Less Energy to Produce Vegetables Than Beef

As producers, it is our task to maintain quality from the field to the shelf through our handling, cooling, and storage. Starting with growing a salubrious ingather and maintaining best practices through harvest, slowing the produce aging procedure, cooling, storage, and finally to mail-harvest handling, this publication discusses keeping produce fresh.

Good Storage Starts with Growing a Good for you Crop

Storage can just prolong the life of the ingather; it cannot amend its quality. Many storage problems kickoff in the field.

Diseases

Plant disease infection volition reduce produce storage and shelf life. For example, bacterial soft rot of carrots, caused by Erwinia carotovora or Pseudomonas spp., starts in the field with lack of rotation, and shows up later in storage. This leaner enters crops from infected ingather residue in the soil. Sufficient crop rotation allows time for found tissue to degrade. Without a host, the pathogen dies and cannot infect the side by side crop.

Carrots with bacterial soft rot and pythium. Photo by Beth Gugino, Penn State Plant Pathology

Cultural controls to minimize disease such as a three-year rotation away from host crops, using resistant cultivars, and increasing air circulation by controlling weeds will help reduce plant disease and associated storage losses.

Insects

Insects can cause visible blemishes on produce, straight reducing consumer appeal. Additionally, these blemishes are holes in the protective layer of the produce that permit easier entry for the plant diseases that cause post-harvest rots. Some insects can also vector diseases. For instance, thrips can carry and transfer leaner in their mouth-parts to onions when they feed on the greens. These bacteria lead to bacterial soft rot in storage.

Thrips can vector leaner-causing soft rot in onions. Photograph by Ruth Hazzard, UMass

Fertility

Proper fertility is critical not but for yield but also quality. For example, calcium-deficient strawberries can be pocket-sized, hard, and seedy. Phosphorus-deficient strawberries tin can be soft with insipid flavour. High-nitrogen fertilization is related to water loss in storage for sweetness potato, decreased season in celery, and hollow stem in broccoli. Calcium deficiency can lead to blossom end rot in tomatoes, blackheart in celery, and tip burn in lettuce. Brand sure to maintain fertility levels based on soil examination recommendations. Often tissue tests can further aid growers avert nutrient deficiencies.

Irrigation

Adequate moisture is disquisitional to maintaining quality. Water stress may reduce the overall yield too every bit the size of the harvested produce. On the other paw, too much moisture can spread institute pathogens and increment the risk of infection from post-harvest decays. Too much water and likewise much fertilizer too produce more succulent simply weaker leafy greens.

The canopy in well-weeded carrots will dry out out faster compared to weedy carrots, reducing the propagation of bacterial disease. Photo past Tianna DuPont, Penn State Extension

Good Cultural Management

Option of disease-resistant varieties is important for post-harvest success. Additionally, practices that promote crop health such as staking and pruning tomatoes and using row covers to exclude plant pests will help produce loftier-quality vegetables and berries. Another case of a cultural management practice is the employ of biodegradable mulches to reduce post-harvest affliction. In this organization the soil stays cooler and is less conducive to bacterial soft rot diseases.

One case of a cultural management which reduces post-harvest affliction is the utilize of biodegradable mulches for onions. In this arrangement the soil stays cooler and is less conducive to bacterial soft rot diseases. Photo by Beth Gugino, Penn State Plant Pathology

Harvest

How y'all handle produce during harvest directly affects produce quality. Injuries such equally bruising, surface abrasion, and cuts leave produce open to disease-causing organisms, accelerate loss of nutrients such as vitamin C, and reduce consumer entreatment.

Selection produce with high transpiration early on in morning when the produce is the coolest and fully hydrated.
Shade harvested produce.

Canopies on harvest trailers help keep produce cool and keep birds from contaminating produce. Photograph by Tianna DuPont, Penn State Extension

Go on humidity high effectually virtually produce.
Maintain air circulation.
Harvest at the right stage of maturity.
Practice gentle and sanitary picking.
Discard damaged produce.
Option make clean (some crops).
Don't overfill containers.
Remove tomato stems and pack fruit shoulder side downward.

Trimming stems reduces scratching. Photo by Andrew Puglia, Hillside Subcontract

Delicate zucchini should exist placed in bins with stems all facing one direction to reduce scratching. Photograph by Andrew Puglia, Hillside Farm

Prevent Bruising and Scraping

Worker training is important to ensure that delicate produce is non bruised. This tin can be difficult. Farmer Atina Diffley, Gardens of Eagan, has a strategy to show instead of just tell her crew. She has a new worker choice i box of tomatoes and put it in the libation with his/her name on information technology. The next mean solar day she has him/her sort the box. Just like human bruises, bruises on produce have some fourth dimension to develop, and by the side by side twenty-four hours the new worker can clearly encounter his/ her fingerprints where he/she squeezed ripe fruit besides tightly. Hopefully next time he/she is more conscientious.

Cup zucchini with your hand as you remove from the establish to protect fruit from scratching past vines. Photo past Andrew Puglia, Hillside Farm

Mechanical injury can impact the interior besides as exterior of fruit. Photo past UC Davis

Minimize Hauling

Bumping and scraping produce during hauling can damage produce and provide entry points for affliction.

