Fruit and berry storage
What is the keeping quality of fruits and berries?
The ability of fruits and berries to maintain food and nutritional properties for a certain time is called keeping quality. For example, the coloration of the fetus is largely influenced by the storage temperature: increased promotes the rapid decomposition of chlorophyll in the cells and yellowing of the product, low - can worsen the color of fruits and berries. So, in some varieties of apples, the flesh is darkened at a temperature of about 0 ° C. Optimum keeping quality is manifested only with the correct harvest and storage conditions, taking into account the characteristics of the species and variety.
Do fertilizers affect the quality of fruits and berries?
Various fertilizers do not equally affect the quality and keeping quality of the crop. So, mineral fertilizers to a certain extent determine the chemical composition of fruits and berries, their growth and ability to store. The application of some fertilizers to the soil usually leads to a corresponding accumulation of these substances in the product. An excess of nitrogen is harmful, as the density of fruits and berries decreases, their color and transportability deteriorate. resistance to mechanical damage. A sufficient amount of potassium and phosphorus in the soil contributes to the accumulation of sugars, coloring and aromatic substances in fruits, and improves their keeping quality. Mineral fertilizers affect the appearance of certain physiological diseases during storage. In this case, calcium plays a decisive role. The insufficient content of it in apples contributes to the occurrence of physiological diseases (bitter fissure, browning of the pulp), leading to rapid aging of the fetus. An effective remedy for such diseases is the pre-harvest treatment of trees with a 0.3-0.7% solution of calcium chloride or immersion of fruits in a 4% solution of this salt. Potassium, unlike nitrogen, has a positive effect on the color and density of fruits and berries. Under the influence of mineral fertilizers, the taste of fruits can change. For example, with an excess of phosphorus, the fruits acquire a rough consistency.
Does rootstock affect the keeping quality of fruits?
The shelf life of the fruit depends on the stock. Trees grown on dwarf rootstocks early in fruiting and give large fruits. But such fruits ripen faster and are stored worse than those grown on vigorous rootstocks. Therefore, they must be removed from storage earlier.
Does watering affect the quality of the fruit?
High temperature combined with a large amount of precipitation contributes to the growth and faster ripening of fruits, but keeping quality in this case is reduced. In rainy but cold summers, the fruits have reduced sugar content, increased acidity, are poorly colored, ripen slowly and are poorly stored. Good keeping quality is characterized by fruits grown with sufficient and uniform precipitation, the absence of sharp temperature fluctuations and good illumination. Gardens should not be watered shortly before harvest. Otherwise, the keeping quality of the fruit is reduced, they are more affected by physiological diseases.
Do the size of the fruits and their placement on the tree, age and load of the crop affect keeping quality?
Yes. Excessively large fruits of the same variety are stored worse than medium and small, so the crop must be normalized. An important role is played by the age of the tree. Fruits from young plantations are less downy, as they are more susceptible to various kinds of diseases. Better and lower-lying fruits from the outer parts of the crown, well-lit by the sun.
What fruits can be stored?
When choosing a variety for storage, we must first take into account its natural keeping quality. In apples, the set of varieties should be such that they can be consumed in the summer, autumn and autumn-winter periods. In the middle lane for long-term storage, the fruits of the varieties Bogatyr, Wellsi, Northern Sinap, Zhigulevskoye, Lighthouse, Oryolsky Zimny, Lobo, Cortland, Vityaz, Antonovka vulgaris, Banana, Melba should be grown; in the south - Mekintosh, Calville Snow, Jonathan, Renet Si-Mirenko, Golden Delishes, Starking, Starkrimson.
When choosing a variety, its winter hardiness and resistance to diseases and pests are also taken into account.
Is it necessary to sort and calibrate apples after picking?
Before laying for storage, apples of each variety must be sorted, selected affected by diseases and pests or with mechanical damage. Only healthy fruits need to be stored. The larger the fruit, the earlier it ripens, breathes harder, releases more substances, which, in turn, affect the surrounding fruits, accelerating their ripening. Therefore, the fruits of one variety before storage is better to sort by size: large, medium, small. A calibration board is convenient for such an operation; it is easy to make it yourself. Holes must be made to the maximum caliber limit. Calibrated fruits should be packed separately and removed from storage at different times.
