LT5567B - Process for dezinfecting food and surfaces interfacing therewith - Google Patents

Abstract

The present invention relates to the treatment of food and interfaced surfaces to neutralizme microorganizms by irradiating without heating applying at the same time photosensitizers that do not effect food properties. The method claimed is characterized in that food or a surface interfaced therewith is macerated with the solution of photosensitizer the concentration of the latter being not higher than 7,5x10-3 M and the the photo-sensitive material having been chosen from the group consisting of hematoporphyrine dimethyl ether, 5-aminolevulinic acid, chlorophyll sodium salt and hypericine. After drying the surface it is subjected to irradiation by the light having wavelenght that correspondes the absorbtion peak of photosensitizer ?max 40 nm and light intensity does not exceed 50 mW/cm2, preferably û does not exceed 20 mW/cm2. The present invention concernes the food industry and may be applied in preserving fruits and vegetables (carrots, beens, tomatoes, cucumbers, germinated seeds) used for sa

Description

The present invention relates to the decontamination of food and food-related surfaces from microorganisms by irradiation treatment without the use of food-harmless photosensitizers. The invention relates to the food industry and can be used in food-related surfaces (tables, tools, ¹⁰ dishes), packaging materials (packaging containers, packaging film) for fruits and vegetables used in prepared salads (carrots, green beans, tomatoes, cucumbers, sprouted grains). ), fruits and vegetables (such as strawberries, peaches, nectarines, mandarins).

Food-related illnesses and health crises continue to be a threat to public health worldwide. There are currently over 250 food-borne diseases known to be caused by bacteria, viruses, fungi or parasites. In the US, about 5,000 patients die of food-related illnesses in ¹⁵ years. Health experts estimate the economic cost of these diseases at $ 10-83 billion annually. Semi-prepared or ready-to-eat food remains the main source of food-related diseases. Such food preparation and storage technologies do not prevent the growth and development of unwanted and pathogenic microflora. These types of food ²⁰ inevitably create new niches for microbial growth (vacuum packaging, low heat treatment, freezer storage at temperatures below 4 ° C) (M. Peck, S. Stringer, the foodbome hazard of botulism, Meat Science, 2005,70,461-475). These facts indicate that existing microbiological controls on food raw materials are not effective.

²⁵ As the demand for organic food grows, the problem arises not only of more efficient, non-thermal but also of microbiological safety technologies for ecologically neutral food raw materials. Alternative microbiological food control technologies are sought between non-chemical and non-thermal effects, including:

- a high hydrostatic pressure, which operates non-covalent bond inactivates vegetative cells ³⁰ (in combination with a light thermal effects) and spores applied liquid and semi-liquid products preparation (Devlieghere F., L. Vermeiren, Devebere J. New preservation technologies. Possibilities and limitations , Int. Diary J., 2004, 14, 273-285);

- the powerful impulse light that affects both vegetative cells and spores can be adapted to kill microbes on the surface of food (V.M. Gomez-Lopez, P. Ragaert, J. Devebere,

F. Devlieghere, Pulsed light for food decontamination, Trends in Food Science and Technology, 2007,18,464-473);

- pulsed electric field: 10-20 kV / cm2 electroporate membranes, low spore action, and, together with mild thermal effects, may be effective for pasteurization of alcoholic beverages (Gould GW, Proceedings of the Nutrition Society, 2001, 60, 463-474) ;

- Microwave: 2450MHz efficiently kills germs throughout the depth of the food matrix, but is combined with other methods due to uneven temperature distribution (Gould G.W., Proceedings of the Nutrition Society,

2001.60.463-474);

- ionizing radiation: affects the structure of DNA and affects vegetative cells and spores (except lactobacteria).

- use of natural agents bacteriocins (nisin, lysozyme), plant extracts.

All of these high intensity non-thermal technologies also have their disadvantages:

High Hydrostatic Pressure Changes the Structure of Proteins and Polysaccharides At the Same Time Intensive Ultrasonic Effects Denaturate Proteins, Produce Free Radicals That Change Fruits, and High Dose Ionizing Radiation Changes the Fragrance of Fatty Foods (Gould GW New Processing Technologies: an overview, Proceedings of the Nutrition Society,

2001.60.463-474). Radiated products have altered taste characteristics and will not appeal to consumers.

With the recent rise in consumer interest in natural, minimally processed and non-chemical safe food, germinated grains or seeds can be offered as a nutritious, valuable and health beneficial product. However, sprouted seeds are also associated with increased microbial contamination, which is still unresolved in the world.