Harvest produce into bins and remove the bins with pallet jacks.
Utilise roller tables to unload the pallets into sheds.
Consider using harvest conveyors. (A new harvest conveyor may price only $1,200. When information technology allows harvest of ½ mile of sweet corn in 20 minutes the returns are noticeable!)
Employ loading docks.

Does your produce look like this in the shop? Minimize abrasion of produce while harvesting to increase consumer appeal on the shelf. Photograph by Tianna DuPont, Penn State

Harvest conveyors are ane way to minimize handling and promote efficiency. Photograph by Tricia Borneman, Blooming Glen Farm

Rots such as this bacterial soft rot are commonly associated with physical injury. Photograph past UC Davis

Use Systems to Go along the Produce Clean

Minimizing clay on the produce reduces your labor to clean it and the potential to contaminate produce with human and plant pathogens.

Straw, plastic, and living mulch reduce splash onto produce.
Harvest in non-dirty conditions when possible.
Use clean and sanitized tools, knives, and harvest containers.
Trim produce in the field, leaving the dirt in the field instead of bringing it into the packhouse.

Annual ryegrass and clover planted between rows keeps harvest bins out of the mud and reduces splash. Photo past Tianna DuPont, Penn State Extension

When to Harvest

Harvest crops when they are at the appropriate maturity.

Continue in heed that the appropriate ripeness volition depend on your buyer. For example, wholesalers more often than not desire "turners," tomatoes with only a blush versus full ripe. Also consider whether the produce is best harvested wet or dry. For instance, potatoes, eggplants, tomatoes, summer squash, and green beans are best harvested dry out. Storage onions, garlic, and winter squash need to be dry out before storage and are better harvested dry out.

Table 1. Recommended maturity for harvest

Produce	Maturity
Broccoli	Bud cluster meaty (overmature if loose)
Cabbage	Head compact (overmature if head cracks)
Cauliflower	Curd compact (overmature if blossom cluster elongates and becomes loose)
Celery	Big enough before it becomes pithy
Eggplant, cucumber	Desirable size reached but still tender (overmature if color dulls or changes and seeds are tough)
Green onion	Leaves at their broadest and longest
Honeydew melon	Modify in fruit color from a slight green white to cream; slight aroma noticeable
Lettuce	Big enough before flowering; business firm, just not hard
Lima bean, pigeon pea	Well-filled pods that are starting time to lose their greenness
Muskmelon	Easily separated from vine with a slight twist, leaving clean cavity
Okra	Desirable size reached and the tips can be snapped
Potato, onion, and garlic	Tops beginning to dry out and topple downwards
Radish and carrot	Large enough and crispy (overmature if pithy)
Snap bean	Well-filled pods that snap readily
Sweet corn	Exudes milky sap from kernel if cutting
Sweet pepper	Deep green color turning dull or red
Tomato	Seeds are not cut when fruit is sliced, or green color turning pink
Watermelon	Color of lower part turning flossy yellow; tedious hollow sound when thumped

Source: Bautista and Mabesa (1977).

Additional detailed maturity indices for fruits, vegetables, and cut flowers tin be found at postharvest.ucdavis.edu.

Slowing the Produce Aging Process

A one-hour delay in cooling can reduce the shelf life of produce by a day or more than.

Produce is alive. Even after we harvest it from the found, produce continues the metabolic activity that allowed it to grow while on the constitute. But after harvest, produce cannot photosynthesize, or have up water to replace the water and free energy it is expending. Learning the basics about these metabolic processes can assistance usa learn how to slow them downwards and prolong the life of our harvested produce.

Respiration

Fresh produce respires to produce free energy. Information technology uses stored carbohydrates, proteins, and fat, and releases CO₂ (carbon dioxide) and heat.

Plants respire carbon and transpire water. When harvested these processes continue simply the constitute is no longer able to replenish itself. Source: FAO.

As produce loses carbohydrates to the air as CO_two, consumers lose flavor and shelf life, and the produce appears shriveled.

Fresh produce continues to respire after it is harvested. Photo past Marita Cantwell, UC Davis

Plants need oxygen in order to respire. If there is non enough oxygen bachelor, the produce will ferment. Some crops respire at higher rates than others. Brand certain you know which crops have college respiration and how to manage them.

Table 2. Respiration rates of common produce

Respiration Rate	Article
Very low	Nuts, stale fruit
Depression	Apple, beet, celery, garlic, onion, murphy, sugariness potato, watermelon
Moderate	Cabbage, cantaloupe, cucumber, lettuce, peach, pear, pepper, plum, potato (young), radish (topped), summer squash, tomato
High	Blackberry, carrot (w/tops), cauliflower, leeks, leafage lettuce, radish (w/tops), raspberry
Very loftier	Bean sprouts, broccoli, Brussels sprouts, endive, green onions, kale, okra, snap beans
Extremely loftier	Asparagus, mushroom, parsley, peas, spinach, sweet corn

Ethylene

Ethylene (C₂H₄) is a natural hormone that plants produce and use to regulate growth and evolution. More often than not, ethylene rates increase with maturity and when produce is injured.

