FIELD OF THE INVENTION

The present invention relates to a solid, non-hygroscopic water-soluble curing agent in a powder/granular form, comprising a plant-based nitrite derived from a liquid juice concentrate obtained from plant material selected from cabbage, beet, celery, radish, spinach, onion, swiss chard, chicory leaf and the combination thereof. The invention also relates to a process for preparation of non-hygroscopic curing agent using carrier excipients like amino acids, gums, protein salts, whey protein, skimmed milk powder, protein hydrolysates and the combination thereof, which results in water-soluble granular composition. The process as described herein may be comprised of blending of the liquid juice concentrate comprising the nitrite with suitable carrier to obtain a non-hygroscopic composition which is free-flowing, easy to use, handle and optionally reconstitute. The non-hygroscopic powder/granular product may be comprised of nitrite content of about 10,000 to 30,000 ppm and exhibits excellent solid-state stability, water solubility, free flow property, longer shelf-life and ease of packaging and storage. It can be used to preserve or cure meat or meat products and other applications in the food industry.

BACKGROUND OF THE INVENTION

The preservation of meat and meat products has been practiced for many years in a variety of ways, such as by smoking, treatment with nitrite, or combinations thereof. In one method for preparing cured meat and meat products, the meat or meat product desired to be cured is exposed to a nitrate-containing substance. It is prepared by addition of bacteria or other organisms capable of converting the nitrate to nitrite to ferment the nitrate to nitrite as in the case of vegetable juice concentrates like those of cabbage, beet, celery, radish, onion, swiss chard and chicory leaf. The presence of nitrite helps in curing of meat to give the meat a distinct colour, retention of freshness and flavour, in addition to preventing the growth of harmful microorganisms. Advancements in this field have resulted in readily available nitrite containing liquid concentrates from various plant materials such as celery, beet, cabbage, radish, onion and chicory leaf. However, a disadvantage is that liquid agents are difficult to use, transport and when concentrated extracts are converted to a powdered form, they are unstable and highly hygroscopic. The major problem with such solid forms of concentrated liquid extracts obtained by processes such as spray drying, or drum drying is the unstable hygroscopic form that is obtained which changes its characteristics when stored or exposed to open atmosphere.

Figure 1 demonstrates this instability wherein a commercially available celery extract in powdered form turns into an unstable black mass within 30 minutes when exposed to room atmosphere.

There is a need in the art for a solid, non-hygroscopic water-soluble curing agent in a powder/granular form which would be free flowing, easy to use, handle and optionally reconstitute, comprising a plant-based nitrite derived from a liquid juice concentrate obtained from plant material selected from cabbage, beet, celery, radish, spinach, onion, swiss chard, chicory leaf or the combinations thereof.

The present invention is directed towards a non-hygroscopic powder/granular agent which is water soluble, having an excellent free flowing property, solid-state stability, longer shelf-life, easy to package and store. It can be used to preserve or cure meat or meat products and other applications in the food industry.

US 20150225683 relates to a powdered vinegar comprising partly neutralized vinegar, e.g. neutralized with a sodium and/or potassium hydroxide, and free acid. The invention also provides a process for producing such a powdered vinegar and the use of this powdered vinegar in a foodstuff or a beverage, for example as a preservative.

US 20170107468 relates to an invention in the field of liquid, concentrated food preservation products, in particular concentrated vinegar products. The present invention provides a method of producing highly concentrated vinegar, enabling the production of food-grade liquid preservation products comprising high amounts of vinegar. Such liquid preservation products and their uses are also encompassed by the invention.

