Claims:We Claim:

1. A chemical method of decontaminating herbal material by reducing microbial load thereof, comprising the following steps:
i) obtaining a herbal material;
ii) subjecting the material of step (i) to demineralized water to produce an extract;
iii) obtaining a concentrated extract by subjecting the extract of step (ii) to at least one additional extraction step(s);
iv) homogenously mixing the extract of step (iii) with a first antimicrobial agent with subsequent filtering;
v) homogenously mixing the extract of step (iv) with a second antimicrobial agent with subsequent filtering, wherein the first and second antimicrobial agents are different, and wherein the second antimicrobial agent is plant-based;
vi) treating extract of step (v) with activated charcoal
vii) obtaining concentrated liquid extract under vacuum; and
wherein the microbial load of the extract is reduced by at least 90%.

2. The chemical method according to claim 1 wherein the first antimicrobial agent is selected from silicon dioxide, sodium dichloro isocyanurate, or silver nitrate.

3. The chemical method according to claim 2 wherein silicon dioxide is added in concentration ranging from approximately 5% to approximately 30%.

4. The chemical method according to claim 2 wherein sodium dichloro isocyanurate is added in concentration ranging from approximately 0.025% to approximately 10%.

5. The chemical method according to claim 2 wherein silver nitrate is added in concentration ranging from approximately 1 mM to approximately 15 mM.

6. The chemical method according to claim 1 wherein the second antimicrobial agent is plant-based.

7. The chemical method according to claim 6 wherein the plant-based antimicrobial agent is thymol.

8. The chemical method according to claim 7 wherein thymol is added in concentration ranging from approximately 50 ppm to approximately 3000 ppm.

9. The chemical method according to claim 1 wherein the herbal material shall be any part of a plant or an extract thereof.

10. The chemical method according to claim 9 wherein the herbal material shall be obtained from Salacia reticulata, Salacia ?oblonga, Salacia chinensis, Aegle marmelos, Aerva lanata, Alangium salvifolium, Albizia amara, Aloe Vera, Phyllanthus emblica Syn., Emblica officinalis, Andrographis paniculata, Bixa Orellana, Withania somnifera, Asparagus racemosa, Avena sativa, Bacopa monnieri, Bambusa arundinacea, Lagerstromia speciosa, Basella alba, Beta vulgaris, Boswellia serrate, Capsicum annum, Caralluma fimbriata, Cardiospermum helicacabum, Daucus carota, Cassia auriculata, Cassia fistula, Castus spicata, Centella asiatica, Cinnamomum zeylanicum, Cissus quadrangularis, Citrus sinensis, Salvia officinalis, Coccinia indica, Coleus forskohlii, Commiphora mukul, Coriandrum sativum, Cuminum cyminum, Curcuma longa, Murraya koenigii, Datura stromonium, Anethum graveolens, Dioscorea deltoidea, Dodonaea viscosa, Euphorbia hirta, Foeniculum vulgare, Trigonella foenum- graecum, Garcinia cambogia, Allium sativum, Gentiana lutea, Zingiber officinalis, Camellia sinensis, Gymnema sylvestre, Hemidesmus indicus, Hibiscus subdariffa, Hibiscus rosa-sinensis, Aesculus hippocastanum, Equisetum arvense, Hyoscyamus muticus, Syzygium cumini, Lantana camara, Lawsonia inermis, Glycyrrhizia glabara, Calendula arvensis, Garcinia mangostana, Mentha piperita, Momordica charantia, Morinda citrifolia, Morus alba, Azadiracta Indica, Urtica dioica, Nigella sativa, Myristica fragrans, Carica papaya, Passiflora incarnate, Mentha spicata, Phaseolus vulgaris, Phyllanthus niruri, Piper betel, Piper nigrum, Plumbago zeylanica, Poligala senega, Punica granatum, Pongamia pinnata, Trifolium pretense, Rhamnus purshiana, Rosa canina, Rosmarinus officinalis, Chlorophytum borivilianum, Senna angustifolia, Asphaltum, Annona squamosal, Solanum indicum, Solanum nigrum, Syzygium aromaticum, Syzygium cumini, Tamarindus indica, Terminalia bellerica, Terminalia chebula, Thymus vulgaris, Tinospora cordifolia, Tribulus terrestris, Tridax procumbens, Trigonella foenum-graecum, Triphala, Ocimum sanctum, Valeriana officinalis, Valeriana jatamansi, Adathoda vasaka, Viola odorata, Vitex agnus-castus, Vitex negundo, Dioscorea villosa, or Ziziphus jujube.

