Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D85/00—Containers, packaging elements or packages, specially adapted for particular articles or materials
  • B65D85/50—Containers, packaging elements or packages, specially adapted for particular articles or materials for living organisms, articles or materials sensitive to changes of environment or atmospheric conditions, e.g. land animals, birds, fish, water plants, non-aquatic plants, flower bulbs, cut flowers or foliage
  • B65D85/52—Containers, packaging elements or packages, specially adapted for particular articles or materials for living organisms, articles or materials sensitive to changes of environment or atmospheric conditions, e.g. land animals, birds, fish, water plants, non-aquatic plants, flower bulbs, cut flowers or foliage for living plants; for growing bulbs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D81/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
  • B65D81/18—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient
  • B65D81/20—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas
  • B65D81/2069—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas in a special atmosphere
  • B65D81/2084—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas in a special atmosphere in a flexible container

Definitions

• the present invention is concerned with methods and means for the packaging of plant parts, and with packages thereof. It is primarily concerned with edible parts, particularly fruit and vegetables (including mushrooms), especially potatoes. It may be applied to immature ('early' or 'new') potatoes, or to maincrop potatoes.
• Fresh fruit and vegetables are living things, with natural processes occurring inside them. Respiration causes the uptake of oxygen and the production of carbon dioxide and water. There are also various spoilage processes. For example it is well known that potato tubers exposed to light produce chlorophyll and turn green. The green colour is generally unacceptable to consumers, and conditions which induce greening are also known to be associated with increased levels of glycoalkaloids which are known to be toxic and also cause bitter flavours. As a result of this phenomenon, food distributors, such as supermarkets, will generally mark the potato packaging with a "use by" date (or a "display until" date or a "best before” date) that is as little as 3 - 7 days after the potatoes have been packed. Even within this time, light induced greening may still cause considerable wastage both at point of sale and after purchase (in the home).
• the atmosphere has substantially the following composition: OXYGEN - 3 vol.% to 8 vol.% CO 2 - 3 vol.& to 18 vol.% OTHER GASES - 79 vol.% to 84 vol.%
• the other gases will generally be predominantly nitrogen, and usually some water vapour. It is important to avoid excessively low oxygen levels, as this can allow the occurrence of processes which may lead to increased susceptibility to microbial spoilage, tainting of the product, and potential food safety hazards.
• composition ranges it is probably the oxygen content that is important, with the carbon dioxide being probably of lesser, or no, significance.
• the package atmosphere it is highly desirable for the package atmosphere to have a relative humidity which is not too high and for there to be no condensation. This may then operate in synergy with the gaseous atmosphere to enhance pack life. Such a package can help prevent greening whilst at the same time minimising internal condensation and its negative effect on other spoilage mechanisms such as sprouting and wet and other rots.
• a package of plant parts comprising the plant parts and packaging therefor, said packaging defining an enclosure for said plant parts and comprising plastic film material having a moisture vapour-transmission rate (MVTR)in excess of 70 mg/day.m 2 (and preferably in excess of 100 mg/day.m 2 ; said enclosure being provided with restricted atmosphere communication means such that if said enclosure initially contains atmospheric air, then respiration of said plant parts causes a depletion of oxygen therein and this is partially counteracted by ingress of oxygen through said communication means, leading to a modified atmosphere with an oxygen content which remains in the range 2-14% by volume for at least 7 days.
• MVTR moisture vapour-transmission rate
• All MVTR values are measured at 38° and 100% RH.
• said plastic film material delimits at least 15%, preferably at least 25% and often essentially 100% of the enclosure so that the enclosure as a whole has good moisture transmission properties.
• the packaging itself will usually comprise a bag made of a film material, or a carton or tray usually of a rigid material at least partially enclosed by a film material.
• a bag made of a film material or a carton or tray usually of a rigid material at least partially enclosed by a film material.
