Device for storing vegetables under home conditions

Abstract

The invention solves the problem of long-term storage of vegetables, especially potatoes, onions and garlic, under home conditions. This problem is relevant for many consumers due to the increase in urban population with a lack of suitable storage spaces, such as cellars. Specifically, the invention relates to a device for storing vegetables that comprises a small- volume container and a means for releasing a sprout inhibitor. The sprout inhibitor is a natural volatile substance such as a plant essential oil, e.g. essential oil of caraway, cinnamon, oregano and mint, or its chemical constituent. The container has a specific wall composition, so it ensures that the crop is in the dark and is in an atmosphere with suitable concentration of the sprout inhibitor and with a suitable air humidity.

Description

[0001] Device for storing vegetables under home conditions

[0002] Field of technology

[0003] The invention relates to long-term storage of vegetables, in particular potatoes, onions and garlic, in particular under conditions of the ordinary household. Specifically, it relates to a device that comprises a small-volume container for storing vegetables, and further comprises a means that releases a sprout inhibitor.

[0004] Prior art

[0005] When storing vegetables, such as potatoes, onions or garlic, it is necessary to create conditions in which the weight, consumer quality and biological value of the given crop are lost as little as possible. In large warehouses, the said crops are therefore kept in rooms where darkness and suitable low temperature are maintained to prevent sprouting, and where air exchange is ensured, which removes the increased amount of CO2 and excess humidity (or, contrary, the humidity is artificially increased, if needed), in short, a specific microclimate is maintained. Small-scale growers and ordinary consumers usually store potatoes and vegetables in cellars or at least in a pantry, where it is dark and the temperature is lower than the usual temperature in living rooms, or in the refrigerator, where it is dark and the temperature is around 4-10 °C. Here, however, the consumer is usually limited to only a small amount of the vegetables due to space constraints, and in addition, the air humidity in the small refrigerator space is often almost 100 %. In large quantities, vegetables are stored in large warehouses, where the necessary microclimate is maintained, e.g. for potatoes, a temperature of 5-8 °C and a relative air humidity of 90-95 %. Unsuitable storage conditions often lead to a sprouting, weight loss, an occurrence of microbial diseases and consequently a decrease in the quality of the crop stored. For this reason, synthetic or natural sprout inhibitors (anti -sprouting agents) are used in the storage of potatoes in particular, which has been known for a long time. Commonly used chemical inhibitors are isopropyl-N-(3-chlorophenyl)-carbamate (CIPC) and isopropyl-N- phenylcarbamate (IPC). CIPC is currently banned in the EU countries, and substitutes include maleic hydrazide (MH), 1,4-dimethylnaphthalene, ethylene or ethanol, or plant essential oils (orange, mint). Garlic and onions have different storage requirements than potatoes, especially when it comes to humidity. For storing garlic in the household, a slightly lower temperature than room temperature (13 - 18 °C) and a relative humidity of approximately 60 % are recommended to prevent it from drying out, but excessive humidity is harmful to it. Storage of the onions is recommended at a relative humidity of 65 - 75 %, at room temperature or slightly lower temperature. Both garlic and onions can be stored in the light, but storage in the dark is preferable.

[0006] Patent EP0287946B1 dealt with the use of essential oils from plants of the genus Mentha as potato sprout inhibitors.

[0007] Patent CZ291110B6 concerns the use of volatile monoterpenes as potato sprout inhibitors, D-carvone is listed as the most preferred inhibitor, which suppresses germination to an extent comparable to synthetic inhibitors.

[0008] Patent US6313073B1 relates to a potato sprout inhibitor, which is a mixture of acyclic monoterpenes selected from citral, geraniol, citronellol and citronellal.

[0009] Patent application US20120328749A1 relates to a potato storage system that provides air circulation with CIPC vapours in storage areas.

[0010] Patent application WO2021247958A1 deals very generally with a method of releasing an active agent, such as a sprout suppressant, and a device for implementing this method. It describes a composition that contains a porous sorbent to which a sprout suppressant, such as peppermint or caraway seed essential oil, is bound. The preferred suppressant is carvone. The sorbent is a carbonaceous or silicate material. The method of the sprouting suppression consists of placing the said composition in a release device that is placed in a storage container. The patent application does not address the problem of the container properties or storage conditions other than the concentration of the sprout suppressant.

[0011] The prior art does not comprehensively solve the problem of small-volume (consumer) medium-term to long-term (for several weeks to several months) storage of vegetables at normal room temperature. This problem is typical for many consumers due to the increase in urban settlements with a lack of suitable storage spaces (such as cold cellars). Summary of the invention

[0012] The aim of the present invention is to contribute to solving the above problem and to provide a small-volume (so-called consumer) storage device suitable mainly for storage of about 5 - 10 kg of potatoes or 1 - 3 kg of garlic or onions, in the home, or also usable for school cafeterias / small restaurants / family guesthouses (e.g. for amounts of about 25 - 50 kg vegetables), allowing long-term (z.e. not only for several days, but several weeks to several months) storage of vegetables at normal room temperature, and moreover, in a healthy way, i.e. without the use of synthetic chemicals, only with inhibitors of sprouting and undesirable organisms of natural origin. The term “vegetables” means all common vegetables that are stored in the household (not intended for immediate consumption only), such as potatoes, onions, garlic, celery, parsley, carrots, beets, Jerusalem artichokes, sweet potatoes, yams, but especially potatoes, onions and garlic. In addition, a design of the device is made using as many natural materials as possible (wood, jute), and the device is fully functional without electricity and electronics, and further, most of the materials used are recyclable.

