Method of producing inulin and intermediate derivatives thereof from sun-dried chicory roots

Abstract

Disclosed is a method of producing inulin and intermediate derivatives thereof from sun-dried chicory roots. The method of the present invention comprises steps like purification using anyone of precipitation by lime and phosphoric acid, clarification by decantation and centrifugation, decolorization to remove organic impurities, demineralization to remove ash, mineral and metal impurities, and finally fractionation by membrane filtration technique to remove impurities like reducing sugars (mono and di-saccharides), color, organic and inorganic impurities to enhance the inulin content to 90 to 98 %. The method of the present invention facilitates inulin manufacturing carried out throughout the year without the limitations of harvesting and processing time of fresh chicory, as sun-dried chicory can be stored for a year without the degradation of inulin content thereof and average chain length (DP) of the inulin.

Description

[0001] METHOD OF PRODUCING INULIN AND INTERMEDIATE DERIVATIVES THEREOF FROM SUN-DRIED CHICORY ROOTS

[0002] FIELD OF THE INVENTION

[0003] The present invention generally relates to inulin manufacturing and more particularly, to a method of producing inulin and intermediate derivatives thereof from sun-dried chicory roots.

[0004] BACKGROUND OF THE INVENTION

[0005] Inulin is a non-digestible carbohydrate, dietary fiber also called as fructans, is a polymer of fructose with DP (degree of polymerization / chain length) value ranges between 2 to 60. It consists of linearly bonded fructose molecules attached by a P (2^1) bond, and has a terminal glucose molecule attached with a (1^2) linkage. Inulin’s are a group of naturally occurring polysaccharides produced by many types of plants, grown in temperate region.

[0006] Main plant sources for inulin are roots of Chicory (Cichorium intybus)' and tubers from Dahlia and Jerusalem artichoke, in which inulin is present, respectively, in concentrations of about 15 - 18%, 12% and 14 to 18 % on fresh weight. Inulin has a major application as an ingredient and used in food industry by virtue of its diversified nutritional and functional properties. It is commonly used as a source of soluble dietary fiber, prebiotic supplement to enhance the growth of beneficial probiotic microorganisms present in gut, it is also used in a functional food as a fat replacer, sugar replacer, and texture modifier to provide health benefits. Inulin is industrially extracted from the roots of chicory plant (Cichorium intybus) which is a species of the Asteraceae family.

[0007] Conventionally, inulin manufacturing is done with fresh chicory roots and the manufacturing plant of inulin are commonly operated during only a few months in a year and are sized to process a very large quantity of chicory roots in a very limited period. Belgium has been active in processing of fresh chicory roots for the extraction and production of pure form of inulin and its hydrolysis products such as oligofructose and fructose. The inulin is obtained from plants or plant parts mostly through the conventional manufacturing techniques. European companies commercially do the chicory farming to produce chicory and inulin, however, industry is steadily facing the problem of providing technically and economically attractive methods and processes enabling the manufacture of inulin at industrial scale, preferably with improved yield and / or improved characteristics and properties, as, for example, an increased average degree of polymerization.

[0008] The extraction of inulin from chicory roots, followed by purification, involves conventional refining i.e., lime and carbonation, involving treatment over ionexchangers, treatment with active carbon and filtration, optionally followed by fractionation, and isolation in particulate form of inulin by chromatographic separation, which constitutes the most important manufacturing method of inulin at industrial scale. This is a result of the fairly availability of chicory roots, the inulin content of the roots, and the suitability of the roots for processing at large scale.