During storage ethylene can impairment sensitive crops. For example, exposure to ethylene causes russet spotting on lettuce and yellowing in broccoli. Ethylene harm generally does non occur in less than 24 hours of exposure. Exposures are cumulative.

Ethylene harm in collards. Photo past Marita Cantwell, UC Davis

Rapid and efficient cooling aid prevent damage. Eliminate internal combustion engines that generate ethylene from storage rooms, and periodically vent the storage area. Producers can also place ethylene-absorbing filters in storage rooms.

Ethylene filter. Photograph by Tianna DuPont, Penn Land Extension

Market growers often see ethylene damage when they store apples, which release loftier ethylene levels, with sensitive crops like broccoli.

Continue ethylene-producing crops in separate coolers, especially for long-term storage. Photograph past Tianna DuPont, Penn State Extension

Transpiration and Water Loss

Each hour of exposure to warm, dry out air results in over twice as much water loss as property produce in high-humidity cold storage for i week.

Most fresh produce is 85 to 95 per centum water when harvested. Within growing plants in that location is a abiding flow of water. Liquid h2o is captivated from the soil by the roots, then passed upwards through the stems, and finally lost from the aerial parts, specially leaves, equally water vapor.

The passage of water through the plants is chosen the transpiration stream. Information technology maintains the high water content of the plant. A lack of h2o volition cause plants to wilt and peradventure die.

Fresh produce continues to lose water after harvest, but unlike in the growing plant, it tin can no longer replace lost water with water from the soil. Instead it uses upwards water in the harvested produce. This loss of water from fresh produce afterwards harvest is a serious trouble that causes wilting and shriveling besides equally loss of weight.

When harvested produce loses 5 or 10 pct of its fresh weight, information technology begins to wilt and shrivel and becomes unusable. To extend the usable life of produce, its charge per unit of water loss must be as low as possible.

The charge per unit of water loss varies with the type of produce. Leafy green vegetables, particularly spinach, lose water quickly because they have a thin skin (epidermis) with many pores. Others, such as potatoes, which have a thick corky peel with few pores, accept a much lower rate of water loss.

Water loss symptoms. The tomato on the far left shows no loss, while the one to the correct exhibits loftier loss. Photo by Marita Cantwell, UC Davis

After six days of refrigeration without protective packaging, lettuce to the left has lost much of its water due to transpiration. Photo by Tianna DuPont, Penn State Extension

A significant factor controlling water loss is the ratio of produce surface area to its book. The greater the surface area in relation to the volume, the more rapid the loss of water will exist.

Primary ways to deadening transpiration:

Lower the temperature.
Increase the humidity.
Reduce air move.
Protect the produce with packaging.

Polyethylene liners keep humidity high and reduce water transpiration losses. Photograph by Tianna DuPont, Penn Country Extension

The faster the surrounding air moves over fresh produce, the quicker water is lost. Air motility through produce is essential to remove the heat of respiration, but the charge per unit of movement must be kept equally low as possible during storage. Well-designed packaging materials and suitable stacking patterns for crates and boxes can contribute to controlled airflow through produce.

Bin liners can reduce transpiration losses. Photo by Andy Andrews, Pennypack Subcontract, courtesy of Spiral Path Farm

Tabular array 3. Percent weight loss per day of sample crops at lower and higher relative humidity.

		Relative humidity (%)
Crop	Storage Temperature (°F)	95	xc	85	80
Brussel sprouts	32	i.six	3.2	4.8	six.iv
Cabbage	32	0.06	0.12	0.eighteen	0.23
Carrots	32	0.315	0.63	0.95	1.three

Chilling Injury

Freezing injury occurs when produce is held below its freezing temperature. More often than not, collapse of the tissues and full loss of the commodity occur when it is rewarmed.

Spooky injury is a unlike problem. Certain types of produce are also injured when they are held at temperatures above their freezing signal but below their critical point of 41 to 59°F, depending on the produce.

Tabular array 4. Typical chilling injury symptoms on fruits/vegetables.

Commodity	Symptoms
Beans	Darkening or dullness if stored below 41°F; rusty brown lesions if stored at 41 to 46°F; discoloration of seeds, increased susceptibility to decay, surface pitting
Cantaloupe	Only sensitive to chilling injury if stored beneath 36°F for extended periods; fruit can evidence surface browning and decay afterwards removal from storage
Eggplant	Brown, discolored areas; surface pitting leading to large sunken areas; calyx discoloration; seed and flesh browning
Melons	Failure to ripen normally; h2o-soaked areas; increased susceptibility to decay; slow or bronzed surface
Okra	Concealment and discoloration; pitting; water-soaked areas; increased susceptibility to disuse
Peppers	Surface pitting leading to large sunken areas; seed browning; calyx discoloration; water-soaked tissue; increased susceptibility to decay, particularly Alternaria rot
Summertime squash/cucumber	Surface pitting followed by brown or black lesions; water-soaked areas; increased susceptibility to decay
Tomatoes	Short exposure (4 to 6 days at less than fifty°F) results in poor flavour; longer exposure causes failure to ripen commonly, pitting, shriveling, and softening, and increased susceptibility to decay with Alternaria rot a diagnostic symptom
Watermelon	Surface pitting and sunken areas that dehydrate upon removal from storage; off-flavors; internal brown discolored areas on rind
Winter squash	Weakening of tissue, specially on the stem with increased susceptibility to decay, specially Alternaria rot

Source: Dris, Niskanen, and Jain (2001).