Dated this on 14th Day of August 2020
, Description:FIELD OF THE INVENTION

The invention relates to method which uses chemicals for decontaminating herbal materials by reducing microbial load for better efficacy in humans. Particularly, the invention relates to use of antimicrobial agents for decontamination of herbal materials. More particularly, the method relates to use of plant-based antimicrobial agent and other chemical antimicrobial agents in combination to reduce the microbial load of the herbal material. The method further find use in the preservation of agricultural products, herbal extracts, herbal raw material and cut flowers.

BACKGROUND OF THE INVENTION

World Health Organization has recognized the important contribution of herbal medicine to provide essential care. Herbal medicine comprises products derived from plants and processed into required form. This field of medicine has been the oldest field of medicine in human history, as all medicine originally started with the use of plant materials for remedial action against various natural ailments. The field has experienced a resurgence in recent years due to the growing demand among consumers for naturally oriented, chemical-free medicine. Preference for personal medication drives the global herbal medicine market at a strong rate.

Consumers are increasingly demanding all-natural alternatives to conventional medicine, which has driven the demand for herbal medicine across the world, including developed regions such as North America and Europe as well as developing countries in Asia Pacific, Latin America, the Middle East, and Africa. Currently, herbs are applied to the treatment of chronic and acute conditions and various ailments and problems such as cardiovascular disease, prostate problems, depression, inflammation, and to boost the immune system, to name but a few.

Herbs and medicinal plants can be processed and can be taken in different ways and forms, and they include the whole herb, teas, syrup, essential oils, ointments, salves, rubs, capsules, and tablets that contain a ground or powdered form of a raw herb or its dried extract. Herbal extract vary in the solvent used for extraction, temperature, and extraction time, and include alcoholic extracts (tinctures), vinegars (acetic acid extracts), hot water extract (tisanes), long-term boiled extract, usually roots or bark (decoctions), and cold infusion of plants (macerates).

Herbs and medicinal plants are subject to deterioration during the harvesting, processing, storage and their distribution. Microbial contaminants such as bacteria, fungi and viruses are reported to be associated in medicinal plants. Presence of such pathogens limits the use of medicinal plants and also exerts an important impact on the overall quality of herbal drugs and preparations. Also, since presence of such pathogenic microorganisms constitute a potential hazard to human health, reducing their concentration from their source is critical. Microbial contamination can lead to impaired performance of the product due to disruption of the stability of the formulation, modification of physical characteristics and appearance and lead to inactivation of the active ingredients and excipients in the formulation. Herbal drugs have more microbial contaminants than a chemically well-defined drug, hence, if good manufacturing practices are adopted, such contaminants can be reduced in the final end product.

It is crucial to decontaminate and preserve these herbs and medicinal plants so as to get more safe, natural and potent medicines. Regulatory bodies of different countries prescribe limits and parameters for what they consider safe products. One of the parameters of defining safety is the microbial load. Microbial loads are higher when the herbal material is in the form of raw materials such as stem, roots, leaves, flowers, and so on; and they are observed to be lower when the herbal material is in extract form. The amount of microbial load can also be a determining factor while choosing microbial load reduction technique. In any case, the ultimate aim is to reduce the microbial load of the material in order to make it safe for human consumption and compliance of the guidelines issued by the regulatory bodies. A number of physical methods are employed for decontamination such as heat treatment, UV irradiation and fumigation. However, these methods are not without substantial drawbacks. Volatility and heat sensitivity of the delicate flavor and aroma components of the medicinal plants do not permit the use of heat treatment. Low penetration power of UV radiations makes the irradiation method unsuitable. Fumigation with gaseous ethylene oxide brings down the microbial burden but this method is now prohibited or restricted in many countries due to the carcinogenic nature of one of its residue in treated medicinal plants. In addition, and above all, the physical methods may also cause damage to the herbal material. The inherent nature of these techniques subjects material to alteration in their structural integrity. In other words, the herbal material may undergo changes in addition to removal of presence of microbes including bacteria and fungi.

Consequently, a safe alternative technology is the need of the day. This is in addition to significantly reducing the microbial load of the herbal material. It is imperative that the physical decontamination techniques be replaced with chemical methods that specifically act towards reducing microbial loads. Use of antimicrobial agents will only reduce microbial load by specifically acting on the microbes present in the material, and not act on the herbal material per se thus preserving the integrity of the herbal material. Further, it is also required that the proposed methods must be economic and scalable in addition to being safe. It is crucial that the final extract remain safe for human use and consumption.