Emerging microorganisms on sprouted seeds adversely affect product quality, affect shelf life, and some of them can cause serious human illness, as some grain-damaging micromycetes produce and release toxic substances - mycotoxins, which can cause human and animal disease - or cause of cancer.

The problem of microbiological contamination of sprouted seeds is further complicated by the fact that the disinfectant used must not affect the germination of the seed. The most common and commonly recommended and used (especially in the USA) chemical disinfectants for food sprouts: calcium or sodium hypochlorite, hydrogen peroxide. Tests were conducted on a wide range of disinfectants (potassium sorbate, calcium propionate, gallic acid, benzoic acid, salicylic acid, dihydroxybenzoic acid, riboflavin, nisin, etc.) but failed to produce the expected results (US Food and Drug Administration National Advisory Committee on Microbiological Criteria). for Food Adopted May 28, 1999, Microbiological Safety Evaluations and Recommendations on Sprouted Seeds)

Existing microbiological control methods using chemicals have drawbacks: 2% calcium hypochlorite inactivates micromycetes, but cannot destroy all native microflora (Fett, FW, Reduction of native microflora on alfalfa sprouts during propagation by antimicrobial compounds). of Food Microbiology 30.13-18). In addition, both 2% calcium hypochlorite and 6% hydrogen peroxide are reactive chemicals that disrupt fruit and vegetable surfaces and inactivate grain sprouting (National Advisory Committee on Microbiological Criteria for Foods, 1999). Sodium hypochlorite is an effective antimicrobial agent, but at concentrations greater than 1% it also inactivates grain sprouting (Soylemez, G., Brashears, M.M., Smith, D.A., Cuppett. SL. 2001. Microbial activity of alfalfa seeds and sprouts after a chlorine. treatment and packaging modifications. Journal of Food Science 66 (1), 153-157).

As a result, these and other chemical methods used to date for disinfecting fruits, vegetables, sprouted grains become obsolete due to residual chemical compounds and environmental contamination (Fett, FW, 2002.) Reduction of native microflora on alfalfa sprouts during propagation by antimicrobial compounds to irrigation vater.International Journal of Food Microbiology 30, 13-18).

It is stated in the patent literature that the disinfection of foodstuffs is sometimes carried out with solutions containing hydrogen peroxide or derivatives thereof (patent RU 2207036), with ozone produced in situ (patent US 6171625); hydrogen peroxide vapor (International Application Publication WO 9404036) or the like (EP 0397228). However, all these measures are chemical and should be avoided in the case of ready-to-eat food.

Natural antimicrobials such as organic acids, ascorbic acid, grapefruit seed extract are not effective enough: 250 mg / l grapefruit seed extract only slightly modifies the initial microbiological seed infestation (Park, W.P., Lee, D.S., Cho,

S.H., 1999. Effect of grapefruit seed extract and antibrowning agents on the maintenance of minimally processed vegetables. In: Lee, J.M., Gross, K.C., Watada, A.E., Lee, S.K. (Eds.), On Quality of Fresh and Fermented Vegetables: Proceedings of the International Symposium. Act in Horticulture, vol. 483, p. 325-328).

Ultraviolet irradiation is known, particularly in medicine, as a self-contained disinfectant but requires longer exposure times, which is not rational in food preparation as it can cause alteration and / or degradation of valuable food components.

In order to reduce microbiological contamination of sprouted grains, fruit and vegetable raw materials before washing, the present invention proposes the use of an antimicrobial photosensitization method.

Photosensitivity is based on the interaction of two agents, visible light and photosensitive. Under certain conditions, photosensitive material accumulates readily in microorganisms and is excited by light of appropriate wavelength and power, inducing photocytotoxic reactions and death. Photosensitization requires a total of harmless non-ionizing radiation, visible light or UV range. (P. Man, R. Pagan, Microbial inactivation by new technologies of food preservation, J. Applied Microbial. 2005, 98, 1387-1399).