• suitable water vapour transmission can be effected by transmission through the film material if it has a moisture vapour transmission rate of at least 100 and more preferably at least 200g/day.m 2 (measured at 38° and 100% RH), eg 100-1000 g/day.m 2 , preferably 200-800 g/day.m 2 .
• the film may have an oxygen transmission rate of 8-260 cm 3 /day.m 2 (at 23°C and 0%RH) though this is less critical since additional means for oxygen ingress may also be provided.
• Carbon dioxide transmission rates of 37-780 cm 2 /day.m 2 (at 23°C and 0%RH) may be suitable.
• Potatoes are usually packed in portions of 0.5 - 10 kg and apart from the transmission properties the packaging film should have sufficient physical strength to contain and support weights of this magnitude. This will be particularly important in areas where the pack construction requires that it is sealed to itself or to other films or materials.
• the film is preferably a film comprising polyamide (nylon), and suitably one which has been extruded by the blown or cast film process, and which may be mono or bi-axially oriented.
• the polyamide can be a homopolymer such as nylon 6 or co-polymer such as nylon 6.66, and can be blended, laminated, or coextruded with other suitable polymers which could include other polyamides, EVA, ionomer (e.g. Surlyn (trademark)), polyester, polycarbonate, styrene/butadiene resins, and polyolefin polymers including copolymers and metallocene resins.
• blends are preferred to laminates or coextrusions for maintaining good moisture vapour transmission properties.
• Blends may contain up to 40% by weight of the other polymer(s), preferably up to 30%, more preferably up to 25%.
• the film is transparent and glossy in order to facilitate the viewing of the package contents, this is not essential. In circumstances where transparency is not required, any of these films can be laminated to paper and still provide good anti-greening performance.
• Estima potatoes (a maincrop variety which is prone to greening) were packed in 2.5 kg portions in bags formed from 25 ⁇ m cast nylon. Two bags (H1 and H2) were heat sealed and three bags (T1 - T3) had their necks closed by taping. A further 2.5kg portion was packed in a conventional LLDPE bag with 6mm apertures as control (C). The bags were stored under illumination. Oxygen and carbon dioxide levels inside the nylon bags were measured after 4 and 7 days. The results are shown in Table 1.
• potatoes were analysed for glycoalkaloid contents, in peel and in whole tubers.
• the values found for packs embodying the invention ranged from 70 and 6 mg to 127 and 15 mg.
• the "127 and 15" bag had an oxygen content of 8.3% at 6 days.
• At 11 days 70% of its tubers showed some slight greening.
• NB 15 mg/kg of whole tubers is a very low value: values of 110 mg/kg are needed for perceptible bitterness, and toxicity requires in excess of 200 mg/kg.
• This experiment used potatoes which had passed their dormancy period and hence were prone to sprouting.
• the U bags contained 3.9 - 7.1% oxygen (mean: 5.8%) while the P bags contained 9.7% - 11.8% oxygen (mean: 10.5%).
• Greening the control bag showed severe greening after 6 days.
• the U bags showed no greening after 10 days.
• the P bags showed slight greening of 15% of tubers after 6 days, rising to 50% with slight greening after 10 days.
• Rotting The control and P bags showed no rotting after 6 days, and some rotting (0-6% of contents of each bag) after 10 days.
• King Edward potatoes which are very susceptible to greening, were packed in 2.5kg portions in bags made of 20 ⁇ m Nylon 6/Nylon 6.66 blend("NN") (water vapour transmission 680g/m 2 .day); and in bags made from a 25 ⁇ m film of a blend of 80% Nylon and 20% of another polymer(by weight) ("XN") (wvtr:400g/m 2 .day).
• a control sample (C) was packed in a punch-perforated LLDPE bag, as before. Bags were taped and stored as in Experiment 3.
• Atmospheres were analysed after 4 days. They were similar in the NN and XN bags, with oxygen level means of 10-12%.
• control bag showed misting whereas the NN and XN bags showed none.
• control bag showed greening after 4-5 days, the NN and SN bags showed none after 7 days. No evidence of soft rotting was seen.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Botany (AREA)
• Health & Medical Sciences (AREA)
• Evolutionary Biology (AREA)
• General Health & Medical Sciences (AREA)
• Marine Sciences & Fisheries (AREA)
• Toxicology (AREA)
• Zoology (AREA)
• Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)
• Storage Of Fruits Or Vegetables (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=10821435

Family Applications (1)

Country Status (2)

Cited By (1)

Family Cites Families (5)

• 1997
  • 1997-10-31 GB GBGB9723100.5A patent/GB9723100D0/en not_active Ceased
• 1998
  • 1998-11-02 EP EP98308953A patent/EP0918022A3/fr not_active Withdrawn

Also Published As

Similar Documents

Legal Events