How to store apples - in containers or on shelves?
It is better to lay fruits and berries in storage in containers, because it not only protects against mechanical damage, but also creates favorable conditions for temperature and humidity around the product, and allows for more efficient ventilation and cooling. Regardless of the shape, size and design, the container must be durable, clean, made of softwood or moisture-proof cardboard. The more tender the fruits and berries, the smaller layer they need to be laid. It is advisable to store strawberries, raspberries, cranberries, currants, gooseberries in potato baskets and sieves, cherries, pears of summer varieties, plums in trays, apples and pears of late varieties in crates. However, boxes with too wide gaps between the boards spoil the fruits and are unsuitable for transportation and storage. Apples can be stacked in cardboard boxes, large trellised chests, plastic bags, on racks.
How to lay apples for storage?
Additional packaging protects the fruit from mechanical damage, infection, and also serves as a reliable protection against drying out of products. The packaging material must not absorb water, not have an odor and toxic properties.
It is best to isolate each apple from those adjacent to it: wrap it in paper or layered with loose material (peat, husk, buckwheat husk, linen towels, moss, wood leaves, sand). Shavings of soft hardwood with a thickness of 0.1-0.15 mm are not inferior in their advantages to other packaging materials. Wrapped, you need to store apples of varieties Melba, Pepin saffron, Lobo, Cortland, Spartak. The more fruitful the fruit is, the less mechanical damage there will be during transportation.
It is advisable to stack the fruits in boxes diagonally or in rows. In order to protect apples from sunburn, they should be packed in various materials: paper, napkins, shavings, soaked in liquid paraffin (100 g per 500 napkins). To do this, wrap the cloth on a rolling pin or roller, lightly soak it with oil and roll paper or napkins, after which each impregnated sheet should be transferred dry.
In such packaging, it is very good to store the fruits of the Antonovka variety ordinary (they are poorly stored in non-impregnated paper).
How to store pears?
For the middle band, it is still difficult to recommend pear varieties that, according to their keeping quality and taste, would meet consumer requirements. Fruits must be stored at a very low temperature - from minus 1 - minus 0.5 to 0-5 ° C. In this case, they are stored for several months, at elevated temperatures for several weeks.
Do not remove the pears too early. If, nevertheless, the fruits are picked green, it is advisable to store them at a temperature of 2-4 ° C, otherwise they will not ripen.
Is it possible to store fruits and berries in a plastic film?
Apples, pears, plums and black currants can be stored in plastic bags with a capacity of 1-1.5 kg, made of an unstabilized translucent high-pressure film with a thickness of 50-60 microns (a thicker film is unsuitable because it weakly transmits oxygen and carbon dioxide, so the products deteriorate quickly). As a result of the respiration of fruits and berries, carbon dioxide accumulates (4-6%) inside the package and the oxygen content decreases. These changes in the composition of the gaseous medium reduce the respiration rate of fruits and berries.
High air humidity (90-99%) in the bag causes insignificant moisture loss, therefore, the natural mass loss decreases to 0.6-1% and the product does not lose commercial quality.
The duration of storage is increased by 1.5-2 months. Polyethylene has another property. Through it pass various volatile (aromatic) substances secreted by fruits and berries. If these substances accumulated in the bag, the products would quickly mature. In this way, it is good to store varieties of apples Autumn striped, Saffron Pepin, Lobo, Spartan, Melba, Cortland. It is not recommended to pack varietal fruits in plastic wrap Antonovka ordinary, as in this case they quickly deteriorate.
The storage mode of apples and pears packed in a plastic container does not differ from the usual one (temperature 0–3 ° С, relative humidity 90–95%). Pre fruits must be cooled. To avoid moisture condensation in the bag, temperature fluctuations should be small. Bags with fruits should preferably be placed in containers or on racks previously coated with paper so that rough boards do not violate the tightness of the package. The condition of the products must be regularly monitored.
