HOS 5085 - PRINCIPLES OF POSTHARVEST HORTICULTURE
Instructor:
Dr. Jeffrey K. Brecht
1217 Fifield Hall
392-1928 x213
jkb@ifas.ufl.edu
Format: Two 1-hour lectures and one 2-hour laboratory per week for 3 credits. Offered bi-annually, fall semester, even years. Prerequisites are BOT 3503 and BCH 3023 or equivalent.
Description: Biological principles involved in harvesting, grading, packaging, transportation, and marketing horticultural crops, and their effects on quality maintenance.
Objectives: 1. To develop an appreciation for the factors related to quality deterioration and wastage of horticultural commodities after harvest. These factors include physiological, biochemical and pathological considerations, as well as compositional and physical changes occurring during maturation and deterioration. 2. To develop an understanding of commercial procedures of harvesting, preparation, packaging, transportation, and storage in relation to biological principles and individual commodity requirements and responses.
Evaluation: Participation in discussions and lab exercises is expected.
Points
Midterm 1 = 100
Midterm 2 = 100
Final exam = 200
Lab reports = 100
TOTAL = 500
Grading scale
A = 450-500
B+ = 430-449
B = 400-429
C+ = 380-399
C = 350-379
D+ = 330-349
D = 300-329
E = 299-below
Text:
Required
Postharvest physiology of perishable plant products. 1991. S.J. Kays (Van Nostrand
Reinhold).
Suggested
Postharvest technology of horticultural crops. 1989. A.A. Kader, et al. (Coop. Ext.
Univ. of Calif. Div. Nat. Res.).
Additional reading assignments will place emphasis on:
Posharvest physiology of food crops. 1982. W.G. Burton (Longman).
Handling, transportion and storage of fruits and vegetables. Vol. I, 1979. A.L. Ryall and
W.J. Lipton; Vol. II, 1982. A.L. Ryall and W.T. Pentzer (Van Nostrand Reinhold).
Postharvest: an introduction to the physiology and handling of fruit and vegetables. 1997.
R.H. Willis et al. (CAB International).
Lecture Schedule:
A. BIOLOGICAL CONSIDERATIONS
1. Postharvest deterioration and losses of horticultural commodities
2. Morphology, structure, growth and development
3. Respiration - introduction, measurement
4. Respiration - internal and environmental factors
5. Ethylene and other plant hormones - role in senescence
6. Ethylene and fruit ripening
7. Composition of horticultural crops
8. Compositional changes during maturation and ripening
9. Transpiration - introduction, psychometry
10. Transpiration - commodity and environmental factors
11. Physiological disorders
MIDTERM EXAM through lecture 10.
12. Postharvest pathology - host-parasite interactions
13. Postharvest pathology - environmental factors and control
B. COMMERCIAL PRACTICES
14. Maturity and quality standards
15. Harvesting and handling
16. Packinghouse operations
17. Temperature management - cooling methods and principles
18. Commercial storage
19. Transportation
20. Distribution and marketing
MIDTERM EXAM through lecture 20
C. COMMODITY REQUIREMENTS
21. Cut flowers and potted plants
22. Vegetables - leafy and succulent tissues
23. Vegetables - bulky vegetative organs
24. Vegetables - immature and mature fruit tissues
25. Small fruits
26. Pome and stone fruits
27. Subtropical fruits
28. Tropical fruits
FINAL EXAMINATION - comprehensive
Laboratory Schedule
1. Introduction - tour of facilities, methods for measuring respiration and ethylene,
quality evaluation systems.
2. Factors affecting respiration, ethylene production and deterioration: commodity type,
time and temperature, modified/controlled atmospheres, ethylene, physical damage.
3. Factors affecting transpiration and water loss: water vapor pressure difference, air
velocity, product surface:volume ratio and surface properties, water vapor barriers (films
and coatings).
4. USDA grade standards.
5. Physiological disorders: low temperature (chilling) injury, high temperature injury.
6. Pathological considerations: physiological state of commodity, temperature and
moisture, surface barriers, chemical control.
7. Field trip to observe harvesting, packinghouse, storage and transport operations.
8. Field trip to a wholesale produce distribution center.