Title of Invention	A PROCESS FOR THE PREPARATION OF DOG CHEWS
Abstract	A process for the preparation of dog chews is disclosed wherein chrome shavings are subjected to alkali hydrolysis followed by fiber size reduction and subsequent drying and shaping. The dog chews find potential use in the pet food industry, which is flourishing recently.

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Field of the Invention: The present invention relates to a process for the preparation of dog chews using chrome shavings as the raw material. The material prepared by the process of this invention is envisaged to have enormous potential application in pet food industry. It may be also used for cottage or small-scale industries relating to the preparation of dog chews. Background of the Invention: The process of preparation of dog chews from hide/skin trimmings and splits is well known. As reported earlier by Sastry et al (Technologies for value realization of carcass products in developing countries - A Handbook., eds. T. Ramasami and N.R. Rajagopal, 197, 2001) the hides/skins are limed, dehaired, delimed, bleached and the bleached pelts are sized & shaped according to the requirement, dried and sold as dog chews. These trimmings are also used as raw material for the preparation of glue/gelatin which are value added products used in the edible, pharmaceutical and other industries. The main limitation associated with this process is the cost of the raw material i.e., trimmings/splits of hides/ skins. This has generated a need for exploring possibilities of using cheaper sources for the preparation of dog chews. Enormous quantity of chrome shavings is generated by the leather processing industry as solid waste. Since chromium is known for its toxicity, the disposal of chrome shavings has been identified as a serious problem from the environmental point of view. Some tanneries are disposing chrome shavings as land fills but these land fills in longer duration convert Cr (III) in chrome shavings in to Cr (VI) which is toxic and thereby contaminating ground water, as reported by Taylor et al (Journal of American Leather Chemists Association, 85, 264, 1990). At present, the popular utilization mode for chrome shavings is in the manufacture of leather boards and related products. However, the return per ton of chrome shavings is low if used for leather board production. Thus, it is of immense interest to explore other value added uses of chrome shavings. Taylor et al (Journal of American Leather Chemists Association, 85, 264, 1990) developed a method which entails the proteolytic treatment of chrome shavings at a temperature from 60 - 65°C in the presence of 5-6% of C2(OH)2. Following the treatment, the protein can be separated by filtration, leaving chromium cake. Extraction of chromium cake with sulfuric acid produces a chromium solution which may be used directly in the pickle step of leather processing. The protein hydrolysate thus prepared contains less than 4.5ppm chromium and can be used as feed and fertilizer. Changdao et al (Waste Management,23, 835, 2003) treated chromium containing leather waste (CCLW) with various alkali and enzymatic treatments and compared the effectiveness of hydrolysis. Calcium oxide was found to be important for effective (but still incomplete) hydrolysis. On the basis of results, a three step CCLW treatment process was proposed. The gelatin extracted in the first step was chemically modified to leather finishing agents. The collagen hydrolysates isolated in the second step are used as retanning agents after chemical modification. The remaining chrome cake was further hydrolyzed with acids in the third step, and the obtained protein hydrolysates could be used as retanning agents in the tanning industry. Cabeza et al (Journal of Society of Leather Technologists and Chemists 82, 173, 1998) pretreated the chrome shavings with pepsin at room temperature and gelatin was extracted with water at 70°C. The chrome sludge recovered after centrifugation was treated with trypsin or alkaline protease and the hydrolysate was extracted at 70°C. Kupec et al (Journal of American Leather Chemists Association, 97, 349, 2002) processed chrome shavings by enzymatic hydrolysis employing alkaline proteases. Under mild reaction conditions, a soluble collagen hydrolysate is formed and solid fraction with high chromium content (chrome cake) formed after filtration. This work performed de-proteinization of the chrome cake by decantation washing with water and enzyme hydrolysis. Cabeza et al ((Journal of American Leather Chemists Association, 94, 190, 1999) studied the influence of surfactant on gelatin isolated from chrome shavings. First, the need for surfactant during the extraction process in the one-step process and two- step process was studied in the laboratory. Then, the two-step process was carried out with and without surfactant in pilot scale experiments to evaluate the foam formation during the first step. The physical