How to keep fruits and berries in plastic bags with selectively permeable membranes?
The oxygen content in the air is 21%, carbon dioxide - 0.03, nitrogen - about 79%. If the ratio is changed in such a way that the concentrations of oxygen and carbon dioxide respectively decrease and rise to a level that would hold the breath of the product without disturbing this process, then under such conditions some fruits and berries can be stored for a longer time. The following oxygen to carbon dioxide ratios are recommended: 12 and 9; 3 and 5; 3 and 1.
Storage in plastic bags with selectively permeable membranes (round, panel) is becoming more widespread. Inside the package, as a result of the vital activity of fruits and berries, the oxygen concentration decreases, and carbon dioxide increases. The optimal composition of the atmosphere provides a membrane.
What are the conditions for short-term storage of blackcurrant, wild strawberry, raspberry and gooseberry?
Black currant under normal conditions, it does not last long. In sealed plastic bags at a temperature of 0 ° C, it can be stored for 1-2 months. As a result of breathing, carbon dioxide accumulates inside the plastic packaging (up to 4-6%) and the oxygen content decreases. Due to these changes, the respiratory rate of the product decreases. With high humidity in the package (95-99%), moisture loss is negligible, so the natural loss of mass decreases to 1% and the product does not fade.
Strawberries - a very tender berry. It should be removed in the cool morning hours, quickly cooled and placed in a glacier or cellar with snow. When overripe, strawberries quickly deteriorate, so you need to collect it daily, at the same time sort the berries, folding unusable specimens in a separate container. After picking, it is impossible to sort and transfer berries, as their quality deteriorates, juice is lost. Even with rapid cooling with ice crumbs and subsequent storage in a refrigerator or in a glacier, it is difficult to keep strawberries for longer than five days. Dense berries of the varieties Talisman, Zenga Zengana, Nadezhda, Zenit are better preserved.
Raspberry - also a delicate berry. After careful removal, the berries are stored for only two to four days at a temperature of 0-0.5 ° C and a relative humidity of 85%. Therefore, you need to try to process raspberries in a timely manner.
Unripe berries gooseberry quite a long time stored in dry clean trays of 4-5 kg. Such a gooseberry can be stored in a refrigerator for three to five days, and mature for one to two days.
What is the best way to preserve berries?
In the collected, but not processed berries, biochemical processes continue that contribute to the deterioration of their quality. To reduce the harmful effects, the following conditions must be strictly observed: pre-cool the product (quickly remove heat from the collected berries); pick berries in a small container immediately upon picking, avoiding further transshipment and sorting of products; to harvest selectively and regularly, avoiding overriding of berries. This condition is easy to observe if there are varieties of berry crops in the garden with different ripening periods.
What are the features of storing cherries and plums?
Plums can be stored for two to four weeks, the fruits of varieties Vengerka vulgaris, Pamyat Timiryazev, Hungarian azhanskaya - four to five weeks (in favorable years). Harvest must be done carefully so as not to damage the wax coating, remove the fruit with the stem, carefully put it in a container and immediately send it for storage. In the first two weeks they can be stored at a temperature of about 0 ° C, then at a temperature of 5-6 ° C and a humidity of 85-90% (when the air is very dry, the drains quickly fade). Long-term storage at a temperature of 0 - minus 0.5 ° C leads to browning of the pulp. Cherry in the refrigerator is usually stored for no more than 10-15 days. It must be removed early in the morning, when the fruits have the best density of pulp. Sometimes, at too low a storage temperature, browning of the pulp is observed.
What air temperature should be maintained during storage of fruits and how to do it?
After picking, the fruits must be cooled and stored quickly at low temperature and high relative humidity. Elevated temperatures contribute to the rapid breakdown of chlorophyll in cells, too low can adversely affect the preservation of the fruit (the freezing temperature of apples is minus 1.4 - minus 1.8 ° C). The best temperature for many varieties is considered to be 0 ° C, for apples of the Antonovka variety and Renet Simirenko - the temperature is 2-3 ° C. To reduce the temperature (in the absence of ice or snow), the room must be thoroughly ventilated at night or during cooling. The temperature should be measured with two alcohol thermometers, one of which is suspended close to the floor and the place where air ventilation is (near the door, window), the other in the middle of the room. Constant temperature is the key to storage success.