Thymol, abundantly found in thyme (Thymus vulgaris), is the main monoterpene phenol component of essential oil. Thymol has been registered by the European Commission for use as flavourings in foodstuffs due to the lack of health risk to the consumer and the Food and Drug Administration (FDA) has classified these substances as ‘generally recognized as safe’ (GRAS) or as approved food additives. The antibacterial activities of thymol show a wide spectrum. It inhibits both Gram positive and Gram negative bacteria and also fungal species. Other effective antimicrobial compounds such as silicon dioxide, silver nitrate, hypochlorous acids, sodium dichloroisocyanurate (NaDCC), are widely used as broad spectrum bactericidal agents in food, agriculture, and cosmetics industry to name a few.

Currently there is no specific chemical process to decontaminate herbal material. The present inventors demonstrate that a combined use of plant-based antimicrobial agents and other antimicrobial compounds, at optimum durations, can be used on an industrial scale. The present inventors propose that chemical methods of decontamination show superior results in reducing microbial load and are safer than the physical methods.

It is therefore desirable to have a chemical based decontamination method for herbal material on an industrial scale and which moreover, overcomes the shortcomings and limitations of the current physical decontamination techniques. The disclosed invention is based on the observation that the chemical decontamination method also provides superior results in reducing microbial load as compared to the physical decontamination methods.

According to the present invention there is therefore provided a method that uses chemical compounds for decontamination of herbal material by reducing the microbial load. More particularly, the method employs use of plant-based antimicrobial agents and antimicrobial chemicals in combination to reduce the microbial load in the herbal material. Further, the claimed chemical method reduces the microbial load of the herbal material by at least 90%.

SUMMARY OF THE INVENTION
In view of the foregoing, for overcoming the disadvantages of the prior art, the object of the invention is to provide a chemical method to decontaminate herbal material using antimicrobial chemicals to reduce the microbial load.

Yet another object of present invention is to provide a chemical method that uses a combination of plant-based antimicrobial agent with other chemical antimicrobial agents to reduce the microbial load in herbal material. A further object of the present invention is to provide a chemical method, which is simple, efficient and cost-effective on an industrial scale which reduces the microbial load by at least 90%.

An aspect of the invention is a chemical method of decontaminating herbal material by reducing microbial load thereof, wherein the first step is obtaining the herbal material, the second step is subjecting the said material to demineralized water to produce an extract, the third step is obtaining a concentrated extract by using at least one additional extraction steps, the fourth step is homogenously mixing the concentrated extract with a first antimicrobial agent at optimum concentration and then filtering, the fifth step being homogenously mixing the extract with a second antimicrobial agent at optimum concentration with subsequent filtering, wherein the first and second antimicrobial agents are different, and wherein the second antimicrobial agent is plant-based, the sixth step being treating extract with activated charcoal, and the final and seventh step is obtaining concentrated liquid extract under vacuum, wherein the microbial load of the finally obtained extract is reduced by at least 90%.

Another aspect of the invention is the use of chemical antimicrobial agents to reduce the microbial load of the herbal material.

Another aspect of the invention is a combination of plant-based antimicrobial agent and other suitable chemical antimicrobial agents to reduce the microbial load of the herbal material.

Yet another aspect of the invention is reduction in microbial load of the herbal material by at least 90%.

According to one embodiment, herbal material is obtained from a plant. According to another embodiment, the said herbal material is subjected to extraction processes including treatment with demineralized water. According to another embodiment, the said herbal material may be subjected to at least one additional extraction process in order to obtain a concentrated extract which shall be decontaminated to reduce the microbial load. In a preferred embodiment, the extract shall be concentrated by at least five times it initial amount and wherein the total dissolved solids shall be from approximately 20% to approximately 25%.

According to one embodiment, a combination of plant-based antimicrobial agent and other suitable chemical antimicrobial agents is used to reduce the microbial load of the herbal material. In an alternate embodiment, the antimicrobial agents may be used alone i.e. not in combination.

According to one embodiment, the extract herbal material is subjected to a first antimicrobial agent wherein the first antimicrobial agent is selected from silicon dioxide, sodium dichloro isocyanurate, or silver nitrate. According to a preferred embodiment, the first antimicrobial agent is silicon dioxide. In another embodiment, the herbal material is subjected to this antimicrobial agent at optimum concentration for an optimum duration at a pre-decided ambient temperature.

According to another embodiment, use of other chemicals may be employed to enhance the efficacy of the first antimicrobial agent.

According to one embodiment the herbal material extract is subjected to a second antimicrobial which is plant-based. According to a preferred embodiment, the second antimicrobial agent is thymol. In another embodiment, the herbal material is subjected to this antimicrobial agent at optimum concentration for an optimum duration at a pre-decided ambient temperature.

According to one embodiment, silicon dioxide, as the first antimicrobial agent, shall be added in concentration ranging from approximately 5% to approximately 30%.

According to one embodiment, silver nitrate, as the first antimicrobial agent, shall be added in concentration ranging from approximately 1 mM to 15 mM.

