FORM -2 THE PATENTS ACT, 1970 (39 OF 1970) COMPLETE SPECIFICATION ( See Section 10 ) 1. TITLE OF INVENTION METHOD OF MANUFACTURING OF HUSK FROM LEPIDIUM SATIVUM SEEDS 2. (a) BLUE CROSS LABORATORIES LIMITED, (b) a Company incorporated under the Companies Act, 1956, of A-12, Ambad Industrial Area, Nashik -422 010, State of Maharashtra, India. The following specification particularly describes the nature of the invention and the manner in which it is to be performed. METHOD OF MANUFACTURING OF HUSK FROM LEPIDIUM SATIVUM SEEDS Field of Invention This invention relates to a novel method of manufacturing of husk from Lepidium sativum seeds. Background of Invention Lepidium sathiim (Family: Cruciferae) popularly known as Garden Cress or Water Cress in English and haliv/ ahaliv / Chandrashoor in local languages in India, is a native plant of southwest Asia and spread many centuries ago to Western Europe. Xenophon (400 BC) {Neglected Crops: 1492 from a Different Perspective, 1994, J. E. Hernando Bermejo and J Leon (eds.) Plant Production and Protection Series No. 26 FAO, Rome, Italy, p-303-332} mentions that Persians used to eat this plant even before bread was known. Seeds of Cress plant have been found in the tombs of ancient Egyptian pharaohs. (from web sitewww.ks.essortment.com/naturaIhomesre_rmss.html) Garden Cress is a small, herbaceous glabrous, annual growing plant up to 50 cm. This plant is cultivated as salad plant throughout India. (The Wealth of India, A Dictionary of Indian Raw materials & Industrial Products, Raw Material, Vol- VI, Council of Scientific & Industrial Research, New Delhi, 1962, p- 70-73) From ancient times, garden cress seeds, leaves, roots and flowers are regularly used for treating various diseases or disorders. Leaves are gently stimulant and diuretic. Seeds are aperients, diuretic, alternative tonic, demulcent, aphrodisiac, carminative. (Indian Medicinal plants, VoI-IH, Vaidyratnam P. S. Varier's Arya Vaidya Sala, Kattakal, Orient Longman Publication, 1995, p-313.) Mucilage of the seeds allays the irritation of mucous coat of intestine (The Wealth of India, A Dictionary of Indian Raw materials & Industrial Products, Raw Material, Vol- VI, Council of Scientific & Industrial Research, New Delhi, 1962, p- 70-73). Following preparations containing seeds of Lepidium sativum are described in traditional Indian as well as in International Literature. Nadkarni et al (The Indian Materia Medica, Vol-II, p-736-738) described following household formulations containing Lepidium sativum seeds. 1) One part of seeds added to twenty parts of boiling water or ten parts of cold water, when consumed orally, is remedy for dysentery, diarrhea and skin diseases caused by impurity of blood. 2) Seeds are recommended for the dispersion of certain chronic enlargement of spleen. 3) Powder of Lepidium sativum seeds with sugar can also be used to cure diarrhea, indigestion and dysentery. 4) A preparation made of seeds, ghee and sugar in the form of "laddoos" is a common household remedy useful as a restorative in general weakness. Indians very commonly eat Lepidium sativum seeds in the form of laddoos. The laddoos are specifically given to lactating mothers in the postnatal period. (Sahastrabuddhe, M B., and N. N. De, Current Science, 12, 1943,, 1, p-23-24) Bhavpraksh, (a standard reference book of Ayurveda) described emulsion made by soaking or boiling one part of Lepidium sativum seeds in eight part of water for relieving hiccups. Balsubramaniam et al (Ind. Jour. Med. Res., 50, 5, 1962, p-779-793.) from Nutrition Research Laboratory, Hyderabad also confirmed the use of Lepidium sativum seeds as a food item with a remark "seeds with 100% edible portion" Thus there are quite a few references in ancient standard Indian medicinal books regarding safe consumption of seeds of Lepidium sativum. In fact ahaliv seeds are used as household food item. Adam et al ("Effect of various levels of dietary Lepidium sativum in rats", Am. Jr. of Chinese Medi., 27 (3.4), p-397-405, 1999) performed a toxicity study on Lepidium sativum seeds using Wistar albino rats at 2 % (w/w) of the diet was found to be non-toxic, 10 %(w/w) of the diet was toxic but not fatal and 50 % (w/w) of the diet for 6 weeks was lethal and caused depression in growth rate and entero-hepato-nephrotoxicity. Karnick et al (Pharmacopoeial Standards of Herbal plants, Vol-I, 1994, Sri Satguru Publ., Ind. Medical Sci, Ser. No. 