WO 2019075016 is an invention that discloses an antimicrobial powder, which includes a low molecular weight antimicrobial organic acid and a hygroscopic ingredient, prepared according to a process wherein the components are combined in a solution to form a liquid slurry composition prior to drying to form a powder, such that drying the liquid slurry composition involves co-drying the components. The low molecular weight antimicrobial organic acid in the antimicrobial powder can be present in a crystal phase of both anhydrous and hydrate forms. The antimicrobial powder exhibits excellent properties, such as shelf stability, without the requirement of encapsulating agents. Methods for preparing the antimicrobial powders as well as applications of the antimicrobial powders in food and beverage products are also disclosed. SUMMARY OF THE INVENTION

The present inventors have developed a solid, non-hygroscopic curing agent in a powder/granular form, which is easy to use, handle and optionally reconstitute, water soluble comprising a plant-based nitrite derived from a liquid juice concentrate obtained from plant material selected from celery, cabbage, beet, radish, spinach, onion, swiss chard, chicory leaf or the combination thereof. The non-hygroscopic powder/granular product has an excellent free flow property, solid-state stability, is water soluble, has a longer shelf-life, easy to package and store. The nitrite content in the water-soluble curing agent may range from 10,000 to 30,000 ppm. It can be used to preserve or cure meat or meat products and other applications in the food industry.

It has been surprisingly found that excipients like amino acids, amino acid salts, gums, protein salts, whey protein, skimmed milk powder, protein hydrolysates can act as carriers for celery liquid juice concentrate comprising nitrite and result in a composition which is water soluble, exhibits free flowing property and does not leave any residue or sludge while using for its intended use and application for curing of meat.

The invention comprises mixing or blending of the concentrated liquid celery extract comprising the nitrite with suitable carrier excipients like amino acids, amino acid salts, gums, protein salts, whey protein, skimmed milk powder, protein hydrolysates to obtain a composition which is in a granular/powdered form, non-hygroscopic, water soluble and exhibits free flow property. The advantage in having such a non- hygroscopic water- soluble composition is the ease of application to substrates like meat and other food products which require preservation. Another advantage is that the product does not leave any residue or sludge after making its solution in water, for application to meat and related products.

The method according to the present invention comprises the steps of: a. Preparing an aqueous composition of carriers selected from the protein salt, gum, whey protein, amino acid or salt derivatives, protein hydrolysate, skimmed milk powder (low fat content). b. Addition of the concentrated liquid extract obtained from the plant material celery onto the aqueous composition of the carrier mentioned in step (a) to obtain a thick paste, suspension or solution. c. Drying the aqueous paste, suspension or solution to remove water using a suitable drier like an oven, tray drier, fluid bed drier, fluid bed processor with a top spray attachment, spray drier for a suitable period of time and at a temperature till LOD is less than 10%, to get granules/ powder. d. Instantizing the granules/powder with spraying of water, using suitable equipment, followed by drying e. Sifting the granules/ powders through a suitable sieve to obtain uniform granules/powders

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a solid, non-hygroscopic water-soluble curing agent in a powdered/granular form, comprising a plant-based nitrite derived from liquid juice concentrate obtained from plant material selected from cabbage, spinach, beet, celery, radish, onion, swiss chard, chicory leaf and the combination thereof. The invention also relates to a process for preparation of said curing agent using carrier excipients selected from amino acids or amino acid salts, gums, protein salts, whey protein, skimmed milk powder, protein hydrolysates, and the combination thereof, which results in the water-soluble granular composition.

Accordingly, a first aspect of the invention concerns a process of producing a non- hygroscopic water soluble, granular/powdered curing agent comprising the steps of: a) Preparing an aqueous composition of the protein salt, gum, whey protein, amino acid, amino acid salt derivatives, protein hydrolysate, skimmed milk powder (low fat content) , caseinates salts thereof. b) Addition of the concentrated liquid juice or extract obtained from the plant material celery into the aqueous composition mentioned in step (a). c) Optionally adding other excipients to improve the wettability and solubility of the overall composition. d) Optionally adjusting the pH to alkaline side before drying. e) Drying the aqueous phase from (c) above, to remove water using a suitable drier like an oven, tray drier, fluid bed drier, fluid bed processor with a top spray attachment for a suitable time period and at a temperature till LOD is less than 10% to 15%, to get granules / powder. f) Sifting the granules/powders through a suitable sieve to obtain uniform granules/powders. g) Instantization of the powder using fluid bed processor with a top spray attachment for water, for improving the solubility if required, followed by sifting the granular powder through a 20 to 80 sieve. h) Optional addition of any excipients and blending and mixing for a suitable period of time in a suitable mixer i) Packing in suitable containers of the final product