Mutual symptoms are internal browning, pitting, water-soaked areas, failure to ripen, and accelerated decay.

Shelf life of chilling sensitive to active produce decreases at excessively common cold temperatures. For example, cucumbers could be stored for 90 days at 55°F but simply 20 days at 32°F.

Chilling injury on eggplant includes pitting, large sunken areas, and internal browning. Photo by Tianna DuPont, Penn Land Extension

Spooky injury can cause seed browning in peppers. Photo by Tianna DuPont, Penn State Extension

Sweet potato chilling injury. Photograph by UC Davis

Cooling

Crops harvested earlier in the 24-hour interval will accept a lower internal temperature, which means less energy and time to cool them. A ane-hour filibuster in cooling reduces produce shelf life past one day or more.

It is disquisitional to promptly cool produce to slow downwards sugar and vitamin loss from respiration, reduce water loss from transpiration, and decrease decay. For example, a half-dozen-hour delay in strawberry cooling can result in 50 per centum more than water loss. Prompt cooling is especially critical for crops with high respiration rates and high surface expanse. For example, the respiration rate of salad greens at 50°F is four times higher than it is at 32°F (Table 2).

On this moderate summertime day with a loftier of 85°F at eight:00 a.grand., the produce temperature was 61°F. At 11:00 a.m., it was 74°F. Photo by Tianna DuPont, Penn Country Extension

Cooling delays tin also reduce quality due to physiological changes in the produce. For example even a 4-hour delay in cooling asparagus tin can let it to create more lignin and result in 50 per centum tougher spears.

Minimize the delay between harvest and the start of cooling.
Start harvest early to protect produce from temperatures above 70 to 75°F.
Shade produce afterward harvest to prevent excess temperature ascension, sunburn, and sunscald damage.
Use shaded receiving areas.
Even placing an empty picking box on top of a filled box protects produce from temperature gain.
Protect produce from moisture loss during cooling past using vented plastic liners, bin covers, or plastic containers.
Some produce, like carrots, tin can be sprinkled with water to reduce moisture loss during temporary holding at warm temperatures before cooling.

Insulated cogitating covers tin keep produce cool during harvest and transport. Photo by Andy Andrews, Screw Path Subcontract

Shaded fruit temperature is usually inside a few degrees of air temperature, but produce exposed to sunlight can be seven to 11°F (4 to 6°C) warmer than air temperature.

Room Cooling

Room cooling is a standard cooling practice on small and medium farms. It has the advantage of providing storage and cooling in the same place and a unproblematic design. Nonetheless, room cooling has several disadvantages:

Cooling tin exist slow, requiring 24 hours to several days.
Produce is often shipped without adequate cooling.
Sensitive produce can deteriorate measurably in the time required for cooling.
Meaning moisture is lost.
Produce containers without sufficient venting or stacked likewise close together are particularly tedious to cool.
Moisture released past the warm-interior produce may condense and cause wet on colder outside produce, causing decay growth.

Design your room libation correctly. Talk to your local cooling engineer for a pattern. Your libation should have:

A fan chapters of 100 cubic feet per minute (cfm) per ton of maximum produce chapters to use during cooling
An air-handling arrangement that distributes air uniformly throughout the room
The ability to reduce airflow charge per unit to twenty to xl cfm per ton after produce is fully cool for storage

Room cooler. Photo past Andrew Puglia, Hillside Subcontract

Large shared cooler. Photo by Tuscarora Organic Growers

Forced-air Cooling

Forced-air cooling uses fans in conjunction with a cooling room to pull cool air through packages of produce. Although the cooling rate depends on the air temperature and the rate of airflow, this method is commonly 75 to 90 per centum faster than room cooling. Fans should be equipped with a thermostat that automatically shuts them off equally before long as the desired produce temperature is reached.

A tunnel cooler is the most common pattern for forced-air cooling. Pallet loads of produce are placed in two lanes on either side of an open channel in a cold room. A tarp is placed over the produce, covering the open aqueduct. A fan is placed at the terminate of the tunnel and situated to suck cold air through the tunnel and back to the cooling unit to cool produce downwardly equally apace as possible.

Figure 2. Forced-air cooling.

Source: WSU TFREC.

Bins and packaging must have openings to allow common cold air to pass over individual pieces of produce.
Packaging/bin vents should contain 5 percent of the side area.

Make clean baby greens are cooled by forced-air cooling inside a larger walk-in. Photo by Andy Andrews, Spiral Path Farm

Hydrocooling

Dunking produce into cold h2o or running cold h2o over produce is an efficient style to remove field rut and can serve equally a means of cleaning at the aforementioned time. In addition, hydrocooling reduces water loss and wilting. Using an appropriately labeled disinfectant in the water is recommended to reduce the spread of foodborne pathogens and postharvest diseases. Due to food safety concerns, hydrocooling is becoming less widely used because of the potential for water to movement pathogens among produce.