[0009] Chicory is conventionally cultivated in certain northern parts of Western Europe, where it is seeded in Spring (usually in April) and the roots are harvested and processed for inulin production late Autumn, usually from about mid-September to about end November, yielding through conventional manufacturing techniques manufactured standard grade chicory inulin with a mean (DP) of about 10. The whole growing and processing period covers about 150 to about 230 days. It is known that the degree of polymerization (DP) of the inulin, as well as the content of inulin in the chicory roots (i.e. the % by weight of inulin in the fresh root material) are increasing during the growing season to reach a maximum after about 150 days of growing, whereas the biomass of the roots and thus the yield (in AMG-1 ton / ha) of inulin increases till about the end of the growing season. The end of the growing season is the time when the biomass of the roots ceases to increase significantly (i.e. after about 180 to about 200 days of growing), which usually corresponds to the end of October. Towards the end of the growing season, the DP of the inulin in roots remaining in the soil, as well as in harvested and stored roots, are decreasing with time, and the rate of decrease is usually significantly increased from about beginning of November. This situation considerably limits the periods for growing (including seeding and growing) and for processing, including harvesting (harvesting period and harvesting as such), storage, and processing as such, of the chicory roots for the production of inulin and derivatives of inulin in a technically and economically attractive manner.

[0010] In India chicory cultivation started in late 1950’s, however it was not widely practiced because farmers were not aware of the crop's marketability. Its popularity has grown only recently because it has found applications in coffee blending industry where it is used as a complementary to coffee. In India, chicory cultivation is confined mostly in Western and Northern Part - Uttar Pradesh and Gujarat as climate is suitable to grow chicory - these two states account for 97 % of total chicory production in India. Recently it has been cultivated in few regions of Punjab and Karnataka. In India the sowing of chicory seeds starts in the early October and last up to late November, and harvesting of the crop happens in April and May months.

[0011] The processing as such of the fresh chicory roots for the manufacture of inulin, or of an intermediate, commonly takes about a day, whereas the processing period, including the harvesting (harvesting period and harvesting as such), storage and processing as such, of the roots, commonly lasts about 60 to about 90 days. In spite of the fact that the manufacture of inulin from chicory roots constitutes the most important route to inulin, the manufactures are nevertheless confronted with considerable hurdles and problems, including: (i) the limited period, including limitations in duration of the period as well as in time period of the year, during AMG-1 which chicory roots can be seeded, grown, harvested, stored and processed for the manufacture of inulin in a technically and economically attractive manner and / or without undergoing a significant degradation of degree of polymerization (DP - average chain length) of the inulin in the roots, (ii) the need to include a chromatographic fractionation step in the manufacturing process of chicory inulin when, e.g. for technological or nutritional reasons, inulin is required with a DP which is higher than the DP of about 10 of known standard chicory inulin, (iii) the rather poor yields of the known fractionation processes leading to inulin with a higher DP when chicory inulin of standard grade (with a mean (DP) of about 10) is used as the source of inulin, and (iv) the economical unattractive situation of the plants for the processing of the chicory root.

[0012] Therefore, there is a need to develop a sustainable and commercially viable process of manufacturing of high pure inulin with DP >10 and operation of inulin manufacturing plant throughout the year, which will reduce the overall process and utility equipment sizes and cost of the equipment’s.

[0013] Accordingly, there exists a need to provide a method of producing inulin and intermediate derivatives thereof from sun-dried chicory roots that overcomes the above-mentioned drawbacks of the prior art.

[0014] OBJECTS OF THE INVENTION

[0015] An object of the present invention is to produce inulin with purity ranging from 90 to 98% containing chain length of 2 to 60 molecules long and average degree of polymerization (DP) 10 to 13 molecules long.

[0016] Another object of present invention is to facilitate inulin manufacturing throughout the year without the limitations of harvesting and processing time of fresh chicory. AMG-1