Photosensitization can be used as an effective antimicrobial agent. It is known that the vast majority of Gram-positive and Gram-negative bacteria can be destroyed during photosensitization by selecting the appropriate photosensitive organic substance for photosensitization. Even the most resistant micromycetes, which cause a number of problems in food preparation, from the field to the table, are susceptible to photosensitivity (Lukšiene, Z., Pečiulyte, D., Jurkoniene, S. & Pūras, R. (2005). Inactivation of possible fungal food contaminants by photosensitization. Food Technology and Biotechnology, 43, 1-7) ·

Previous work by the authors has shown that many micromycetes - // fe / vzariu alternata, Fusarium avenaceum, Acremonium strictum, Rhyzopus oryzae, Aureobasidium sp., Rhodotorula sp., Penicillium stoloniferum, Aspergillus fumigatus, Aureobasidium pullulans,

Oclocladium chartarum - can be inactivated by photosensitization (Lukšiene, Z., Pečiulyte, D. & Lugauskas, A. (2004). Inactivation of fungi in vitro by preliminary photosensitization. Annals of Agricultural and Environmental Medicine, 11, 215-220 ; Lukšiene, Z., Pečiulyte, D., Jurkoniene, S. & Pūras, R. (2005). Inactivation of possible fungal food contaminants by photosensitization. Food Technology and Biotechnology, 43, 1-7). It turns out to be an effective tool for killing even the most resistant micromycetes and their spores and conidia without harming the environment or human health.

The phenomenon of photosensitization is known to be used in medicine for the destruction of tumorous structures, for the treatment of arthritis, atherosclerosis, and infectious diseases (U.S. Pat. No. 6,821,189 and several others).

5-Aminolevulinic acid (hereinafter ALA) is known to be effective in killing microflora (Lukšiene, Z., Pečiulyte, D. & Lugauskas, A. (2004). Inactivation of fungi in vitro by preliminary data. Annals of Agricultural and Environmental. Medicine, 11, 215-220; Lukšiene, Z., Pečiulyte, D., Jurkoniene, S. & Pūras, R. (2005) Inactivation of possible fungal food contaminants by photosensitization, Food Technology and Biotechnology, 43, 1-7. ). It is also known as a growth factor in plants, a pioneer in the synthesis of chlorophyll and other tetrapyrrole molecules (Tanaka, Y., Tanaka, A. & Tsuji, H. (1992). Stabilization of light-harvesting chlorophyll-a / b protein complex. by Feeding 5-Aminolevulinic Acid Under Intermittent Illumination, Plant Physiology and Biochemistry, 30, 365-370; Wang, LJ, Jiang, W. B. Huang, B.J., 2003. Promotion of 5aminolevulinic acid on photosynthesis of melon (Cucumis melo) seedling under low light and chilling stress conditions Physiologia Plantarum 121, 258-264 Wang, L.J., Jiang, W.B., Liu, H., Kang, L., Hou, XL, 2005. Promotion by 5-aminolevulinic acid of germination of Pakcboi (Brassicca campestris ssp. chinensis var. communis Tsen et Lee) seeds under salt stress Journal of Integrative Plant Biology 47, 1084-109 l; von Wettstein, D ,, Gough, S., Kananagara, CG, 1995. Chlorophyll biosynthesis, Plant Cell. 7. 1039-1105; Bindu, RC, Vivekanandan, M., 1988. Hormones ac tivities of 5-aminolevulinic acid in callus induction and micropropagation. Plant Grovvth Regulation 26, 15-18). However, the efficacy of the ALA diluted solution in inactivating the food and food contact surface, in direct contact with it, and after a definite time irradiation with UV light of up to 20 mW / cm was not evident.

Bacteriochlorophil, a product of bacterial metabolism, is known as a photosensitizer in cancer photodynamic therapy (PTD) (EP 0468997).

WO 2008023378 mentions that for the photodynamic therapy of tumors, chlorophyll or derivatives thereof, in particular conjugates of RGD-containing protein with specific bacteriochlorophil (preferably) or chlorophyll derivatives, may be used in addition to bacteriochlorophil. However, only substances included in the list of food supplements, colorings and food ingredients may be used in the preparation of food.

Chlorophyll sodium is the base of the plant's green pigment, a known food coloring agent E140 (For Nature Green 3, 075810) widely used in the food industry. However, no reports on the use of chlorophyll sodium for photosensitization, in particular for the decontamination of ready-to-eat foods, have been found.

US patent application 2006/0124442 describes a method for removing pathogens, bacteria and other molecules from an outflow medium and a device in which the medium (air, water, etc.) flowing through the device channel is irradiated with at least one LED light source in the presence of photosensitizers. , where the intensity of light emitted by the light source is 90-110 mW / cm ² . This method is proposed for use, for example, in air purification in some rooms.

There is a known microbial and viral inactivation device where objects are usually fluids such as blood - about 1 minute. irradiated in cameras using a LED light source as a light source, after prior injection of an appropriate photosensitive agent into the subject (patent CN1416904,2003).

