NATS 1560 (test 1) Questions and Answers 100% Verified

NATS 1560 (test 1) Questions and Answers 100% Verified Food science •scientific and technological research on the properties of food substances, aimed at inventing new food products and new methods of preservation and processing Nutrition science the scientific study of the processes through which food provides nourishment to the body what are the general characteristics of the modern sciences? materialism, reductionism & experimentalism What are macronutrients? carbohydrates, lipids, proteins what are micronutrients? vitamins and minerals Atomic theory •all material substances are constituted of atoms Element •substance composed only of atoms of the same species Compound A substance made up of atoms of two or more different elements joined by chemical bonds Mixture •can be separated and purified into simpler substances by physical means Chemical formula •symbolic expression representing the chemical composition of a molecule, (i.e. the species and numbers of atoms composing it) Chemical reaction re-arrangement of the atoms of the reactants into new molecules (products) catalyst is a substance that facilitates the reaction but is not changed by the reaction Molecular structure arrangement of atoms in a molecule in 3d space Structural formulas 2d representations of molecular structure Isomers molecules having the same chemical composition but different structures Functional groups recurring groups of atoms that determine the reactivity of organic molecules What are the "macromolecules of life"? •Carbohydrates •Lipids •Proteins •DNA Macronutrient distribution (for adults 19 & over) -carbohydrates 45-65% -proteins 10-35% -fat 20-35% ADMR (Acceptable Macronutrient Distribution Ranges) -the percentage range for macronutrients intakes that is associated with reduced risk of chronic disease while providing adequate intakes of essential nutrients our body needs food for? −molecules, needed for the growth and repair of organs and tissues −energy, needed for all physiological processes kilocalorie •amount of energy required to raise the temperature of 1 kg of water 1°C at standard atmospheric pressure Metabolizable energy of a food =energy in the food - energy losses due to incomplete digestion and excretion Campylobacter bacteria •Clostridium perfringens •Clostridium botulinum bacteria Listeria monocytogenes bacteria Mycobacterium tuberculosis bacteria functions of fat in the body •Concentrated source of energy •Energy storage •Storage and transport of fat-soluble vitamins •Sources of essential fatty acids (needed for cell membranes, body tissues and bones, immune system, and more) •Body insulation •Protection of inner organs •Palatability of food and satiety Hydrogenation The process of converting unsaturated fats to saturated fats by adding hydrogen trans fat - the hydrogens attached to the carbon atoms are on either side of the double bond - side effect of partial hydrogenation Lipolytic rancidity -microbes produce an enzyme (lipase) that breaks triglycerides into short fatty acids -characteristic flavours of butter and cheese Oxidative rancidity -unsaturated fatty acids become oxidized -release of free radicals, which damage cells, proteins, and DNA, and may cause aging and diseases -rancid smell and taste PBDEs fire retardants PCBs industrial & agricultural pollutants PAHs smoked & charred food BPA hard plastic PFOA found in nonstick surface or pans diabetes type 1 pancreas produces too little insulin diabetes type 2 insulin receptors in cells do not function normally what happens when blood glucose drops? glucagon signals the liver to start breaking down glycogen, fat and proteins basal metabolism minimal expenditure of energy needed by the body to stay alive vitamins organic compounds produced by plants and animals minerals -Nutrients that occur naturally in rocks and soil -elements absorbed from the soil by plants, from plants by animals Food preservation processing of food to delay and minimize spoilage Variables that favour spoilage moisture, temperature, acidity, exposure to oxygen what does sugar do? reduces the moisture available for microbial life quick pickling •Soaking in a vinegar solution •Flavoured with sugar, garlic, spices fermentation or curing •Fruits, vegetables, or meats are salted or brined •Then sealed in a container or otherwise left to the action of beneficial bacteria and yeasts •Development of lactic acid and aromatic compounds (complex flavours and textures) canning Food is placed in airtight containers and sterilized with high heat What does refrigeration do? Cold preserves food by slowing down microbial growth and enzymatic action Pasturization Heat treatment to kill microbes and de-activate enzymes while Irradiation •It damages the DNA •kill microbes and pests •To delay ripening and sprouting types of heat transfer conduction, convection, radiation conduction -The direct transfer of heat from one substance to another substance that it is touching -no movement of bulk matter convection The transfer of heat by the movement of a fluid Maillard reactions sugar combines with protein to form brown molecules caramelization the chemical browning reaction that can occur when a sugar is heated; characteristic color and flavor develops how does cooking affect the nutrition of food? •It makes more calories available to be absorbed and metabolized Ergot (sclerotia) mycotoxin Hepatitis A virus Roundworms (e.g., Trichinella spiralis) parasites Giardia lamblia parasites Entamoeba histolytica parasites