[0017] SUMMARY OF THE INVENTION

[0018] Accordingly, the present invention provides a method of producing inulin and intermediate derivatives thereof from sun-dried chicory roots. The method comprises washing fresh chicory roots, and dicing the washed chicory roots into cubes of 5 mm to 40 mm size. Further, the method comprises sun-drying the diced cubes for 48 to 72 hours to achieve a moisture content of 5-8 % w / w. Furthermore, the method comprises storing the sun-dried diced cubes, and preparing a dried chicory root powder therefrom. Particularly, the sun-dried chicory roots are stored into 5 mm to 25 mm cube sizes by sieving through vibro shifter with mesh size of 4 for 12-15 months without reduction of inulin content and maintaining an average degree of polymerization (DP) of 10-13. The sun- dried chicory roots after drying attend the cube size of 2 to 25 mm and contains inulin on the dry basis (db) in the range of 50 % to 65 %, reducing sugar content in the range of 5% to 15 % on dry basis and moisture content in the range of 5%- 8%. The dried chicory root powder is prepared by successively reducing the size of the sun-dried cubes of size between 5 mm to 25 mm using a multi mill or hammer mill to obtain a particle size of 3 mm to 5 mm, and 1 mm to 3 mm and the sorting of the ground chicory powder is done by vibro shifter with mesh size of 20 and 40 to retain the desired particles. Moreover, the method comprises extracting inulin from the dried chicory root powder using hot water. Particularly, inulin is extracted by contacting the dried chicory root powder with hot water at a temperature of 60 °C to 80 °C for 1 to 3 hours, and at 40 °C to 50 °C for 2 to 5 hours in an agitated jacketed tank reactor / diffuser, wherein the hot water quantity used is in the ratio of 1 : 6 to 1 : 10 on the weight by volume basis .

[0019] Further, the method comprises filtering a chicory extract through a rotary filter followed by screw press equipment for maximum dewatering of an extracted chicory cake followed by a fine filtration with a press filter having a cloth pore size of 5 micron. The press filtered chicory extract is evaporated at 60 °C -80 °C in a double effect evaporator under vacuum to produce concentrated extract of AMG-1 brix 20-30 % which is spray dried subsequently in a dryer at 180 °C temperature with controlled moisture content in the dryer to produce a free-flowing inulin powder of purity between 80 % to 85 %. In accordance with the present invention, the press filtered chicory extract is treated with enzyme endo-inulinase at 50 °C followed by clarification with lime treatment, decolorization and demineralization with resin treatment, and purification by nanofiltration with 150-300 and 300-500 Dalton sulfonated polyethersulfone membranes to produce spray dried oligofructose and partially hydrolyzed inulin. Furthermore, the method comprises evaporating a press filtered chicory extract in a vacuum evaporator. Moreover, the method comprises clarifying a clear extracted chicory liquid to remove impurities. The extract is clarified by raising extract pH to 11 by addition of lime, wherein temperature is kept at 70 °C, and lowering pH of extract to 6.5 using phosphoric acid or carbon dioxide to precipitate calcium phosphate or calcium carbonate, wherein the precipitated calcium phosphate or calcium carbonate along with trapped impurities are removed by decantation at 4000 g followed by centrifugation at 7000 g. Further, the method comprises concentrating a partially purified dry chicory extract in the evaporator. Furthermore, the method comprises purifying the clarified chicory extract to remove the impurities by a membrane filtration using nanofiltration. The nanofiltration is carried out with a sulfonated polyethersulfone polymeric membrane having a cutoff of 300 to 1000 Dalton at 50 °C to 70 °C to remove Mono and Disaccharides into a permeate and retain the large molecular weight inulin (DP 3-60) in the retentate. Moreover, the method comprises treating a purified inulin retentate / concentrate generated after the membrane filtration step with a series of anionic and cationic resins at a temperature of 40 to 60 °C to remove color and reduce conductivity. Finally, the method comprises concentrating the resin treated extract in a vacuum evaporator to obtain inulin powder with inulin content in the range of 85 to 90 %.

[0020] In accordance with the present invention, the purified inulin solution recovered after resin treatment is subjected to second stage membrane filtration and diafiltration operations with a sulfonated polyethersulfone polymeric membrane AMG-1 having a cutoff of 300 to 1000 Dalton at 50 to 70 °C to remove Mono and Disaccharides into the permeate, and retain the higher chain length inulin (DP 3- 60) in the retentate thereby achieving a product concentration of 23% to 25%, and concentrating the concentrated and purified inulin in a vacuum evaporator to the brix value of 30 to 35 % followed by spray drying to produce purified inulin powder with purity ranges between 93 to 98 %.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein

[0023] Figure 1 shows a flow diagram of a method of producing inulin and intermediate derivatives thereof from sun-dried chicory roots, in accordance with the present invention;

[0024] Figure 2 is a graphical representation showing HPAEC-PAD analysis profile indicating the degree of polymerization (DP) and average degree of polymerization (ADP) of the sun-dried chicory inulin, in accordance with the present invention;

[0025] Figure 3 is a graphical representation showing HPLC -RI chromatograph of the purified inulin, in accordance with the present invention; and

[0026] Figure 4 is a graphical representation showing HPAC-PAD fingerprinting of purified inulin, in accordance with the present invention.