Similar systems with LEDs for inactivating microorganisms in fluids containing biologically active proteins may have means for controlling temperature (International Application Publication No. WO02 / 26270; U.S. Pat. No. 7,094,378). In the latter systems, photosensitizers use synthetic materials, such as 1-200 mM 7,8-dimethyl-10-ribityl-isoaloxazine, as synthetic substances.

U.S. Pat. No. 6,692,694 (Publ. 2004) describes a method and apparatus for decontaminating and disinfecting objects, wherein an aerosol containing a photosensitizer is sprayed with a workpiece and then irradiated with a wavelength of 200-320 nm up to 1000 mW / cm ² . The photosensitizers used were peroxy compounds or mixtures thereof, for example containing up to 10% hydrogen peroxide. Although this method is not suitable for the decontamination of the food surface, it could be considered, in its totality, to be the closest to the proposed method.

The problem is that the photosensitizer and the conditions used for microbiological control of fruits and vegetables must not only be effective, but must not be harmful to humans or adversely affect the organoleptic properties of the food. Many photosensitive substances, even being non-toxic chemicals, can affect the cell membranes of not only microorganisms but also of food components. In addition, photosensitive materials are sufficiently selectively absorbed by biological objects.

From the state of the art, it is clear that inexpensive and versatile methods have not yet been developed to protect food and feed grains from contamination by microorganisms and their products, and to prevent harmful effects on humans and warm-blooded animals.

Existing food safety concerns call for new eco-friendly and human and environmentally friendly technologies.

The main object of the present invention is to provide a method of inactivating food products which enables the inactivation of pathogenic microorganisms without affecting the "viability" properties of the food matrix (e.g. 100% preserved germination of seeds) and does not impair the nutritional and organoleptic properties of the product. Therefore, one object of the invention was to find conditions that ensure the quality and nutritional value of the processed foods. Another important object of the invention is to find photosensitizers that are absorbed efficiently by microorganisms so that inactivation of the main food bacteria can be expected.

The object is achieved by the totality of the features set forth in claims 1-10 of the invention. The main object of the invention is a method of decontaminating food or food-related surfaces, wherein the decontaminating object is treated with a photosensitizer and irradiated with a light flux sufficient to absorb the photosensitizer. This method is characterized by treating the subject by moistening a food or food contact surface with a photosensitizer solution, holding it dry and then irradiating with a light having a wavelength corresponding to a photosensitizer absorbance k _max + 40 nm and a light intensity not exceeding 50 mW / cm ² . - does not exceed 20 mW / cm ² ; The photosensitizer is a photosensitive substance of plant origin and the processed food is sprouted grains, whole vegetables or whole fruits.

The surface to be treated is moistened by soaking and maintaining a photosensitive material of plant origin in a concentration not exceeding 7.5 * 10 ' ³ M. The photosensitive material of plant origin is selected from the group comprising hematoporphyrin dimethyl ether 5aminolevulinic acid chlorophyll sodium and hypericin.

Sprouted grains up to 4 hours. retains hematoporphyrin dimethyl ether in aqueous solution at concentrations up to 5 x <10 ' ⁶ M, holds until dry and then for up to 30 min. irradiated with 405 + 40 nm light with an intensity of less than 20 mW / cm ² .

Alternatively, the sprouted grains or food-related surface are maintained for 5 to 30 min in aqueous solution of 5aminolevulinic acid at a concentration not exceeding 7.5 x 10 ³ M until dry and thereafter for up to 30 min. irradiated with 405 + 40 nm light with an intensity of less than 20 mW / cm ² .

Sprouted grains, uncut vegetables, uncut fruit or food-related surfaces retain the chlorophyll sodium in aqueous solution at concentrations up to 1.5 * 10 ' ⁵ M for up to 10-30 min, dry until dry and then irradiate for up to 30 min with 405 + 40 nm light of an intensity not exceeding 20 mW / cm ² .

Or sprouted grains up to 2 min. retains hypericin in aqueous solution at a concentration not exceeding 2 * 10 ⁸ M, holds until dried and then irradiates 589 + 40 nm light with a light intensity not exceeding 20 mW / cm ^{2 for} 10-80 min.

For the detailed description of the invention, the conditions under which photosensitization without harm to humans and the environment can inactivate harmful and pathogenic microorganisms on the surface of food raw materials (fruits, vegetables, sprouted grains) and food packages are important.

