Unit 5 - flashcard review questions PDF

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TRUE OR FALSE: Lipids are organic compounds soluble in organic solvents but not in water True The Role of Fats in foods -Provide essential nutrients (e.g., essential fatty acids, fat soluble vitamins) -Provide concentrated source of energy & raw materials for making needed products -Provide taste, smell and texture to foods -Stimulate appetite and contribute to feelings of fullness -Can be used for heat transfer without burning food during heat transfer Classification of lipids: There are 3 major groups of fats and oils: Triacylglycerols (triglycerides) Phospholipids Sterols Triglycerides Major form of fat found in foods and in our body. They are made up of 3 fatty acids and a glycerol backbone. 1 point of unsaturation = monounsaturated fatty acid (MUFA) 2 or more points unsaturation = polyunsaturated fatty acid (PUFA) 0 points of unsaturation = saturated fatty acid Most vegetable and fish oils are rich in.... PUFAs; some (e.g., canola oil and olive oil) are also rich in MUFAs. Butyric acid found in butter has 4 carbon atoms, single bonds and is saturated. Stearic acid found in beef has 18 carbon atoms, single bonds and is saturated. Palmitic acid found in palm oil and cocoa butter has 16 atoms, single bonds and is saturated. Oleic acid found in olive oil and canola oil has 18 carbon atoms, one double bond and is unsaturated (monounsaturated). Linoleic acid has 18 carbon atoms and 2 double bonds. It is found in most foods especially oilseeds such as canola and soybean. Linolenic acid has 18 carbon atoms but contains 3 double bonds and is found mostly in soybean and hempseed. TRUE OR FALSE: Trans fatty acids have a higher melting point than the cis fatty acids. True Hydrogenation

Hydrogenation is a process where hydrogen is added to unsaturated fatty acids (e.g., turning vegetable oil into hard margarine).This makes the fatty acid more solid at room temperature and increase the shelf life. Phospholipids Phospholipids are similar to triglycerides, however they have only 2 fatty acids attached to the glycerol backbone and 1 phosphorus molecule. Sterols Sterols are large molecules consisting of interconnecting rings of carbon atoms, with side chains of carbon, hydrogen and oxygen. Winterization of fats A process to produce salad oils that do not crystallize (i.e., become cloudy) at refrigerator temperatures. What are the two types of rancidity? Oxidative rancidity and Hydrolytic rancidity Define Oxidative rancidity Occurs primarily with the unsaturated fatty acid portions of triglycerides. Define Hydrolytic rancidity Hydrolysis involves breaking of chemical bonds due to the addition of water and enzyme activity. What are Fat Replacers Fat replacers are ingredients that replace some or all of the functions of fat and may or may not provide energy. What are Artificial fats Zero-energy fat replacers that are chemically synthesized to mimic the sensory and cooking qualities of naturally occurring fats, but are totally or partially resistant to digestion. Define Omega-6 (n-6) Fatty Acids Omega-6 fatty acids get their name because of a double carbon bond 6 carbons from the end of its chain. Linoleic acid is an example of an omega-6 fatty acid. DRI recommendation: 5-10% energy from n-6 fatty acids Sources: vegetable oils, seeds, nuts, whole grain products Define Omega-3 (n-3) Fatty Acids Omega-3 fatty acids get their name because of a double carbon bond 3 carbons from the end of its chain. Linolenic acid is an example of an omega-3 fatty acid. DRI recommendation: 0.6-1.2% energy from n-3 fatty acids Sources: flaxseed, flaxseed oil, canola oil, fish (especially deep sea fish) What are the three main types of omega-3 fatty acids? ALA (alphalinolenic acid) - from plant sources EPA (eicosapentaenoic acid) - from fish sources DHA (docosahexaenoic acid) - from fish sources Proteins are compounds made up of..... carbon, hydrogen, oxygen and nitrogen

Define Caramelization A series of chemical reactions occur when sugars are heated to temperatures greater than their melting point. Maillard reaction Reaction between the carbonyl group (CO) of carbohydrates and amine group (NH2) of an amino acid or protein at high temperatures. What are the Varieties of milk Cultured (fermented) milk,Evaporated milk, Ultra high temperature (UHT) milk, Skim milk powder What are the Functional characteristics of eggs? Emulsification: lipoproteins and phospholipids present in the egg yolk help to keep fat dispersed in water. Used in products such as mayonnaise, salad dressings, sauces (like hollandaise and béarnaise), ice cream and some cakes. Foaming: proteins in the egg white have a high capacity to form strong protein films that surrounds air bubbles to produce stable foams. The foams can become six to eight times the original volume. Used in foods such as soufflés, fluffy omelets, meringues and some cakes (e.g., angel food). Coagulation: egg white proteins can set and form a gel during heating. They can help to bind food mixtures together, such as meat loaf, meat patties and manicotti. Plant proteins can be divided into four broad groups based on solubility properties: Albumins-soluble in water. Globulins-soluble in salt solutions but insoluble in water. Gliadins-soluble in 70-90% alcohol. Glutelins-insoluble in neutral aqueous solutions, saline solutions or alcohol. Can only be solubilized by dilute alkaline solution. vitamins are divided into: Fat-soluble: vitamins A, D, E and K. Water-soluble: vitamin C and the 8 B vitamins: thiamin, riboflavin, niacin, pantothenic acid, folate, biotin, B6 and B12....