Hydrocooling is not appropriate for berries, potatoes to exist stored, sweet potatoes, seedling onions, garlic, or other commodities that cannot tolerate wetting.

Green onions are cooled and rinsed every bit they are unloaded from the truck onto roller tables, which convey produce into the pack area. Photo past Andy Andrews, Pennypack Farm, courtesy of Screw Path Farm

Water removes heat virtually v times faster than air just is less energy efficient. Well water is a good option. Nevertheless, it usually comes out of the ground with temperatures in the 50 to sixty°F range. If you are cooling with well water, you will need to create a multistep system that cools the residue of the way with room or forced-air cooling.

Almost well water is 55 to 60°F and will not bring all produce down to optimum temperature. Photo by Tianna DuPont, Penn State Extension

Mechanical refrigeration is the nearly efficient method for cooling h2o. A thermal storage immersion hydrocooler organization can be fabricated economically to conform various volume requirements.

Used stainless steel bulk farm milk coolers may exist an choice. If hydrocooling water is recirculated, it should be chlorinated (or other approved sanitizer) to minimize illness problems.

Large majority tanks tin can be used to hydrocool produce. Photo by Sandy Arnold, Pleasant Valley Subcontract

For large volumes of produce, shower hydrocooling over boxes/ bins may not reach the center of the stack of bins.

In shower-type hydrocoolers, produce moves slowly through a continuous shower of cold water. Smaller bore produce will cool more quickly than larger diameter produce. You need a large amount of water, about ten gallons per minute per square foot of cooling area, to rapidly cool produce. Information technology is also of import that the distance between the spray nozzles and the produce never exceeds six–eight inches. Water force per unit area tin crusade surface pitting and water–soaked damage on sensitive leaves and fruit.

Berries move on a conveyor through a chilling room. Photo past Sand Colina Berries Farm

In this hydrocooling organization, lettuce on a conveyor goes through chilled (34°F) water in social club to apace cool. Photo by Andy Andrews, Screw Path Subcontract

Icing

In top icing, crushed water ice is added to the container over the peak of the produce past manus or motorcar. For liquid icing, a slurry of water and water ice is injected into produce packages through vents or handholds without removing the packages from pallets and opening their tops. Icing methods work well with high-respirating bolt such as sweet corn and broccoli. I pound of ice volition cool nearly 3 pounds of produce from 85°F to 40°F. See Table 5 for which produces tin can exist iced and what produce is harmed past icing. However, dripping water from iced containers can be a liability issue and the water ice adds to produce weight and transport costs.

Tabular array five. Cooling methods for unlike crops.

Ingather	Cooling Method
Asparagus	H, I
Basil	R
Beans, snap	R, F, H
Beets, bunched	H, I
Beets, no tops	R
Blackberries	R, F
Blueberries	R, F
Broccoli	I, F, H
Cabbage	R, F
Cantaloupe	H, F
Carrots, topped	I, R
Corn, sweet	H, I, V
Cucumbers	F, H
Eggplant	R, F
Endive	H, I
Garlic	N
Leeks	H, I
Lettuce	H, I
Onions, green	H, I
Onions, storage	N
Peas	R, H, I
Peppers	R, F
Potatoes, early	R, F
Potatoes, late	R, F
Potatoes, sweetness	N
Pumpkins	N
Radishes	H, I
Rutabagas	R
Spinach	H, I
Squash, summer	R, F
Squash, winter	N
Strawberries	R, F
Tomatoes	R, F
Turnips	R, H, V, I
Watermelon	N

F = forced-air cooling, H = hydrocooling, I = icing, R = room cooling, Five = vacuum cooling, Northward = no precooling needed.

Source:Kitinoja and Thompson (2010).

Other Options

Explore options for cooling if advisable, including vacuum cooling. Vacuum coolers can arrange a truckload of lettuce, and small vacuum coolers are available for one or 2 pallets. Tables 5 shows which cooling method is preferred for different produce, and Table six provides a comparison of cooling methods.

Tabular array 6. Comparing of cooling techniques.

	Room Cooling	Forced-air Cooling	Hydrocooling	Parcel Water ice
Typical Cooling Time (hours)	xx–100	1–10	0.i–ane.0	0.ane–0.3
Produce Moisture Loss (%)	0.1–2.0	0.1–2.0	0–0.5	No data
Water Contact with Produce	No	No	Yes	Yep
Potential for Decay Contagion	Low	Low	Loftier	Low
Capital Cost	Low to medium	Low	Low	High
Portability	No	Sometimes	Rare	Aye

Source: Kitinoja and Thompson (2010).

Storage

The most efficient mode to extend the shelf life of your produce is to quickly remove field heat and then maintain your produce at the correct temperature (Table seven). For example, in one trial, broccoli stored at 55°F started yellowing in just 6 days compared to 35 days at 32°F.

Practiced cold-storage facilities contain:

Adequate insulation
A vapor barrier on the warm side of insulation to forestall moisture condensation
Effective distribution of refrigerated air
Sensitive and properly located controls
Plenty refrigerated coil surface to minimize the difference betwixt whorl and air temperatures
Adequate chapters

Table seven. Uniform fresh fruits and vegetables during seven-day storage.