Importantly, dilute aqueous solutions of photosensitive substances of plant origin, namely aminolevulinic acid, hematoporphyrin dimethyl ether, hypericin, chlorophyll sodium at concentrations up to 7.5 ^χ 10 ′ ³ M, have not only proved to be effective photosensitizers when used to inactivate food-bound food. The surface according to the invention also fulfilled the specific requirements for food-related materials, in particular ready-to-eat food. For example, a particularly attractive embodiment of the present invention is a photosensitizer that is sodium chlorophyll, a natural part of our food that is authorized for use in many foods such as salads and sandwich spreads; dairy products including cheese; fruits and vegetables in vinegar, oil, brine, pickled vegetables (can not be processed only sliced vegetables); preserved red fruits; fruit spreads; fruit and vegetables in sugar; desserts; cereals, dressings, etc. This material can be used in unlimited quantities, such as in a vegetable washer, which would significantly reduce the cost of technology introduction and use in production without the need for additional equipment for the sensitization process. Studies have shown that the concentration of chlorophyll sodium used can be greatly reduced and give the same good antimicrobial effect from 10 ' ³ M as ALA or from 10' ⁶ M as hematoporphyrin dimethyl ether to 10 ' ⁷ M, which is a very attractive food technology.

Another valuable plant-based photosensitizer available for use in food safety according to the invention is St. John's wort, a hypericin pigment. Not only is this substance an effective photosensitizer, it is also a non-genotoxic, non-mutagenic, non-carcinogenic, multifunctional drug. Side effects (photosensitivity) are unlikely as photosensitivity is only observed at 20mg / kg body weight hypericin.

The present invention provides for treating a food surface or a food contact surface (e.g., for use in ready-to-eat food packaging) by moistening it, preferably by dipping in a dilute aqueous photosensitizer solution. The solution is allowed to dry for about 20 minutes, which, together with the soaking time, allows sufficient time for incubation with the photosensitizer. Thereafter, the light is irradiated in a light-free range of optimum intensity of 20 mW / cm ² . The average duration of irradiation was about 30 min. and depends on the subject (surface shape, roughness, etc.) and the photosensitizer selected.

The irradiation was carried out in a small chamber which provided the possibility to place trays (eg 40x40 cm) containing foodstuffs to be irradiated at various heights. The height of the shelf can be changed by adjusting the illumination of the shelf surface. A high power, symmetrically arranged array of LEDs is mounted internally on the top plate of the camera, eg by symmetrically arranged Optodevice Co., Ltd. manufacturing high optical power S8D40 LEDs with a wavelength of 405 nm. The LED light block was used as a controlled light source, with a scheme consisting of three main parts: a controlled high energy power unit digital radiation detection system and an irradiation duration controller that determines the desired irradiation duration. A ventilation system was installed in the chamber to cool the block of lights.

The scope of the present invention is further illustrated by the following examples, which are provided by way of illustration and are not intended to limit the scope of the invention.

example. Inactivation of food grains with hematoporphyrin dimethyl ether.

A small portion (about 100 grains) of wheat grain is filled with 50 ml of 5 10 ' ⁶ M hematoporphyrin dimethyl ether aqueous solution (phosphate buffer, pH 7.2) for 4 hours. maintained at 18 ° C. After the aqueous solution was decanted, dried in an open dish grains ⁵ for about 20 minutes and illuminated chamber LED LEDs emit UV 405 nm, 20mW / cm ² intensity Continuous light. Exposure time 20 minutes. After exposure, mold fungi (micromycetes) on the grain surface decreased from 3000 to 100 colony forming units. Here, the results of inactivation were further determined by conventional colony forming units (CFU / ml).

Examples 2-4. Use of hematoporphyrin dimethyl ether as a photosensitizer to inactivate microbial contamination of food surface.

Comparative samples were made with sprouted wheat grain according to the procedure of Example 1.

Table 1 ¹⁵ Effect of hematoporphyrin dimethyl ether (40 mM) and / or light (405 nm; 20 mW / cm ² ) on overall reduction of mold micromycetes infection

Example # Processing Co-infestation with mold decrease,% 2 soaking alone (4 hours) not detected 3 irradiation alone (30 min) not detected 4 soaking (4 hours) and irradiation (30 minutes) 88

The data in Table 1 show that if the grains are only soaked in a solution of hematoporphyrin dimethyl ether ²⁰ or exposed to UV light alone, the antimicrobial effect is not achieved in the meantime. Only soaking in a photosensitizer solution in combination with UV light illumination can clean the grains of microorganisms without compromising their germination and physiology. After exposure, the grains can be germinated.

