WO2016071875A1

WO2016071875A1 - Polymer packaging that delays the ripening and senescence process in fresh vegetable products

Info

Publication number: WO2016071875A1
Application number: PCT/IB2015/058582
Authority: WO
Inventors: Cesar Augusto SIERRA ÁVILA; Sugey Maryuri MARTÍNEZ GÓMEZ; Luis Alejandro GUTIERREZ CARRANZA; Ricaurte RODRÍGUEZ ANGULO
Original assignee: Universidad Nacional De Colombia
Priority date: 2014-11-06
Filing date: 2015-11-06
Publication date: 2016-05-12

Abstract

The present invention relates to a polymer composition for absorbing ethylene and other gaseous compounds, which comprises a polymer substrate that consists of polyolefin or a mixture of polyolefins and one or more ethylene capture agents in a concentration between 0.5% and 5%. The invention also relates to a packaging that delays the process of ripening and senescence in fruits, vegetables and foliage and which is characterised in that it contains the above-mentioned composition, and a method for extending the shelf life of said perishable products during transport, storage and sale thereof.

Description

POLYMER PACKAGING THAT DELAYS THE PROCESS OF MATURATION AND SENESCENCE OF FRESH VEGETABLE PRODUCTS

The present invention relates to the sector of food chemistry, specifically to a package polymer made from polyolefins that incorporates in its composition at least one additive that allows to delay the maturation and senescence process in fruits, vegetables and foliage, thus offering the possibility of extending the life of these products perishable during transport, storage and marketing.

Throughout history they have developed techniques and processes aimed at the challenge of preserve food in the best conditions both sensory as phytosanitary. The design and creation of food packaging is a very important piece within the techniques aimed at maintenance and food quality assurance, since the packaging is directly related to two basic functions that are: the conservation process and Food protection. So, the performance that fulfills a package, in addition to having an active role in the extension of the shelf life of food, is to take care of the nourishment of environmental conditions such as light, oxygen, moisture, microorganisms, mechanical damage and pollutants (Ahvenainen, R. 2003).

In this way a definition of "Active packaging" as one that can alter or preserve several aspects in the food to achieve extend their lifespan, which focus on the modification of physiological processes such as Breathing in fruits and vegetables. To accomplish with the conservation process, active packaging can contain additives that perform specific functions inside the packaging as the modification of the process of breathing stated above. The mechanisms of operation of an active package can be: a) compound release (eg breathing gases) required in the atmosphere surrounding the food, b) of adsorption-absorption of a compound of interest (Ex. Ethylene) or c) obstruction of compound activity determinant in maturation.

In the surrounding atmosphere of plant-based foods (fruits and vegetables, among others), gases are found that affect their maturation process generating changes in color, taste and aroma, these are: oxygen (O ₂ ), carbon dioxide ( CO ₂ ) and ethylene (C ₂ H ₄ ). In the processes of post-harvest management and preservation of perishable foods, the control of the levels of the gases mentioned above is useful to delay the maturation process and thus extend the shelf life in fruits and vegetables. When the levels of O ₂ inside the packaging are reduced and those of CO ₂ are increased, it is possible to achieve that the ripening of fruits and vegetables can be delayed, since the speed of ethylene production is reduced and the speed of softening maturation itself manages to be delayed (Yahia, E. 2009).

When using films as packaging, the control of O ₂ and CO ₂ is carried out using the permeability of the film to said gases, or by means of adsorbent agents contained in a disposable hermetic bag known in English as sachet, (derived from the French word "sachet"); These sacks are additional envelopes that are not part of the packaging, but that travel inside the package together with the food and are made of a generally inorganic or polymeric material, with a specific pore size (US 4856650) that contains the active agent that It is responsible for the adsorption of gas. When oxygen trapping is required using the said sacks, good results have been found using copper and iron salts as adsorbents (US 7147799); Another possibility is to use the oxygen absorbing agent directly in the packing material and for these applications, transition metal salts (US 5700554), or porous aluminosilicates with high gas retention power (US 5221571) have generally been incorporated.