Group 1A: Vegetables, 32–36°F, 0–2°C, ninety–98% relative humidity

Alfalfa Sprouts
Artichoke
Arugula*
Asparagus*
Beans: Fava, Lima
Bean Sprouts
Beet
Belgian Endive*
Bok Choy
Broccoli*
Brussels Sprouts
Cabbage*
Carrot*
Cauliflower*
Celeriac
Celery*
Chard*
Chinese Cabbage
Chinese Turnip
Collard*
Corn: Sugariness, Baby
Cut Vegetables
Daikon*
Endive* - Chickory
Escarole*
Fennel
Garlic
Green onion*
Herbs* (non Basil)
Horseradish
Jerusalem Artichoke
Kale
Kohlrabi
Leek*
Lettuce*
Mint
Mustard Greens*
Parsley*
Parsnip
Radicchio
Radish
Rutabaga
Rhubarb
Salsify
Shallot
Snow Pea*
Spinach*
Sweet Pea*
Swiss Chard
Turnip
Turnip Greens*
H2o Chestnut
Watercress*

Group two: Vegetables, 45–fifty°F, 7–10°C, 85–95% relative humidity

Basil
Beans: Green, Wax
Cactus Leaves (Nopales)
Calabasa
Chayote*
Cowpea
Cucumber*
Eggplant*
Long Bean
Okra*
Pepper: Bell
Pepper: Chili
Summer Squash*
Tomatillo

Group 2: Fruits, 45–50°F, 7–10°C, 85–95% relative humidity

Grapefruit*
Lemon*
Lime*
Orange
Passion Fruit
Pummelo
Tamarillo
Tamarind
Tangelo
Tangerine
Ugli Fruit
Watermelon

Group 3: Vegetables, 55–65°F, 13–18°C, 85–95% relative humidity

Cassava
Dry out Onion
Ginger
Potato
Pumpkin
Squash: Winter, Difficult Rind*
Sweet Potato*
Tomato
Yam*

Group three: Fruits, 55–65°F, 13–eighteen°C, 85–95% relative humidity

Crenshaw Melon
Honeydew Melon

*Ethylene level should be kept below one ppm in storage area.

Keeping High Relative Humidity in Cold Storage

In club to minimize water loss, keep relative humidity at 85 to 95 pct for fruit, and 90 to 98 percent for vegetables except for garlic, dry onions, and pumpkins (lxx to 75 pct).

To maintain relative humidity:

Add together wet with misters (not recommended for nutrient safety).
Regulate air movement and ventilation.
Maintain refrigeration coils within 2°F of the air temperature.
Utilize polyethylene liners (polyliners) in containers.

Liners help reduce transpiration loss during cooling and storage. Photo by Andy Andrews, Screw Path Subcontract

Tips for Cold Storage

Stack bins in cold rooms with spaces between pallets and room walls to ensure that cold air tin circulate and cool produce.
Use plastic curtains on doors to reduce loss of cold air.

Bins should take spaces between them to allow for good airflow. Photograph past Andy Andrews, Pennypack Farm

Plastic curtains on doors help retain cold air and salvage energy. Photograph past Tuscarora Organic Growers

Examples of Storage Facilities

The about common produce storage is a refrigerated cooler or insulated room. Coolers should be sized accordingly to handle the maximum volume of produce expected.

For some growers (east.chiliad., those on rented ground), ownership a used, insulated marine shipping container and adding a refrigeration unit may evidence price effective.

Insulated shipping container retrofitted with a cooling unit to provide produce storage. Photo past Roots to River Subcontract

CoolBot-equipped Cold Room

Another option for providing refrigeration is to use a modified air conditioner. The control system of the unit is modified to let it to produce low air temperatures without building up ice on the evaporator coil. Without this unit, the ice buildup restricts airflow and stops cooling. Recently a company developed an easily installed controller that prevents ice buildup but does not require modifying the control system of the air conditioner (CoolBot, Shop It Cold, LLC, storeitcold.com). Assuming prices in U.S. dollars, a room air conditioner with a CoolBot control organization costs about 90 pct less than a commercial refrigeration system of equivalent chapters. Notwithstanding, keep in listen that while the air conditioner/ CoolBot organization has the capacity to keep the air temperature at 36°F, it does not have the capacity to cool big volumes of produce rapidly, which is of import for produce quality.

CoolBot command arrangement and air conditioner for a small cold room. Photograph past Roots to River Farm

Packing Shed

Why Update Your Packhouse Design?

Every extra movement equals time and money. I Pennsylvania subcontract shared that packhouse labor is i-quarter the labor on their subcontract, which is second merely to harvest labor. Making workers in the packhouse comfortable, happy, and efficient by creating a healthy and efficient working environs volition make you money. For loftier-quality produce your packhouse must exist designed with postharvest science and food safety in mind.

