Postharvest Losses & Causes Flashcards
What are stages in the postharvest chain?
harvest prep/pack cold storage (MA/CA) transport/distribution retail home prep consumption
postharvest processing is considered to be ____ processing.
primary
Postharvest begins with ____. What begins to happen after this step?
harvest (separate from mother plant)
deterioration
The longer the period between harvest and consumption, the ____ the quality. What is the exception?
lower
certain fruits that require ripening
What are some causes of produce losses?
field losses microbial spoilage animal contamination quality loss culling/grading mechanical damage sprouting rancidity
produce is categorized as ___ or ____.
durables; perishables
What are some characteristics of durable produce? What usually causes spoilage?
low moisture (10-15%) small size (<1g) low resp rate hard texture long natural shelf life
spoilage caused by rodents/bird/mold (external)
What are characteristics of perishable produce? What causes spoilage?
high moisture (50-90%) larger size (5g-5kg) high resp rate soft texture shelf life few days-few months
spoilage caused by external and internal factors (sprouting, enzymes, etc)
estimated total losses in postharvest chain:
25-40%
What are advantages of Minimizing Post harvest losses?
- Better nutrition quality
- economic incentive
- Feedback incentive (producers unlikely to produce more food, fear of further losses)
- Cost effective
- environmentally friendly
- consumer satisfaction
The further down the chain that losses occur, the ____ the cost associated
greater $$$$$
How should the problem of post harvest losses be approached?
- understand causes
- identify factors that affect them
- use conditions to control factors -> minimize spoilage
primary causes of postharvest losses:
- biological/microbial
- chemical/biochemical
- mechanical
- physical
- physiological
- psychological
- foreign substances
What are biological/microbial causes of postharvest loss?
contamination by spoilage bacteria, mold, fungi
eaten by rodents, birds
What are chemical/biochemical causes of postharvest loss?
enzyme activity (browning, softness), rancidity, off-flavors
What are mechanical causes of postharvest loss?
physical damage: bruising, cuts, crushed, punctured
What are physical causes of postharvest loss?
improper storage conditions (temperature, humidity, light)
What are physiological causes of postharvest loss?
sprouting, aging, respiration, transpiration
What are psychological causes of postharvest loss?
human aversion (religion, personal)
What are the secondary causes of postharvest losses?
- improper handling/harvest
- inadequate storage conditions
- inadequate transportation
- inadequate refrigeration
- inadequate marketing system
What are causes of postharvest loss related to the produce itself?
- respiration
- transpiration
- ethylene production
- compositional changes
- growth/development
- physiological breakdown
- other (bruising, microbial)
What is essential to success in postharvest handling?
- harvest at right time
- good initial quality
- careful handling
- control storage environment
- sanitation
