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16 Cards in this Set
- Front
- Back
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Describe the chemical composition of a triglyceride
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Ester of glycerol and three fatty acids
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Outline the process of hydrogenation
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addition of hydrogen gas to a unsaturated fat.
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Name the catalyst used in hydrogenation
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finely divided Cu or Ni
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How does canning increase shelf life
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Excludes air/oxygen to prevent oxidation.
Prevent decomposition by microbes |
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State one function of sodium nitrite in food
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Preservative
Fixes color prevent growth of microbes |
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State the function of ascorbic acid or soidum ascorbate in food
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antioxidant
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Define a food
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Any substance whether process, semi processed or raw that is intended for human conusmption.
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Define a nutrient
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A substance obtained form food and used by the body to provide energy, regulate growth, maintenance and repair the body's tissues.
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List nutrients in order of increasing amounts needed for a balanced diet
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vitamin & minerals > fats > protein > carbohydrates
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Describe the chemical composition of carbohydrates
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Contain one C=O group and at least two -OH groups and have the empirical formula CH2O. Simplest are monosaccharides. They are the building blocks of disaccharides and polysaccharides.
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Name the type of browning and the conditions needed
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enzymatic browning
foods containing the enzyme polyphenoloxidase |
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What does this pyramid represent
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Relative amounts of nutrients needed for a healthy/balanced diet.
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What does this pyramid represent
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Relative amounts of nutrients needed for a healthy/balanced diet.
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How does the melting point of a fatty acid change with increasing saturation and why.
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Increases.
As number of carbon-carbon double bonds decreases the amount of kinking in the fatty acid chain decreases. The molecules can pack more closely and strength of van der Waals forces between them increases |
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Distinguish between a cis and trans carbon-carbon double bond.
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cis - hydrogen atoms of carbon-carbon double bond are on the same side.
trans - hydrogen atoms of the carbon-carbon double bond are on opposite sides. |
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Which geometric isomer, cis or trans fatty acids have the higher melting point.
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trans because the molecules are straighter and so can pack more closely together, increasing the strength of the van der Waals forces between the molecules, increasing the melting point.
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