[0027] DETAILED DESCRIPTION OF THE INVENTION

[0028] The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques, and approaches are AMG-1 overcome by the present invention as described below in the preferred embodiments.

[0029] The present invention provides a method of producing inulin and intermediate derivatives thereof from sun-dried chicory roots. In the context of the present invention, intermediate derivatives specifically mean the inulin with various purity products isolated at various stages of manufacturing as well as enzymatically hydrolyzed products. The method of the present invention comprises steps like purification using anyone of precipitation by lime and phosphoric acid, clarification by decantation and centrifugation, decolorization to remove organic impurities, demineralization to remove ash, mineral and metal impurities, and finally fractionation by membrane filtration technique to remove impurities like reducing sugars (mono and di-saccharides), color, organic and inorganic impurities to enhance the inulin content to 90 to 98 %.

[0030] If the specification states a component or feature “may” “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.

[0031] As used in the description herein and throughout the claims that follow, the meaning of “a”, “an”, and “the” includes plural reference unless the context clearly dictates otherwise.

[0032] The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

[0033] Referring to figure 1, a flow diagram of a method of producing inulin and intermediate derivatives thereof from sun-dried chicory roots in accordance with the present invention is shown. AMG-1

[0034] In a first step, the method comprises washing fresh chicory roots in water and dicing the roots into cubes either by manual cutting or machine cutting.

[0035] In the next step, the method comprises drying the cubes in bright sunlight. The diced roots approximately 5 mm to 40 mm in size are dried on an open plot under the bright sunlight. Specifically, the drying is carried out for 48 to 72 hours until the moisture level goes down up to 5-8 % w / w basis. The cubes tend to lose the weight up to % of its original weight. The sun drying is done by manually spreading the wet chicory cubes over the plane surface covered with fiber sheets. The drying is done by making and breaking of long columns (width - 300mm x height - 150mm) of the cut chicory roots. This process is followed to expedite the drying process by rotating the mass of the chicory upside down and exposing to sunlight. In accordance with the present invention, the sun-dried chicory roots after drying attend the cube size of 2 to 25 mm and contains inulin on the dry basis (db) in the range of 50 % to 65 %, whereas the reducing sugar content is in the range of 5% to 15 % on dry basis and the moisture content is in the range of 5%-8%. In the context of the present invention, the sun-dried chicory roots are sourced from chicory plant variety Orchies, where the seeds of the same plant variety are grown under conventional climatological temperature conditions.

[0036] In the next step, the method comprises storing the sun-dried diced cubes into 5 mm to 25 mm cube sizes by sieving through vibro shifter with mesh size of 4. The sieved material is filled in the gunny bags and stored in a well-ventilated ware house by pilling the bags one over other to make a bag stacking up to 15 bags. The stacking of bags done on the wooden palate to keep the bottom of the bag ventilated to avoid static charge generation and the fire. This way the sun-dried chicory can be stored for 12-15 months without the reduction of inulin content and maintained its average degree of polymerization (ADP) 10-13. AMG-1

[0037] In the next step, the method comprises preparing dried chicory root powder by reducing the size of the sun-dried diced cubes of size between 5 mm to 25 mm. Particularly, multi mill or hammer mill is used to reduce the particle size and generate the dried chicory root powder having particle size of 3 mm to 5 mm, and 1 mm to 3 mm.

[0038] In the next step, the method comprises grinding the dried chicory powder of size 3 mm to 5 mm with electrically driven multi mill or hammer mill. While grinding, the moisture level of the chicory cubes and powder is maintained between 5 to 8 % by passing hot and dry air through the conveying section of the mill. Further, the sorting of the ground chicory powder is done by vibro shifter with mesh size of 20 and 40 to retain the desired particles and avoid undersized and oversized material. The inulin content of the dry chicory powder varies between 50 to 65 %, depending upon the cultivation site, harvesting time, moisture level, storage period, or addition of any kind of diluents - like plant biomass, anticaking agents, starch and cellulose derivatives, protein derivates, carbohydrate derivatives, any kind of calcium, silica, etc. may reduce the overall inulin content in the dry Chicory powder. This way processed dry chicory roots are used as a source of fiber in food and feed applications.