According to one embodiment, sodium dichloro isocyanurate, as the first antimicrobial agent, shall be added in concentration ranging from approximately 0.025% to approximately 10%.

According to one embodiment, thymol, as the plant-based second antimicrobial agent, shall be added in concentration ranging from approximately 50 ppm to approximately 3000 ppm.

According to one embodiment, the extract which has been treated with the first and second antimicrobial agent is further treated with activated charcoal. In another embodiment, the extract is subjected to activated charcoal for an optimum duration at a pre-decided ambient temperature.

According to one embodiment, the final extract is obtained as a concentrated liquid extract which is extracted under vacuum.

According to one embodiment, reduction in microbial load of the herbal material is by at least 90%.

According to one embodiment, the herbal material shall be any part of a plant or an extract thereof. According to another embodiment, the herbal material shall be obtained from Salacia reticulata, Salacia?oblonga, Salacia?chinensis, Aegle marmelos, Aerva lanata, Alangium salvifolium, Albizia amara, Aloe Vera, Phyllanthus emblica Syn., Emblica officinalis, Andrographis paniculata, Bixa Orellana, Withania somnifera, Asparagus racemosa, Avena sativa, Bacopa monnieri, Bambusa arundinacea, Lagerstromia speciosa, Basella alba, Beta vulgaris, Boswellia serrate, Capsicum annum, Caralluma fimbriata, Cardiospermum helicacabum, Daucus carota, Cassia auriculata, Cassia fistula, Castus spicata, Centella asiatica, Cinnamomum zeylanicum, Cissus quadrangularis, Citrus sinensis, Salvia officinalis, Coccinia indica, Coleus forskohlii, Commiphora mukul, Coriandrum sativum, Cuminum cyminum, Curcuma longa, Murraya koenigii, Datura stromonium, Anethum graveolens, Dioscorea deltoidea, Dodonaea viscosa, Euphorbia hirta, Foeniculum vulgare, Trigonella foenum- graecum, Garcinia cambogia, Allium sativum, Gentiana lutea, Zingiber officinalis, Camellia sinensis, Gymnema sylvestre, Hemidesmus indicus, Hibiscus subdariffa, Hibiscus rosa-sinensis, Aesculus hippocastanum, Equisetum arvense, Hyoscyamus muticus, Syzygium cumini, Lantana camara, Lawsonia inermis, Glycyrrhizia glabara, Calendula arvensis, Garcinia mangostana, Mentha piperita, Momordica charantia, Morinda citrifolia, Morus alba, Azadiracta Indica, Urtica dioica, Nigella sativa, Myristica fragrans, Carica papaya, Passiflora incarnate, Mentha spicata, Phaseolus vulgaris, Phyllanthus niruri, Piper betel, Piper nigrum, Plumbago zeylanica, Poligala senega, Punica granatum, Pongamia pinnata, Trifolium pretense, Rhamnus purshiana, Rosa canina, Rosmarinus officinalis, Chlorophytum borivilianum, Senna angustifolia, Asphaltum, Annona squamosal, Solanum indicum, Solanum nigrum, Syzygium aromaticum, Syzygium cumini, Tamarindus indica, Terminalia bellerica, Terminalia chebula, Thymus vulgaris, Tinospora cordifolia, Tribulus terrestris, Tridax procumbens, Trigonella foenum-graecum, Triphala, Ocimum sanctum, Valeriana officinalis, Valeriana jatamansi, Adathoda vasaka, Viola odorata, Vitex agnus-castus, Vitex negundo, Dioscorea villosa, or Ziziphus jujube.

DETAILED DESCRIPTION OF THE INVENTION
To clarify the above and other purposes, features, and advantages of this invention, specific embodiment of this invention is especially listed and described in detail with the examples as follows. The principal and mode of operation of this invention have been described and illustrated in its embodiment. At the outset, a person skilled in the art will appreciate that this invention may be practiced otherwise than is specifically described and illustrated. The invention should not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention. Also, in the following description of the invention, certain terminology may be used for the purpose of reference only, and is not intended to be limiting.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value and/or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

The invention sets out a chemical method that is used for decontaminating herbal material. It should be noted that herbal material is defined as any and one or more part of a plant or an extract thereof. This includes raw material, any part of the plant such as roots, leaves, stems, barks, flowers, and so on. It should be noted that terms ‘herbal material’ and ‘plant material’ have been used interchangeably throughout this application. Herbs and plants can be processed and can be taken in different ways and forms, and they include the whole herb, teas, syrup, essential oils, ointments, salves, rubs, capsules, and tablets that contain a ground or powdered form of a raw herb or its dried extract. Accordingly, a part of the plant may be used as a raw material, or a liquid and/or solid extract thereof. That is to say, that an extract of the plant material may be obtained in form of a liquid or a powder depending upon the requirement. Plants and herbs extract may vary in the solvent used for extraction, temperature, and extraction time, and include alcoholic extracts (tinctures), vinegars (acetic acid extracts), hot water extract (tisanes), long-term boiled extract, usually roots or bark (decoctions), and cold infusion of plants (macerates). The extract may be prepared by a number of extraction procedures. Suitable procedures include multiple steps, for example maceration, percolation, and extraction using supercritical fluids, liquefied gases or suitable solvents.