[0013] Specifically, the invention relates to a device for long-term storage of vegetables in home conditions, which comprises a container for storing vegetables and a means releasing a sprout inhibitor, the means being placed in the container. The sprout inhibitor is a substance that inhibits sprouting and optionally also has an antimicrobial effect.

[0014] Long-term storage means storage for a period of several weeks to several months, e.g. up to 2, 3, 4, 5 and 6 months. Storage in home conditions refers in particular to storage at normal room temperature (e.g. 18 - 24 °C), not only in the household, but also, for example, in school cafeterias, family boarding houses or small restaurants.

[0015] The container ensures with its properties that the stored vegetable is in the dark and is in an atmosphere with suitable air humidity and with a suitable concentration of the sprout inhibitor. The container can be, for example, a bag or a box, the wall of which is impermeable to light and partially permeable to gases (O2, CO2, H2O), and which is optionally provided with at least one ventilation opening, preferably adjustable ventilation opening.

[0016] In one embodiment, the means releasing the sprout inhibitor comprises a sorbent (also called carrier), a sprout inhibitor that is bound to the sorbent, and a packing that allows a release of the sprout inhibitor from the carrier into an interior of the container. The sprout inhibitor used in the present invention is natural sprout inhibitor, i.e. natural volatile substance such as a plant essential oil (briefly also essential oil) or its chemical constituent (briefly also constituent), e.g. essential oil of caraway, cinnamon, anise, mint. The sorbent is a material capable of binding the largest possible amount of sprout inhibitor and releasing it in the desired amount for the longest possible time, such as zeolite, bentonite (aluminosilicate), silica gel and other types of silicates, biochar or wood sawdust. An exemplary packing is for example a porous bag, such as "tea bag" type bag, preferably a bag made of perforated polypropylene or non-woven polyester (PES) fabric.

[0017] The term “binding” means any connection or association between the sorbent and the sprout inhibitor that ensures that the sorbent retains and gradually releases the inhibitor for some time. The term therefore does not mean only adsorption or chemical bonding per se.

[0018] The means for releasing the sprout inhibitor could also be an evaporator - a container with openings or a permeable closure made of porous material (a wooden porous lid, an absorbent plate (felt) or a wick). The evaporator can also be porous ceramics, wood or other suitable absorbent material of compact shape, which is saturated with a solution of the sprout inhibitor.

[0019] In one embodiment, the container is a bag (sack), in another embodiment it can be a box (case, crate). A wall of the container comprises at least two layers, preferably multiple layers of different materials. It is essential that the wall must ensure a suitable internal environment inside the container - darkness, adequate humidity and sufficient concentration of the sprout inhibitor. In a preferred embodiment, the container is a bag, the wall of which comprises, in various embodiments, variously combined at least two layers selected from polyethylene (PE, polyethylene foil), aluminium (Al, aluminium foil), polypropylene (PP, polypropylene foil), polyvinyl chloride (PVC, PVC foil), polyester (PES, non-woven fabric) and a fabric or knitwear, preferably a natural fabric or knitwear, i.e. a fabric or knitwear made of natural fibres (e.g. jute, cotton, linen). The wall of the container may optionally comprise at least one ventilation opening. In the case that at least one layer of the wall is completely impermeable to water vapor, the wall comprises at least one ventilation opening. At least one layer of the wall is substantially impermeable to light, the total light transmittance of all layers should be as low as possible, less than 10 %, preferably less than 5 % and more preferably less than 1 %.

[0020] In preferred embodiments, jute refers to jute fabric, with a basis weight of 100 - 1000 g / m2, preferably about 305 g / m2. Polyester refers to polyester fabric, woven or non-woven, preferably thermo-plastically bonded non-woven fabric, with a basis weight of 50 - 1000 g / m2, more preferably about 100 g / m2. Aluminium refers to aluminium foil, or an aluminium layer applied to a plastic foil, polyethylene refers to a polyethylene foil. In one preferred embodiment, instead of the aluminium and polyethylene layers, a multilayer membrane is used, which contains a thin aluminium layer applied between a layer of polypropylene and polyethylene (so called metallized polyethylene), the membrane having a diffusion equivalent air layer thickness (sa) in the range of 10 - 200 m, preferably about 50 m. This membrane is oriented with the polyethylene side towards the inside of the container. The bottom of the bag can be the same as the walls or preferably made of a fabric with a leak-proof coating covered with a fabric or knitwear, e.g. cotton fabric, on the inside of the bag.

[0021] The preferred arrangement of the layers (from the outer to the inner layer) is jute-aluminium, polyester-aluminium, jute-polyester-aluminium-polyethylene. The most preferred wall appears to be one containing jute as the outer layer, then polyester, aluminium foil and polyethylene as the inner layer. Jute can be replaced by another natural fabric, e.g. cotton, linen, nettle or hemp fabric or a mixed fabric.

[0022] The volume of the bag (after closing, for example with a drawstring) is 1 - 50 1, preferably 2 - 30 1, more preferably 3 - 20 1, so that it allows for example for storing about 1 kg of garlic, 2 - 3 kg of onions, 2 - 5 kg of potatoes, 10 kg of potatoes, or even 25 kg of potatoes.

[0023] In another embodiment, the container is a box (case / crate). For example, it can be a case with a hinged or removable lid, which is made of metal, plastic, wood or solid cardboard. One embodiment is, for example, a crate with a lid, which is made of wood, e.g. spruce or pine wood, and is lined on the inside, e.g. first with aluminium foil and then with polyethylene or is lined with polyester, aluminium foil and finally with polyethylene on the inside.

[0024] It is advantageous to provide ventilation openings, preferably regularly spaced, in the wall of the container, which corresponds to 1 to 4 % of the surface of the container, preferably approximately 2 % of the surface of the container. The area of the ventilation openings is preferably adjustable.