The term “non-hygroscopic granular / powder curing agent” as used herein refers to a solid curing agent preferably in the form of granules or powder or a mixture thereof that does not take up significant amounts of moisture from the atmosphere when exposed, such that there is no liquefaction or change in the solid form of the curing agent to semisolid wet mass. Moreover, the solid curing agent, preferably in the form of granules or powder or a mixture thereof, exhibits excellent free flowing property, irrespective of the moisture uptake, even when exposed to variable conditions of temperature and humidity. The solid curing agent, comprising a carrier agent, exhibits good flow property over the shelflife, it is non-hygroscopic, water soluble and is thus easy to use, handle and reconstitute for its intended use, in applications such as curing of meat products.

The term “liquid juice concentrate obtained from a plant material” as used herein refers to an aqueous liquid juice concentrate that may be in a concentrated or diluted form comprising the curing agent preferably nitrite and may have a solid content varying from about 20 to 60% w/w, preferably 30 to 45% w/w, most preferably from 35 to 40% w/w, obtained from the plant material of celery. The nitrite content may vary from 9 to 60 mg/ml of the liquid juice concentrate and can be adjusted during the formulation based on the desired nitrite content in the final product. The term “concentrated liquid juice-obtained from a plant material” as used herein also refers to a concentrated aqueous product that contains the curing agent preferably nitrite at a solid content of about 40%w/w preferably corresponding to a nitrite concentration of approximately 10,000 to 60,000 ppm and is obtained from plant material selected from celery.

Liquid juice concentrate or concentrated liquid juice may be used synonymously within the scope of the invention.

The term “water soluble”, as used herein refers to a composition that is completely soluble in water and includes use of mechanical force like stirring and temperature as aids to achieve solubilization.

The term “granulation” refers to a process of converting the powder into granules employing a suitable process with the aid of equipment’s like a rotary mixer granulator, blender, coater, spray granulation, spray drying, or a combination of processes mentioned.

The term “excipients” refers to any substance that is used in the composition excluding the liquid celery concentrate.

The term “instantization” refers to the process, wherein the powder or granules formed by the granulation process of celery juice concentrate and a carrier, are treated with spray of water, using suitable equipment, to improve solubility of the granules and then dried to get free-flowing water soluble non-hygroscopic celery product. According to a preferred embodiment of the invention, the excipients used include protein salt, gum, whey protein, amino acid or amino acid salt derivative, protein hydrolysate, skimmed milk powder (low fat content).

Protein salts may include caseinate salts of casein with any salt forming entity and preferably may be sodium and or calcium caseinate.

Gums may include plant derived gums and preferably include guar gum, xanthan gum, locust bean gum (carob gum), gellan gum, cellulose gum, and relative newcomer tara gum. Hydroxypropyl methyl cellulose (HPMC) derived from cellulose which in turn is derived from plant gum or HPMC available commercially from various companies like Methocel ^R (Dow) can be used. In addition, other cellulose derivatives like carboxymethylcellulose can be used preferably in the form of their water-soluble sodium salts.

Amino acids occur in various forms and preferably include L-lysine, L-glycine, L- glutamic acid, L-tyrosine, L-leucine, L-aspartic acid and L-serine to name a few.

Protein hydrolysate may be prepared using process of either enzymatic, or acid hydrolysis of plant or animal protein. It may be comprised of smaller fractions of protein and peptides that has good water solubility. It is easy to digest and also gets easily absorbed in human metabolic system. It is suggested for people allergic to proteins.

The percentage of carrier excipients used in the invention may range from 20 to 80% by weight of the finished product. According to one embodiment, the percentage may vary from 30 to 60% by weight of the finished formulation. The invention provides a solid, non-hygroscopic water-soluble curing agent in a powder/granular form, comprising a plant-based nitrite derived from liquid juice concentrate obtained from plant material. The nitrite content in the water-soluble curing agent may range from 10,000 to 30,000 ppm. The invention also provides a process for preparation of said curing agent using carrier excipients selected from amino acids or salts, gums, protein salts, sodium caseinate, calcium caseinate, whey protein, skimmed milk powder, protein hydrolysates and the combination thereof, which results in the water-soluble granular composition.