With regard to the management of the levels of ethylene inside food packaging, this one It is generally carried out by methodologies complementary to the packaging itself, as they are, the use of adsorbent agents in “saches” (Ahvenainen, R. 2003) and direct treatments in the plant material that inhibits ethylene biosynthesis, in which the use of 1-MCP, AOA and AVG stand out (1-methylcyclopropane, aminooxyacetic acid and aminovinylglycine, respectively) in solution (Paliyath, et al ;, 2008).

Applications where polymeric packaging directly, due to a synergism of its properties barrier and / or the presence of additives in the film, produce a decrease in ethylene concentration in the internal atmosphere of the packing they are not very common, being the closest to this type of mechanism, the work developed by Holland Robert (US 5334623), the which is based on the use of electro-deficient dienes incorporated in polymeric polyethylene packages or polycarbonates The additive used consists of a tetrazine diesteroctyl that induces red coloration, and when ethylene is absorbed into the film its coloration disappears, serving as much as Functionality indicator, for periods of time between 40 hours and several days (eg four days) at 20 ° C.

The present invention relates to a polymeric package that prolongs the shelf life of fresh vegetable products, which can be used in the fruit, vegetable and foliage marketing chains. This invention offers a product of easy production and agro-industrial implementation, capable of replacing existing technologies such as the use of specialized packaging materials in packaging systems with modified atmosphere, which only control the levels of O ₂ and CO ₂ , and that for Control ethylene use complementary attachments, such as the sacks already referred to, which are not part of the packaging entity. This invention shows polymeric packages with "additives" within the film, which modify the transmission rate of O ₂ and CO ₂ (gas barrier property) and also the concentration of ethylene, without the need for additional elements.

The initial consideration for the design of the formulation was to find chemicals sufficiently active and compatible (with nature of the polymer used) to be part of the packaging film and at the same time exercise control over the internal atmosphere of the bag removing ethylene. For that purpose different substances of the family of fatty acid derived esters, terpenes and pyridine compounds taking into account a possible affinity with ethylene. Experimentally it they placed various chemical compounds from families mentioned in contact with fresh fruits of optimal quality, within appropriate containers for Study of the fruit ripening process. And of according to the preliminary results on the incidence of the chemical compound in the properties external organoleptic of the fruit (color, texture and smell) its number was reduced to seven: monooleate polyoxyethylene, sorbitan oleate, α-monooleate glycerol, mixture of mono and triglycerides, squalene, diludine and AOA (aminooxyacetic acid).

Defined substances, named in this invention as an "additive", with the best features to produce the film that desired, the percentages of additive that were determined should be added to achieve the optimal effect on the fruits or vegetables that could be stored. Be found that percentages below 5% addition of additive allow to reach the best conditions of packing. The useful time of the packaging was determined with a single fruit; gulupa, the family's climacteric fruit of the passionflower, whose respiration rate is high in relation to other fruits and vegetables normally Found in a supermarket.

There are several fruits that present a crisis climacteric and therefore the production modification of ethylene can allow to delay the senescence of this type of fruit and extend its useful life (Hernández et al. 2010).

“According to the respiratory pattern and the ethylene synthesis at an early stage of maturity, The fruits have been classified into two categories: climacteric or non-climacteric (Kuntz et al. 1998, Seymour et al. 1993).

Rhodes (1980), cited by Blacksmith and Guard (1992), defines the climate crisis as a period of evolution of certain fruits in which a series of biochemical changes that begin with the autocatalytic production of ethylene, marking the step of growth towards senescence, presenting a increased breathing, which lead to maturation. In tropical fruits like guava (Psidium guajava), arazá (Eugenia stipitata), copoazú (Theobroma grandiflorum), gulupa or cholupa (Passiflora edulis) se find that there is a climate crisis at the beginning of the maturation; however, in other cases such as camucamu (Myrciaria dubia), coconá (Solanum sessiliflorum) and some varieties of chili pepper (Capsicum spp), ripening It is not accompanied by weather crisis (Bardales et al. 2008; Hernández et al. 2007; Barrera et to the. 2008; Jiménez et al. 2008) ”.