²⁵ Example 5. Inactivation of food grains with 5-aminolevulinic acid.

Following a procedure analogous to that described in Example 1, the germinated grains were decontaminated using ALA as a photosensitizer.

100 grains are covered with 50 ml of 110 ' ³ M 5-aminolevulinic acid solution (PBS buffer) and kept at room temperature for 4 hours. After the aqueous solution was decanted, ³⁰ grains were dried in an open dish for about 20 minutes. and exposed to 20mW / cm ² 405 nm continuous light.

II

Exposure time 20 minutes. After exposure, the micromycetes on the grain surface decreased from 2500 to 300 colony forming units.

It was observed that this procedure is 100% germination of grain stores and improves the root (5 cm in the control have not been affected by the grain 6 cm - treated) and the stem (3 cm ⁵ controls not affected by grain and 4 cm - treated) development. Seedlings become more green due to improved chlorophyll synthesis: from 0.8 pg chlorophyll / g grain in untreated grains to 1.88 pg chlorophyll / g grain in exposed grains.

After exposure to food (eg prepared salads), it is not necessary to rinse the grains used.

Examples 6-11. Use of 5-aminolevulinic acid as a photosensitizer to inactivate microbial contamination of food surface.

The results in the Table show that the important food pathogen cereus as well as the overall microbiological contamination on the grain surface can be reduced by ¹⁵ soaking in 7, 5 mM ALA and 30 min in the chamber.

Table 2

Effect of ALA and / or light (405 nm; 20 mW / cm ² ) on microbial inactivation

For example No. Processing ALA machine, mM Decrease in B.cereus,% % Reduction in total microbiological contamination 6th Just soaking, 3.0 not detected not detected 7th 30 min 7.5 not detected not detected 8th Irradiation alone, 3.0 not detected not detected 9th 30 min 7.5 not detected not detected 10th Soaking (30 min) and 3.0 not detected not detected 11th irradiation (30 min) 7.5 59 40

Examples 12-17. Inactivation of cereals by spraying with 5-aminolevulinic acid. ²⁰ in an analogous fashion grains were treated by spraying ALA 3.0 mM or 7.5 mM solution, and drying the allowing and then irradiation as in the previous examples. About 0.150 ml of solution was used per spray; Grains sprayed with ALA solution were stored in the dark before irradiation for a minute.

Table 3

Example # Processing ALA machine, mM Decrease in B.cereus,% 12th Spray alone, 10 times on each side 3.0 not detected 13th 7.5 not detected 14th Irradiation alone, 30 min. 3.0 not detected 15th 7.5 not detected

16th Spray (10 times each) 3.0 not detected 17th and irradiation (30 min) 7.5 6th

As can be seen from the results presented, an analogous treatment by wetting the food surface by spraying it with a photosensitizer solution proved to be less effective than soaking.

18-25 Examples. Removal of harmful micro-organisms from the surface of food packaging containers

Retention in 3.0 mM and 7.5 mM ALA solutions and appropriate irradiation were used to decontaminate the surface of the packing vessels. For this purpose, samples of packaging (10 cm x 10 cm) ¹⁰ 20 min. were soaked in the dark in 160 ml of the appropriate concentration (3.0 and 7.5 mM) of ALA. The control sample was 20 min. soaked in phosphate buffer (pH 7,2) only. After soaking and drying 40-120 min. at room temperature, the package was irradiated for 5 min, 10 min, 15 min. and 20 minutes The results are shown in Table 4.

Table 4

Effect of photosensitizer ALA concentration and irradiation (405 nm; 20 mW / cm) on the removal of harmful microorganisms from the surface of food packaging containers. Exposure time with ALA is 20 minutes.

For example, No. 18th For example, No. 19th For example, No. 20th For example, No. 21 ALA machine, m M Time of irradiation 5 min Time of irradiation 10 min Time of irradiation 15 mins Time of irradiation 20 mins Decrease,% Decrease,% Decrease,% Decrease,% B. cereus S.enterica B. cereus S. enterica B. cereus S.enterica B. cereus S. enterica 3.0 95 27th 99 32 100 38 100 39 For example, No. 22nd For example, No. 23rd For example, No. 24th For example, No. 25th 7.5 100 65 100 87 100 95 100 97

Studies have shown that lower levels of ²⁰ ALAs and shorter soaking and irradiation times are sufficient to decontaminate the surface of food packaging.

Examples 26-31: Decontamination of sprouted grains with chlorophyll sodium.