[0039] In the next step, the method comprises extracting inulin from the dried chicory root powder of particle size 3-5 mm and 1-3 mm using hot water at 60 °C to 80 °C temperature for 1 to 3 hours and at 40 °C to 50 °C temperature for 2 to 5 hours in an agitated jacketed tank reactor / diffuser to obtain inulin. The particle size of the dry chicory is important to increase the extraction efficiency to >70%. In an embodiment, the hot water quantity utilized for the extraction / diffusion of inulin from the sun-dried chicory roots is in the ratio of 1:6 to 1: 10 on the weight by volume basis. The quantity of water is important to achieve overall extractability >70% and inulin extractability particularly > 97 %. However, it is understood here that the quantity of hot water may vary in other alternative embodiments of the present invention. AMG-1

[0040] In the next step, the method comprises filtering the chicory extract through a rotary filter followed by screw press equipment for maximum dewatering of the extracted chicory cake, which reduces water level in the cake up to 40 %. Further, the fine filtration is performed with press filter with cloth pore size of 5 micron.

[0041] In the next step, the method comprises evaporating the press filtered chicory extract in a vacuum evaporator at 60 °C -80 °C in a double effect evaporator under vacuum to produce concentrated extract of brix 20-30 % and spray dried subsequently in a dryer at 180 °C temperature with controlled moisture content in the dryer to produce a free-flowing inulin powder of purity between 80 % to 85 0 / / o.

[0042] In the next step, the method comprises conversion of native inulin to hydrolyzed products. The filtered material is either treated with enzyme to produce the oligofructose or directly processed for the inulin manufacturing. The clarification and purification steps are common for both the products. The enzyme endoinulinase, treatment is done at 50 °C for 12 hours and followed the purification steps of the inulin manufacturing. Particularly, the press filtered chicory extract is treated with enzyme endo-inulinase at 50 °C followed by clarification with lime treatment, decolorization and demineralization with resin treatment, and purification by nanofiltration with 150-300 and 300-500 Dalton sulfonated polyethersulfone membranes to produce spray dried oligofructose and partially hydrolyzed inulin.

[0043] In the next step, the method comprises clarifying a clear extracted chicory liquid with the addition of lime (Ca(OH)2) and phosphoric acid (H3PO4). The solution of lime is added in the extract and pH is raised to 11, subsequently concentrated phosphoric acid is added to bring down the pH of the solution to 6.5. This treatment leads to the formation of calcium phosphate Ca3(PO)4 precipitate, which traps the denatured proteins, precipitated organic and inorganic salt impurities, suspended particles and like. Before addition of lime temperature of the solution AMG-1 is raised to 70 °C, and reaction is completed within 5 minutes. Alternatively similar reaction can also be performed by lime and Carbon di-Oxide (CO2), the pH of the solution is raised to 11.0 by addition of lime solution and it is further brought down to 6.5 by addition of CO2 gas. The temperature of the solution is kept at 70 °C. This reaction forms calcium carbonate (CaCCh) precipitate which traps the denatured proteins, precipitated organic and inorganic salt impurities, suspended particles, and like.

[0044] In the next step, the method comprises removing the precipitated calcium phosphate or calcium carbonate along with trapped impurities by decantation at 4000 g force in a decanter separator followed by high-speed centrifugation at 7000 g.

[0045] In the next step, the method comprises concentrating the partially purified dry chicory extract in the evaporator to brix value of 30-35% and spry drying to produce inulin powder of purity 85 % to 88%. The spray drying is carried out at 160 °C to 180 °C with controlled humidity in a dryer to produce free flowing inulin powder.