Polyoxyethylene monooleate additives, sorbitan oleate, glycerol α-monooleate and the mixture of monkey and triglycerides were chosen by their nature non-ionic surfactant that provide the properties required on the packaging, as considered non-toxic, and because of the thermal stability that allowed the processing of the packaging by means of extrusion. further to a possible antifog activity, the structure chemistry of these aliphatic esters allows to wait for a interaction with ethylene produced by fruits and vegetables and thus have anti-ripening capacity.

Squalene is an olefinic substance capable of retaining within the polymeric film of the packaging to ethylene, the molecule responsible for maturation and over-ripening of fresh plant products. Squalene, due to its physicochemical properties, can become an integral part of the film of the polyolefin keeping unsaturations active present in its chemical structure, which favors the ethylene retention.

On the other hand, diludine 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate diethyl) is a nitrogen heterocyclic compound that when incorporated, it provides a polymeric film slight yellow color. The high reducing power of the diludine allows to eliminate ethylene from the environment internal packing, possibly turning it into ethane, which is not recognized by the receptors of ripening of the fresh vegetable product. While he is reaction takes place, in turn the color of the packaging it is modified until it becomes translucent, this being last one indicative of its functionality and the end of the conservation capacity provided by the packaging.

The effect of squalene and diludin, as absorbent and reducing additives, in retention or ethylene removal at a temperature of 8 ° C can see in Figures 1 and 2, respectively. The Ethylene production was determined as the amount of ethylene present in the atmosphere surrounding the whole of fruits with respect to the weight in kg of fruit within the packing, which at the initial moment is zero and its increase is due to ethylene production by Fruits with the passing of days. For packing with additive a reduction in the amount of ethylene (produced by the fruit) present in the atmosphere inside the package compared to the Unpacked fruit and film without additive. This reduction becomes more evident in the climacteric peak (time of increased production of ethylene for one fruit climacteric), which occurs 5 weeks after storage, where ethylene production is greater than 600 microliters / kg / h in the case of unpacked fruits and reduced to approximately 100 microliters / kg / h with the "polyolefin film with absorbent ”or“ polyolefin film with reducer ” of the present invention.

As for aminooxyacetic acid (AOA), its function has been widely studied as alternative to control over-ripening in fruits weather. It is known that the AOA intervenes in the hormone biosynthesis that affects the function of the ACC enzyme (acid-1-aminocyclopropyl-1-carboxylic acid, by its acronym in English), which participates in the ethylene production

The additives introduced in the film retarding packaging of the ripening process and senescence in fruits, vegetables and foliage, have a high capacity to extend product life of plant origin. According to the results, the products Fresh vegetables can maintain their properties organoleptic for times longer than 6 weeks. Additionally, the chemical characteristics and Biological additives, concentration used and affinity with the polymer chains of the film of packaging allow to ensure the safety of that type of active packaging, see the Material Safety Data Sheet, MSDS, for each additive according to registration number chemical: squalene: CAS # 111-02-4; diludine: CAS # 1149-23-1; AOA or aminooxyacetic acid: CAS # 645-88-5; polyoxyethylene monooleate: CAS # 9005-65-6; sorbitan oleate: CAS # 9015-08-1; Glycerol α-monooleate: CAS # 111-03-5; and the mixture of mono and triglycerides: CAS # 111-03-5 and 122-32-7, respectively.

Figure 6 shows the effect on production of ethylene, when using as an additive aliphatic esters to different concentrations (0.5%, 1.0% and 1.5% identified as AA1, AA2 and AA3, respectively) in a package of fruits, where it is appreciated that for times Less than 6 weeks of storage, production of ethylene does not exceed 160 microliters / kg / h, for None of the additive concentrations evaluated.

Figure 7 shows the effect on the ethylene production, using diludin as an additive at different concentrations (0.5%, 1.0% and 1.5% identified as AR1, AR2 and AR3, respectively) in a packing of fruits, where it is appreciated that the production of ethylene does not exceed 160 microliters / kg / h, for none of the additive concentrations evaluated and appreciate a variation of approximately 20 microliters / kg / h in ethylene production between the three concentrations.