The non-hygroscopic powder/granular product has an excellent solid-state stability, longer shelf-life and ease of packaging and storage. It can be used to preserve or cure meat or meat products and other applications in the food industry.

The invention is now illustrated with non - limiting examples.

A typical example for preparation of a water-soluble composition using caseinate salts as an excipient is given in Example 1 below:

EXAMPLE 1: Water-soluble curing agent using caseinate salt

Note: * Celery liquid juice concentrate (active) is 15700 ppm and solid content is around 33%.

Targeted nitrite concentration in powder = 23502 PPM Process: Celery liquid juice concentrate was kept under stirring for 20 minutes. The solution was passed through sieve 40 and sodium caseinate was added in celery solution to make thick paste. The product is dried using suitable equipment such as tray dryer or spray dryer. The dried product was passed through suitable sieve to get uniform size granule/powder. The spray dried powder was instantized in fluid bed processor spraying water using a top spray attachment and sifted through a suitable sieve preferably 20 mesh to obtain uniform granule/powder.

The physicochemical characteristics for the celery granules/powder prepared by process as depicted in Example 1 are given below: a. Appearance: free flowing granular powder b. Colour and odour: Light yellowish coloured with characteristic odour. c. Bulk density: 0.50 gm/ml d. Tapped Density: 0.52 gm/ml e. pH (5% solution): 7.31 f. General hygroscopicity of powder: free flowing granular powder and non-hygroscopic in nature during 24 hrs observations. g. Angle of repose: 39.6°

The stability of the free-flowing granular powder for its non-hygroscopic behaviour was studied in an open petri dish in a closed chamber maintained at 40°C/75%RH

It was observed that less than 15% moisture was absorbed in open atmosphere even after exposure for 3 hours, while the powder was free flowing for 24 hrs.

The theoretical targeted nitrite content in ppm was 23502 ppm and experimental value obtained after chemical analysis was ppm 23158 ppm.

Water solubility: It was observed that one could get a clear solution of these granules in water when dissolved in water at a temperature of around 4°C to 40°C with around 1 to 5 minutes of stirring.

Another example for preparation of a water-soluble composition using caseinate salts with use of NaOH is depicted below wherein NaOH is used to adjust the pH of the mixture to basic side before processing the product to a solid form in Example 2 below:

EXAMPLE 2: Water-soluble curing agent using caseinate salt and NaOH Note: * celery juice concentrate (Active) is 17148 ppm and solid content is around 32%.

Targeted nitrite concentration in powder = 27004 PPM Process: A process used for Example 1 was followed here, but NaOH solution was used to adjust the pH of the mixture of celery and caseinate before processing to powder form.

The physicochemical characteristics for the celery granules/powder prepared by process as depicted in Example 2 are given below: a. Appearance: Granular free flowing powder b. Colour and odour: Light yellow to brown colour, Celery like smell c. B.D.: 0.41 gm/ml d. Moisture: 10.28% e. pH (5% solution) = 9.82

The stability of the free-flowing granular powder was studied in open petri dish in accelerated chamber at 40°C/75% RH It was observed that less than 18% moisture was absorbed in open atmosphere even after exposure for 7 hours. It absorbed further moisture up to 25% after exposure to 24 hours and become slightly sticky; but retained its flow property.

The theoretical targeted nitrite content in ppm was 27004 ppm and experimental value obtained was 27663 ppm.

Water solubility: It was observed that one could get a clear solution of these granules in water when dissolved in water.