[0025] A natural sprout inhibitor is a natural volatile substance such as a plant essential oil (also called briefly essential oil, ethereal oil or aromatic oil) or its chemical constituent, for example essential oil of wild maijoram (Origanum vulgare . clove (Syzygium aromaticum), camphor (Cinnamomum camphora), caraway (Carum carvi), dill (Anethum graveolens), maijoram (Origanum majorana . mint (Mentha arvensis. Mentha piperita), wild thyme (Thymus pulegioides), savory (Satureja hortensis), cinnamon (Cinnamomum verum, Cinnamomum cassia), thyme (Thymus vulgaris), litsea (Litsea cubeba), lemon grass (Cymbopogon citratus), ginger (Zingiber officinale) and others, as known to experts, or a combination of two or more different essential oils. The name oregano will also be used interchangeably with wild marjoram in the specification.

[0026] The preferred chemical constituent is cinnamaldehyde, citronellal, eucalyptol, eugenol, geraniol, hexanal, camphor, carvacrol, carvone, limonene, linalool, menthol, pinene, terpineol, thymol and others, including possible isomers, as known to those skilled in the art, or combinations of two or more different constituents. Most preferably, it is carvone.

[0027] Plant essential oils as such are well known to those skilled in the art, and methods of obtaining essential oils from plant material and methods of isolating the ingredients are also known.

[0028] The sorbent may be, for example, zeolite, bentonite (aluminosilicate), nanoclay, activated carbon, biochar, gel, wax, cotton, or wood sawdust. Preferably, it is bentonite or wood sawdust. Most preferably, it is wood sawdust.

[0029] The packing is, for example, a small bag, sachet or box made of a porous material, for example the bag or box made of porous paper (filter paper), or the box with holes (a perforated surface that forms at least part of the surface of the box), more preferably a "tea bag" type bag, made for example from paper, cellulose, Manila hemp, lactic acid polymer, polyethylene, PES or any combination thereof, most preferably the bag made of the porous paper or non-woven PES fabric.

[0030] The present invention relates to a device for long-term storage of vegetables under home conditions, the device comprising a container and a means for releasing a sprout inhibitor, placed in the container, where the container is a sealable container in the form of a bag or box, the wall of which comprises at least two layers, where at least one layer is impermeable to light, and the wall is partially permeable to air and water vapor and / or comprises at least one ventilation opening; and the means for releasing a sprout inhibitor comprises a natural sprout inhibitor and a sorbent, wherein the sprout inhibitor is bound to the sorbent.

[0031] In a preferred embodiment, the container wall comprises at least two layers selected from a woven or knitted fabric, a polyester fabric, a polypropylene layer, an aluminium layer, a polyethylene layer, a polyvinyl chloride layer; and optionally comprises at least one ventilation opening; and a means releasing a natural sprout inhibitor further comprises a porous packing, wherein the natural sprout inhibitor bound to the sorbent is inserted in the porous packing; wherein the natural germination inhibitor is an essential oil or its chemical constituent or a combination thereof and the sorbent is selected from bentonite or wood sawdust or a combination thereof.

[0032] Preferably, the sorbent is wood sawdust.

[0033] In a preferred embodiment, the natural sprout inhibitor is selected from the essential oil of oregano (Origanum sp.), clove (Syzygium sp. camphor (Cinnamomum sp.), caraway (Carum sp.), dill (Anethum sp.), marjoram (Origanum sp.), mint (Mentha sp.), wild thyme (Thymus spi), savory (Satureja sp.), cinnamon (Cinnamomum spi), thyme (Thymus sp.), litsea (Litsea spi), lemon grass (Cymbopogon sp.), ginger (Zingiber sp.) or combinations thereof or chemical constituents of said essential oils or combinations thereof.

[0034] In another preferred embodiment, the constituent is selected from cinnamaldehyde, citronellal, eucalyptol, eugenol, geraniol, hexanal, camphor, carvacrol, carvone, limonene, linalool, menthol, pinene, terpineol, thymol or any combination thereof.

[0035] Preferably, the natural sprout inhibitor is an essential oil of oregano, an essential oil of caraway or carvone.

[0036] In another preferred embodiment, the container is a bag, the wall of which comprises layers, in the direction from the outside to the inside, natural fabric or knitwear + polyester fabric + aluminium layer + polyethylene foil, or natural fabric or knitwear + polyester fabric + polypropylene foil + aluminium layer + polyethylene foil, or natural fabric or knitwear + polypropylene foil + aluminium layer + polyethylene foil.

[0037] In yet another preferred embodiment, the container is a box, made entirely or partially of metal, wood, plastic or paper, the wall of which comprises layers, in the direction from the outside to the inside, polyester fabric + aluminium layer + polyethylene foil, or polyester fabric + polypropylene foil + aluminium layer + polyethylene foil, or polypropylene foil + aluminium layer + polyethylene foil.

[0038] Preferably, the container wall comprises a membrane comprising a thin layer of aluminium between a layer of polypropylene and a layer of polyethylene, which is oriented with the polyethylene side towards the inside of the container.

[0039] In a preferred embodiment, one or more ventilation openings in the container wall constitute 1 to 4 % of the surface area of the container, preferably approximately 2 % of the surface area of the container. The total light transmittance of all layers of the wall is less than 10 %, preferably less than 5 % and more preferably less than 1 %.

[0040] In a preferred embodiment, the sorbent with the bound sprout inhibitor is placed in a porous packing, which is a small bag made of a material selected from paper, cellulose, Manila hemp, lactic acid polymer, polypropylene, PES or any combination thereof.

[0041] The vegetables are preferably potatoes, onions or garlic.

