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