EXAMPLE 2.1: Water-soluble curing agent using caseinate salt and NaOH

1. Sodium nitrite in active (Celery Juice): 17148 ppm

2. Solid content in active (Celery Juice): 32%

3. pH of active (Celery Juice): 9.5-10.5

Process: Celery liquid juice concentrate was kept under stirring for 20 minutes. The solution was passed through sieve 60. Sodium caseinate was dissolved in water under continuous stirring and pH adjusted with sodium hydroxide to 10-11. Add filtered liquid celery to the prepared sodium caseinate solution to make thick paste. The product is dried using suitable equipment such as tray dryer or spray dryer to a target LOD of 5% to 15% w/w. The dried product was passed through suitable sieve preferably 30 mesh to get uniform size granule/powder product. The spray dried powder was instantized in fluid bed processor spraying water using a top spray attachment and sifted through a suitable sieve preferably 20 mesh to obtain uniform granule/powder.

The physicochemical characteristics for the celery granules/powder prepared by process as depicted in Example 2.1 are given below: a. LOD: 10.28% b. Appearance : Free flowing powder c. Color and odor: Light to dark greenish off white powder with characteristic odor The stability of the free-flowing granular powder was studied in open petri dish in

Accelerated chamber at 40°C/75%RH. It was observed that less than 18% moisture was absorbed in open atmosphere even after exposure for 6 hours. It absorbed further moisture up to 25% after exposure to 24 hours and become slightly sticky.

The theoretical targeted nitrite content in ppm was 27270 ppm and experimental value obtained was 26070 ppm.

Water solubility: It was observed that one could get a clear solution of these granules when dissolved in water

A typical example for preparation of a water-soluble composition using an amino acid salt L-lysine hydrochloride as an excipient is given in Example 3 below: EXAMPLE 3: Water-soluble curing agent using amino acid salt

Targeted nitrite concentration in powder = 21151 PPM

Process: Similar process as used in Example 1 and 2 was followed for preparation of the product. Celery juice concentrate was filtered through 40 mesh sieve. Sodium hydroxide was dissolved in water and to this was added L-lysine hydrochloride to prepare a 30%w/v solution and stirred till all the amino acid salt dissolves and a clear solution was obtained. The filtered celery concentrate was added to the amino acid solution and the mixture was introduced into a spray-drier to obtain granules which was passed through a 30-mesh sieve to obtain a uniform powder. The physicochemical characteristics for the celery granules/powder prepared by process as depicted in Example 3 are given below: a. Appearance: Light to dark brown coloured granular powder b. Flowability: Free flowing, slightly hygroscopic when kept in open plate for 3 hours c. LOD: 8.46% d. pH (5% solution): 7.86

The product was also evaluated for moisture absorption by keeping in open petri dish using specific conditions of temperature and humidity.

Hygroscopicity Study (At 70-80% RH, 30-40°C Temperature):

It was observed that around 13% moisture was absorbed in open atmosphere even after exposure for 6 hours. It absorbed further moisture up to 22.2 % after 24 hours. The theoretical targeted nitrite content in ppm was 21151.9 ppm and experimental value obtained was 20850.9 ppm.

Water solubility: It was observed that one could get a clear solution of these granules in water when dissolved in water.

EXAMPLE 3.1: Water-soluble curing agent using amino acid salt

1. Sodium nitrite in active (Celery Juice): 25762 ppm

2. Solid content in active (Celery Juice): 50%

3. pH of active (Celery Juice): 9.5-10.5

Process: Similar process as used in Example 2.12 was followed for preparation of the product. Celery juice concentrate was filtered through 60 mesh sieve. Dissolve L- Lysine HC1 in water under continuous stirring, followed by addition of calcium silicate. The filtered liquid celery was added to the prepared amino acid solution and the mixture was introduced into a spray-drier to obtain granules which was passed through a 30-mesh sieve to obtain a uniform powder.

The physicochemical characteristics for the celery granules/powder prepared by process as depicted in Example 3 are given below: a. Appearance: Free flowing powder b. Color and Odor: Light to Dark brown powder with characteristic odor c. LOD: 5.13% The product was also evaluated for moisture absorption by keeping in open petri dish using specific conditions of temperature and humidity.

Hygroscopicity Study (At 70-80% RH, 30-40°C Temperature):

It was observed that only around 16% moisture was absorbed in open atmosphere even after exposure for 6 hours. It absorbed further moisture up to 26 % after 24 hours.

