Post Harvest-HandlingSaturday, December 8th, 2007OSU Extension Small Farms
Why is Post-Harvest Handling Important?
Food SafetyIncrease shelf-life and marketing opportunitiesFinal Step
Post Harvest Steps
1. Production Practices2. Harvest Handling3. Pre-cooling4. Packaging5. Sanitation6. Refrigeration7. Storage (for some crops)
1. Production Practices
Choice of cultivarsEnvironmental factorsManagement practicesFood Safety
2. Harvest Handling
Harvest during coolest time of the dayAvoid unnecessary wounding or bruisingShade harvested produce in the field
Harvest Handling continued
Use only clean transporting containersHandle as little as possible- field pack if possibleTrim fingernails and/or wear glovesBegin post-harvest treatment as soon as possibleDo not mix high quality produce with damaged produceUse appropriate harvest tools
Temperature- most important factor!
Aging due to ripening and softeningRespiratory heat productionMoisture lossSpoilage due to bacteria, fungi and yeastsUndesirable growth
3. Pre-cooling Most important for crops with high respiration rates
MethodsRoom coolingForced-air coolingHydro-coolingTop or liquid icingVacuum cooling
Crop Respiration Rates
High respirationArtichokesCut flowersGreen onionsSnap beansAsparagusBroccoliPeasCorn
Low respirationApplesNutsGrapesGarlicOnionsPotatoesSweet potatoes
4. Sanitation
Pre-wash handlingWater Disinfectant options
Chlorine (organic considerations)OzoneHydrogen peroxide
5. Packing
Boxes
Flats
Plastic Bags
6. Refrigeration
CoolersRefrigeratorRefrigerator truckWalk-in coolerPorta-cooler
Preventing Moisture Loss
Monitor humidity with hygrometerSpectrum Technologies 800-248-8873Barr, Inc 920-231-1711
Understand crop-by-crop humidity needsHumidification methods
Humidification deviceBuckets of waterKeeping the floor wet
Chilling Injury
Highly sensitiveBasilCucumbersEggplantsPumpkinsSummer squashSweet potatoes
Moderately sensitiveSnap beansMusk melonsPeppersWinter squashTomatoesWatermelons
Ethylene
Ethylene ProducersApplesApricotsCantaloupesHoneydewPeachesPearsPlumsTomatoes
Ethylene-sensitiveSnap beansBroccoliCabbageCucumbersEggplantLettucePeasPotatoes
Lettuce
32 degrees95% humidityVacuum cooling or forced air coolingSensitive to ethyleneSensitive to freezingWill store for two-three weeks
Broccoli
32 degrees95-100% relative humidityIce-coolingWill store for 2 weeks
Tomatoes
46-50 degrees90-95% relative humidityRoom cooling or forced air coolingWill store for 1 week
7. Storage CropsSeason extensionHome useRoot cellarsCoolersIn-groundCuring
Cold and Moist32-40 degreesF and 90-95% RH
CarrotsBeetsParsnipsRutabagaTurnipsCeleryCeleriacSalsifyLeeksCollardsKohlrabiBroccoli (short-term)
Cold and Moist32-40 degrees F and 80-90%RH
PotatoesCabbageCauliflowerApplesGrapesPearsEndive
Cool and Moist40-50 degrees and 80-90% RH
CucumbersSweet peppersCantaloupeWatermelonEggplantRipe tomatoes
Cool and Dry32-50 degrees F and 60-70% RH
GarlicOnionsGreen soybeans
Moderately Warm and Dry50-60 degrees F and 60-70% RH
Dry hot peppersPumpkinsWinter squashSweet potatoesGreen tomatoes
Resources
Peaceful Valley Farm SupplyGrangeQuality Maintenance of Mixed LoadsCes.ncsc.edu/depts/hort/hil/post-index.html
Kansas Sate University PublicationsOznet.ksu.edu/library
Porta-cooler Designattra.ncat.org/new_pubs/attra-pub/postharvest.html?id=Oregon