Description:TECHNICAL FIELD
[0001] The present invention generally relates to composition and process for the conservation of food.
BACKGROUND
[0002] Prevention of food spoilage and food poisoning has been attempted throughout history often through trial and error. The early attempts have resulted in the adoption of such food preservation methods as the drying, salting and/or smoking of foods in order to preserve them. It has been relatively recent in recorded history that food preservation has been placed upon a scientific foundation. In the nineteenth century, work of such scientists as Louis Pasteur and Robert Koch elucidated the bacterial causes of food poisoning and spoilage and provided new methods of identifying pathogenic bacteria and of preserving food.
[0003] Spoilage organisms also play an important role in reducing the shelf-life of both raw (fresh) and uncured RTE refrigerated meat and poultry. For example, species of Pseudomonas and Lactobacillus are predominantly responsible for undesirable defects such as off-flavors, discoloration, gas and slime etc. Present food technologists utilize an array of physical, chemical, and biological processes and agents to preserve food and prevent the transmission of disease via foodstuffs. In addition to such processes as irradiation, fermentation, pasturization, control of temperature, pH and/or water activity, a plethora of chemical agents exist. These agents include antioxidants to prevent chemical degradation of food, as well as compositions which kill or inhibit deleterious bacteria and/or other microbes thereby preserving food i.e. preventing both spoilage and the transmission of disease.
[0004] An increasing number of consumers believe foods that are free of synthetic or chemical additives are healthier. In response to these consumer trends and preferences, the food industry has focused efforts on offering various alternatives such as clean label and/or natural products that are free from artificial preservatives while retaining similar microbial safety characteristics as compared to conventionally prepared products.
[0005] As a result of the many shortfalls of the prior art, there is a need of a composition that will preserve food, and which overcomes the aforementioned problems.
SUMMARY
[0006] Embodiments of the present disclosure present technological improvements as solutions to one or more of the above-mentioned technical problems.
[0007] Before the present subject matter relating to composition and process for the conservation of food, it is to be understood that this application is not limited to the particular system described, as there can be multiple possible embodiments which are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the implementations or versions or embodiments only and is not intended to limit the scope of the present subject matter.
[0008] This summary is provided to introduce aspects related to composition and process for the conservation of food. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the present subject matter.
[0009] In an embodiment, a process for conservation of food using an antimicrobial composition is disclosed. The process includes the step of treating food using antimicrobial solution, wherein the antimicrobial food solution comprising acetic acid, or its salt and a fermentation derived antimicrobial peptide. The process includes the step of processing food surface with a synergistic mixture of a chelating agent and a Pedi coccus-derived bacteriocin or synthetic equivalent in an amount effective to kill or inhibit growth of pathogenic Listeria monocytogenes bacteria for a period of at least 24 hours. The process includes the step of packing the food by maintaining the temperature of food.
[0010] In an embodiment, a composition for preserving food is disclosed. The composition includes a acetic acid or its salt and a fermentation derived antimicrobial peptide and a synergistic mixture of a chelating agent and a Pediococcus-derived bacteriocin.
DETAILED DESCRIPTION
[0011] The invention will now be described with reference to the accompanying drawings and embodiments which do not limit the scope and ambit of the invention. The description provided is purely by way of example and illustration.
[0012] One or more embodiments are provided so as to thoroughly and fully convey the scope of the present invention to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present invention. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present invention. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
[0013] The terminology used, in the present invention, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present invention. As used in the present invention, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the system of the present invention is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
[0014] In an embodiment, a process for conservation of food using an antimicrobial composition is disclosed. The process includes the step of treating food using antimicrobial solution, wherein the antimicrobial food solution comprising acetic acid, or its salt and a fermentation derived antimicrobial peptide. The process includes the step of processing food surface with a synergistic mixture of a chelating agent and a Pedi coccus-derived bacteriocin or synthetic equivalent in an amount effective to kill or inhibit growth of pathogenic Listeria monocytogenes bacteria for a period of at least 24 hours. The process includes the step of packing the food by maintaining the temperature of food.
