G1264

Storing Fresh Fruits and Vegetables

The following NebGuide outlines proper storage methods and conditions for fresh fruits and vegetables.

---

Laurie Hodges, Extension Horticulturist
Durward A. Smith, Extension Horticulture Crops Processing Specialist

---

• Harvest Methods and Post-Harvest Care
• Curing Vegetables to Improve Shelf-life
• In Garden Storage
• Recommended Handling of Specific Vegetables and Fruits
• Acknowledgment

Harvesting fruits and vegetables from your garden at the proper stage of maturity is only the first step to fresh table quality. Proper harvesting and post-harvest handling methods, as well as proper storage of fruits and vegetables not immediately eaten, will help maintain the flavor, texture and nutritive value of the produce.

Proper storage means controlling both the temperature and relative humidity of the storage area. All fruits and vegetables do not have the same requirements. This NebGuide will help you select the best storage conditions for home-grown and purchased produce.

Harvest Methods and Post-Harvest Care

Most fruits and vegetables are easily bruised when not handled carefully. When harvesting, treat produce as if it were fine china. Tossing fruits and vegetables into baskets or boxes may not leave visible bruises and damage, but decay will begin under the skin. Seemingly sturdy vegetables such as sweet potatoes are actually quite tender and will not store well if bruised.

Not all produce should be washed upon harvest. Berries, for example, are very delicate and fragile. Rinse them in cold water just before consuming, as prior washing will cause them to break down and turn mushy. Potatoes store better if they have a fine layer of soil left on the skin to reduce moisture loss and prevent the infestation of water-borne bacteria or fungi. Water can transport bacteria and fungi into the pores of fruits and vegetables as well, reducing viable storage time.

Some produce, however, is washed and dried before storing. Commercial packing houses use sanitizers in packing line water to kill the fungi, bacteria and yeast that might otherwise cause spoilage. Sodium hypochlorite (liquid laundry bleach) is the most readily available of these sanitizers. Excessive use of hypochlorite can result in off-flavors, tissue damage and may change the surface pH of the produce, encouraging microbial growth. Therefore, it is important to use only the recommended amount of bleach in the wash water when cleaning produce.

Crops that may benefit from rinsing with water and very diluted chlorine bleach are noted in Table I.

 

<<<<<<< g1264.htm

Table I. Storage Requirements for Fruits and Vegetables.
Commodity	Storage Temperature* (°F)	Relative Humidity (%)	Average Storage Life	Storage Notes
Vegetables
Artichoke, Jerusalem	31-32	90-95	2-5 months
Asparagus	32-36	95-100	2-3 weeks
Bean & pea, dry	32-40	65-70	1 year
Bean, green or snap	40-45	90-95	7-10 days
Bean, lima	37-41	90-95	5-7 days
Beet (topped)	32	90-95	3-5 months
Broccoli	32	90-95	10-14 days
Brussels Sprout	32	90-95	3-5 weeks
Cabbage, late	32	90-95	3-4 months
Cabbage, Chinese	32	90-95	1-2 months
Carrot	32	90-95	4-5 months	trim tops to 1/2"
Cauliflower	32	90-95	2-4 weeks
Celeriac	32	90-95	3-4 months
Celery	32	90-95	2-3 months
Chard	32	90-95	7-10 days
Collard Greens	32	90-95	10-14 days
Corn, sweet	32	90-95	4-8 days
Cucumber	50-55	90-95	10-14 days
Eggplant	45-55	90-95	1 week
Endive, escarole	32	90-95	2-3 weeks
Garlic, dry	32	65-70	6-7 months	1, do not remove skins
Horseradish	30-32	90-95	10-12 months
Kale	32	90-95	10-14 days
Kohlrabi	32	90-95	2-4 weeks
Leek	32	90-95	1-3 months
Lettuce	32	95	2-3 weeks
Melon, muskmelon (Cantaloupe)	32-40	85-90	5-14 days
Melon, honeydew	45-50	85-90	3-4 weeks
Melon, watermelon	40-50	80-85	2-3 weeks
Mushroom	32	90	3-4 days
Okra	45-50	90-95	7-10 days
Onion, dry	32	65-70	1-8 months	1, do not remove skins
Onion, green	32	90-95	3-5 days
Parsley	32	90-95	1-2 months
Parsnip	32	90-95	2-6 months
Pea, green	32	90-95	1-3 weeks
Pepper, dry	32-50	60-70	6 months	4
Pepper, sweet	45-50	90-95	2-3 weeks	4
Potato, late	40-45	90	2-9 months	4
Pumpkin	50-55	70-75	2-3 months	2, 4
Radish	32	90-95	3-4 weeks
Rhubarb	32	95	2-4 weeks
Rutabaga	32	90-95	2-4 months
Salsify	32	90-95	2-4 months
Spinach	32	90-95	10-14 days
Squash, summer	40-50	90	5-14 days
Squash, winter	50-55	50-75	2-6 months	2
Sweet Potato	55	85-90	4-6 months	1, 4
Tomato, mature green	55-70	85-90	1-6 weeks	2, 4
Tomato, colored, firm	46-50	85-90	4-10 days	2, 4
Turnip	32	90-95
Fruits
Apple	30-40	90	3-8 months	4
Apricot	31-32	90	1-2 weeks
Avocado	50-55	90-95	3-10 days
Blackberry	31-32	90-95	2-3 days	3
Blueberry	31-32	90-95	2 weeks	3
Cherry, sour	32	90-95	3-7 days	3
Cherry, sweet	30-31	90-95	2-3 weeks	3
Grapefruit	40-50	85-90	4-6 weeks
Grape	31-32	85	2-8 weeks
Orange	32-40	85-90	3-10 weeks
Peach	31-32	90	2-4 weeks
Pear	29-31	90-95	2-4 months	4
Plum	31-32	90-95	2-4 weeks
Raspberry	31-32	90-95	2-4 days	3
Strawberry	32	90-95	5-7 days	3
1 - do not wash, brush off excess soil 2 - wash with 1 1/2 teaspoons liquid chlorine laundry bleach (5.25 percent sodium hypochloride) in one gallon of water 3- do not wash before storing, rinse just before using 4- see detailed section on storing this product *Note the storage temperatures of several commodities ranges from 45-55°F. Most fruits and vegetables of tropical and subtropical origin may be damaged by cool temperatures. Chilling injury, a result of prolonged exposure to low but not freezing temperatures, may interrupt the ripening process. Symptoms of chilling injury include dark circular pits on the surface, shriveling, internal darkening, loss of the ability to ripen and the development of off-flavor and poor texture. Careful attention to the storage conditions will help achieve maximum post-harvest life.