and chemical analysis of the gelatin extracted showed good repeatability, with no significant differences between the gelatins isolated with and without the use of surfactant. In our co-pending patent application No. 300Del2001, a process has been described for the preparation of parchment like material from chrome shavings. The process involves treating chrome shavings initially with alkali and later with acids to remove the chromium from the shavings. Later the dechromed shavings was made into a paste, cast as sheets and dried. The resultant dried sheet is parchment like membrane. The parchment material prepared by the process of this invention is envisaged to have enormous potential application in the puppet industry and interior decoration. The major limitation associated with the hitherto known processes for treating chrome shavings is that the use of enzymes followed by alkaline treatment increases the cost of production. Further, the extraction of protein and chromium from the chrome cake is time consuming and costly process when large amounts of chrome shavings are used. The novelty and non-obviousness of the present invention lies in identifying chrome shavings as a new source for making dog chews and filtering the dechromed chrome shavings at a particular pH. Hence, this process explains complete utilization of chrome shavings and thereby reducing pollution problem. Objects of the Invention: The main objective of the present of invention is thus to provide a process for the preparation of dog chews which obviates the limitations as stated above. Another objective of the invention is to use chrome shavings as raw material for the preparation of dog chews. Yet another objective of the invention is to provide a process for the preparation of dog chews, which can be stored at room temperature. Still another objective of the invention is to provide a process for the preparation of dog chews, which are palatable and safe for canine consumption. Summary of the Invention: Accordingly the present invention provides a process for the preparation of dog chews comprising the steps of: a) alkaline hydrolysis of chrome shavings at pH in the range of 10 to 13 for a period in the range of 0.5 to 4 hrs to get a semi solid mass; b) adjusting the pH of the semi solid mass as formed in step (a) in the range of 2 to 8 by conventional methods; c) reducing the size of the semi solid mass as obtained in the step (b) to 2 to 3 mm fiber size by known methods; d) separating the semi solid mass as obtained in step (c), to obtain a paste; e) optionally casting the paste as formed in step (d) in required shapes/sizes and subsequent drying to get dog chews. Detailed description of the invention: The process of preparation of the dog chew comprises of subjection of chrome shavings to alkali hydrolysis by conventional method at a pH in the range of 10 -13 for a period in the range of 0.5 - 4 hrs to get a semi solid mass. pH of the resulting mass is gradually brought down by known method in the range of 6.5 -7. Further the pH of the resulting semi solid mass is reduced to a point in the range of 2 - 5.0. Later the pH was raised to pH 6.5 to 7 by known methods. The fiber length is reduced to 2 - 3 mm by know methods. Further water is removed from the resultant product by filtration using conventional filters. Later the paste is optionally cast into shape/size using dyes. The shaped products are later dried at a temperature in the range of 40 - 50 ° C and resultant product is dog chew. In an embodiment of the present invention the machinery used for the size reduction of the chrome shavings may be such as ball mills, hammer mills, homogenizer In another embodiment of the present invention the conventional alkali used for alkali hydrolysis may be such as calcium hydroxide, sodium hydroxide, potassium hydroxide. In yet another embodiment of present invention the conventional acid used may be selected from hydrochloric acid, sulfuric acid, acetic acid, formic acid. In still another embodiment of present invention.-the process for separation used may be such as filtration of the dechromed chrome shavings at a particular pH.using pressure filters. In yet another embodiment of present invention, the conventional method of drying used may be such as air-drying, sun drying, and vacuum drying. The following examples are given by way of illustration of the present invention and therefore should not construed to limit the scope of the present invention. EXAMPLE-1 1 Kg of chrome shavings were taken in a plastic bucket and 8 lit of water was added to it. The chrome shavings were washed in water by stirring the mass continuously. After 30 min the shavings are filtered through a mesh and resulting mass taken in a plastic bucket. 