fruit and vegetable harvest and postharvest operationsatlas.massey.ac.nz/courses/ep/section 15...
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Section 15
1
Fruit and Vegetable Harvest and Postharvest Operations
The following mind maps provide an outline that should be used in conjunction with the provided readings. A excellent additional reference is: “Postharvest Technology of Horticultural Crops” 2nd Edition Edited by A.A.Kader, published by University of California, Publication 3311. The subjects covered by the mindmaps include:
• harvesting • Transport to Packhouse • Packhouse operations
o Sorting Colour Size
o Packing • Quality Assurance
o HACCP • Packaging (Additional note)
EXERCISE: Using the Mindmaps as the basis, develop a more detailed summary of the readings provided. 1.0 REFERENCES
Wong, L.S. & Bagshaw, J., 2001. Assessment of the postharvest handling system for broccoli grown in the Lockyer Valley, Queensland, Australia. In Postharvest Handling of Fresh Vegetables, Proceedings of a workshop held in Beijing, 2001. Pub by Australian Centre for International: Agricultural Research, Cnberra, 2001, pp26-32 Prussia, S.E. & Shewfelt, R.L. 1993. Systems Approach to Postharvest Handling. Chapter in Postharvest Handling – A systems approach. Ed. by Shewfelt & Prussia, Pub. by Academic Press, San Diego. pp43-71. Chakraverty, A. & Singh, R.P., 2001. Postharvest Technology, Cereals, Pulses, Fruit and Vegetables. Published by Science Publishers, Inc. Enfield, USA.
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Wills, R., McGlasson, B., Graham, D. & Joyce, D., 1998. Postharvest. An Introduction to the physiology and handling of fruits, vegetables and ornamentals. 4th Ed., Published by UNSW. Handbook of Postharvest Technology. Cereals, Fruits, Vegetables, Tea and Spices. Edited by Chakraverty, A., Mujumdar, A.S., Raghavan, G.S.V. & Ramaswamy, H.S. Published by Marsel Dekker, New York, 2003. Kadder, A.A. (Ed), 1992. Postharvest Technology of Horticultural Crops, 2nd Edition. Publ by University of California, Pub No. 3311.
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FRUIT CROP HARVESTING AND
HANDLING
Fundamental Principles
Engineering
Traceability
Principles
Harvesting
Post-Harvest
System Performance Specification
Quality Assurance • Quality Attributes • Physical Parameters • Physical properties • Food safety • HACCP
Product Quality Safety
DEFINE Performance
Specification and Engineering
Quality Assurance
Value Chain
Food Safety
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SUPPLY CHAIN MANAGEMENT
7 Principles
Strategic Alliance
Relationship Management
FOCUS
DEVELOP CUSTOMER-DRIVEN PERFORMANCE MEASURES
BEGIN WITH CUSTOMER
MANAGE LOGISTICS ASSETS
ORGANISE CUSTOMER MANAGEMENT
INTEGRATE SALES AND OPRATIONS PLANNING
LEVERAGE MANUFACTURING AND SOURCING
• S.A.P. • J.I.T. • T.Q.M.
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ventilated
PRODUCE HANDLING
HARVEST
FIELD HEAT REMOVAL
TRANSPORTATION FROM FIELD
LIVING RESPIRING
TISSUE
STORAGE
USDA Handbook 66
Details
Incompatible Table 6
Chiller
Table 5
Payment
hourly
quality incentivest
Highly perishable cooler
early morning
night Harvest
Bruises/cuts
Quality selection
disease
insect bird
over maturity
Produce injury
improper picking
dropping
Dumping from picking container to transport centre
Trasnport containers
Overfilling Ride
crushing
base and top of container
bruisng rubbing
smooth
reducing tyre pressure
attention to tracks
Cooling
Methods
Sunlight/Heat
slows decay organisms
slows respiration
misting water okay
refrigeration water damage shade fruit vegetables
light coloured taurpaulin 10 cm gap between
tarpaulin and fruit allows airflow
Less field contamination
Removal of damaged or
spoiled produce
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HARVEST
AIM REDUCE
QUALITY SELECTION
HARVEST DATE
HIGHLY PERISHABLE
QUALITY
HAND HARVESTING
MACHINE AIDED
MACHINE HARVEST
Bruises (Table 6.1)
Cuts/injury
Diseases
Insect
Bird
Over maturity
Blemishes
Latent damage
Improper picking
Dropping
Dumping from harvest container
Yield
Cooler Anticipated price
Field conditions
Processor demand Early morning
Mechanical damage
Accuracy of selection
Time of day
Pulp temperature at harvest
Machine
Human Acceptable
Unacceptable
QUALITY
Crop choice Capital intensive Cropping patterns Labour required Working conditions Rapid harvest potential
Special breeding
improved
Less Must be trained or skilled
Easiest crop
Already machine harvested
Robotics ?