 

Table II. Ideal Temperatures and Humidity Levels for Curing Vegetables
Commodity	Curing Temperature (°F)	Curing Relative Humidity (%)	Length of Curing Time	Storage Temperature after curing (°F)
Irish Potato	60-70	80-90	10-14 days	35-45
Onion	60-80	40-50	3-7 days	32
Pumpkin	80-85	80-90	10 days	55-60
Sweet Potato	80-95	95	10 days	55
Winter Squash (except acorn)	80-85	80-90	7-14 days	55-60

 

Curing Vegetables to Improve Shelf-life

Several vegetables benefit from post-harvest curing. Curing heals or suberizes injuries from harvesting operations. It thickens the skin, reducing moisture loss and affording better protection against insect and microbial invasion. Curing is usually accomplished at an elevated storage temperature and high humidity.

Produce can be cured in home storage areas. Tem-perature and humidity should be managed as accurately as possible. A space heater in an enclosed area can provide the needed heat for curing. Humidity can be increased by over-laying containers with sheets of plastic.

In Garden Storage

Produce can be cured in home storage areas. Temperature and humidity should be managed as accurately as possible. A space heater in an enclosed area can provide the needed heat for curing. Humidity can be increased by over-laying containers with sheets of plastic.

In Garden Storage

Root crops such as beets, carrots, rutabagas, parsnips and turnips can be left in the garden into late fall and early winter. A heavy mulch of straw will help prevent the ground from freezing so the roots can be dug when needed. The mulch will also maintain the quality of the roots, as it will reduce repeated freezing and thawing of the vegetables. Many people prefer the taste of these root crops after they have been frosted because their flavors become sweeter and milder.

When temperatures drop low enough to freeze the ground under the mulch, finish harvesting the roots. Cut off all but one-half inch of the leafy top and store at 32° to 40°F in high humidity to reduce shriveling.

Recommended Handling of Specific Vegetables and Fruits

Irish Potatoes — Late-crop potatoes are better for long-term storage than early potatoes since outdoor temperatures are usually lower when they are harvested. After harvest, cure late potatoes by holding them in moist air for 1 to 2 weeks at 60 to 75°F. Wounds will not heal over at 50°F or below. After curing, lower the storage temperature to about 40-45°F. Potatoes will keep even longer at 35-40°F but at 35°F, potatoes tend to become sweet. This condition can be corrected by holding the potatoes at about 70°F for a week or two before you use them.

Potatoes will keep well for several months in a cool basement or cellar. They keep best in moderately moist air which helps prevent shriveling. Do not wash potatoes before they are put into storage.

Store potatoes in the dark; exposure to light causes them to turn green. The green pigment contains the toxic alkaloid solanine. Green sections of potatoes should be removed before cooking.

Onions can be harvested when the tops have fallen over and begun to dry. Do not bend over the tops during the growing season to “force the energy into the bulb.” This practice reduces the growth of the onions as they will not be able to translocate sugars to the bulb for storage.