[0046] In the next step, the method comprises purifying the clarified chicory extract to remove the unwanted impurities like phenolic compounds, mono and di saccharides, mineral impurities by using nanofiltration membrane filtration technique. The filtration is carried out with 300 to 1000 Dalton polymeric membranes, sulfonated polyethersulfone. Specifically, the nanofiltration is done at 50 °C to 70 °C to remove smaller molecular weight impurities like Mono and Disaccharides into a permeate and at the same time retain the large molecular weight inulin (DP 3-60) in the retentate side. By this technique 50 % of the minerals, color and organic impurities are removed and purity of the inulin is improved up to 90 %. AMG-1

[0047] In the next step, the method comprises treating the purified inulin retentate / concentrate generated after membrane filtration step with anionic and cationic resins. In an embodiment, three types of resins in the ionic form C1-, H+ and OH- are used to remove both color and inorganic impurities. Operations of resin columns are specifically carried out at temperature of 40 to 60 °C, with column sequence (in series) of Strong Base Anion - >Strong Base Anion -

[0048] >Strong Acid Cation >Strong Base Anion >Strong Acid Cation — >Week Base Anion. The final polishing of the inulin solution is done with mixed bed polishing reins with Strong Acid Cation (H+) + Strong Base Anion (OH-) resins. The above configuration of resin columns designed such a way that it removes the 6000 ICUMSA color of the chicory extract as well as reduces the conductivity of extract from 5000 micro Simens to 10 micro Simens. In accordance with the present invention, the membrane filtration step is performed before the resin treatment to reduce the colour, organic and inorganic impurity load on the resin column, this step ultimately improves the performance of resin columns and reduces the overall requirement of resin quantity and reduces the water and chemical consumption by 50%.

[0049] In the next step, the method comprises concentrating the resin treated extract containing purified inulin in a vacuum evaporator to the brix value of 30 to 35 % and spray drying to produce purified inulin powder with purity of 85 % to 90 %. The spray drying is carried out at 160 to 180 °C, and at the same time moisture level of air in the dryer is maintained at 7 gram / Kg of air to produce free flowing inulin powder with inulin content in the range of 85 to 90 %.

[0050] In the next step, the method comprises subjecting the purified inulin solution recovered after resin treatment to second stage membrane filtration and diafiltration operations. The second stage of filtration and diafiltration is performed with membrane cutoff of 300 to 1000 Dalton polymeric membranes, sulfonated polyethersulfone, specifically because of its stability at high temperature. The filtration and diafiltration is performed at 50 to 70 °C to remove AMG-1 specifically Mono and Disaccharides into the permeate and retain the higher chain length inulin (DP 3-60) in the concentrate / retentate side and achieved 23-25% product concentration. The above concentrated and purified inulin is further concentrated in vacuum evaporator to the brix value of 30 to 35 and spray dried to produce purified inulin powder with purity ranges between 93 to 98 %.

[0051] The purified and spray dried inulin powder produced according to the method of the present invention has a unique composition with respect to its average degree of polymerization (average chain length-DP 10 to 13) and its soluble fiber content (90 to 95%), reducing sugar (0.5 to 5 %) and other mineral and antioxidant contents (0.01 to 0.5 %). The solubility of the above composition of inulin is also improved. The composition of final purified inulin powder is demonstrated in the Table 1 below: Table 1: Analysis of the final purified Inulin from the sun-dried chicory roots AMG-1

[0052] The present invention is further described in the light of following experimental examples which is set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The experimental example can be scaled up to industrial / commercial scale and the results obtained can be extrapolated to industrial scale.

[0053] Examples:

[0054] Example 1: Production of sun-dried chicory roots to manufacture inulin and derivates thereof

[0055] The seeds of the chicory, variety Orchies, coated seeds, were sown in the month of late October in Punjab regions of the India and grown under conventional climatological temperature and irrigation conditions. Crop was manually harvested during the Month of April and May (180 days) and the roots were processed without delay on the same day of harvesting. The average yield of the crop was 17 tons / acer (0.4 Hectare), when crop was harvested in 180 days from sowing.