36, p- 219-220) described pharmacology of ethanolic extract of seeds of Lepidium sativum. Ethanolic extract have anti-spasmodic effects on isolated guinea-pig ileum with LD50 1000 mg/kg body weight of albino mice when given intraperitonally. Patole et al ("Effect of mucilaginous seeds on in vitro rate of starch hydrolysis and blood glucose levels of NIDDM, subjects with special reference to Garden Cress Seeds", Jr. of Medi. and Aromatic Plant Sci., 20 (4), p-1005-1008, December, 1998) studied the antidiabetic activity of Lepidium sativum seeds on 11 NIDDM subjects as well as 14 normal healthy subjects by administering 15 gm seeds per day. In the long term (21 days) treatment they found that seeds possess some hypoglycemic activity. All the above information proves beyond doubt that Garden cress seeds are very safe with respect to human consumption. Kulkarni et al ("Some Physicochemical Characteristics of Lepidium sativum (haliv) seeds", Die Nahrung, 37, (1993), 1, p-69-7I) studied physical characteristics of Lepidium sativum seeds such as colour, length, shape, bulk density, weight and swelling Index and chemical characteristics such as proximate composition and carbohydrate profile. Water holding capacity of seeds was measured at room temperature, refrigeration and at 50°C. They have found high pentosan content (11%) and also high fiber values and concluded that Lepidium sathmm seeds can be a non-conventional but promising source of dietary fiber and associated nutritional properties in addition to its high nutritional and caloric value. Bailey (Biochem Jr., 1935, 29, p-2476-2485) and Tyler (J. Chem. Soc, 1965, part I & II, p-5288-5310) performed detail study of Cress Seed Mucilage. Bailey isolated cress seed mucilage by first soaking cress seed in water and then swelled seeds are sheared at high-speed for a fixed period of time and then separated by centrifuging. The mucilage is further purified by acid treatment (0.1 N Hydrochloric acid) and then precipitating in 95% alcohol. The product obtained by acid hydrolysis of separated mucilage was characterized and showed that mucilage of cress seed is heterogeneous polysaccharide system. Bailey also discussed factors responsible for hydration and dispersion of cellulose component in seed mucilages and in other seeds containing cellulose polyuronide system. Kalac et al. ("Seed mucilage of Lepidium sativum, (I) Isolation and characterization of basic products", Biologia, 1969 24(6), 433-9) also isolated mucilage from Lepidium sativum seeds and characterized basic products in the mucilage. The isolation method consisted of 5 stages. First step involved twenty hours extraction by 0.02 M. Solution of Sodium Acetate (pH 4.6). The ratio of seeds to extracting solvent was 1: 10. Extraction was followed by alcohol treatment. Further steps involved centrifugation and washing with ethanol, ether and then vacuum drying. Further extraction of residue was done with hot solvent and then purification using CM-cellulose column to yield five different polysaccharide portions. Eluting agent was acetate buffer pH 4.5. Different sugars were separated by hydrolyzing and then performing paper chromatography. In between these five polysaccharide fractions, first had a characteristic property of mucilage, which was proved by measuring viscosity of solution. The essential component of mucilage was established by contents of sugar components L-arabinose, D-xylose, L-rhamnose, D-galactose and of acid components D-galactouronic acid and 4-0-methyl-D-glucuronic acid. Here they also mentioned that because of an autohydrolysis of mucilage, there can occur a cleavage of molecules characterized by a rapid decrease of viscosity of mucilage solution and liberation of free sugar units of pentosan type. The method discussed over here for isolation of mucilage from Lepidium sativum seeds is very tedious, time consuming and laborious. The wealth of India gives detail composition of garden cress seeds as follows, (The Wealth of India, A Dictionary if Indian Raw materials & Industrial Products, Raw Material, Vol- VI, Council of Scientific & Industrial Research, New Delhi, 1962, p- 70-73) Moisture 5.69%, Protein 23.5%, fats 15.9%, ash 5.7%, Phosphorous (P205) 1.65%, Calcium 0.31% and sulphur 0.9 %. The seed contains an alkaloid (0.19 %), glucotropaeolin, sinapin (Choline ester of sinapic acid), sinapic acid (4-hydroxy, 3,5 dimethoxy cinnamic acid C11H12O5 