[0015] In another implementation, chelating agent comprises citric acid or a salt thereof, EDTA or a salt thereof, or cyclodextrin.
[0016] In another implementation, the fermentation derived antimicrobial peptide comprises bacteriocins and antimicrobial peptides that differ from the bacteriocins by one to ten amino acids.
[0017] In another implementation, the antimicrobial composition has an antimicrobial activity against Gram-positive and Gram-negative bacteria.
[0018] In another implementation, the treating step comprises immersing, spraying, or coating the food product with the composition.
[0019] In another implementation, the packaging conditions of the food or beverage products are one of vacuum and modified atmospheric conditions.
[0020] In another implementation, the food product is selected from the group consisting of fruits, vegetables, meat, poultry, seafood, dairy products, and processed food items.
[0021] In an embodiment, a composition for preserving food is disclosed. The composition includes an acetic acid, or its salt and a fermentation derived antimicrobial peptide and a synergistic mixture of a chelating agent and a Pediococcus-derived bacteriocin.
[0022] In another implementation, the acetic acid or its salt is present in a concentration ranging from about 0.5% to about 5% (w/v).
[0023] In another implementation, the fermentation-derived antimicrobial peptide is selected from the group consisting of bacteriocins, defensins, and cecropin.
[0024] Food products containing a high moisture content are more favorable substrates for the outgrowth of pathogens and spoilage bacteria and therefore should be formulated with efficient antimicrobial(s) to minimize the public health risks as well as economic losses to the processors. Some examples of food products include processed cheeses, milk beverages and other dairy products, raw meats and processed meats, refrigerated or shelf stable meat snacks, non-meat snacks, meat substitutes such as tofu-based products, and processed meal kits. Additional examples include beverage syrups, ready to drink beverage products such as iced coffee, milk coffee, and vegetable-based protein milks, for example, soy milk, coconut milk, almond milk. Other products include egg-based ingredients such as liquid egg products. Also included in this category are bakery products, soups, meals, side dishes and sauces.
[0025] The antimicrobial formulation in the methods described are comprised of an organic acid or its salt and an antimicrobial peptide, whereby the organic acid in one embodiment is acetic acid at an inclusion level of at least about 0.275% by weight, and the antimicrobial peptide is nisin, used at a quantity to deliver activity in the range of about 1-50 ppm, preferably about 7-30 ppm.
[0026] As per the present invention, mixtures of either Streptococcus-derived or Pediococcus-derived bacteriocins, such as nisin and pediocin, with one or more chelating agents may be usefully employed. Such mixtures may be solid in liquid suspensions or solutions. Unless otherwise noted, use of the term "solution" herein includes not only solids or liquids dissolved in a liquid but also solid-in-liquid suspensions or mixtures. Suitable solvents, diluents or carriers for the mixture of chelating agent and bacteriocin are water, alcohols, propylene glycol, oils such as mineral, animal or vegetable oil, glycerine or lecithin. Mixtures of the present invention containing a mixture of bacteriocin and chelating agent may be applied to foodstuffs including dairy products and nondairy products such as sausages, other meats, vegetables and fruits by any conventional coating means such as spraying or dipping of the foodstuff into the solution or by use of an impregnated or coated film as described below. Such solutions may be formulated with widely varying pHs, but advantageously will be neutral or acidic. Acidic solutions are believed to enhance or maintain the antibacterial effective of these novel solutions and are therefore preferred. Solutions having a pH less than or equal to about 6 are preferred, and less than or equal to 5 especially preferred. Amounts of the bacteriocin and chelating agent components may vary depending upon such factors as: type of bacteriocin, type of chelating agent, pH, other constituents present (e.g. type of solution solvent), application i.e. type of foodstuff to which the materials are being applied, how applied (e.g. mixing with foodstuff or surface coating), subsequent processing conditions (e.g. heat treatment), a desired time period of effectiveness to kill or inhibit bacteria, and type of bacteria the foodstuff is being protected against, etc. The inventive solution may be used against other bacteria and is especially effective against gram positive bacteria. The amounts of chelating agent used may vary widely e.g. amounts between about 0.2 to about 0.8 or 3.0 weight percent or more may be usefully employed. The inventive composition may also contain other antimicrobial or antibacterial agents, or other additives such as colorants and flavorists e.g. gaseous or liquid smoke.