Following a procedure analogous to that described in Example 1, the germinated grains were decontaminated using chlorophyll sodium as a photosensitizer.

²⁵ were used for preparing the solution, chlorophyll, sodium salt (specifically, E140, Fluka) at room temperature in preparation of a concentrated (1,5x10 ^'3 M) aqueous solution. This concentrated chlorophyll sodium salt solution was used in dilution to obtain all the required concentrations of chlorophyll sodium salt in water at 20 ° C. 100 grains were macerated 50ml l, ^5xl0's chlorophyll M sodium chloride solution for 10 minutes. at room temperature, followed by draining and drying in a plate for 60-90 minutes. At 37 ° C, the grain was illuminated at 405 nm with 20mW / cm ² light for 30 min. After exposure to ⁵ microorganisms on the grain surface decreased by 74%.

Other concentrations of chlorophyll sodium (e.g., 10 M) may also be effective (99% reduction in microbiological contamination), but 10 ' ⁵ M should be considered as the initial optimum because lower concentrations (10' ⁶ M) will inactivate microorganisms very poorly. In food technology, the lowest operating ¹⁰ concentrations are paramount, so a concentration of 10 ' ⁵ M is chosen.

The effect of microbial inactivation does not occur with soaking in chlorophyll Na salt alone or under illumination alone for 30 minutes. selected by UV light flux (Table 5).

Table 5

Chlorophyll, sodium salt (ChlNa) and light (405 nm, 20 mW / cm ²⁾ on the ¹⁵ microbial inactivation (corn)

For example No. Processing ChlNa machine, mM % Decrease in B. cereus % Reduction in total microbiological contamination 26th Just soaking, 7, 5x10 ' ⁷ not detected not detected 27th 10 min 1.5 x 10 ⁵ not detected not detected 28th Irradiation alone, 7, 5x10 ' ^z not detected not detected 29th 30 min 1.5 χ 10 ′ ⁵ not detected not detected 30th Soaking for 10 minutes and 7, 5 x 10 ' ^z not detected not detected 31st irradiation for 30 min. 1.5 χ 10 ′ ⁵ 87 74

Examples 32-40: Surface decontamination of vegetables and fruits with chlorophyll sodium.

²⁰ In a similar manner to Example 26, vegetables (green beans, green peas) or fruits (nectarines) were treated by soaking for 10 minutes. to 1.5 x 10 &lt; ⁵ &gt; ⁵ M chlorophyll sodium salt solution allowed to dry and then for 30 min. by irradiation as in the previous examples. The results are shown in Table 6.

Effect of chlorophyll sodium (ChlNa) and / or light (405 nm; 20 mW / cm ² ) on microbial inactivation (fruits, vegetables)

Table 6

For example No. Processing Food sticker B.cereus decrease, % Reduction of total microbiological contamination, % 32 Just soaking, Nectarines 20th 0 33 10 min Bean sprouts 30th 8th 34 Green peas 10th 25th 35 Irradiation alone, Nectarines 0 0 36 30 min Bean sprouts 0 0 37 Green peas 0 0 38 Soaking for 10 minutes and Nectarines 97 22nd 39 irradiation for 30 min. Bean sprouts 85 28th 40 Green peas 94 95

It was found that by treating, for example, 32 other fruits (strawberries, peaches, tangerines) or whole vegetables (carrots, tomatoes, cucumbers), for example, by dipping in 1.5 x 10 ⁵ M sodium chloride solution for 30 min and then The microbiological contamination of the products was reduced by at least 2 to 3 times after drying for 30 min at 405 nm with 40 nm UV light of ¹⁰ 20mW / cm ² . Exposure to light of lower power (2mW / cm ² ) prolonged the exposure time by 10 times to obtain a 2-3-fold reduction in surface contamination.

Examples 41-42: Removal of Harmful Microorganisms from the Surface of ¹⁵ Food Containers with Chlorophyll Sodium Salad.

By the procedure similar to Examples 18 to 25 presented in packaging bottles surface treated chlorophyll sodium salt 7,5x10 ^'6 M and 7,5xl0' ⁷ M solution, keeping the bottles in 2 minutes. After drying (20-40 min), the dishes were irradiated in a chamber for 5 min. 405 nm, 20 mW / cm ² light. The results are shown in Table 7.