[0042] The features of the preferred embodiments can be combined independently of each other.

[0043] Brief explanation of the drawings

[0044] FIG. 1 : Storing potatoes - inhibition of the potato sprouting when using storage bags with different wall compositions.

[0045] FIG. 2: Storing potatoes - weight loss of the potatoes using storage bags with different wall compositions.

[0046] FIG. 3 : Storing potatoes - inhibition of the potato sprouting in an 82-day experiment.

[0047] FIG. 4: Storing onions - weight loss after 8 weeks of storage.

[0048] FIG. 5: Storing onions - number of the rotten onions after 8 weeks of storage.

[0049] FIG. 6: Storing garlic - weight loss after 13 weeks of storage.

[0050] FIG. 7: Storing garlic - number of the rotten bulbs after 13 weeks of storage.

[0051] FIG. 8: Storing garlic - weight loss after 20 weeks of storage.

[0052] FIG. 9: Storing garlic - number of the rotten bulbs after 20 weeks of storage.

[0053] Examples of the embodiments of the invention

[0054] Example 1

[0055] Selection of the essential oils and its constituents

[0056] This example describes a preliminary experiment, the aim of which was to select suitable active ingredients (i.e. essential oil or its chemical constituent) with an inhibitory effect on potato sprouting. Potatoes of the " Adela" variety were used, stored in a refrigerator at 4 °C and 90 % relative humidity for several months before the experiment. After treatment with the active ingredient the tubers were stored in the dark at 21 °C and 60 % relative humidity for 14 weeks (simulation of home conditions).

[0057] 7 essential oils (all obtained from Biomedica spol. s.r.o., Prague, Czech Republic) and 21 pure substances of the constituents (all obtained from Sigma-Aldrich, Merck Life Science, Czech Republic) were used to treat stored potatoes, an overview of which is given in the following table 1.

[0058] Table 1. Essential oils used in the experiment

[0059] Table 2. Chemical constituents used in the experiment

[0060] For the purpose of the experiment, jars with a volume of 1 1 were used as storage containers. To ensure air exchange in the jar with the surrounding environment, 3 holes with a diameter of 3 mm were drilled in the lid. Based on preliminary experiments, the amount of active substance (i.e. sprout inhibitor) was 300 l / 1. The active substance was applied to 3 g of bentonite (Sigma- Aldrich, Merck Life Science, Czech Republic) at the bottom of the container and then the bottom was covered with KA4 filter paper. The experiments were performed in 3 replications, the control contained bentonite without active substance.

[0061] Over the course of 14 weeks, the following parameters were monitored: sprouting (number of sprouting buds), weight loss and occurrence of fungal infection. The numerical results are presented in the form: arithmetic mean ± standard deviation.

[0062] The value of the average sprouting showed the most significant inhibition of sprouting with menthol and caraway oil (0 + 0 %; 0.52 ± 1.38 %). Significant inhibition was also provided by carvone with sprouting values of 2.78 ± 7.35 %, 4-terpineol with 2.85 ± 7.54 %, camphor 4.54 ± 8.35 % and citronella essential oil 4.46 ± 11.81 %. Linalool with a value of 5.7 ± 10.20 % and citronellal with 6.66 ± 16.75 % did not exceed the sprouting limit of 10 %. The sprouting value of the control was 71.81 ± 4.88 %.

[0063] Weight loss was observed to some extent for all essential oils and constituents. The smallest tuber weight losses (mean ± standard deviation) were observed in the treatment with anisole (4.51 ± 1.91 %) and lemongrass essential oil (3.10 ± 1.36 %). The weight loss of the control was 8.12 ± 1.75 %. A weight loss smaller than that of the control was also recorded for limonene, linalool, cintronellal, terpineol, caraway essential oil (5.33 ± 27.51 %) and geranium essential oil.

[0064] For some active ingredients, the inhibition of fungal diseases was weak, so that it was not even possible to complete the experiment. The active ingredients which provided complete inhibition of fungi until the end of the experiment (14 weeks) are marked with an asterisk in the Tables 1 and 2.

[0065] Example 2

[0066] Sorbents and sorption tests

[0067] Bentonite (trade name Superbenton DC, ZAN-AROMI, spol. s r.o., Czech Republic), nanoclay (Sigma- Aldrich, Merck Life Science, Czech Republic), biochar and wood sawdust were tested as the sorbents.

[0068] Bentonite was characterized by a content of 85 - 90 % montmorillonite and 1 - 4 % inert silica and a surface area of 88.0 m2g-1.

[0069] Biochar was prepared from dry raw wood chips with high initial moisture content (40-60 % wt. on a wet basis), which were gasified with hot air at a temperature between 500 and 600 °C for 6 hours. Gasification was carried out in a cogeneration unit in a multi-stage fixed-bed gasifier.

[0070] Wood sawdust came from different woods. Before application, dry sawdust was sieved (mesh size 0.5; 1.0; 2.0 or 3.0 mm) and washed with hexane to remove unwanted impurities. In a preliminary experiment, sawdust from beech (0.5 - 3 mm), alder (0.5 - 2 mm) and cherry (0.5 - 2 mm) and from a mixture of spruce and pine wood were tested. Sawdust from a mixture of spruce and pine wood sieved on a sieve with a mesh size of 1.0 mm proved to be the best.

[0071] Before the test, all of the listed sorbent materials were dried at 95 °C for 24 hours. After drying, 15 % (0.075 g) of the active substance, i.e. sprout inhibitor, was applied to 0.5 g of the sorbent, sealed in glass vials and shaken on a shaker for 24 hours at a temperature of 50 °C.