[0027] In addition to delaying the toxin production of spore formers, the antimicrobial composition is bacteriostatic and in some cases bactericidal for controlling vegetative pathogens as well as spoilage bacteria. Consequently, it can enhance the product safety and extend shelf life. By way of example, the inventors have achieved a shelf life of 120 days at 4° C. through application of the disclosed antimicrobial formulations containing an organic acid at an inclusion level of at least 0.275% by weight and at least 1 ppm nisin. Shelf life is defined herein as the period of time during which a material may be stored and remain fit for purpose from a microbiological and organoleptic perspective.
[0028] In another embodiment, there is provided a cellulosic substrate comprising the compositions as defined herein. The expression “cellulosic substrate” refers to a thin material produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses and drying into flexible sheets. The cellulosic substrate could also be produced from recycled material such as recycled paper. The antimicrobial activity of the compositions as described herein on a cellulosic substrate could be determined by soaking the cellulosic substrate in the compositions to be tested and plating the cellulosic substrate on agar. An agar diffusion test could then be performed.
[0029] In further embodiment describes the antimicrobial composition to control the outgrowth of pathogens such as S. aureus in a model system simulating the pH conditions encountered in processed cheese. Tryptic Soy Broth (TSB) (Becton, Dickinson and Company), whereby the pH was adjusted to 5.8 using 88% phosphoric acid, was used as the model system. Treatments included uninoculated samples and variables inoculated with S. aureus. Multiple propionic acid and nisin antimicrobial treatments were added to TSB with efficacy compared to TSB supplemented with sorbic acid. For each treatment, the broth was inoculated with 3.5-log of a 2-strain cocktail consisting of S. aureus ATCC 25923 and S. aureus 6538P. All treatments (uninoculated and inoculated with S. aureus) were stored at 27° C. for 22 hours after which the temperature was increased to 30° C. for a further 38 hours. The TSB samples were added to a 100 well microtiter plate which was placed in a bioscreen CTM automated microbiology growth curve analysis system (manufactured by Oy Growth Curves AB Ltd, Finland). The samples were measured at a wavelength of 600 nm every hour. Plates were incubated statically and automatically shaken for 5 seconds prior to measurement. Treatments included 12.5 ppm nisin, 2,400 ppm sorbic acid, 300 ppm propionic acid, 12.5 ppm nisin combined with 300 ppm propionic acid and 0.78 ppm nisin combined with 300 ppm propionic acid. Growth was determined by measuring the optical density (OD) at 1-hour intervals. In an embodiment, the synergistic effect inhibiting the outgrowth of S. aureus was observed when 12.5 ppm nisin was combined with 300 ppm propionic acid. The synergy is demonstrated by the lower concentration of each antimicrobial when used in combination in contrast to the higher concentrations when used alone. As further demonstrated, the antimicrobial compositions disclosed herein may be used as an effective alternative to sorbic acid in food and beverage products, such as processed cheese, to control outgrowth of Staphylococcus aureus.
[0030] In another embodiment, the food packaging could comprise the antimicrobial composition described herein. In one embodiment, the antimicrobial composition described herein is applied, coated, vaporized or immobilized on the food packaging. In one embodiment, the food packaging comprising the antimicrobial composition described herein is an active food packaging. The active food packaging comprising the antimicrobial composition described herein could inhibit and/or reduce the growth of microorganisms and as such be used to maintain and/or enhance food quality, food sensory properties, food safety and/or food shelf-life.