The method of the present invention has been scaled and designed to accommodate a large number of medicinal plants being used in a variety of herbal applications. According to one embodiment, the herbal material shall be obtained from Salacia reticulate, Salacia oblonga, Salacia chinensis, Aegle marmelos, Aerva lanata, Alangium salvifolium, Albizia amara, Aloe Vera, Phyllanthus emblica Syn., Emblica officinalis, Andrographis paniculata, Bixa Orellana, Withania somnifera, Asparagus racemosa, Avena sativa, Bacopa monnieri, Bambusa arundinacea, Lagerstromia speciosa, Basella alba, Beta vulgaris, Boswellia serrate, Capsicum annum, Caralluma fimbriata, Cardiospermum helicacabum, Daucus carota, Cassia auriculata, Cassia fistula, Castus spicata, Centella asiatica, Cinnamomum zeylanicum, Cissus quadrangularis, Citrus sinensis, Salvia officinalis, Coccinia indica, Coleus forskohlii, Commiphora mukul, Coriandrum sativum, Cuminum cyminum, Curcuma longa, Murraya koenigii, Datura stromonium, Anethum graveolens, Dioscorea deltoidea, Dodonaea viscosa, Euphorbia hirta, Foeniculum vulgare, Trigonella foenum- graecum, Garcinia cambogia, Allium sativum, Gentiana lutea, Zingiber officinalis, Camellia sinensis, Gymnema sylvestre, Hemidesmus indicus, Hibiscus subdariffa, Hibiscus rosa-sinensis, Aesculus hippocastanum, Equisetum arvense, Hyoscyamus muticus, Syzygium cumini, Lantana camara, Lawsonia inermis, Glycyrrhizia glabara, Calendula arvensis, Garcinia mangostana, Mentha piperita, Momordica charantia, Morinda citrifolia, Morus alba, Azadiracta Indica, Urtica dioica, Nigella sativa, Myristica fragrans, Carica papaya, Passiflora incarnate, Mentha spicata, Phaseolus vulgaris, Phyllanthus niruri, Piper betel, Piper nigrum, Plumbago zeylanica, Poligala senega, Punica granatum, Pongamia pinnata, Trifolium pretense, Rhamnus purshiana, Rosa canina, Rosmarinus officinalis, Chlorophytum borivilianum, Senna angustifolia, Asphaltum, Annona squamosal, Solanum indicum, Solanum nigrum, Syzygium aromaticum, Syzygium cumini, Tamarindus indica, Terminalia bellerica, Terminalia chebula, Thymus vulgaris, Tinospora cordifolia, Tribulus terrestris, Tridax procumbens, Trigonella foenum-graecum, Triphala, Ocimum sanctum, Valeriana officinalis, Valeriana jatamansi, Adathoda vasaka, Viola odorata, Vitex agnus-castus, Vitex negundo, Dioscorea villosa, or Ziziphus jujube.

Central to this invention is the object to decontaminate the aforementioned herbal material, by reducing its microbial load, by specifically using antimicrobial chemicals over the traditional physical decontamination techniques. It should be noted that the present invention claims a ‘chemical decontamination method’ which is distinct from the physical decontamination method in that it employs use of antimicrobial compounds, chemicals or reagents to specifically reduce the microbial load of the herbal material. The chemical decontamination is achieved using a multi-step method wherein the obtained herbal material, in the form of a raw material or extract, is subjected to a combination of antimicrobial agents. Accordingly, this method of decontaminating herbal material is initiated by obtaining the herbal material. This is followed by subjecting the said material to demineralized water to produce an extract. Next, a concentrated extract is obtained by using multiple extraction steps which is then treated with antimicrobial agents. The first antimicrobial agent, at optimum concentration, is homogenously mixed with the concentrated extract and then filtered. The resultant extract is then homogenously mixed with a second antimicrobial agent at optimum concentration with subsequent filtering. It should be noted that herein the first and second antimicrobial agents are different. It should also be noted that the second antimicrobial agent is plant-based. This filtered extract is treated with activated charcoal. The resultant and final extract is obtained as a concentrate liquid under vacuum, wherein the microbial load of the finally obtained extract is reduced by at least 90%. This method is described in greater detail as follows.