[0072] The active substance was pure carvone (Prvni Jilovska a.s., EXAR division, Jilove u Prahy - Radlik, Czech Republic), cinnamon essential oil (Biomedica spol. s.r.o., Prague, Czech Republic) comprising 73.1 % cinnamaldehyde, 5 % limonene, 5 % linalool, 3.7 % cinnamyl acetate, 3.5 % eugenol, and oregano essential oil (Biomedica spol. s.r.o., Prague, Czech Republic) comprising 64.5 %, carvacrol, 5.2 % p-cymene, 2.9 % thymol. Two more preliminary experiments were conducted with wood sawdust. The sorption duration (6 - 48 hours) was tested on two types of sawdust - from beech and cherry. The results of this experiment were not conclusive, the essential oil evaporated at a very similar rate in all treatments.

[0073] The evaporation rate of sawdust from alder, beech and cherry ground to different fineness (knife grinder, grinding time 1.5 min for the roughest, 4.5 min for the finest result), with two essential oils (cinnamon, oregano), was also tested for 20 hours. The results were also not conclusive, the fineness of grinding in this experiment did not have a significant effect on the evaporation rate.

[0074] Sorbents with bound active substance and a control (sorbent without active substance) were placed on dishes in a space with regular air flow and the weight loss during evaporation of active substances from the sorbent was monitored for 10 to 14 days.

[0075] The evaporation processes from wood sawdust were very similar for all substances. In the initial hours, a relatively sharp decrease in the content of active substances was seen, in the first fast phase (approximately linear), within approximately 36 hours from the beginning of the experiment, 60 - 65 % of the active substance was evaporated, in the second, slower phase (approximately exponential), between 36 hours and 70 hours, the content of the active substance decreased to approximately 15 - 30 % of the original content, and in the third slow phase (approximately linear) from 70 hours to 240 hours, the content of active substances decreased very slowly to a value of approximately 7 - 14 % of the original content.

[0076] When using other sorbents, the release processes were similar to wood sawdust, but the parameters of the three phases differed. When using the nanoclay sorbent, the first rapid phase lasted 10 - 14 hours and 30 - 40 % was released, the second phase lasted up to approximately 56 hours and the active substance content dropped to 25 - 35 % of the original content, in the last phase after 240 hours from the beginning the balance was 10 - 15 % of the original content. The control showed a relatively high air moisture binding.

[0077] The evaporation of active substances from bentonite was characterized by the first rapid phase, which lasted 7 - 10 hours and 30 - 40 % was released, the second phase lasted up to approximately 70 hours and the active substance content dropped to 15 - 30 % of the original content, in the last phase after 240 hours from the beginning the balance was 10 - 15 % of the original content. When using biochar, the first rapid phase lasted 7 - 14 hours and 15 - 20 % was released, the second phase, this time rather linear, lasted up to approximately 70 hours and the content of the active substance decreased to 55 - 65 % of the original content, in the last phase the decrease was very slow or the weight was practically constant and after 240 hours from the beginning the balance was 50 - 55 % of the original content. The inspection showed that biochar bound a relatively large amount of air moisture. It was able to absorb and retain the active substances for a longer period of time, but apparently released only a part of the substances that it bound.

[0078] Evaporation of the active substances from wood sawdust showed that sawdust is an exceptionally suitable sorption material for the purposes of the present invention. Bentonite appeared to be the second best, while biochar proved to be the least suitable due to the high rate of absorption of air moisture and the relatively low rate of release of the active substance.

[0079] Example 3

[0080] Potatoes: Experiment 1

[0081] Carvone (Prvni Jilovska a.s., EXAR division, Jilove u Prahy - Radlik, Czech Republic) bound to three different sorbents, namely wood sawdust (spruce + pine mixture), bentonite and biochar (for details see Example 2), was used to treat stored potatoes (Laura variety). Temporary containers with a volume of 0.65 1 (jam jars) with a lid in which ventilation openings were drilled (3 holes with a diameter of 3 mm) were used for storage. The amount of 1.105 g of the sorbent with 195 pl of carvone (for adsorption on the sorbent see Example 2) placed in a porous bag (tea bag) were used for one container. Re-sorted healthy tubers were placed in containers and a bag with carvone was inserted between them, the containers were placed in a completely darkened room with a temperature of 22 ± 1 °C and a relative humidity of 60 %. The control contained a sorbent without active substance. Everything was carried out in 3 repetitions and statistically evaluated. For 105 days, the weight loss of tubers, the number of sprouts and the weight of sprouts were monitored. Microbiological spoilage was also continuously monitored, tubers that were affected by microbial contamination were excluded from the experiment and they were not monitored further, the sample weight was corrected accordingly. After the end of the experiment, a sensory evaluation was also performed. Weight loss of the tubers

[0082] Table 3 shows the relative weight loss (in % of the initial weight) after 105 days of the storage. The smallest loss was demonstrably with carvone bound to wood sawdust and carvone bound to bentonite, the same loss was also shown by the control with biochar.

[0083] Table 3: Total weight loss of the tubers in % and final weight in % of the initial weight

[0084] Number of sprouts

[0085] The strongest inhibition of sprouting was shown by carvone sorbed on wood sawdust, in this treatment an average of 1.03 ± 1.07 sprouts per 1 tuber appeared by the end of the experiment, and carvone sorbed on bentonite with a value of 2.13 ± 0.37 (the values given here and in other experiments represent the mean ± standard deviation). The pure control showed values with a number of sprouts of 3.9 ± 0.82. The differences between the treatments with carvone and the control were highly significant. Carvone sorbed on biochar showed the highest number of sprouts per tuber, 3.11 times greater than in sawdust. Carvone bound to biochar did not reduce the number of sprouts, signs of the beginning of sprouting also appeared first in carvone sorbed on biochar.

