10 The energy value of food is usually measured ____________
calories. The number _______ calories one uses _______ any
one moment normally depends _______ the activity one does.
11 ________ the engineer, efficiency means output divided
______ input. His job is ______ secure a maximum output
_______ a given input or ________ secure given output
______ a minimum input.
12 Artificial Intelligence (AI) is the science________ developing
computers that can learn and follow instructions ________
great accuracy and speed. An example __________ AI is the
use _________ expert systems.
II Insert the articles ‘a’, ‘an’ and ‘the’ 4x1/2=2 U
13 Liquid samples assume the shape of its container ___ kinetic
theory explains this property by saying that there are no fixed
position for _____ molecules.____ molecules in the liquid are
free to slide over each other in order to occupy position of
____ lowest possible potential energy.
14 I spoke to one of ____flight attendants for ____ while. Then I
managed to fall asleep for about _______ hour.
After I woke up, I ordered for _______.
15 Just imagine _____ biology teacher explaining _____
respiratory system or just _______ body part like _______
larynx, to the class.
16 ________ National green Tribuanl (NGT) has directed
_________ UP Pollution Control Board to identify and
install sewage treatment plants at major sources of pollution
in _______ Kali river,_____ tributary of the Ganga.
17 In ____urban concrete jungle, to be ____ urban farmer,
people are interested in setting up terrace
gardens.______ ―green conscious movement‖ is ______
initiative by environmentalists.
18 Sherlock Holmes is _____ fictional private detective created
by Arthur Conan Doyle. Though not ___ only private
detective, he is arguably ________ most well-known of all
detectives. He is widely considered _______ icon in Britain.
19 It is true that his error amounted to less than one tenth of ___
percent, in ____ total, but it was _____error all _____same.
20 Idleness is ____great vice and _____ great danger. It is ____
father of all sins. _____idle man turns his attention to sins.
21 There was ____ easy question at ____ beginning of paper.
But there was ____ difficult one at ____ end of the paper
some questions very easy.
22 ____Ganges is ____ longest river in India. It originates at
____ place called Gangotri. Banaras ____ancient town, is
Answers
CHAPTER 3: CALCULATION OF THE ENERGY CONTENT OF FOODS - ENERGY CONVERSION FACTORS
As stated in Chapter 1, the translation of human energy requirements into recommended intakes of food and the assessment of how well the available food supplies or diets of populations (or even of individuals) satisfy these requirements require knowledge of the amounts of available energy in individual foods. Determining the energy content of foods depends on the following: 1) the components of food that provide energy (protein, fat, carbohydrate, alcohol, polyols, organic acids and novel compounds) should be determined by appropriate analytical methods; 2) the quantity of each individual component must be converted to food energy using a generally accepted factor that expresses the amount of available energy per unit of weight; and 3) the food energies of all components must be added together to represent the nutritional energy value of the food for humans. The energy conversion factors and the models currently used assume that each component of a food has an energy factor that is fixed and that does not vary according to the proportions of other components in the food or diet.
3.1 JOULES AND CALORIES
The unit of energy in the International System of Units (SI)[8] is the joule (J). A joule is the energy expended when 1 kg is moved 1 m by a force of 1 Newton. This is the accepted standard unit of energy used in human energetics and it should also be used for the expression of energy in foods. Because nutritionists and food scientists are concerned with large amounts of energy, they generally use kiloJoules (kJ = 103 J) or megaJoules (MJ = 106 J). For many decades, food energy has been expressed in calories, which is not a coherent unit of thermochemical energy. Despite the recommendation of more than 30 years ago to use only joules, many scientists, non-scientists and consumers still find it difficult to abandon the use of calories. This is evident in that both joules (kJ) and calories (kcal) are used side by side in most regulatory frameworks, e.g. Codex Alimentarius (1991). Thus, while the use of joules alone is recommended by international convention, values for food energy in the following sections are given in both joules and calories, with kilojoules given first and kilocalories second, within parenthesis and in a different font (Arial 9). In tables, values for kilocalories are given in italic type. The conversion factors for joules and calories are: 1 kJ = 0.239 kcal; and 1 kcal = 4.184 kJ.
3.2 THEORETICAL FRAMEWORK FOR AN UNDERSTANDING OF FOOD ENERGY CONVERSION FACTORS
As described in detail in the report of the most recent Expert Consultation on Energy in Human Nutrition (FAO, 2004), humans need food energy to cover the basal metabolic rate; the metabolic response to food; the energy cost of physical activities; and accretion of new tissue during growth and pregnancy, as well as the production of milk during lactation. “Energy balance is achieved when input (or dietary energy intake) is equal to output (or energy expenditure), plus the energy cost of growth in childhood and pregnancy, or the energy cost to produce milk during lactation” (FAO, 2004).
The total combustible energy content (or theoretical maximum energy content) of a food can be measured using bomb calorimetry. Not all combustible energy is available to the human for maintaining energy balance (constant weight) and meeting the needs of growth, pregnancy and lactation. First, foods are not completely digested and absorbed, and consequently food energy is lost in the faeces. The degree of incomplete absorption is a function of the food itself (its matrix and the amounts and types of protein, fat and carbohydrate), how the food has been prepared, and - in some instances (e.g. infancy, illness) - the physiological state of the individual consuming the food. Second, compounds derived from incomplete catabolism of protein are lost in the urine. Third, the capture of energy (conversion to adenosine triphosphate [ATP]) from food is less than completely efficient in intermediary metabolism (Flatt and Tremblay, 1997). Conceptually, food energy conversion factors should reflect the amount of energy in food components (protein, fat, carbohydrate, alcohol, novel compounds, polyols and organic acids) that can ultimately be utilized by the human organism, thereby representing the input factor in the energy balance equation.
(see Figure 3.1).