M.P. 192°C), mucilaginous matter (5 %) and uric acid (0.108 g/kg). The mucilage consists of a mixture of cellulose (18.3 %) and uronic acid containing polysaccharides, acid hydrolysis of which yields L - arabinose, D-galactose, L-rhamnose, D-galactouronic acid and D-glucose. Need of Husk: Garden Cress seed contains many ingredients as described above. Here the ingredient essential for viscosity imparting and gelling is husk, which is mainly, consists of polysaccharides. Other ingredients impart undesirable properties, for e.g., fats and alkaloid present in seed may have some therapeutic effect. These are unnecessary when the material is to be used as an excipient. To eliminate these non-required components, it is necessary to separate the husk from seeds and treating it properly to get desired material with excellent swelling and gelling properties. 5 It is evident from prior art that there is no teaching as to obtaining and using the husk from Lepidium sativum seeds. Thus the principal object of the present invention is to provide an easy, cost effective and efficient method for de-husking the seeds and process and use them as thickening agents in diverse fields of technology. A further object of the present invention is to propose a method of producing husk from lepidium sativum seeds having viscofying and swelling properties useful in applications like, toiletries, food, pharmaceuticals, cosmetics, etc. It is also an object of invention to provide a novel and economical source of thickening agent for industrial use. Other objects and advantages of this invention will become readily apparent from the ensuing description. Summary of invention Thus the invention relates to a method for manufacturing husk from seeds of lepidium sativum which is particularly suitable for use as a thickening agent, the method comprising the steps of (i) crushing the seeds to average particle size of between 250-350 um, (ii) subjecting crushed mass to solvent extraction to remove lipophilic constituents of lepidium sativum husk. In the process of the invention husk swells in presence of aqueous solution giving desired rheological properties. According to a preferred embodiment the steps of the process step comprises: sifting through sieves, crushing of seeds, treatment with volatile, non-aqueous solvent, drying, pulverizing, purification and drying to remove traces of solvent. Detailed description of the invention Firstly, physical characterization of seeds were done, seeds were brownish red, length around about 300 jiim, width round about 100 urn, oval shaped, 100 seeds weighing about 0.2 g. Swelling index of seed was found to be 17-18ml. Following steps are involved in the separation of husk from seeds of'LepiJium sativum. A| Heat Treatment of Seeds: The seeds of Lepidium sativum possess some characteristic odour. This may not be preferred in some industrial applications like cosmetic industry. To remove this odour seeds can be roasted or heated in oven at high temperature (above 150°C) for a short period of time. (15-30 minutes). In a preferred embodiment seeds were heated at 170-180° C for 15-20 minutes. This heat treatment helped in total elimination of the characteristic odour and also helped to reduce the moisture content of the seeds. It was observed that there was no significant change in swelling behavior of final product due to roasting or heating. This step is optional and can be used depending on intended use of final product. B] Size Reduction of Seeds: The seed material was then sifted through 1 mm sieve (BSS) to remove unwanted materials and adulterants if any, the seeds were crushed in a mixer with blades for a pre-determined time to achieve coarse material having particle size between 250um and 350 urn. Excessive crushing results in finer material, which is undesirable with respect to percentage yield of final product. C] Solvent Treatment: I) Choice of Solvent: Selection of solvent was a major step in terms of quantity and quality of product. Since the aim of present invention was to get husk portion of seed so it was essential to remove fatty material, protein and other material from the crushed seeds Thus the non-aqueous vehicle was selected. Thus the selection of non-aqueous vehicle was based on three criteria. 