1 lit of 3N N2OH was then added to the above mass with continuous stirring. After a period of 30 min pH of the resulting mass was noted to be 11. Required amount of 0.25N h SO4 was then added slowly to the bucket containing semi solid mass with continuous stirring to get a pH of 7. The above mass was filtered through nylon mesh and pH of the solid mass brought to 2.5 by using required amount of 0.25N H2SO4. After a period of 20 min the resultant mass was filtered out and collected in plastic bucket. Required amount of 0.25N Na2CO3 solution was added to bring the pH of the lot to 7 and filtered through a conventional filter. Later the paste was cast in to required shape/size using a dye and dried at 40°C for 8 hr to get a final product shaped dog chew. EXAMPLE-2 1 Kg of chrome shavings were taken in a plastic bucket and 8 lit of water was added to it. The chrome shavings were washed in water by stirring the mass continuously. After 30 min the shavings are filtered through a mesh and resulting mass taken in a plastic bucket. 2 lit of 0.1N C2(OH)2 was then added to the above mass with continuous stirring. After a period of 30 min pH of the resulting mass noted to be 11. Required amount of 0.25N HCI was then added slowly to the bucket containing semi solid mass with continuous stirring to get a pH of 7. The above mass was filtered through nylon mesh and pH of the solid mass brought to 2.5 by using required amount of 0.25N After a period of 20 min the resultant mass was filtered out and collected in plastic bucket. Required amount of 0.25N Na2CO3 solution was added to bring the pH of the lot to 7 and filtered through a conventional filter. Later the paste was cast in to required shape/size using a dye and dried at 45°C for 7 hr to get a final product shaped dog chew. EXAMPLE -3 1 Kg of chrome shavings were taken in a plastic bucket and 8 lit of water was added to it. The chrome shavings were washed in water by stirring the mass continuously. After 30 min the shavings are filtered through a mesh and resulting mass taken in a plastic bucket. 2 lit of 1N KOH was then added to the above mass with continuous stirring. After a period of 30 min pH of the resulting mass noted to be 11. Required amount of 0.25N A2OH was then added slowly to the bucket containing semi solid mass with continuous stirring to get a pH of 7. The above mass was filtered through nylon mesh and pH of the solid mass brought to 2.5 by using required amount of 0.25N H2SO4. After a period of 20 min the resultant mass was filtered out and collected in plastic bucket. Required amount of 0.25N Na2CO3 solution was added to bring the pH of the lot to 7 and filtered through a conventional filter. Later the paste was cast in to required shape/size using a dye and dried at 45°C for 7 hr to get a final product shaped dog chew. Advantages of the Invention: The main advantages of the invention are the following. 1. Value added product "dog chew" prepared from chrome shavings will have better market value than the glue, parchment etc. 2. Dog chew from chrome shavings improves the raw material value. 3. A new feed item from the tannery solid waste can be introduced in the market. We Claim: 1. A process for the preparation of dog chews comprising the steps of: f) alkaline hydrolysis of chrome shavings at pH in the range of 10 to 13 for a period in the range of 0.5 to 4 hrs to get a semi solid mass; g) adjusting the pH of the semi solid mass as formed in step (a) in the range of 2 to 8 by conventional methods; h) reducing the size of the semi solid mass as obtained in the step (b) to 2 to 3 mm fiber size by known methods; i) separating the semi solid mass as obtained in step (c), to obtain a paste; j) optionally casting the paste as formed in step (d) in required shapes/sizes and subsequent drying to get dog chews. 2. A process as claimed in claim 1, wherein the alkali used for alkaline hydrolysis is selected from calcium hydroxide, sodium hydroxide, potassium hydroxide. 3. A process as claimed in claim 1, wherein the acid used is selected from hydrochloric acid, sulfuric acid, acetic acid, formic acid. 4. A process as claimed in claim 1, wherein the machinery used for the size reduction of the chrome shavings is selected from ball mills, hammer mills, homogenizer. 5. A process as claimed in claim 1, wherein the separation is preferably carried out by filtration of the dechromed chrome shavings at a pH of 7 using pressure filters. 6. A process as claimed in claim 1, wherein the method of drying used is preferably air drying, sun drying and vacuum drying. 7. A process for the preparation of dog chews substantially as herein described with reference to the foregoing examples.

Documents:

665-del-2006-abstract.pdf

665-del-2006-Claims-(11-11-2013).pdf

665-del-2006-Claims-(23-11-2012).pdf

665-del-2006-claims.pdf

665-del-2006-Correspondence Others-(11-11-2013).pdf

665-del-2006-Correspondence Others-(23-11-2012).pdf

665-del-2006-correspondence-others 1.pdf

665-del-2006-correspondence-others.pdf

665-del-2006-description (complete).pdf

665-del-2006-description (provisional).pdf

665-del-2006-form-1.pdf

665-del-2006-form-18.pdf

665-del-2006-form-2.pdf

665-del-2006-form-3.pdf

665-del-2006-form-5.pdf