Minimum Packhouse Requirements

A roof with sidewalls volition protect workers and produce from the dominicus, air current, and rain.
A walk-in cooler allows you to preharvest crops and evangelize them chilled to the heir-apparent.
A supply of drinkable water and drains to move the water abroad. This could be as simple as a gear up of hoses or a deep gravel bed.
Bathrooms and handwashing facilities are necessities. Workers handling produce must exist able to take care of sanitation needs easily. The handwashing station does not have to have warm water, but warm water volition encourage workers to wash for the recommended 20 seconds. Soap and single-employ towels are a must.
To accost other food safety concerns, protocols should be fabricated for sanitizing equipment and facilities, and pests should be excluded. Open-air packing facilities can't exclude pests, but they tin can make the packing expanse less inviting to rodents, flies, and birds by keeping the area clean of debris, installing bird netting over open rafters, and moving pallets regularly. For more information, go to Keep Fresh Produce Safety Using Proficient Agronomical Practices .

A carport serves as protection for workers and produce. Bathroom facilities and walk-in coolers are located in befouled direct to the rear. Photograph past Tianna DuPont, Penn State Extension

Befouled converted to a packhouse with nutrient-form-painted walls, covered ceilings, and cement floors to allow for easy cleaning. Photo by Penn State Extension

Packhouse Location

Centralized admission to the packhouse on the farm can be helpful. Also call up about how produce volition enter the area. Doors that open to the level of your produce wagons and/or commitment trucks tin can better efficiency.

Design and Menses

Have you ever taken the time to watch how produce moves through your pack area from the field/truck to the cooler and back out to delivery? Does it look like this?

Figure 3. Inefficient design.

Source: Healthy Farmers, Healthy Profits, University of Wisconsin (Newenhouse et al., 2000).

In social club to see your packhouse with new eyes, enlist the help of a fellow farmer or other person new to your farm, or video tape the packhouse in action. Think about how you can reduce the number of movements (steps, bending over, etc.) past creating a stride-by-footstep chore line.

Consider the following:

Is your space big plenty for your packing needs?
Is there a clear, uncluttered path for produce and workers to follow?
Is there plenty of light?
Does some produce demand to be sprayed and others dunked?
Could you run two lines into a shared workstation that has water and electricity?
Is the scale handy and easy to utilise?
Are supplies such as numberless and rubber bands kept where needed?

Convenient storage of numberless, twist ties, and other packing materials increases worker efficiency. Photo past Barefoot Gardens

Packhouse at New Morning Farm

Jim Crawford wants to ensure efficient flow in the packhouse (Figure 4). Produce comes in on trucks or carts that back up to the correct height then workers can unload with pallet jacks and move directly into the cooler for cooling without having to elevator boxes. For produce that must be spray washed after cooling, the crew washes at spray tables that tin be adjusted to an ergonomic top for each worker. Directly after spray tables are the spinner for greens and dry pack area. User-friendly shelves contain bags, twist ties, knives, and other postharvest tools.

Figure four. Packhouse

Source: New Morning time Farm

Packhouse Worker Health

Washing and packing involve a lot of repetitive labor. Think about means to brand workers more comfortable.

Are workstation heights adjusted to private workers?
For lightweight items, efficient work peak is halfway betwixt wrist and elbow measured when the arm is held down at the worker'due south side (slightly lower for heavier items).
Do electric cords have basis fault circuit interrupters? They are piece of cake to install and can prevent electrocution.

Variations on Basic Components

Douse tanks. Greens are oft triple-rinsed to remove soil and freshen them. Depending on the book of produce you are working with, you may want to have larger or smaller basins.
Spray tables. Tables tin be of different materials, such equally stainless steel; however, wood is not recommended for surfaces that contact produce. Spray tables may also accept screens, plastic liners, floor tiles, and other components to aid in keeping the expanse clean and produce safe.

Plastic laundry basins (right) can exist plumbed to part every bit triple-rinse sinks that can be sanitized hands. Photo by Penn State Extension

Ane-hundred-gallon and 150-gallon equus caballus troughs are oft used for washing medium-scale amounts of greens. Photograph by Penn State Extension

Spray tables made with flooring tiles provide an easily cleanable surface that is also smooth and less probable to nick produce. Tianna DuPont, Penn State Extension

This spray table uses a cement mixing pan to catch spray h2o; the screen is on hinges for easy access to clean the basin; and the overhead piping of water keeps hoses off the flooring. Photo by Andy Andrews

Labor Savings and Efficiencies

Washing and packing can eat a quarter of the labor on a farm. A well-designed packhouse can pay for itself rapidly in reduced labor costs. Here are a few examples of potential labor saving components to include in your packhouse where advisable:

Pallets and pallet jacks
Roller tables
Conveyors
Sorting tables
Barrel washers
Brush washers
Foldable bins

Butt washers make washing root crops quick. For example, 160 pounds of turnips can be washed in 10 minutes. The barrel is at a slight bending. Information technology rotates at various speeds driven by a pocket-sized motor and a chugalug. Crops are fed into ane cease. Every bit crops proceed down the barrel they are sprayed by a series of small jets from the metal pipage bracketed inside the butt. A worker on the other end monitors the vegetables inbound a bin placed at the exit. Roots that are not clean plenty are tossed dorsum in for another washing. Speedily spraying bins with a hose before they are poured into the washer helps remove larger clumps of soil and reduce the number of roots that have to be thrown back in for a second washing.