1. Husk is made up of mucilaginous matter, which swells in presence of aqueous vehicle resulting in building up of viscosity of solution, those who are skilled in the art can only appreciate that, any viscous solution is always difficult to handle as compared to non- viscous solution. This problem is solved by using non-aqueous vehicle. 2. There is loss of energy and time in separating and drying of separated mucilage, which is avoided by using volatile non-aqueous vehicle. 3. The formation of gel is a complex phenomenon involving various physicochemical factors. During drying of the gel formed in presence of aqueous vehicle, it is exposed to continuous high temperature for a prolonged time, which may result in batch-to-batch variation of the swelling properties of resultant material. Thus the ideal solvent for extraction should have following characteristics. 1. It should be volatile. 2. It should be non-polar, so that it will extract maximum amount of fatty material. 3. It should be non-inflammable. 4. It should not solubilize polysaccharide part of seeds. 5. Very low solubility of water in the solvent. Thus keeping in view the above requirement, following solvents were given due consideration to select the most appropriate solvent. a. From Hydrocarbon series Hexane, Ether and petroleum ether were tried. Though hexane is a non-polar, volatile solvent it did not give proper separation of husk layer and also its flammability is not in favour of its selection. The same was true for Ether and Petroleum ether also. b. From hydroxylated aliphatic hydrocarbons (alcohol) C-l to C-4 alcohols were considered because of their volatile nature. After various experiments it was decided not to prefer them for the following reasons, i) The separation between fatty layer and husk layer was not satisfactory may be due to their intermittent polarity. ii) They are highly inflammable. c. From solvents with carbonyl functional group, acetone and ethyl acetate were given due consideration. But they were not preferred because of following reasons i) Both acetone and ethyl acetate have intermittent polarity; therefore they were not giving proper and complete separation of husk layer and fatty proteinaceous layer, ii) Both solvents are less volatile thus amount of residual or bound solvent is comparatively at higher side which was resulting in residual solvent odour, iii) In addition both solvents are inflammable c. From chlorinated hydrocarbon group, carbon tetra chloride. Chloroform and methylene chloride were considered. Since chloroform is known to be anesthetic in nature, it was abandoned. Carbon tetra chloride was not preferred because of its toxicity and environmental hazards. (It is included in Class 1 solvents according to ICH Topic Q 3 C) Finally methylene chloride was found to be the solvent of choice as it fulfilled all the prerequisites such as i) Excellent and instantaneous separation of husk layer and fatty proteinaceous layer, ii) Its high volatility enables removal of traces of residual solvents to a level far below than allowed limit of 600 ppm, which is accepted internationally. (According to ICH guidelines Topic Q 3 C, it is included in Class 2 solvents) iii) Its safe use in industry is well established. Thus after various trials, it was concluded that methylene chloride is the best solvent available for separation of husk from seeds. 11) Treatment of Crushed seeds with the solvent: The crushed seeds were added in a vessel with bottom discharge tap They were treated with methylene chloride and then husk layer was allowed to settle at the bottom for a predetermined period of time. Settled husk layer was removed by opening bottom discharge tap. This bottom discharge was given further washing with methylene chloride to remove traces of fatty and unwanted material. The process of washing was continued till washed methylene chloride was colorless. Typically numbers of washes of methylene chloride required were ranging from two to five. In a preferred embodiment, washes required were three to four. All fractions of methylene chloride were collected, filtered and then methylene chloride was recovered by distillation. The redistilled methylene chloride was used for next batch. D| Drying of Husk: For drying of husk, two methods were tried. 