Herbal materials are prone to microbial contamination and insect infestation during storage and transportation resulting in quality deterioration. The microbial load in the materials increases significantly over the period of time. Microbial load of the material can be tested using standard techniques such as Total Plate Count (TPC). For example, the microbial load in untreated sample of Salacia reticulata is found to be approximately 2 x 102 cfu/g. Studies have reported that this microbial load increases to approximately 3.2 x 108 cfu/g when stored upto 15 months. It should be noted that the approach to using chemical antimicrobial agent and the subsequent process may vary and depend upon the initial microbial load in the material. Typically, raw herbal materials have higher microbial load as compared to herbal extracts. Further, there may not always be a clarity on how fresh or old an herbal raw material sample is. Therefore, an initial evaluation of the microbial load is a useful means of determining the strategy for the subsequent process. This is termed as the initial microbial load in the herbal material. A person skilled in the art will appreciate the versatility of the chemical method of the present invention in that, it can be used successfully irrespective of presence of high or low initial microbial load in the herbal material.

One embodiment of the invention is treating the herbal material with demineralized water. This is a part of standard procedure during herbal material extraction on an industrial scale. This step is typically performed at approximately 80°C for approximately one hour.

In another embodiment of the invention, multiple extraction steps may be performed in order to obtain an extract of a desired concentration. It should be noted that processes and requirements of concentration may vary with respect to the choice of starting herbal material, the form of the herbal material, and its end use. The number of extraction steps and its nature may vary and depend on such a requirement. In a preferred embodiment, the extract shall be concentrated by at least five times it initial amount and wherein the total dissolved solids shall be from approximately 20% to approximately 25%. However, it should be appreciated that this is an important milestone in designing this method since the concentrated extract obtained at the end of this step shall be used for the further decontamination method. Accordingly, the number of additional extractions steps may increase or decrease.

Central to this invention, is the use of antimicrobial chemicals for the purpose of decontamination of herbal material, measured by the reduction in its microbial load. This is the essence of the invention, since it presents a solution to the challenges of the physical decontamination techniques used in the prior art. Accordingly, the choice of antimicrobial agents at optimum concentration coupled with the optimum treatment time and ambient temperature play a crucial role in the current invention.

It should be appreciated that the herbal raw material treated with the antimicrobial reagents are inactivated in a manner that the raw material will not provide any conditions for resumption of bacterial replication once its action is terminated. This provides for use of a starting material for herbal extraction in a controlled manner. Further, since the raw herbal material have reduced concentration of microbes, its ability to replicate relative to untreated raw material, and thus produce extracts with relatively insignificant few progeny in the course of use in the methods described herein, the likelihood of the generation and selection of higher amounts of microbes is decreased.

Antimicrobials are a broad class of chemicals used in food, agriculture, medicinal, etc. applications to kill or inhibit the growth of microbes including bacteria, fungi, viruses, and so on. Originally derived from natural sources, many herbs and spices exhibit antimicrobial activity: thyme, cinnamon, garlic, ginger, chamomile, oregano, sage, echinacea, wasabi, to name a few. The antibacterial activity of thymol (obtained from thyme) is dictated by its dispersion homogeneity since it has poor water solubility. Thymol has been registered by the European Commission for use as flavourings in foodstuffs due to the lack of health risk to the consumer and the Food and Drug Administration (FDA) has classified these substances as ‘generally recognized as safe’ (GRAS) or as approved food additives. The antibacterial activities of thymol show a wide spectrum. It inhibits both Gram positive and Gram negative bacteria and also fungal species.

From a chemical standpoint, synthetic antimicrobials chemicals are also used widely to inhibit microbial growth. Hypochlorous acid (HOCl) is the form of free available chlorine that has the highest bactericidal activity against a broad range of microorganisms. Similarly, silver ions cause marked inhibition of bacterial growth and inhibit cell division and damaged the bacterial cell envelope and contents of bacteria. Various forms of silver including silver metal, silver acetate, silver nitrate, silver protein, and silver sulfadiazine exhibit antibacterial activity. Silicon dioxide is also known to function as a broad spectrum antimicrobial agent. The present method is based on a combination of plant-based antimicrobial agent with other suitable chemical antimicrobial agent. It should be noted that exclusion of any compound/ chemical is not a reflection of its value.