Barrel washer. Photograph by Blooming Glen Subcontract

Castor washers can be used for many types of produce. Be careful to have a thorough and frequent cleaning and sanitizing schedule for brushes that tin can hold foodborne-illness-causing pathogens. Because about cannot be taken autonomously to be cleaned they can be a food safety concern. Gears will somewhen wear on these machines.

Brush washer. Photo by Scholl Orchards

Food Safe in the Packhouse

Do you take a handwashing station?
An enclosed packing area is preferred.
Open up walls are okay if measures are taken to continue pests out.
Keep the surface area clean and uncluttered.
Check the roof and walls for signs of water entry.
Water should drain away.
Glass fixtures should be shatterproof or covered.
Have a regular cleaning schedule for all areas.
Avoid using h2o-arresting materials (e.one thousand., wood) where produce comes in contact with the surface.
Avoid surfaces that are difficult to clean.
Water must be potable.
Use a sanitizing amanuensis in wash water.
Use a test strip or ORP (oxidation- reduction potential) meter to check the concentration of launder water sanitizer.
Change the water when it's dingy.
Make clean/sanitize the tank betwixt uses.
Monitor the temperature.
Do not wash overly dirty produce; prewash it.
Clean your hands and equipment!
Be sure sanitizers used are approved for food contact.

Crates on wheels, knife racks, automatic front doors, and a cement floor in the cooler all assistance improve efficiency in the pack surface area. Photo by Sandy Arnold, Pleasant Valley Farm

Pocketknife racks keep harvest knives organized and clean. Photograph by Pleasant Valley Farm

Sorting tables allow workers to efficiently size produce and check for quality. Photo past Scholl Orchards

This wash surface area has stainless steel spray tabular array and triple-basin sinks likewise as dry-pack tables. Shelving conveniently houses waxed boxes. Lights are covered with shatter proof plastic. The painted concrete floor is easy to clean and contains a floor drain. Mats make standing for long periods easier on workers. The handwashing sink is located to the rear. Photo by Tianna DuPont, Penn State Extension

This packhouse is covered to protect produce. All clean produce-contact surfaces are stainless steel or washable hard plastic. A sanitizer is used to clean all surfaces before each wash-pack. Drinkable well water is used for triple-rinsing produce with a nutrient-rubber sanitizer in the start and concluding washes. Photograph by Tianna DuPont, Penn Land Extension

For more detailed data, visit Penn State Extension Good Agricultural Practices .

For More Information

Fruit Growers News Buyers' Guide
Leopold Center for Sustainable Agronomics Mail-Harvest Handling Decision Tool
UC Davis Postharvest Xanthous Pages
Vegetable Growers News Buyers' Guide

References

Bautista, O. K., and R. C. Mabesa, eds. Vegetable Product. University of the Philippines at Los Banos, 1977.

Blanchard, C. "Post-harvest Handling Determination Tool." Ames, Iowa: Leopold Centre for Sustainable Agriculture and the Iowa State University Extension Value Added Agriculture Program, 2009.

Dris, R., R. Niskanen, and Southward. M. Jain, eds. Crop Direction and Postharvest Handling of Horticultural Products. Enfield, NH: Scientific discipline Publishers, 2001.

DuPont, S. T., and L. LaBorde. "Reducing Food Safety Risks During Harvest." University Park: Penn Land Extension, 2015.

DuPont, S. T., and L. LaBorde. "Reducing Food Safety Risks in the Packhouse." University Park: Penn Land Extension, 2015.

DuPont, S. T., and L. LaBorde. "Safe Uses of Agricultural H2o." University Park: Penn State Extension, 2015.

Kader, A., ed. Postharvest Engineering of Horticultural Crops. 3rd ed. Davis: University of California, 2002.

Kitinoja, L., and J. R. Gorny. Postharvest Technology for Pocket-size-Calibration Produce Marketers: Economic Opportunities, Quality and Food Condom. Davis: UC Postharvest Applied science Enquiry and Information Centre, 1999.

Kitinoja, L., and J. F. Thompson. "Pre-cooling systems for smallscale producers." Stewart Postharvest Review 2, no. ii (2010): 1–fourteen.

Newenhouse, A., et al. "Packing Shed Layout." Work Efficiency Tip Sail. Madison: University of Wisconsin Healthy Farmers, Good for you Profits Project, 2000.

Thompson, J., A. Kader, and K. Sylva. Compatibility Chart for Fruits and Vegetables in Brusk-term Transport or Storage. Oakland: Academy of California Division of Agriculture and Natural Resources, 1996.

Thompson, J. F., et al. Commercial Cooling of Fruits, Vegetables, and Flowers. Oakland: University of California Sectionalisation of Agriculture and Natural Resources, 2008.

Thompson, J. F., et al. "Effect of cooling delays on fruit and vegetable quality." Perishables Handling Quarterly 105 (2001): 2–5.

Prepared by Tianna DuPont, one-time sustainable agriculture educator, in collaboration with the Seed Farm, Emmaus, Pa.

Reviewed by Dr. Marita Cantwell, UC Davis, and Tom Ford, Penn Land Extension.

This project was funded in part past a grant from The Redevelopment Fund.

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Source: https://extension.psu.edu/keeping-produce-fresh-best-practices-for-producers