Not easily damaged
Tubers
Root crops Nuts
Perennial crops - damage
Processing – not handling harvest Obsolescence Social impact of low labour requirements
Processing Tomatoes Corn
Potatoes
Belt conveyors Platforms Moveable worker positions
Accuracy
Damage
Harvest rate
Maturity Grading Multiple harvest
Minimal
Hire more workers
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Integrated Approach to
Handling
Guidelines • How do preharvest cultural factors
affect consumer acceptance? • How does storage at non-optimal
conditions affect quality and consumer acceptance?
• Are handlers who adopt new
methods properly rewarded for their improvements?
Quality Management • Operations Research • Application of Technology and
Engineering • Clearer spec of quality and packing ,
value, consumer perspectives • Preharvest factors = variability in quality
and storage • Mean to predict mathematically
(modelling systems) period of optimal marketability – to specific handling conditions
Food Safety • Agricultural chemicals • Cosmetic appearance • Alternative methods, e.g. organic • Pathogens, e.g. E.coli species • Listeria monocytogenes (refrigeration.
Latent damage • Early detection important • Lower quality increased cost of
production (transportation and sorting add cost)
• Damage incurred at one step but not apparent until later step. o Bruising o Quiescent infections o Physiological disorders o Postharvest stress disorders,
e.g. chilling injury
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TRANSPORTATION FROM FIELD In field
Packhouse
Special breeding
Sellers
Wholesale buyers
Customer
Resistance - mechanical
damage - insect/disease
damage
Harvest - uniform
maturity - once-over
harvest
Appearance
Firmness
Flavour
Appearance
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TRANSPORTATION FROM FIELD
(Kadir) Compression
- Over filled bins - Bottom layers - Shallower bin
Bounced
BRUISING
Field container - wooden – vented – cooling
– smooth surface - plastic liners - drop height important
(Table 6.2, pp31)
Picking container Fruit type = container type
- plastic bucket – softer fruit
- bottom dump – less pot for compression damage
- delicate – pack directly from bucket (peaches)
- very soft delicate – pick into package, e.g. strawberries
1. Avoid extended forklift movement 2. minimise rough handling during loading 3. grade farm/orchard track – keep smooth 4. avid uneven/rough public roads 5. restrict transportation speeds to minimize
free movement of front (vibration) 6. use suspension systems – air shocks best. 7. reduce vehicle tyre pressure 8. plastic liners – bubble wrap – bubbles out –
minimise damage 9. top bin pads for long trips – use of shrouds.
Bin dropped Impact
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PACKING HOUSE OPERATION
(1) Sorting
Economics
Design & Operation of sorting equipment • Optimising
o Accuracy o Sorting
• Evaluation o Sorter productivity o Quality
• Space o Size
• Variable flow o Translation speed o Product loading
• View product o Sorter position o Lighting o Location of reject
chutes and conveyors • Worker comfort • Product injury • Training/supervision
Analysis of sorting operations • performance • modelling • empirical model • signal detection theory
Marketing factors • producer • wholesaler • retailers/distributors • customer • price quality
Sorting terminology • Separation (removal of non-useable
material) • Uniform size (free of insects, blemishes,
diseases) • Maturity (firmness, damage levels) • Sorting (segregation, marketable, quality
categories) o Mechanical (colour, sizes o Manual (visual, tactical)
• Graders – sorting line, not graders (3rd party inspectors e.g. ENZA, meet classification, online, off-line.
• Sample inspection (Q.C.)
1
Visual perception • Brightness • Product presentation • Vision difficulties • Concentration for long
periods
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PACKING HOUSE OPERATION (A)
2 Fruit sizing • Colour • Image sizers • Weight and/or size 3
Fruit selection • Capacity • Accuracy • Injury Adjustment ease • Incoming fruit change • Adjust fruit diversion patterns • Ease: cleaning, maintenance
4
Special treatments • Presizing • Cleaning and washing • Waxing/coating • Disease control treatment
OPERATION: Monday: (Frank Bollen, Prussia & Lidrow)
“To transform the highly variable product received from the harvest operation into uniform lots of product for shipments that comply with the requirements of the buyer.”
Wednesday/Thursday - Packaging
MECHANICAL VOLUME-FILL TIGHT FILL
5
PACKING FRUIT • Volume fill packing
system • Packaging material
o Delivery o Removal when
full/packed o QC check
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PACKING HOUSE OPERATION (B)
MECHANICAL • Volume fill • Tight fill
HAND PACKING • Attractive pack • Fixed count (even size) • Immobilization (lateral
tightness)
PURPOSE OF PACKING • Immobilzed
(vibration) • Cushioned (shock)
PACKING LINE • Minimize fruit damage
(padding) • Avoid fruit accumulation • Final sort (QA/QC check • Packaging material
(delivery, removal when full/packed)
• Avoid bottlenecks.