The theoretical targeted nitrite content in ppm was 12001 ppm and experimental value obtained was 13323 ppm.

Water solubility: It was observed that one could get a clear solution of these granules in water when dissolved in water EXAMPLE 4: Water-soluble curing agent using HPMC (derived from cellulose which in turn is derived from plant gum)

1. Sodium nitrite in active (Celery Juice) : 28950 ppm

2. Solid content in active (Celery Juice): 54%

3. pH of active (Celery Juice): 9.5-10.5

Process: Celery juice concentrate was filtered through 60 mesh sieve. Dissolve mannitol in water under continuous stirring, add HPMC slowly under stirring till complete dissolution occurs, followed by addition of calcium silicate under continuous stirring. The filtered liquid celery was added to the prepared mannitol- HPMC solution and the mixture was introduced into a spray-drier to obtain granules which was passed through a 30-mesh sieve to obtain a uniform powder. The spray dried powder was instantized in fluid bed processor spraying water using a top spray attachment and sifted through a suitable sieve preferably 20 mesh to get uniform granule/powder.

The physicochemical characteristics for the celery granules/powder prepared by process as depicted in Example 4 are given below: a. Appearance: Free flowing powder b. Color and Odor: Light to Dark brown powder with characteristic odor c. LOD: 6.78% d. Angle of repose: 35.8°

The product was also evaluated for moisture absorption by keeping in open petri dish using specific conditions of temperature and humidity. Hygroscopicity Study (At 70-80% RH, 30-40°C Temperature):

It was observed that around 16% moisture was absorbed in open atmosphere even after exposure for 2 hours. It absorbed further moisture up to 40 % after 24 hours, but exhibited excellent flow property, as checked by the angle of repose. The theoretical targeted nitrite content in ppm was 23763 ppm and experimental value obtained was 26008 ppm.

Water solubility: It was observed that one could get a clear solution of these granules when dissolved in water.

EXAMPLE 5: Water-soluble curing agent using Carboxymethylcellulose sodium (derived from cellulose). 1. Sodium nitrite in active (Celery Juice) : 25762 ppm

2. Solid content in active (Celery Juice): 50%

3. pH of active (Celery Juice): 9.5-10.5

Process: Celery juice concentrate was filtered through 60 mesh sieve Dissolve Sodium carboxymethylcellulose in water followed by addition of calcium silicate under continuous stirring. The filtered liquid celery was added to the prepared sodium CMC-Calcium silicate solution and the mixture was introduced into a spray-drier to obtain granules which was passed through a 30-mesh sieve to obtain a uniform powder. The spray dried powder was instantized in fluid bed processor spraying water using a top spray attachment and sifted through a suitable sieve preferably 20 mesh to get uniform granule/powder.

The physicochemical characteristics for the celery granules/powder prepared by process as depicted in Example 4 are given below: a. Appearance: Free flowing powder b. Color and Odor: Light to Dark brown powder with characteristic odor c. LOD: 9.5 % d. Angle of repose: 36.2°

The product was also evaluated for moisture absorption by keeping in open petri dish using specific conditions of temperature and humidity.

Hygroscopicity Study (At 70-80% RH, 20-30°C Temperature):

The powder was free flowing for 6 hr, as evidenced by the angle of repose, when kept in open petri plate at 75% RH.

The theoretical targeted nitrite content in ppm is 24112 ppm. and experimental value obtained was 25056 ppm.

Water solubility: It was observed that one could get a clear solution of these granules when dissolved in water.

The non-hygroscopic, solid, water-soluble curing agent comprising a plant-based nitrite derived from a liquid juice concentrate, as described herein is in a powder/granular form and exhibits free flowing property, during the shelf life, even when stored at various temperature and humidity conditions. The non-hygroscopic powder/granular product is easy to use, handle and optionally reconstitute. The non- hygroscopic product exhibits excellent solid-state stability, free flow property, longer shelf-life and ease of packaging and storage, which can be used in applications such as preservation or curing meat or meat products and other applications in the food industry.