1) Tray drying and 2) Fluidized bed drying In these two methods fluidized bed drying was preferred because of following reasons, a) Faster and uniform drying without using higher temperature and b) Easy optimization of drying procedure. Husk of Lepidium sativum seeds was dried in the Fluidized bed dryer till desired moisture content was obtained. (Not more than 2.0 % for heat-treated seeds and not more than 7.0% for unheated seeds) The time required for drying typically ranged from ten minutes to half an hour. But a preferred time range is of about fifteen to twenty minutes. E| Pulverization of Husk: The above dried material was pulverized to fineness and was passed through 250\xm sieve (BSS 60#). The preferred particle size distribution of husk was between 150u.m to 250|am. V\ Purification of Husk: This pulverized material was finally washed with Methylene Chloride to remove adhered traces of fatty material and then dried to remove the traces of solvent. The ratio of methylene chloride required for complete process to Lepidium sativum seeds typically ranged from 3:1 to 6:1 (w/v) respectively. In a preferred embodiment the ratio of methylene chloride to Lepidium sativum seeds was 4:1 to 5:1. Method for production of Husk from Lepidium sativum seeds A) Seeds of Lepidium satiwm was sifted through 1 mm sieve (BSS 16 #). 1.0 kg of seeds were weighed and crushed in a mixer with blades for thirty to 60 seconds. The seeds were added to a vessel with bottom-discharged tab or in five-liter glass beaker. Three washes of methylene chloride of 1L each were given. Further, if required two more washes of methylene chloride were given of 200ml. each. The husk was dried in fluidized bed dryer with inlet temperature not exceeding 30°C for 15 minutes. The dried material was removed and pulverized to fineness. This material was passed through 250u.m sieve (BSS 60#). Purification of pulverized material was done by treating again with of 400 ml methylene chloride. Solvent was removed completely by fluidized bed drying at temperature below 45°C. Stored the husk in a well-closed container. Material was brown in colour, browner the material, purer it is. Final yield of Lepidium sativum husk was around 200 g. i.e. 20 % of initial weight of seeds. B) In method (B), initially the seeds were exposed in an oven at 200°C for 15-20 minutes. Then the seeds were cooled to room temperature and were sifted through 1 mm sieve (BSS 16 #). 1.0 kg of seeds were weighed and crushed in a mixer with blades for thirty to 60 seconds. The seeds were added to a vessel with bottom-discharged tab or in five-liter glass beaker. Three washes of methylene chloride of 1L each were given. Further, if required two more washes of methylene chloride were given of 200ml. each. The husk was dried in fluidized bed dryer with inlet temperature not exceeding 30°C for 15 minutes. The dried material was removed and pulverized to fineness. This material was passed through 250/im sieve (BSS 60#). Purification of pulverized material was done by treating again with of 400 ml methylene chloride. Solvent was removed completely by fluidized bed drying at temperature below 45°C. Stored the husk in a well-closed container Characterization of Husk from Lepidium sativum seeds A) Viscosity: Viscosity of solutions in water of different concentration ranging from 0.2 % to 2.0 % was measured using Brookfield viscometer (LVF Model) at 25°C data is given in Table 1 and Graph 1. Table 1 Concentration (%) *Viscosity (cp) (In water) 0.2 80 0.5 400 1.0 920 1.5 1760 2.0 3000 Spindle no.2 for 0.2% and spindle no 3 for remaining solutions at speed of 30 RPM Graph 1 Viscosity Profile 3000 0.4 1.6 0.8 1.2 Concentration (%) B) Hydration rate To study the rate of hydration of husk obtained from Lepidium sativum seeds, viscosity-building behavior was evaluated with respect to time. To study this effect husk with particle size in range 150um to 250um was used. Data is given in Table 2 and Graph 2. Table 2 Time (Minutes) Viscosity (cp)* 0.5 % Solution 1.0% Solution 10 240 880 20 260 900 30 280 920 60 320 1000 120 440 1020 180 440 1020 240 440 1020 At 25°C, spindle no. 3 at the speed of 30 RPM It was observed that material has a good hydration rate profile and hydration getting completed within two hours. Graph 2 Hydration Rate -♦— Viscosity (cp)* 0.5 % Solution -•-Viscosity (cp)* 1.0% Solution 0 60 120 Time (Min) 180 240 C) Effect of particle size on viscosity The effect of particle size of husk obtained from Lepidium satiwm seeds on viscosity was studied by segregating the material of different particle size, for example between 150u,m to 250um, between 75|im to 150um and finer than 75|im. A 0.5 % solution in water was prepared and its viscosity was