[0086] Sprout weight

[0087] The weight proportion of sprouts per potato weight was monitored. The lowest mass proportion of sprouts was measured in tubers treated with carvone sorbed into sawdust with a percentage value of 0.46 ± 0.57 %. The pure control had a mass proportion of sprouts 3.01±0.16 %. Carvone on sawdust was significantly different from the control, while carvone on biochar was practically without effect. Microbiological spoilage

[0088] The highest number of spoiled tubers were in carvone sorbed into biochar, the second most frequent occurrence of microbial spoilage was bentonite, the least microbiological spoilage was recorded for carvone on sawdust, where there was not a single microbiological spoilage during the entire experiment. The pure control showed only one microbiological spoilage. Thus, carvone on wood sawdust completely inhibited the growth of pathogens causing microbial spoilage during potato storage.

[0089] Sensory evaluation

[0090] The sensory evaluation showed that potatoes treated with carvone have the best-rated appearance, the most natural aroma and the most satisfactory taste of all samples, along with the control, i.e. tubers treated with pure sawdust.

[0091] The experiment showed that carvone bound to wood sawdust significantly inhibited sprouting, reduced the number and weight of sprouts, completely eliminated microbial spoilage and in the sensory evaluation the sample appeared to be the same or even better than the control.

[0092] Potatoes: Experiment 2

[0093] Potato tubers (see Experiment 1) were stored for 3 months in bag-type container, the wall of which was made of various materials and their combinations (from the outer layer to the inner layer):

[0094] Jute; polyester; aluminium; polyethylene; jute + polyester; jute + aluminium; jute + polyethylene; polyester + aluminium; polyester + polyethylene; jute + polyester + polyethylene; jute + polyester + aluminium + polyethylene. In multi-layer treatments, the first name refers to the outer layer, the last to the inner layer of the container wall.

[0095] The simplified names of the materials mean: Jute is a jute fabric, with a weight of 100 - 1000 g / m2, preferably approximately 305 g / m2. Polyester is a polyester thermoplastically bonded non-woven fabric, with a weight of 50 - 1000 g / m2, preferably approximately 100 g / m2. Aluminium means aluminium foil, polyethylene means polyethylene foil. In a preferred embodiment, instead of these two layers, a multilayer membrane (KRUMBER REFLEX ALU90, KRUMBER GROUP Marcin Tomaszewski, Ksawerow, Poland) was used, which contains a thin layer of aluminium between a layer of polypropylene and polyethylene (so-called metallized polyethylene) with diffusion equivalent air layer thickness (sa) in the range of 10 - 200 m, preferably approximately 50 m. The aluminium layer is essential for light impermeability, the polymers ensure strength and vapor tightness. This membrane was oriented with the polyethylene side towards the inside of the bag.

[0096] The bottom of the bag was made of PES fabric with a PVC coating resistant to leakage (KORTEXIN®, KINETIC s.r.o., Drzovice, Czech Republic) covered with cotton fabric on the inside of the bag.

[0097] Approximately 2.5 kg of potatoes were placed in each bag and 2.5 g of carvone adsorbed on bentonite were added (for preparation, see Example 2), i.e. 1 g of carvone per 1 kg of potatoes. The sorbent with carvone was placed in a tea bag and thus inserted into the bag between the potatoes.

[0098] The bags with potatoes were placed in a room with normal lighting (250 lx) and darkness in a 12-hour / 12-hour mode, a temperature of 22 °C and a relative humidity of 55 % to simulate an average home environment.

[0099] The following parameters were evaluated every week: weight loss, number of the sprouts and incidence of the diseases.

[0100] Graphical representation of the course of the sprout inhibition and weight loss are shown in FIG. 1 and FIG. 2.

[0101] In terms of weight loss, the material combinations jute + aluminium and jute + polyester + aluminium + polyethylene proved to be the best.

[0102] In terms of sprout inhibition (reduction in the number of sprouts), the combinations jute + polyester + aluminium + polyethylene, jute + aluminium, polyester + aluminium showed the best results.

[0103] The best option in terms of minimizing microbial spoilage was jute + polyester + aluminium + polyethylene and jute + aluminium.

[0104] The experiment proved that the most advantageous container, i.e. the container in which the highest inhibition of sprouting, the highest inhibition of microbial spoilage and the smallest weight loss occurred, was the bag with the wall of the layers (from outside to inside) of jute + polyester + aluminium + polyethylene and the bag with the wall wherein the outer layer was jute, then polyester, then multilayer membrane (polypropylene, aluminium, polyethylene).

[0105] Potatoes: Experiment 3

[0106] Potato tubers (see Experiment 1) were stored for 82 days in bag-type container with a wall made of jute + polyester + membrane (polypropylene + aluminium + polyethylene) (see Experiment 2). In a bag for 5 kg of potatoes there were 32 ventilation openings (made in the membrane) with a total area of 18 cm2, which represented approximately 2 % of the total surface area of the bag.

[0107] Approximately 2.5 kg of potatoes were placed in each bag. Different concentrations of the active substance (carvone) in different sorbents (sawdust, bentonite) were tested, as shown in the following table 4. After saturation with the active substance (see procedure in Example 2), the sorbent was placed in a tea bag and this was placed between the tubers in the container. The containers were placed in a room with normal lighting (250 lx) and darkness in a 12-hour / 12- hour cycle, a temperature of 22 °C and a relative humidity of 55 % to simulate an average home environment. Sprout inhibition was continuously evaluated.

