Postharvest Physiology

TPSS 473


Robert Paull

Semesters taught:

Fall 2015


The course goal is to compare the physiology and biochemical processes during growth, maturation, ripening and senescence of flowers, fruits and vegetables related to changes in quality and storage life. Tropical commodities are emphasized. It is not the intention of this course to be a catalogue of known storage procedures for commodities but to acquaint the student with the underlying basis for these various procedures.

Skills and knowledge to be acquired:

The course emphasis is on physiology and quality in a general framework not specific to any commodity. This should provide a student with the skills necessary to analyze a situation, appreciate the basis for certain methods used, and understand the problems while attempting to determine solutions from the general case to the specific problem.

Computer skills to be acquired:



TPSS 200, BIOL 171, or BOT 201; CHEM 152 or consent


S. J. Kays. & R.E. Paull, 2004. Postharvest Biology. Exon Press, Athens, Georgia.


Kader, A.A. 2002. Postharvest Technology of Horticultural Crops. University of California


Wills, R., B. McGlasson, D. Graham, D. Joyce. 1998. Postharvest: An introduction to the Physiology and Handling of Fruits, Vegetables and Ornamentals. 4th Edition.

Films and videos:


Guest Speakers:

An entomologist on insect disinfestation procedure and a plant pathologist to cover postharvest diseases and their control.

Field Trips:

Vegetable, ornamental and fruit harvesting, packing and distribution facilities on Oahu.

Course organization:

The lectures cover the following areas:

  • Introduction, overview of course, postharvest losses
  • Quality of horticultural products
  • Biological aspects of deterioration/gross morphology, structure and growth
  • Respiration - measurement, role, factors affecting rate, ethylene
  • Physiological disorders - nutrition/ atmospheres / chilling
  • Compositional changes
  • Senescence and postharvest physiology
  • Transpiration from fresh commodities
  • Standards & specifications for fresh perishable commodities
  • Color, texture, taste, aroma & nutritional quality in horticultural products
  • Sensory methods and objective measures of quality evaluation
  • Maturity indices
  • Pathological disorders of fresh commodities
  • Postharvest entomology & disinfestation
  • Temperature control & attainment
  • Controlled & Modified atmospheres
  • Handling - commercial handling systems/deciduous fruits
  • Subtropical and tropical fruits
  • Vegetable fruits / bulky vegetative organs
  • Leafy vegetables, floral parts and flowers
    - Maturity at harvest
     - Handling
    - Temperature and relative humidity
    - Controlled and modified atmospheres
    - Insect disinfestation
    - Packaging and display techniques


Two mid-terms (25 points each) and a final examination (50 points). The final examination has short answer questions dealing with the last one third of the course, and an essay. The essay will require the student to bring together information from the whole course.