Figure 8 shows the effect on production of ethylene, from AOA at different concentrations (0.5%, 1.0% and 1.5% identified as AI1, AI2 and AI3, respectively) as an additive in a fruit package, where it is appreciated that the maximum peak in the production of ethylene is between 250 and 350 microliters / kg / h at five weeks, this time being observe the biggest difference in ethylene production in the three concentrations.

It is very important to note that the additives mentioned can be added to any polyolefin that Expect to be used in the manufacture of packaging for handling and transport of fruits, vegetables and foliage. The results between one type of polyolefin differ very little, although the tests done for this invention They focused on the use of polyethylene and polypropylene.

In order to ensure that the packaging polymeric with additives in addition to retarding the gulupa maturation process remains unchanged the organoleptic properties of the fruit, the sensory shelf life of the fruit with the help of a panel trained cupping (made up of 8 panelists). The methodology involved the storage of different lots of fruit (8 per package) under the same conditions (8 ° C,% H.R. 54.5 ± 3) at different times, 7, 6, 5, 4, 3, 2 weeks Then a fruit of each period of time was arranged for sensory analysis by The panelists. The analysis was performed on three Critical parameters in fruit quality, with which were previously trained; appearance and color of the shell, appearance and color of the pulp of the fruit and the aroma and flavor of the pulp of the fruit, by means of a descriptive test of scores. The data resulting are compared with those obtained for a commercial polymeric packaging currently used by tropical fruit exporters from the same family Vegetable to the studied.

For the present invention, the aforementioned adsorbents, absorbents, reducers or inhibitors of ethylene that allow reducing or modifying the concentration of ethylene in the atmosphere surrounding the fruits, vegetables or foliage whose ripening and senescence process is sought to be delayed, will be identified as a single group of compounds called ethylene capture agents , regardless of the chemical mechanism of the interaction of said agent with ethylene.

The preferred methodology used in the manufacture of flexible anti-ripening packages for plant material consists in obtaining a plastic film by extrusion and blowing, using as a load a physical mixture between the additives (in the form of pellets; masterbatch ) and the polymer matrix in pellets . The direct addition of the liquid or solid additives used in this invention to the extruder causes problems of processability and heterogeneity of the additive in the film, with a high detriment of the desired anti-aging properties. Therefore, the additive has to be pre-extruded with the polyolefin in order to obtain a " masterbatch " with high percentages of additive (between 10 and 20%) in the form of pellets.

It is recommended to do the extrusion process maintaining a screw temperature between 180 and 210 ° C, a pull ratio 50/100 rpm or less and a proportion between polyolefin and “masterbatch” that results in an additive concentration between 0.5 and 5% by weight. The final presentation of the translucent polymeric packaging It has a thickness between 0.035 and 0.052 mm and no microperforations.

In Fig. 1 the process of maturation over six (6) weeks for a set of gulupa fruits (Passiflora edulis Sims fo. edulis) stored under the same conditions environmental in different types of packaging, where “without pack ”represents fruit samples stored without use of packaging, "polyolefin film" represents a polyethylene or polypropylene packaging without additive some, and "polyolefin film with absorbent" represents a polyethylene or polypropylene gasket which through an extrusion process has been introduced 2% (w / w) squalene as an additive ethylene absorbent.

Figure 2 shows the process of maturation over six (6) weeks for a set of gulupa fruits (Passiflora edulis Sims fo. edulis) stored under the same conditions environmental in different types of packaging, where “without pack ”represents fruit samples stored without use of packaging, "polyolefin film" represents a polyethylene or polypropylene packaging without additive some, and "polyolefin film with reducer" represents a polyethylene or polypropylene gasket which through an extrusion process has been introduced 2% (w / w) diludine as an additive ethylene reducer

Figures 3, 4 and 5 show the gulupa sensory quality parameters in two different packages and at different periods of storage at a temperature of 8 ° C: a package commercial polymer (dark bars) and a gasket asset containing squalene as an absorbent additive of the present invention (light gray bars).