[0108] Table 4: Overview of the concentrations of the active substance - sprout inhibitor (carvone) in different sorbents (wood sawdust, bentonite)

[0109] FIG. 3 shows sprout inhibition (expressed as the number of sprouts) for the combinations of active substance (carvone) concentration and sorbents listed in Table 4.

[0110] Experiment 3 showed that the most effective in terms of germination inhibition was carvone adsorbed on wood sawdust (3.6 g carvone per 14.4 g sawdust), namely at a dose of 1.44 g carvone per 1 kg of potatoes.

[0111] In addition, the effect of ventilation was tested in a preliminary experiment. During carvone treatment, a different number of ventilation openings was chosen (0, 16, 32 and 64 openings, the area of the openings was in the range of 0 - 4 % of the bag surface) for four potato varieties (Dicolora, Gala, Royata, Madison). From the point of view of ventilation, in a bag with a wall composed of jute + polyester + membrane (polypropylene + aluminium + polyethylene) the optimal number of ventilation openings in the inner layer (i.e. membrane) was found to be 32 (2 % of the bag surface). A lower number of openings caused a higher incidence of diseases and sprouting, while a higher number caused faster drying of stored tubers. No significant difference was noted between the tested potato varieties.

[0112] Example 4

[0113] Onion: Experiment 1

[0114] As sprout inhibitors, essential oils were used - cinnamon essential oil and oregano essential oil (both Biomedica spol. s.r.o., Prague, Czech Republic), the composition of which is detailed in the Example 2.

[0115] A bag-type container was used, which has proven successful for potatoes, where the wall was jute + polyester + aluminium + polyethylene (from outside to inside), and which is described in detail in the Example 2. In this case, the bag was without ventilation openings. One container contained 800 - 850g of the onions (Allium cepa, variety Wellington) and a tea bag with sorbent (bentonite or sawdust) and bound essential oil (0.5 g per 2 g or 1 g per 4 g of sorbent). The control was without essential oil. The containers were stored in a room with conditions simulating household conditions (temperature 22 °C, relative humidity 55 %, light / darkness 12 hours. All treatments were implemented in 3 replications.

[0116] Weight loss, occurrence of rot, visible occurrence of microbial contamination, occurrence of roots and sprouting were monitored for 17 weeks. At the end of the storage experiment, a sensory analysis was performed.

[0117] The following table 5 shows the total losses in % of the original quantity after 16 weeks, where the losses include onions that have sprouts and / or roots and / or a rot.

[0118] Table 5: Percentage evaluation of onions with sprouts / roots / rot after 16 weeks of monitoring

[0119] Some onions showed rotting of the first outer layer, but the inside of the onions was undamaged. Sprouting was observed in only three onions from the entire experiment. Roots were most visible in the control groups, and to a lesser extent in onions with essential oil present.

[0120] Wood sawdust proved to be a more effective carrier. In terms of weight loss, oregano essential oil was most effective in a dose of 1 g. In terms of sensory evaluation, on the contrary, onions in the presence of 1 g of cinnamon essential oil were rated as the best. Onions: Experiment 2

[0121] The biggest problems are fungal and bacterial diseases, sprouting, and in the case of low relative humidity, drying out. The second onion experiment was carried out with cinnamon and oregano essential oils sorbed onto bentonite or wood sawdust (see Experiment 1). The treatments were subsequently tested during storage for 8 weeks in a bag with the same wall composition as in the previous experiment, but sized to hold approximately 2 kg of onions. The same bag, but without essential oil (Control 1), a bag of the same size made of non-woven fabric (Control A), a bag with 4-layer wall system (jute-PES-aluminium-polyethylene) without essential oil and with perforations ensuring more intensive ventilation (Control H) were used as controls. Weight loss (see FIG. 4), the occurrence of the rot (see FIG. 5) and of the sprouts were evaluated. Subsequently, a sensory evaluation was performed.

[0122] Drying was most pronounced in the control treatment in the non-woven fabric bag. It is very breathable, and therefore could not maintain the necessary air humidity. On the other hand, thanks to this, it was able to maintain a relatively low level of other undesirable phenomena. The lowest weight loss was in the bentonite + oregano treatment. Oregano essential oil also had a low incidence of the rot, while cinnamon did not inhibit rotting much. The opposite was true in the case of the occurrence of rot, although the difference was not so significant there.

[0123] The lowest incidence of sprouts was observed in the treatment with oregano essential oil, the highest in the control treatments and cinnamon essential oil sorbed on sawdust. Sensory analysis showed that treatment with oregano essential oil had no negative effect on appearance, smell, or overall acceptability. On the contrary, the treatment with cinnamon essential oil had a slightly negative effect, and the worst was the control treatment in a non-woven bag.

[0124] Example 5

[0125] Garlic: Experiment 1

[0126] For the storage experiment, garlic (Allium sativum L., variety Dukat) and 2 types of essential oils (oregano and cinnamon) were selected, the essential oils were adsorbed onto two different sorbents: wood sawdust and bentonite (essential oils and sorbents identical to Example 4). The essential oils were used in two concentrations: 0.5 g of essential oil + 2 g of sorbent, and 1 g of essential oil + 4 g of sorbent. The sorbent with the bound essential oil was placed in a tea bag and this was placed in a container with garlic. The controls were without essential oil. Storage took place in a bag-type container identical to the Examples 3 and 4 for 4 months, continuous control of the garlic sample was carried out once a week. Each bag contained 350-400 g of garlic (5-7 bulbs). The bags were stored in an environment simulating household conditions (see example 4). All treatments were performed in 3 replications. Weight loss (see FIG. 6) and sprouting were monitored. After the storage experiment was completed, the garlic was peeled and selected cloves were cut to check for internal damage and changes, and a sensory evaluation of the garlic was also performed.

