tiny and deformed, assuming they are produced. Drainage is poor and soil and pan/hard clay pan fertility are low.

Fruit cracking is an important physiological disorder found in some commercial cultivars of Bael (Aegle marmelos), which occurs just before the ripening stage. It is correlated with abrupt changes, such as temperature and humidity, in weather conditions. Heavy irrigation or precipitation is also one of the causes of this disease after prolonged drought.