PACKING FRUIT • Volume fill • Tight fill
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SORT
SIZING
AUTO FILLER
PACKAGING
INSPECTION
MARKING
VIBRATION (if req’d)
CLOSING
PALLETING (automatic)
STORAGE
PACKAGING LIDS
TOP PADS (if req’d)
MECHANICAL PACKERS
DROP HEIGHT • Minimized • Shock damage • Major problem
HIGH SPEED • Large volumes • Sorted, graded
fruit required
DELIVER CAREFULLY SORTED & SIZED FRUIT AND PACKAGING • Inspection • Marking • Top padding (closing operation)
VOLUME FILL • Weight as approximation of
volume • Check weights (manual,
automatic) TIGHT FILL • Immobilisation • Without compression • Bruising • Top padding • Tightly fasten lid
PLACE PACKING SYSTEMS • Citrus • Sized fruit • Pack pattern • Rubber/plastic cups
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COOLING METHODS
FIELD HEAT
SUMMER • Rapid cooling and temperature
control o Successful marketing
• Cooling and cold storage requiring different
• Cooling efficiency • Modelling systems TEMPERATURE
PROTECTION • Shade, natural, shade
clothe (silver to reflect) • Prevent warming • Sun scald
RAPID TRANSPORTATION TO PACKHOUSE • Covers
o Silver to reflect o Light colour
PRE-GRADING AND PACKAGING POST-GRADING AND PACKAGING
SELECTION
PRODUCT
limitations mix Temperature req.
OPERATING COSTS
OTHER CONSIDERATIONS
Energy costs
Tradition
ROOM COOLING • Cooling jets • Cooling bays FORCED AIR COOLING • Forced air tunnel • Cold wall • Serpentine cooling • Forced air evaporative
cooling • Container venting HYDRO-COOLING PACKAGE-LANG VACUUM COOLING COOLING BEFORE PAKAGING
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ROOM COOLING
LONG ?? PRODUCE • Common
ADVANTAGE • Cooling and storage in
the same room (minimises transfers)
DISADVANTAGE • Too slow (most
commodities) • More space than
required (good storage)
• Excessive water loss possible
COOLING BAYS • Cooling • Storage
COOLING BAYS • Slow heat removal
STORAGE SPACE MANAGEMENT
WELL VENTILATED CONTAINERS
AIR FLOW • 60 tp 120 m/min
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FORCE-AIR COOLING
Wide range produce
Forced air movement through containers
Slight pressure gradient forces movement
H2O loss prevented by high % RH
Bins
Volume of air
Forced air tunnel (Fig 8.2)
Cold wait (Figs 8.4, 8.5)
Serpentine (Figs 8.6, 8.7)
Forced air evaporative cooling
(Fig. 8.8)
Container renting Req’d SA
Forced air evaporative cooling (Fig. 8.8)
2-3 degrees above outside wet bulb temperature and
% rH + 90%
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HYDRO COOLING
Use of cold water
Advantages • no water loss • quick cooling • efficient heat transfer
Disadvantage • cooling packed produce
• container to pickup • clean
H2O loss prevented by high % rH
Bins
Volume of air
Shower type • 600 – 1000 L/min/m2 SA
(L/min-1.m-2) • low level chlorine
(1 – 2 ppm residual) • produce tolerance
Mechanical water cooling
Cooling times 10 min to 1 hour
Inline cooling • cherries, small fruit
Flume cooling hydro • conveying • cooling
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PACKAGING ATMOSPHERIC MODIFICATION
O2 CONTROL • Recycling/purge
generator • Catalytic burners ⇒
N2 purge liquid N2
MEMBRANE SYSTEMS
CO2 CONTROL • Gases CO2 – gas
cylinders • CO2 scrubbers (lime) –
sodium hydroxide, water, activated carbon, brine, molecular sieve
ACTIVATED ND BROMINATED CHARCOAL • Potassium permanganate • Re,pved C2H4
ETHYLENE REMOVAL
CO ADDITION
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O2
Substrate End product
Starch CO2
Sugars H2O
Organic acids
Amino acids O2H2
Prolin Volatile
Pectin compound Heat
COMMODITY
PACKAGE
STORAGE ROOM/TRANSIT VEHICLE
MAN H2O
N2 78.1%
O2 20.9%
CO2 0.03%
C2H2 plus OTHER
VOLATILES
HEAT
- commodity generated - or passive ACTIVE MODIFIED ATM
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CA/MA STORAGE
ADVANTAGES
DISADVANTAGES
RETART SENESCENCE Slows: Respiration Ethylene production Softening Compositional changes Biochemical Physiological
REDUCTION ETHYLENE SENSITIVITY O2 < 8% and/or CO2 > 1%
PHYSIOLOGICAL DISORDERS Chilling injury
POSTHARVEST PATHOGENS 10 – 75% CO2 Inhibit Botrytis rot on Strawberries Cherries Insects
INSECT CONTROL
DECAY SUSCEPTIBILITY INCR Low O2 damage
STIMULATION Sprouting, e.g. potato –
roots tubers
OFF FLAVOURS/ODOURS Anaerobic Respiration Very low O2
RETARDATION Periderm development
INITIATION/AGGRAVATION Physiological disorders: Blackout – potatoes Brown stain – lettuce Brown heart – apple/pear
IRREGULAR RIPENING (pears, tomatoes) O2 < 2% CO2 > 5%