The present inventors report that characteristics such as molecule size, solubility, efficacy, antimicrobial action spectrum, etc. are crucial factors while choosing one or more antimicrobial agents for the method. Solvents such as ethanol, methanol, DMSO, etc may be used for solvent derived extraction process. Alternatively, the process may use water. The selection of antimicrobial agents is also based on the type of herbal extract being manufactured. The regulatory requirements of different countries are also taken into consideration while choosing the antimicrobial agents. This is particularly crucial because regulatory bodies such as FDA, EMA, PMDA, etc. have specific requirements with respect to residual solvents in the herbal powders. Further, some of the active constituents of the extracts may be susceptible to degradation when antimicrobial agents are used at very high concentrations for such long durations. Degradation of active constituents leads to reduction in quality and increase in residual solvents. This may prove to be counter-effective with respect to regulatory compliance. Therefore, these factors need to be evaluated before choosing an appropriate anti-microbial agent for reducing microbial load in herbal extracts.

To achieve the desired reduction in microbial load, a long duration exposure of the antimicrobial agents is required. Results showed that antimicrobial agents such as thymol, silver nitrate, and sodium dichloro isocyanurate, when used alone, i.e. not in combination, for long duration (at least 10 hours), exhibited reduction in microbial load by at least 98%. This clearly indicates that these agents are effective even when they are used alone, i.e. not in combination. The present inventors report that antimicrobial agents can be used alone i.e. not in combination, when the initial microbial load of the herbal material is significantly low such as approximately 2 x 102 cfu/g.

However, not all antimicrobial agents are suitable for long exposures. For example, silicon dioxide is a very light weight molecule and therefore cannot sustain activity for durations longer than 10 hours. Similarly, while silver nitrate exhibits antimicrobial activity for longer durations, there is a potential risk of heavy metal toxicity associated with it. Thymol – a plant-based antimicrobial agent, not only exhibits superior results (at least 99% reduction in microbial load) over long durations but also is safe due to the very nature of its origin.

The present inventors report that since the antimicrobial agents herein work synergistically, the concentration of antimicrobial agents can be significantly reduced if the agents are used in combination; without compromising on the reduction of microbial load. This is particularly crucial since the antimicrobial agents are used for long duration of exposures. For example, if thymol is used at approximately 3000 ppm when used alone, in a combination with other antimicrobial agent such as silicon dioxide, silver nitrate, or sodium dichloro isocyanurate the amount of thymol can be significantly reduced to approximately 1000 ppm or even lower. This presents a multi-fold benefit – reduction in degradation of active constituents, reduction in subsequent residual material in the final product, higher reduction in microbial load, and a cost-effective method. Further, the combination treatment is particularly crucial in cases where higher initial microbial loads, such as higher than as approximately 2 x 102 cfu/g, are observed.

Also central to the invention is the concentration of antimicrobial agent added to the extract material. It should be noted that the concentration of an individual antimicrobial agent may vary based on the combination used and/or also on the initial microbial load. In an embodiment, and wherever applicable, silicon dioxide shall be added in concentrations ranging from approximately 5% to approximately 30%. In an embodiment, and wherever applicable, thymol shall be added in concentration ranging from approximately 50 ppm to approximately 3000 ppm. In an embodiment, and wherever applicable, silver nitrate shall be added in concentration ranging from approximately 1 mM to 15 mM. In an embodiment, and wherever applicable, sodium dichloro isocyanurate shall be added in concentration ranging from approximately 0.025% to approximately 10%.

The present inventors report that this result formed the basis of using combination treatment to reduce the microbial load in the herbal material. Combination of antimicrobial agents are, thus, selected based on their ability to act for short duration (approximately one hour) and long duration (approximately 10 to approximately 16 hours). In a preferred embodiment, the present method is based on a combination of plant-based antimicrobial agent thymol, at optimum concentration, used for a long duration with other suitable chemical antimicrobial agent silicon dioxide, at optimum concentration, used for short duration. The reduction in microbial load using this combination has been illustrated in Example 1. To reiterate, for the purpose of this invention, the present inventors prefer use of more than one agent, in combination, to achieve the desired reduction in microbial load. This shall not be construed as exclusion of the potential use of antimicrobial agents alone, i.e. not in combination, from the scope of this invention.

According to one embodiment, the extract herbal material is subjected to a first antimicrobial agent wherein the first antimicrobial agent is selected from silicon dioxide, sodium dichloro isocyanurate, or silver nitrate. In a preferred embodiment, silicon dioxide is used as a first antimicrobial agent for treating the herbal extract material. In another embodiment, the herbal material is subjected to this antimicrobial agent at optimum concentration for an optimum duration at a pre-decided ambient temperature. In a preferred embodiment, the first antimicrobial agent is mixed homogenously with the extract at room temperature for approximately one hour. This step is concluded by filtration of the extract.