[0031] In the present embodiment, food packaging films suitable for use include polymeric films such as blown film, oriented film, stretch and shrink film, heat shrinkable bags and food casings. "Food packaging films" as that term is used herein are flexible sheet materials which are suitably 15 mils or less and preferably less than 10 mils (25 microns) in thickness. Suitable films include food casings which are generally flexible films which are preferably tubular and may be formed of polymeric materials including cellulosic materials such as regenerated cellulose or cellulose carbamate or of plastics such as homopolymers or copolymers of polyolefins e.g. polypropylene, polyethylene, or polyamides, polyethylene terphthalate, polyvinylidene chloride copolymers or ethylene-vinyl acetate copolymers or of proteinaceous films such as collagen. Preferably, casings are tubular cellulosic casings, that are prepared by any one of the methods well known in the art. Such casings are generally flexible, thin-walled seamless tubing which is preferably formed of regenerated cellulose, and the like, in a variety of diameters. Also suitable are tubular cellulosic casings having a fibrous reinforcing web embedded in the wall thereof. Casings having a reinforcing web are commonly called "fibrous food casings", whereas cellulosic casings without the fibrous reinforcement, are herein referred to as "non-fibrous" cellulosic casings. Both natural and synthetic casings are contemplated by the present invention. Regular cellulosic casings may also be used in the present invention. Such casings may forego chemical peeling aids. Advantageously, such casings may be acid treated, or encased foodstuffs, particularly protein and fat containing foodstuffs such as freshly stuffed sausages, may be showered with an acidic solution prior to heat treatment (cooking or pasteurization). Such acid treatment may have a beneficial effect which enhances or maintains the ability of antimicrobial agents such as nisin or pediocin either alone or in conjunction with a chelating agent, to protect the encased foodstuff before and after heat treatment and/or casing removal.
[0032] The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the invention.

, Claims:We claim:
1. A process for conservation of food using an antimicrobial composition, comprising:
providing a food product
treating food product with a composition comprising acetic acid or its salt and a fermentation-derived antimicrobial peptide; and;
processing food surface with a synergistic mixture of a chelating agent and a Pediococcus-derived bacteriocin or synthetic equivalent in an amount effective to kill or inhibit growth of pathogenic Listeria monocytogenes bacteria for a period of at least 24 hours;
packing the food by maintaining temperature of food and
storing the treated food product under suitable conditions.
2. The process as claimed in claim 1, wherein said chelating agent comprises citric acid or a salt thereof, EDTA or a salt thereof, or cyclodextrin..
3. The process as claimed in claim 1, wherein the fermentation derived antimicrobial peptide comprises bacteriocins and antimicrobial peptides that differ from the bacteriocins by one to ten amino acids.
4. The process as claimed in claim 1, wherein the antimicrobial composition has an antimicrobial activity against Gram-positive and Gram-negative bacteria.
5. The process as claimed in claim 1, wherein the treating step comprises immersing, spraying, or coating the food product with the composition.
6. The process as claimed in claim 1, wherein the packaging conditions of the food or beverage products are one of vacuum and modified atmospheric conditions.
7. The process as claimed in claim 1, wherein the food product is selected from the group consisting of fruits, vegetables, meat, poultry, seafood, dairy products, and processed food items.
8. A composition for preserving food, comprising:
a acetic acid or its salt and a fermentation derived antimicrobial peptide;
a synergistic mixture of a chelating agent and a Pediococcus-derived bacteriocin.
9. The composition as claimed in claim 8, wherein the acetic acid or its salt is present in a concentration ranging from about 0.5% to about 5% (w/v).
10. The composition as claimed in claim 8, wherein the fermentation-derived antimicrobial peptide is selected from the group consisting of bacteriocins, defensins, and cecropin.