²⁰ Table 7

Removal of harmful microorganisms from the surface of packaging containers by photosensitization using chlorophyll sodium as a photosensitizer

Example # Decrease in microorganisms,% 7.5x10 ' ⁶ mM concentration 7.5x1ο ', mM concentration B. cereus L. monocytogenes B. cereus L. monocytogenes 41-42 100 100 100 100

In the examples, the optimum wavelength of light is 405nm; when illuminated with 350nm light of the same power (?) or 450nm light of the same power (?), the antibacterial effect practically disappears. By reducing the luminous power below 10 mW / cm ² , the antimicrobial photosensitization effect disappears and microorganisms remain on the surface of the product being treated. With the power of light in mW / cm, an additional thermal effect (the fetus heats up) begins.

Examples 43-49: Germination of germinated cereals with St. John's wort pigment hypericin.

According to the procedure analogous to Example 1, the cereals were decontaminated with St. John's wort pigment hypericin. In this case a lower concentration of photosensitizer t Λ O (2x10 'M) was used, the grain was kept in hypericin solution for 2 min and irradiated with light of wavelength 589 nm. Table 7 shows the effect of irradiation time on the inactivation of the food pathogen Listeria monocytogenes.

Table 7

Example # Duration of exposure at 589 nm, min Decrease in Listeria monocytogenes,% 43 1 9th 44 5 14th 45 10th 75 46th 20th 99 47 40 99 48 60 100 49 80 100

The present method of decontaminating food and food-related surfaces according to the invention achieves a reduction in pathogenic microorganisms (Bacillus cereus, Salmonella enterica, Listeria monocytogenes, etc.) of up to 94 percent on the surface of packages and up to 100 percent. to reduce the overall microbiological contamination on the surface of fruits and vegetables to 74 percent. ²⁰ Antimicrobial effect of technology depends on the parameters of the light source (the wavelength of light, light output, duration of exposure), the chemical formula of the selected photosensitizer concentration, soaking it time, surface area and shape.

Claims (10)

DEFINITION OF INVENTION 1. A method of decontaminating a food or food-related surface by treating the subject to be photosensitized and irradiating with a light flux sufficient to absorb the photosensitizer, wherein the object is treated by moistening the food or food-associated surface with a photosensitizer solution, drying, and then irradiating. a wavelength corresponding to a photosensitizer absorption X _max + 40 nm and with a light intensity not exceeding 50 mW / cm ² , preferably not exceeding 20 mW / cm ² ; The photosensitizer is a photosensitive substance of plant origin and the processed food is sprouted grains, whole vegetables or whole fruits. 2. The method of claim 1, wherein the wettable surface is moistened and maintained in a solution of plant-based photosensitive material at a concentration of up to 7.5x10 ³ M, wherein the plant-based photosensitive material is selected from the group consisting of hematoporphyrin dimethyl ether, 5-aminolevulin. acid, chlorophyll sodium, and hypericin. 3. A method according to claim 1 or 2, wherein the sprouted grains are for up to 4 hours. retains hematoporphyrin dimethyl ether in aqueous solution at a concentration not exceeding ⁵ x 10 &lt; 5 &gt; ⁶ M, holds until dry and thereafter for up to 30 min. irradiated with 405 + 40 nm light with an intensity of less than 20 mW / cm ² 4. The method of claim 1 or 2, wherein the sprouted grain or food-associated surface is maintained for 5 to 30 min in aqueous solution of 5-aminolevulinic acid at a concentration of 7.5x10 ³ M until dry and thereafter for up to 30 min. . irradiated with 405 + 40 nm light with an intensity of less than 20 mW / cm ² . 5. The method according to claim 1 or claim 2 characterized in that the germinated seeds of cereals, whole vegetables, whole fruit or surfaces associated with food to 10-30 min retains chlorophyll, sodium salt aqueous solution having a concentration of 1,5x10 ^'5 M, supports long apdžiūva and then irradiated for 40 minutes at 405 + 40 nm with a light intensity not exceeding 20 mW / cm. 6. A method according to claim 1 or 2, wherein the germinated grains are for up to 2 min. retains hypericin in aqueous solution at a concentration not exceeding 2 * 10 &gt; ⁸ M, holds until dried and then irradiated with 589 + 40 nm light with a light intensity ⁵ not exceeding 20 mW / cm ^{2 for} 10-80 min. 7. Use of hematoporphyrin dimethyl ether as a photosensitizer to reduce microbial contamination of food surface ¹⁰ 8. Use of 5-aminolevulinic acid as a photosensitizer to reduce microbial contamination of food surface 9. Use of chlorophyll sodium as a photosensitizer to reduce microbial contamination of food and food contact surfaces 15 Use of hypericin as a photosensitizer to reduce microbial contamination of food surface