It should be noted that chemical processes, may typically require the presence of other reagents to maintain process parameters such as pH, osmolality, and so on. These reagents, chemicals, or regulators are crucial for the enhancement of the process at the prescribed time and temperature. Therefore, the use of such agents, wherever necessary, cannot be excluded from the scope of the invention. According to another embodiment, use of other chemicals may be employed to enhance the efficacy of the first antimicrobial agent.

According to one embodiment the herbal material extract is subjected to a second antimicrobial which is plant-based. In a preferred embodiment, the second antimicrobial agent is thymol, which is plant-based. In another embodiment, the herbal material is subjected to this antimicrobial agent at optimum concentration for an optimum duration at a pre-decided ambient temperature. For obtaining efficient results in this step, it is imperative that there be long exposure of the extract to the plant-based antimicrobial. In a preferred embodiment, the plant-based antimicrobial agent is mixed homogenously with the extract for approximately 12 to approximately 18 hours. In a more preferred embodiment, the plant-based antimicrobial agent is mixed homogenously with the extract for approximately 12 to approximately 16 hours. Since the method of the present invention is designed to be scalable for industrial purpose, it is also critical that the said method be easy, efficient, and cost-effective. It should be appreciated that, with the scale of economy in mind, the treatment with the plant-based antimicrobial agent is performed at room temperature. This step is concluded by filtration of the extract.

According to one embodiment, the extract which has been treated with the first and second antimicrobial agent is further treated with activated charcoal. All commercially available activated carbons are suitable as activated carbon for the purposes of the present invention. In another embodiment, the extract is subjected to 0.5% activated charcoal for an optimum duration at a pre-decided ambient temperature. In a preferred embodiment, the treatment with activated charcoal is performed at approximately 80°C for approximately one hour.

According to one embodiment, the final extract is obtained as a concentrated liquid extract which is extracted under vacuum. This can be performed using an apparatus such as the Rotary Evaporator.

The final extract, obtained at the end of the method of the present invention, is deemed microbe-free and therefore safe after assessing and evaluating the reduction in the microbial content of the material and also estimating the residual amount of the anti-bacterial agents. While the residual amount of anti-bacterial agents can be estimated by methods such as Gas Chromatography, Thin-layer Chromatography, HPLC, gravimetric method etc, the microbial load can be tested by performing standards tests such as the Total Plate Count (TPC) method. TPC is the enumeration of aerobic, mesophillic organisms that grow in aerobic conditions under moderate temperatures of 20-45°C. This includes all aerobic bacteria, yeast, molds and fungi that grows in the specific agar. Therefore, according to one embodiment, reduction in microbial load of the herbal material is by at least 90%. In a preferred embodiment, the reduction in microbial load of the herbal material is by at least 95%. In a more preferred embodiment, the reduction in microbial load of the herbal material is by at least 97%. In the most preferred embodiment, the reduction in microbial load of the herbal material is by at least 99%.

Example 1 – Decontamination of Salacia reticulata material using silicon dioxide and thymol.

The raw material (roots) of Salacia genus was selected for processing for reducing its microbial load in Salacia. Salacia raw material was extracted with 6- volumes of demineralized water at 80°C followed by 3-extraction cycles. To this extract, approximately 12.5% silicon dioxide is added and kept at room temperature for 1-hour with intermittent stirring and then filtered through hyflow supercel bed using Buchner funnel. This is followed by addition of Thymol (approximately 1000 ppm to extract volume) into liquid extract and kept for 16 hours at room temperature. This extract was treated with 0.5% activated charcoal and kept for 1 hour at 80°C and then filter through hyflo supercell bed. The liquid extract is concentrated at 50-55°C under vacuum using Rotary Evaporator. A TPC test was performed on the final extract. Reduction in microbial load was determined.

Result - Total plate count (TPC-cfu/g) was 300, i.e. reduction of microbial load was 99.61%.

Example 2 - Comparison between efficiencies of physical methods of decontamination of herbal extract of Salacia versus chemical methods.

The raw material (roots) of Salacia genus was selected for processing for reducing its microbial load in Salacia. Small quantities of materials were treated with steam sterilization, gamma radiation, fumigation, silicon dioxide, thymol and a combination of silicon dioxide and thymol. Treatment with silicon dioxide, thymol, and the combination of silicon dioxide and thymol was performed for approximately 16 hours. Total Plate Count (TPC) tests were performed to evaluate the reduction in microbial load of the samples. The samples were then compared with control samples which were untreated.

Treatment Reduction in microbial load
Control Not applicable
Steam sterilization 80% reduction
Gamma radiation 40% reduction
ETO treatment No reduction
SiO2 (Silicon dioxide) (25%) 99% reduction
Thymol (3000 ppm) 99.99 % reduction
Silicon dioxide (12.5%) + Thymol (1000 ppm) 99.61% reduction