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PPT720S - POSTHARVEST PHYSIOLOGY AND TECHNOLOGY - 2ND OPP - NOV 2024 |
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nAml Bl A un1ve RSITY
OF SCIEnCE Ano TECHn0LOGY
FACULTYOF HEALTH,NATURALRESOURCESAND APPLIEDSCIENCES
SCHOOLOF AGRICULTUREAND NATURALRESOURCESSCIENCES
DEPARTMENTOF AGRICULTURALSCIENCESAND AGRIBUSINESS
QUALIFICATIONS: BACHELOROF SCIENCEIN HORTICULTURE
LEVEL:7
QUALIFICATIONSCODE: 07BHOR
COURSECODE: PPT720S
DATE: JANUARY 2025
DURATION: 3 HOURS
COURSENAME: POSTHARVESTPHYSIOLOGYAND
TECHNOLOGY
PAPER:2
MARKS: 100
SECONDOPPORTUNITY/SUPPLEMENTARYEXAMINATION QUESTION PAPER
EXAMINER:
MS. PAULINA NDINELAGO NAUPU
MODERATOR: PROF.VICTOR NTULI
INSTRUCTIONS
1. Answer all the questions.
2. Write neatly and clearly.
3. Mark all answers clearly with their respective question numbers.
4. All written work MUST be done in blue or black ink.
5. No books, notes and other additional aids are allowed.
PERMISSIBLEMATERIALS
1. Calculator
2. Examination paper
3. Examination script
THIS QUESTION PAPERCONSISTSOF 4 PAGES
(ExcludingThis Front Page)
Postharvest Physiology and Technology (PPT720S)
2nd Opportunity November 2024
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Section A: Multiple choice questions
[15 marks]
Evaluate the statements below and select the most appropriate answer or phrase from the
given possibilities. Fill in the appropriate letter next to the number of the correct
statement/phrase on your ANSWERSHEET.
1. The art of preventing spoilage on the field before harvest is known as__ _
a) Pre-harvest Factor.
b) Storage.
c) Preservation.
d) Protection.
2. Which of the following pre-harvest factors affect the quality of fruits and vegetables?
a) Genetic/Variety.
b) Water/Irrigation/Rainfall.
c) Humidity.
d) All of the above.
3. The absorption of red light {625-700 nm) through phytochrome is essential for __
a) carbohydrates synthesis.
b) Vitamin synthesis.
c) Total soluble solids.
d) Enzyme synthesis.
4. Which of the following chemicals is commonly used as a growth retardant to improve
the quality and longevity of flower crops?
a) Benzyladenine.
b) lndole-3-acetic acid.
c) Gibberellic acid.
d) Daminozide.
5. For how many days are potato tubers typically held at 7°C - 10°C and 90% relative
humidity during the curing process?
a) 2-4 days.
b) 5-7 days.
c) 10-12 days.
d) 15-20 days.
6. Which of the following is known to improve the quality and longevity of flower crops
after harvesting?
a) Ethylene.
b) Auxins.
c) Gibberellins.
d) All of the above.
7. What is the primary purpose of the curing process in post-harvest handling of
potatoes, onions, and garlic?
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a) To increase moisture content.
b) To enhance storage life and quality.
c) To decrease skin thickness.
d) To lower storage temperature.
8. Degreening of fruits is typically carried out in special treatment rooms. What are the
key environmental conditions that are controlled in these rooms?
a) Light and oxygen levels.
b) Air pressure and ventilation.
c) Temperature and humidity.
d) Carbon dioxide and oxygen levels.
9. Which of the following is an indicator of physiological maturity in tomatoes?
a) The fruit changes color from light green to green.
b) The fruit changes color from green to red or yellow.
c) The fruit remains green.
d) The fruit grows in size and remains green.
10. Which instrument is commonly used to measure the firmness of fruits and vegetables
during harvest maturity testing?
a) Thermometer.
b) Penetrometer.
c) Hygrometer.
d) Refractometer.
11. Which vitamin is abundant in citrus fruits, strawberries, and bell peppers?
a) Vitamin D.
b) Vitamin K.
c) Vitamin E.
d) Vitamin C.
12. Which of the following standards is specifically designed to ensure a safe food supply
chain?
a) ISO 9001.
b) ISO 22000.
c) ISO 14001.
d) ISO45001.
13. Which of the following is an organic acid found in tomatoes and citrus fruits?
a) Malic acid.
b) Oxalic acid.
c) Citric acid.
d) Lactic acid.
14. What characterizes commodities with a low respiration rate?
a) High metabolic activity and longer shelf life.
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b) Low metabolic activity and longer shelf life.
c) High sensitivity to storage conditions.
d) Rapid spoilage.
15. Which type of anthocyanin is responsible for the red and purple colors in cherries and
plums?
a) Delphinidin.
b) Malvidin.
c) Cyanidin.
d) Pelargonidin.
Section B: True/False questions
[15 marks)
Evaluate the statements below and indicate whether the statement is true or false. Write the
word 'True' or 'False' next to the corresponding number on your ANSWERSHEET.
1. lndole-3-acetic acid is a plant hormone that has been reported to enhance the quality
and shelf life of flower crops.
2. Corn is considered physiologically mature when the kernels are soft, and the husks are
still green.
3. Benzyladenine is a chemical that acts as a growth regulator of flowers.
4. The typical concentration of ethylene applied in the degreening process of fruits is 20
ppm.
5. Nitrogen is typically used in the degreening process to induce the decomposition of
chlorophyll in fruits.
6. Physiological maturity in fruits and vegetables occurs when they have fully ripened and
are ready for consumption.
7. Pectinases, cellulases, and hemicellulases are enzymes that contribute to the softening
of fruits and vegetables.
8. Vitamin C is a fat-soluble vitamin.
9. Aroma is a reliable indicator of harvest maturity in the ripening of melons.
10. Vitamin A is found in carrots and sweet potatoes as Beta-carotene.
11. Oxalic acid is primarily found in tomatoes.
12. Nuts, grains, and dried fruits are examples of commodities with a low respiration rate.
13. Chalcone synthase and anthocyanidin synthase are enzymes involved in anthocyanin
synthesis.
14. The softening of fruits is generally considered undesirable for consumption.
15. Pectinases, cellulases, and hemicellulases are enzymes that contribute to the softening
of fruits and vegetables.
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Section C: short/long questions
[70 marks)
Please answer ALL the questions in this section.
Short questions
[35 marks]
1. What is the function of exocarp?
[2]
2. Describe the structure of the plant cell Wall.
[3]
3. Explain the three main layers of a coconut fruit. In your answer, include the layers
that are removed before they are sold and mention any alternative uses for the
removed layers. Use a labelled diagram to support your answer.
[9]
4. Explain the process of carotenoid synthesis during fruit ripening.
[12]
5. Describe the static grading method. In your answer, include how it works, and mention
one advantage and one disadvantage
[5]
6. Describe the Codex Alimentarius. In your answer, include its purpose, the
organizations involved, and its importance for food safety and trade.
[4]
Long questions
[35 marks]
1. As a post-harvest specialist, you are invited to consult a company facing huge losses
owing to microbial degradation of their fruits and vegetables during storage and
transportation. Based on the scenario provided, answer the following:
a) Citing examples of common spoilage microorganisms, describe the microbiological
spoilage of fruits and vegetables after harvest.
[23]
b) List and explain the strategies you would recommend to prevent microbial spoilage
of fruits and vegetables after harvest.
[12]
END OF QUESTIONPAPER
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