The effect is shown in Figures 6, 7 and 8 of other absorbent agents such as aliphatic esters (CAS # 111-03-5 and CAS # 122-32-7 identified as “AA”, Figure 6), reducing agents such as diludine (identified as AR, Figure 7) and inhibitory agents of ethylene as the AOA (identified as AI, Figure 8).

Ways to realize the invention Examples

EXAMPLE 1

Figure 1 shows the process of maturation over six weeks for a set of gulupa fruits (Passiflora edulis Sims fo. edulis) stored under the same environmental conditions in Different types of packaging. The fruit stored in the packing with the adsorbent additive in a concentration of 2%, establishes an atmosphere in the packaging with a lower concentration of ethylene throughout all trial weeks, which makes a big difference with unpacked fruit and fruit in a package plastic without the adsorbent additive. Remarkable is the decrease in the climatic peak (maximum production of ethylene in five weeks) where with the film with additive is presented 3 and 6 times less concentration of ethylene than with the polymer film without additive or with Fruit without packaging, respectively.

EXAMPLE 2

Figure 2 presents the results for the case in which the additive used in one of the packages it is an olefin reducing agent in a concentration less than 2% and its comparison with other types of packaging. Also in this case the gulupa fruits stored in The polyolefin bag with the additive is preserved in better way than the other two samples with which Compare the ripening process. Similar to previous example, in the climacteric peak the reduction of Ethylene production with the reducer packaging is appreciable.

EXAMPLE 3

To measure the senescence of the fruits in the packaging with additives, a shaped cupping panel by 8 trained panelists evaluated the appearance-color of the shell, appearance-color of the pulp and aroma-flavor of the pulp. And it was compared to a package Commercial used currently. Each attribute with a different score scale considering the importance of the attribute in the final consumer, thus the appearance-color of the shell has a maximum score of 7 (this is the first aspect that impacts the consumer), the aroma-flavor of the pulp a score maximum of 5 and the appearance-color of the pulp a maximum of 3 (less impact on the consumer). The values obtained for the three attributes were averaged for all experiments and its value is reported as “Medium scores” in Figures 3, 4 and 5.

Figures 3, 4 and 5 show these results for each attribute, values close to the maximum they represent the best possible quality and close values to one they represent a totally undesirable quality. The results for absorbent and reducing additives ethylene are very similar, therefore only Show the result with the absorbent. Figure 3 and 5 show that the appearance and color of the shell and appearance and color of the pulp during the period of storage suffer small differences with respect to commercial packaging. But after 4 and until 7 week, there are no appreciable changes. Therefore the developed packaging behaves the same as packaging commercial in these attributes. Figure 4 shows how Commercial packaging better preserves the aroma and flavor of the pulp of the fruit during the first 4 weeks of storage. But the packing with absorbent here developed presents better results in recent storage weeks (from week 4 to week 7). The above is very important, since the last weeks of storage, are precisely those that They use to display the fruit to the final buyer. Fits note that within the analyzed attributes, the aroma and taste of the pulp of the fruit is the most important For the final consumer.

EXAMPLE 4

Variations in concentration or nature of the additive at a temperature of 8 ° C storage can lead to inhibit anti-aging capacity of the packaging as shown Figure 6. When an absorbent additive "AA" of ethylene as aliphatic esters (CAS # 111-03-5 and 122-32-7) in concentrations of 0.5: 1.0 or 1.5% (w / w), represented as AA1, AA2 and AA3 respectively, it appreciate that the production of ethylene in fruits is not drastically affects, obtaining lower productions of ethylene but still showing a progressive increase until reaching a climacteric peak at a time equal to obtained by the unpacked fruit.

Similar results are found when use additives "A" ethylene inhibitors "I" such as AOA or "R" ethylene reducers such as diludine a different concentrations ranging from 0.5: 1.0 and 1.5% (w / w).

The scope of this invention is defined to fruit products that in their post-harvest process They produce ethylene within their metabolic process. May be for cargo packaging in transport or for domestic storage

Although the present invention has remained described with the preferred embodiments shown, it is understood that the modifications and variations that keep the spirit and scope of this invention be understood within the scope of the appended claims.