[0127] The results confirmed that the presence of essential oil suppressed the growth of pathogens during garlic storage. A statistically significant difference was demonstrated between the control samples and the samples stored with essential oils. The best effect against the occurrence of microbial contamination (see FIG. 7) was achieved in garlic samples stored with oregano essential oil in both concentrations, which were sorbed on bentonite or sawdust. Sprouting was significantly reduced in all samples where essential oil was present. Sensory evaluation did not demonstrate the effect of essential oils on sensory properties.

[0128] The most advantageous combination was 1g of oregano essential oil in wood sawdust (4 g), which led to a reasonably small weight loss, while completely eliminating microbial contamination and sprouting.

[0129] Garlic: Experiment 2

[0130] The same experiment as on onions (Example 4, Experiment 2) was also carried out on garlic, for a period of 20 weeks. The results are also very similar (see FIG. 8 and FIG. 9). The highest weight loss was observed for the control treatment without essential oil and in non-woven fabric bag. This time, both essential oils significantly reduced the incidence of the rot compared to the control treatment, completely independent of the sorbent used. The incidence of rot was generally at a low level, as was the incidence of the sprouts.

Claims

PATENT CLAIMS1. A device for long-term storage of vegetables under home conditions, comprising a container and a means for releasing a sprout inhibitor, the means being placed inside the container, characterized in that the container is a sealable container in the form of a bag or box, the wall of which comprises at least two layers, where at least one layer is impermeable to light, and the wall is partially permeable to water vapor and / or comprises at least one ventilation opening; and the means for releasing a sprout inhibitor comprises a natural sprout inhibitor and a sorbent, wherein the natural sprout inhibitor is bound to the sorbent.

2. The device for long-term storage of vegetables under home conditions according to claim 1, characterized in that the wall of the container comprises at least two layers selected from a fabric or knitwear, a polyester textile, a polypropylene layer, an aluminium layer, a polyethylene layer, a polyvinyl chloride layer; and optionally comprises at least one ventilation opening; the means for releasing the sprout inhibitor further comprises a porous packing, wherein the natural sprout inhibitor bound to the sorbent is placed in the porous packing; and wherein the natural sprout inhibitor is a plant essential oil or a chemical constituent thereof or a combination thereof and the sorbent is selected from bentonite or wood sawdust or a combination thereof.

3. The device for long-term storage of vegetables under home conditions according to claim 1 or 2, characterized in that the sorbent is wood sawdust.

4. The device for long-term storage of vegetables under home conditions according to any one of claims 1 to 3, characterized in that the natural sprout inhibitor is selected from the essential oils of oregano or marjoram (Origanum sp. clove (Syzygium sp.), camphor (Cinnamomum sp.), caraway (Carum sp.), dill (Anethum sp.), mint (Mentha sp.), wild thyme (Thymus sp.),savory (Satureja sp.), cinnamon (Cinnamomum sp. thyme (Thymus sp.), litsea (Litsea sp.), lemon grass Cymbopogon sp ), ginger (Zingiber sp.) or combinations thereof or the chemical constituents of said essential oils or combinations thereof.

5. The device for long-term storage of vegetables under home conditions according to any one of the preceding claims 2 to 4, characterized in that the chemical constituent is selected from cinnamaldehyde, citronellal, eucalyptol, eugenol, geraniol, hexanal, camphor, carvacrol, carvone, limonene, linalool, menthol, pinene, terpineol, thymol or any combination thereof.

6. The device for long-term storage of vegetables under home conditions according to any one of the preceding claims 1 to 5, characterized in that the natural sprout inhibitor is oregano essential oil, caraway essential oil or carvone.

7. The device for long-term storage of vegetables under home conditions according to any one of the preceding claims 1 to 6, characterized in that the container is a bag, the wall of which comprises layers, which are in the direction from the outside to the inside, natural fabric or knitwear + polyester fabric + aluminium layer + polyethylene foil, or natural fabric or knitwear + polyester fabric + polypropylene foil + aluminium layer + polyethylene foil, or natural fabric or knitwear + polypropylene foil + aluminium layer + polyethylene foil.

8. The device for long-term storage of vegetables under home conditions according to any one of claims 1 to 6, characterized in that the container is a box, made entirely or partially of metal, wood, plastic or paper, the wall of which contains layers, which are in the direction from the outside to the inside, polyester fabric + aluminium layer + polyethylene foil, or polyester fabric + polypropylene foil + aluminium layer + polyethylene foil, or polypropylene foil + aluminium layer + polyethylene foil.

9. The device for long-term storage of vegetables under home conditions according to any one of claims 1 to 8, characterized in that the container wall comprises a membrane whichcomprises a layer of aluminium between a layer of polypropylene and polyethylene and which is oriented with the polyethylene side towards the inside of the container.

10. The device for long-term storage of vegetables under home conditions according to any one of claims 1 to 9, characterized in that the one or more ventilation openings in the container wall constitute 1 % to 4 % of the surface area of the container, preferably approximately 2 % of the surface area of the container.

11. The device for long-term storage of vegetables under home conditions according to any one of claims 1 to 10, characterized in that the total light transmittance of all layers of the container wall is less than 10 %, preferably less than 5 % and more preferably less than 1 %.

12. The device for long-term storage of vegetables under home conditions according to any one of the preceding claims 1 to 11, characterized in that the sorbent with a bound natural germination inhibitor is placed in a porous packing, which is a bag made of a material selected from paper, cellulose, Manila hemp, lactic acid polymer, polypropylene, polyester or any combination thereof.

13. The device for long-term storage of vegetables under home conditions according to any one of the preceding claims 1 to 12, characterized in that the vegetables are potatoes, onions or garlic.

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