measured after 4 hours. Table 3 Particle size (u,m) Viscosity (cp)* 150-250 440 75-150 480 <75 400 At 25°C, spindle no. 3, at the speed of 30 RPM There is no marked difference in viscosities of husk with different particle size. On the contrary, there is some reduction in viscosity of material with particle size <75UM. D) Effect of salts on viscosity imparted by husk To study the effect of salts, solution of various concentrations of Lepidiiim sativum husk was prepared in 5% sodium chloride and 5 % calcium chloride solutions. It was observed that in the presence of calcium ions, there was change in behavior of husk. It did not swell and settled at the bottom of vessel whereas in presence of Sodium Chloride solution, there was marked decrease in the viscosity. Study 1: The observations of study 1 were given in Table No 4 and Graph 3. Table 4 Concentration of Husk (%) Viscosity (cp)* 0.2 — 0.5 100 1.0 380 1.5 820 2.0 1500 Spindle no.2 for 0.2% and spindle no 3 for remaining solutions at the speed of 30 RPM Graph 3 Effect of Salt ■•Viscosity (cp) (In water) ■Viscosity (in 5% NaCI) 0.5 1 1.5 Concentration of husk (%) 2.5 Study 2: The observations of study 2 were given in Table No 5. Table 5 Viscosity (cp)* Concentration of Husk (%) Without NaCI With NaCI (%) 0.06 0.16 0.33 0.5 0.66 0.5 400 260 240 200 200 200 1.0 1040 600 560 540 520 520 * At 25°C, spindle no. 3, at the speed of 30 RPM It is evident from the above data that sodium chloride reduces the viscosity of the mucilage only to some extent and there is no change in viscosity above 0.3%w/v concentration . E) Moisture Content of husk (By Karl Fischer Reagent): Heated: 1.8% Unheated: 6.4% F) Ash Values Total Ash: 7.17% Acid insoluble Ash: 1.53% G) Carbohydrate Content: (Anthrone Reagent Method) Carbohydrate Content was found to be around about 60% w/w of husk. Uses /. In Food industry Husk from Lepidium sativum mainly consist of mucilage, which is made up of polysaccharides. Basically, these are water soluble and thus they improve mouthfeel and pourabiilty, extend shelf life, encapsulate flavours, emulsify beverages, build viscosity, retain moisture and provide elasticity and freeze-thaw stability. Thus because of these properties husk from Lepidium sativum seeds can be used in the following food products. a. Dairy : The water binding and rapid hydration of Lepidium sativum husk in cold water to form a viscous colloidal solution, is its most important characteristic because of which it can be used in various dairy products. For example in ice cream, sharbats it can be used as stabilizer. It binds the free water without disturbing the viscosity characteristics of mix. b. Bakery : Lepidium sativum husk when added to dough while kneading, can increase yield, gives greater resiliency, and a dries less flabby appearance. c. Meat : Lepidium sativum husk binds all the free moisture and retards shrinkage in sausage and pet foods, in addition, it acts as a lubricant in the sausage stuffing operation and decrease loss of weight during storage. Paper industry Lepidium sativum husk can be used as adhesive in manufacture of paperboard. It will act as an inter-fiber adhesive and strength-building agent. Mining industry Lepidium sativum husk can be used as settling agent to speed up the settling of suspended solids in slimes and tailing from ore beneficiation. Husk added to slime or clay pulp can cause coagulation and allows faster filtration since, the filter screen is no longer blinded by small particles. Water treatment Lepidium sativum husk can be used as coagulant aid together with alum, ferric sulfate and lime. It will increase the size of the floe initially formed by the coagulant, thereby increasing the rate of settling of solid impurities, reducing solid carry over to the filters. Tobacco industry Lepidium sativum husk can be used as a binder for fragmented tobacco fines to produce reconstituted tobacco sheets. Petroleum drilling Lepidium sativum husk can be used to control water flow and as a protective colloid in oil well drilling mud's. It can also be used in acid fracturing to increase oil flow. Special fracturing sand combined with gelling action of Lepidium sativum husk in water can be used into the formation to keep the fractures prevented from collapsing on release of hydraulic pressure. Textile Industry Lepidium sativum husk can be used as print-paste thickeners. It can also be used in roller and screen-printing.