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FCH621S-FOOD CHEMISTRY-JAN 2020 |
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p
NAMIBIA UNIVERSITY
OF SCIENCE AND TECHNOLOGY
Faculty of Health and Applied sciences
Department of Health Sciences
QUALIFICATION: BACHELOR OF HUMAN NUTRITION
QUALIFICATION CODE: O8BOHN
LEVEL: 6
COURSE CODE: FCH 6215S
COURSE NAME: FOOD CHEMISTRY
SESSION: JANUARY 2020
PAPER: THEORY
DURATION: 3 HOURS
MARKS: 100
SUPPLEMENTARY/SECOND OPPORTUNITY EXAMINATION QUESTION PAPER
EXAMINER(S) | Mr. Waliomuzibu Mukisa George William
MOoperaToR: | Dr. Adam Flowers
INSTRUCTIONS
1. Answer ALL the questions.
2. Write clearly and neatly.
3. Number the answers clearly.
PERMISSIBLE MATERIALS
NONE
THIS QUESTION PAPER CONSISTS OF 6 PAGES (Including this front page)
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QUESTION 1
SECTIONA
(20 MARKS)
Select the most appropriate answer from the options provided. (Each correct answer earns
1 mark)
1.1 Caramelisation is the same as Maillard reaction:
a. True
b. False
1.2 Cellulose can be digested in the human body because the f-linkages can be broken
down by digestive enzymes:
a. True
b. False
1.3 Vitamin B5 is also known as Biotin:
a. False
b. True
1.4 A food emulsifier molecule usually contains............... in its molecular structure:
a. Atleast one hydrophobic moiety and one lipophilic moiety
b. Two lipophilic moieties
c. Atleast one lipophilic moiety and one hydrophilic moiety
d. Two hydrophilic moieties
L.5 Lactose in milk is a ...............
a. Oligassacharide
b. Homo disaccharide
c. Disaccharide
d. Monosaccharide
1.6 Amylose is has more branched chains than amylopectin:
a. True
b. False
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L7 Which of the following minerals when taken in excess results into hair loss and
fragile nails:
a. lodine
b. Iron
c. Selenium
d. Zinc
1.8 Which of the following terms is used to refer to enantiomeric pair of carbon
compounds, which rotates a plane of polarized light in a clockwise direction:
a. Levorotatory
b. Epilevorotatory
c. Dextrorotatory
d. aandc
1.9 Which of the following sugars is a non reducing sugar:
a. Lactose
b. Maltose
c. Sucrose
d. Galactose
1.10 Which of the following is the product of oxidation of glucose molecule at the
carbonyl carbon atom:
a. Uronic acid
b. Saccharic acid
c. Aldonic acid
d.bandc
4.11 The following are key steps in the maillard reaction except:
a. Amodori rearrangement
b. Formation of N-glucosamine
c. Integration of Amodori products
d.aandb
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1.12 Acrylamide are carcinogenic compounds formed during food processing a reaction
a. Sugars only
b. Reducing sugars and L- asparagine
c. Reducing sugars and D-asparagine
d.bandc
LiLo Which of the following types of starch contributes to gel formation during starch
processing:
a. Amylose
b. Amylopectin
c. Homopolysaccharide
d. AandC
1.14 Elevated deficiency of Vitamin A leads to............ :
a. Squamous metaplasia
b. Xeroftalmia
c. Teratogenia
d.aandc
1.15 Which of the following vitamins is best absorbed in presence of lipids:
a. Vitamin B1
b. Riboflavin
c. Cobalamin
d. None of the above
1.16 Iron is an integral to the formation of haemoglobin and myoglobin:
a. True
b. False
1.17 Hydrolysis of starch and glycogen yield glucose:
a. True
b. False
1.18 Carbohydrate are polyhydroxy aldehyde or ketones:
a. True
b. False
1.19 Lactose intolerance in humans is due to the absence of lactase enzyme:
a. True
b. False
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1.20 Heteropolysaccharides on hydrolysis yield a single type of monosaccharides and
derivatives:
a. True
b. False
SECTIONB
QUESTION 2
Zed Explain the following terms as they relate to caramelisation.
2.1.1 Caustic caramel.
2.1.2 Caustic sulfite caramel.
2.1.3. Ammonium caramel.
2.1.4 Sulfite ammonium caramel.
(49 MARKS)
2.2 Explain the health complications associated with consumption of trans-fatty acids.
2.3 Explain four (4) chemical reactions that result into deterioration of fat.
2.4
Explain three (3) reasons for fat hardening.
2.5 Explain the primary and secondary structure of proteins.
2.6 Explain the meaning of the following terms as they apply to chemistry of
carbohydrates
2.6.1 Gelatinisation.
(2)
2.6.2 Position isomer.
(2)
2.6.3. Functional isomer.
(2)
2.6.4 Maillard browning.
(2)
2.6.5 Geometric isomer.
(2)
2.6.6 Chain isomer.
(2)
2.6.7 Acrylamide.
2.7 Outline five (5) factors that are important in lipid oxidation.
(5)
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QUESTION 3
a1 Explain why an apple when cut and exposed to air turns to brown.
(31 MARKS)
(4)
3.2 Explain four (3) ways of controlling enzymatic browning.
(6)
3.3 Explain digestibility and levels of essential amino acids in relation to protein
Quality of a given food.
(2)
3.4 Explain the chemical method for determining the nutritive value of protein.
(6)
3.5 Outline two (2) advantages and three (3) disadvantages of chemical method
inthe determination of protein quality.
(5)
3.6 Explain the four (4) types of caramelisation colors that important in
the food industry.
(8)
GOOD LUCK