Commercially, onions are dug, windrowed and allowed to cure in the field before they are picked up. Home gardeners should cure onions after harvest by spreading them in a single layer on screens in the shade or in a well-ventilated garage or shed for 1 to 2 weeks or until the tops are completely dry and shriveled. If the bulbs are exposed to full sun, prevent sunscald by covering with a light-weight cloth. When the tops are dry, they should be trimmed to 1 inch lengths. Leave the onion’s dry outer skins on; they help reduce bruising and shrinking and act as an insect barrier.

Store onions in shallow boxes, mesh bags or hang them in old nylons in a cold, dry, well-ventilated room. The tops may be left untrimmed and braided together. Temperatures close to 32°F will give the longest storage. Products prone to absorb odors or flavors should not be stored close to onions.

Sweet and Hot Peppers — Mature, green bell peppers can be kept for 2 or 3 weeks if handled properly. Firm, dark-green peppers free of blemishes and injury are best for storage.

To prevent chilling injury, pick peppers just before frost or before frost threatens if daytime temperatures are consistently below 45°F. Wash them with water containing 1 1/2 tsp. of chlorine bleach per gallon of water. Dry and sort according to maturity and firmness. Store peppers in boxes lined with plastic or in plastic bags which have several 1/4” holes punched in them to maintain high humidity. The temperature should be between 45 and 50°F. Fully mature green peppers may turn red during storage.

Hot chile peppers are easiest to store after they are dry. One exception is habanero or Scotch bonnet type peppers. These do not dry well except in a dehydrator. Peppers can be dried by either pulling the plants and hanging them upside down or by picking the peppers from the plants and stringing together. Ripe chili peppers can be dried in a forced air dehydrator, but it is usually not necessary to do so.

Tomatoes — With care, mature green tomatoes will keep and ripen for about 4 to 6 weeks in the fall. Some cultivars have been developed for even longer storage. Tomatoes from nearly spent vines are more subject to decay and are usually not as good quality as those from vigorous vines. A late planting of tomatoes will provide vigorous vines from which fruit can be harvested for storage.

Harvest tomatoes just before the first killing frost. If an unexpected frost occurs, undamaged fruits can be salvaged and ripened. Prevent chilling injury to the fruit by harvesting everything when temperatures drop regularly to 32° to 50°F.

To store, pick the tomatoes and remove the stems. Reduce rots by disinfecting fruits by washing in water with 1 1/2 teaspoon of chlorine bleach per gallon of water. Dry thoroughly with a soft cloth.

Pack tomatoes 1 or 2 layers deep in shallow boxes. Reduce bruising by separating those showing red; they will ripen sooner and can be used first.

Pumpkins and Winter Squash — Harvest mature fruit with hard rinds before frost. Leave the stem on when cutting from the plants to prevent decay organisms from entering. Pumpkins and winter squash will keep best if they are cured for 10 days at 80-85°F. Acorn squash, however, should not be cured but stored at 45°F to prevent stringiness.

Apples — Many cultivars of apples store moderately well under home storage conditions for up to six months. Late maturing varieties are best suited to storage. These apples can be stored in baskets or boxes lined with plastic or foil to help retain moisture. Always sort apples carefully and avoid bruising them. The saying “one bad apple spoils the barrel” is true because apples give off ethylene gas which speeds ripening. When damaged, ethylene is given off more rapidly and will hasten the ripening of other apples in the container. Because of their sugar content, apples can be stored at 30-32°F without freezing the tissue. In general, apples ripen about four times as fast at 50°F as at 32°F, so they should be kept as close to 32°F as possible for long-term storage.

Apples often pass their odor or flavor to more delicately flavored produce and the ethylene given off by apples can accelerate ripening in other crops. When possible, store apples separately.

Pears — For good flavor and texture, pears, except for ‘Seckel’ must be ripened after harvest. Pick pears when they are fully mature. Fruit is ready to harvest while it is quite firm but the color has lightened to a pale green. It should part easily from the branch when you lift up on the fruit and twist. Pears left to ripen on the tree tend to become grainy or stringy. The center also may turn brown before the exterior shows deterioration.

Pears ripen quickly after harvest when held at 60 to 65°F. Ripening will take 1 to 3 weeks, depending on the type of pear. After ripening, pears should be canned or preserved. To keep pears longer in storage, sort for defects after picking and place sound fruit into cold storage at 29-31°F and 90% humidity. Ripen small amounts as needed, by moving them to a warmer location, 60-65°F. Too high of temperatures (75°F and higher) will cause the fruit to break down without ripening.

Acknowledgment

The authors would like to recognize contributions made by co-author Susan D. Schoneweis to the first edition of this publication.