Bibliography

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Bardales XI, Carrillo MP, Hernández MS, Barrera JA, Fernández-Trujillo JP, Martínez O (2008) Camu-camu fruit (Myrciaria dubia) a new option for productive systems in Colombian Amazonian Region. Minutes horticulture 773, 173-178

Barrera JA, Hernández MS, Melgarejo LM, Martínez O, Fernández-Trujillo JP (2008) Physiological behavior and quality traits during fruit growth of four Amazonic hot pepper accessions. Journal of the Science of Food and Agriculture 88, 847-857

Blacksmith A, Guard J (1991 Conservation of fruits. Technical manual. Mundi press editions. Graph S.A. Bilbao 409pp

Blacksmith, A .; Guardia, J. Conservation of fruits; Technical manual. Editorial Mundi_Prensa, Madrid, Spain, 1992

Hernández M.S., Barrera J.A., Fernández-Trujillo J.P., Carrillo, M.P., Bardales X.L. Handling manual for harvest and post-harvest of fruits of Arazá (Eugenia stipitata Mc Vaught) in the Amazon Colombian Bogotá, Colombia, Amazon Institute of Scientific Research - Sinchi. 2007

Hernandez M.S., Barrera J., Melgarejo L.M .; " IX Postharvest Physiology ”, EXPERIMENTS IN PHYSIOLOGY VEGETAL, ISBN-13: 9789587196689. National University from Colombia. 2010

Jiménez SP, Hernández MS, Carrillo MP, Barrier JA, Martínez O, FernándezTrujillo JP (2008) Points critics in physiology and postharvest conservation of two Amazonian Mirtaceae (Arazá and Camu Camu). X National Symposium and VI Iberian on Maturation and Postharvest Zaragoza, Spain In: Oria, R., Val, J., Ferrer, A. Advances in maturation and post-collection of Fruits and vegetables. pp 410-417

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Claims

A polymeric composition for capturing ethylene comprising:
a) a polymeric substrate consisting of a polyolefin or a mixture of polyolefins, and
b) one or more of the ethylene capture agents, in concentrations between 0.5% and 5% in weight to weight ratio, selected from the group consisting of: squalene, diludin (2,6-dimethyl-1,4-dihydropyridine-3 , Diethyl 5-dicarboxylate), aminooxyacetic acid, polyoxyethylene monooleate, sorbitan oleate, glycerol α-monooleate and the mixture of mono and triglycerides (CAS # 111-03-5 and CAS # 122-32-7).
The polymer composition to capture ethylene according to claim 1 characterized in that the Polyolefin of the polymeric substrate is polyethylene or polypropylene.
The polymer composition to capture ethylene according to claim 1 wherein the capture agent of Ethylene is diludine.
The polymer composition to capture ethylene according to claim 1 wherein the capture agent of Ethylene is squalene.
The polymer composition to capture ethylene according to claim 1 wherein the capture agent of Ethylene is aminooxyacetic acid.
The polymer composition to capture ethylene according to claim 1 wherein the capture agent of Ethylene is polyoxyethylene monooleate.
The polymer composition to capture ethylene according to claim 1 wherein the capture agent of Ethylene is sorbitan oleate.
The polymer composition to capture ethylene according to claim 1 wherein the capture agent of Ethylene is glycerol α-monooleate.
The polymer composition to capture ethylene according to claim 1 wherein the capture agent of Ethylene is the mixture of mono and triglycerides: CAS # 111-03-5 and 122-32-7, in equal parts weight to weight.
Polymeric films and packaging that extend the shelf life of fresh fruits or vegetables for more than 4 weeks at a temperature below 10 ° C which they comprise: a) a polymeric substrate consisting of polyethylene, polypropylene or the mixture thereof between 95% to 98%; b) one or more capture agents of ethylene selected from the group consisting of: squalene; diludine 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate diethyl); aminooxyacetic acid; monooleate polyoxyethylene; sorbitan oleate; α-monooleate glycerol; and, the mixture of said mono and triglycerides between 2% to 5%.