Guidelines for Storing Produce • Harvest fruits and vegetables at optimum maturity for best storage. Only a few fruits ripen after harvest. • Use produce that is free from evidence of disease or severe insect damage. • Avoid cutting or bruising. • Leave an inch of stem on most vegetables. • Store late-maturing varieties & those suited for storage.
Plant Biology Fruits and vegetables come from all parts of a plant: • Seeds and pods – peas, beans • Bulbs - onions • Stems – celery, rhubarb • Leaves – leafy greens • Roots & tubers – potatoes, sweet potatoes
Life of a Plant Development Breakdown Death Growth_ _ _ _ _ _ _____Maturation _ _ Ripening_ _ _ pea summer squash _ _ _ _Senescence apple pear tomato
Is it a fruit or a vegetable? These fruits are most commonly consumed as if they were vegetables: cucumber, tomato, eggplant and avocado. And rhubarb, a vegetable, is most commonly consumed as if it were a fruit!
Postharvest Handling of Produce Harvested fruits and vegetables are living structures. • Respiration: Glucose + O2 CO2 + H2O + Heat • Transpiration: Tissues lose water as they breathe
Postharvest Respiration Climacteric respiration Non-climacteric respiration
Fruit Respiration Patterns • Climacteric fruits exhibit a burst of respiration as senescence begins. This burst of respiration is triggered by the plant hormone ethylene. (apples, avocadoes, bananas, pears, peaches, tomatoes) • Non-climacteric fruits exhibit a decline in respiration through ripening and senescence. (blueberries, cherries, citrus, cucumbers, grapes, pineapple, strawberries)
Quality & Temperature Refrigeration slows respiration, extending shelf life and preserving quality. The right temperature can maintain the proper starch-sugar balance. Sweet Corn & Peas: sugar is desired in these crops; warm temperatures allow sugar to be converted to starch store cool (38ºF) Potatoes: starch is desired; cold temperatures allow breakdown of starch to sugar store warm (52º F)
Chill Injury • Refrigerating some fruits and vegetables (tomatoes, sweet potatoes, bananas), causes chill injury. • Signs of chill injury are pitting of the skin (eggplant, tomatoes), browning of the flesh (avocadoes, bananas, sweet potatoes), and water-soaked areas (cucumbers). • Refrigeration causes toxic products to accumulate in the tissue, and cells die. Store these crops at room temperature for best quality.
Maintaining tissue moisture levels is important for quality. Maintain the natural waxy cuticle – an edible wax is applied to tomatoes, cucumbers, citrus fruits, apples and turnips. Package to maintain moisture Lower the temperature to reduce respiration and transpiration water losses. Quality & Water Content
Situation: Climacteric fruits like bananas and apples will ‘ripen’ if exposed to ethylene. Avocadoes, bananas, pears and other fruits can be forced to go through some changes associated with ripening by exposing them to ethylene gas. At home, hasten ripening of fruits by enclosing them in a paper bag! Induce Ripening with Ethylene
Preventing Disease During Storage • Most fruits and vegetables will resist disease as long as the skin is intact. • Before storage, carefully inspect produce for cuts, bruises and signs of decay. • Maintaining the correct moisture level is also important. Do not attempt to preserve damaged produce!
Successful Storage Begins in the Garden • Harvest early in the day, but after dew is gone • Gently remove soil • Sort produce • Wash, if necessary, and dry
Maximizing Storage Life • Maintain moisture but not too much! • Remove diseased produce • Store at ideal temperature & avoid temperature extremes • Cold & moist: 32°F-40°F & 95% humidity (apples, broccoli, spinach) • Cold & dry: 32°F-40°F & 65% humidity(onions, garlic) • Cool and dry: 50°F-60°F & 60% humidity (winter squash, pumpkins) • See Storing Fruits and Vegetables from the Home Garden (UWEX A3823)
Storage Compatibility • ‘Beware’ of strong odors – don’t store cut onions near apples or potatoes • Ethylene-producing fruits can damage other produce – don’t store apples near lettuce, asparagus, beans • Humidity and temperature requirements can vary
Building a Storage Area • Outdoor storage – in-garden storage, mounds or pits, or buried containers • Indoor storage – basement, cellar, attic….you choose! See Storing Vegetables and Fruits at Home (Washington State EB1326)
Safety First! Avoid foodborne illness with careful handling • Purchase undamaged produce • Purchase cut produce only if surrounded by ice and kept cold • Bag fruits and vegetables separately from meat and poultry • Wash all produce before eating or preparing • Use clean cutting boards and utensile
Wash…For Safety • Wash hands and surfaces well • Rinse all produce under running water; do not use soap • Scrub the surface of melons, potatoes, and thick-skinned produce items • Gently rinse berries • Remove outer leaves of leafy greens • Remove tops of carrots and beets, and stems, where appropriate
Safety Tips & Questions • Avoid sprouted seeds • Avoid unpasteurized juices • Avoid cut melons held at room temperature • Wash bagged produce, just for insurance • Refrigerate all leftovers