What humidity should be maintained during fruit storage?
Increased moisture from the fruit occurs when the air is too warm and dry in the storage, strong ventilation and poor condition of the product. Therefore, during storage it is almost always necessary to increase air humidity. This should be done carefully, since with too high air humidity, molds and fungi develop very actively, and some physiological diseases of the fruits appear. The best relative humidity during storage is 90-95%. It is necessary to constantly control the humidity. For this purpose, it is better to purchase a psychrometer. With its help, you can timely measure the level of humidity and adjust it. To increase the humidity in the room where it is planned to store fruits, it is necessary to water the floor, and if the material allows, then the walls.
With significant temperature fluctuations, too high air humidity is unacceptable, as the fruits may sweat. Moisture condenses on the walls, containers, which contributes to the appearance of fruit rot. Humidity control should be carried out regularly throughout the entire storage period.
Do I need to ventilate the storage?
In the cool time of day, all storage facilities must be aired and equipped with ventilation.The more atmospheric air temperature fluctuates, the more carefully you need to ventilate the store to avoid condensation of moisture on the product.
What facilities can be used to store fruits?
Any rooms where it is easy to maintain a uniform temperature below 5 ° C and a relative humidity of 80–90%. Apples, for example, it is desirable to store in glaciers or cellars filled with snow, because they provide high humidity and a stable temperature of about 0 ° C.
How to build a glacier and a cellar?
Fruits can be stored in earthen cellars. For an in-depth cellar, you need to dig a foundation pit with sloping walls. Wooden poles should be buried in the ground, ground and put on a foundation made of rubble stone or wooden plates. In a land cellar, open earthen walls sometimes collapse, as a result, their annual mandrel is required. Therefore, it is desirable to strengthen them with any material (wattle, croaker). In cellars, sheds, pits, you can install the supply and exhaust pipes. It is acceptable to place barrels with ice-salt mixtures, to snow or to harvest it from spring (packing the cellar) and use in the most critical storage period. Convenient small recessed cellars made by freezing ice on pre-hammered formwork. With good insulation with sawdust and earth, such an ice cellar lasts three to four years.
The glacier is a cellar deepened into the ground with a vestibule, a compartment for storing products and an ice storage. There are three types of glaciers: with bottom, side and top ice loading. They should be stuffed once a year at the end of winter. Especially good to store raspberries, black currants, gooseberries in a glacier.
How to adapt rooms, cold dachas, verandas, balconies for storing fruits?
In the room near the window you can fence off a small room. If the room is cold, then the compartment must be additionally insulated, if warm, provide good ventilation (arrange a ventilation window or install a household fan). In a very cold room, such as on a veranda or balcony, the fruits should be stored in barrels placed in a box and additionally warmed with sawdust. The layer of sawdust should provide an ambient temperature of about 0 ° C. The higher the storage temperature, the fruit laying, their placement in the room should be more free. The use of the film in warm rooms prevents the wrinkling of fruits and reduces the consumption of nutrients for respiration.
How to prepare storage and containers for laying fruit for storage?
The premises should be thoroughly cleaned of residual fruits and debris. Garbage burn. To fight rodents, all supply and exhaust pipes must be covered with a metal mesh, burrows should be filled with broken glass and cement, or filled with a solution of bleach. Premises, containers, racks and various equipment must be disinfected, whitewashed walls and ceilings. For disinfection, you can use formaldehyde (20 cm3 of formalin + 20 cm3 of water per 1 m3 of volume) or sulfur dioxide (burn 10-20 g of sulfur per 1 m3 of room). Containers and equipment must be treated with soda ash or sterile. Do not disinfect rooms in contact with living rooms. All work must be carried out, strictly observing the rules of labor protection and safety, better under the supervision of a plant protection specialist.