[0056] The harvested fresh chicory roots were transported to the nearby industrial scale washing and dicing station to generate cubes of chicory roots. The diced roots approx. 40 mm in size were dried on an open plot under the bright sunlight. Sun drying was done by manually spreading the wet chicory cubes over the plane surface by making and breaking of long columns (width - 300mm x height - 150mm) of the cut chicory roots. This process was followed to expedite the drying process by rotating the mass of the chicory upside down and exposing to sunlight. The drying process was continued for 72 hours until moisture of the diced roots attends the value of 5%. The cubes tend to lose the weight up to % of its original weight. The chicory roots after drying attend the cube size of 2 to 25 mm, which contains inulin on the dry basis (db) 65 + 2%, whereas the reducing AMG-1 sugar content was 5 + 2% on the dry basis (db), at the same time the moisture content was 5%.

[0057] Further, the sun-dried chicory roots of size 2 to 25 mm were sorted with sieving through vibro shifter with mesh size of 4. The sieved material is then filled in the gunny bags (35 Kg / bag) and stored in a well-ventilated ware house by pilling the bags one over the other to make a bag stacking up to 15 bags. The stacking of bags was done on the wooden palate to keep the bottom of the bag ventilated to avoid static charge generation and the fire. This way sun-dried chicory was stored for the period of 15 months without the degradation of its active component i.e. inulin. The same sun-dried chicory roots were then used in the extraction and manufacturing of the inulin and its derivatives.

[0058] For analysis of inulin content and stability of stored sun-dried chicory roots, small samples of dry chicory roots, 100 gram each were collected from three different bags at every three months interval and analyzed for its inulin content, degree of polymerization (DP), reducing sugar content and moisture levels, etc. The collected samples were ground to 1-3 mm particle size and 10 grams of same chicory powder was extracted with 70 ml of DM water at 80 °C for 2 hours, the whole mixture was then filtered with fine filter and clear filtrate was used for the Inulin analysis. The inulin content of the dry chicory roots was analyzed by High Performance Liquid Chromatography (HPLC) method. The analysis was performed using Jasco - LC-2000 Plus series - HPLC system connected with Shodex-SC-1101 (0.8 x 300 mm) sugar analysis column. Analysis was performed at isocratic conditions with deionized water as mobile phase. The temperature of the column was maintained at 60 °C and flow rate of the mobile phase was adjusted to 0.4ml / minutes, the run time was set to 35 minutes and column pressure was maintained at 10-15Mpa. The column was calibrated with reference standards (Inulin, glucose, fructose, sucrose), purchased form Sigma Aldrich company and standard samples and test samples were prepared in DM water at 0. 1 % concentrations. The separated sugars on HPLC column were detected with RI AMG-1 detector maintained at 35 °C temperature. Degree of polymerization (DP) value of inulin from chicory roots was analysed by High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection (HPAC-PAD) method, using Dionex ICS-6000 chromatography system (Dionex Corporation) attached with Dionex CarboPac PA200 analytical column, calibrated with sugar reference standards (glucose, fructose, sucrose and Inulin) purchased from Sigma Aldrich company. A 25 pL of 0.01% concentration of standards and samples were injected on a column and sugars were separated with 100 mM NaOH as eluent. The mobile phase flow rate was maintained at 0.5 m min-1. The separated sugars were detected by electrochemical detection cell. Identification of sugars were done from the retention time of the reference standards. The inulin content of the test sample was determined from the % area distribution with reference to standards. The results of the analysis are indicated in Table 2 below. Basis this it is found that sun-dried chicory roots are stable up to 12 months at normal storage conditions and its inulin content also does not get hydrolysed and reduced. The average DP value of inulin (DP >10) was also retained till 15 months of storge.

[0059] Table 2: Storage stability, inulin content and degree of polymerization (DP) of the sun-dried chicory roots AMG-1

[0060] Figure 2 is a graphical representation showing HPAEC-PAD analysis profile indicating the degree of polymerization (DP) and average degree of polymerization (ADP) of the sun-dried chicory inulin.

[0061] Example 2: Manufacturing of crude inulin powder as source of fiber for animal feed

[0062] The sun-dried chicory roots with moisture content of 7 % and cube size of 5-25 mm were cut successively into 3 to 5 mm size and subsequently in to 0.4 to 0.8 mm size by grinding with electrically driven multi mill or hammer mill. While grinding the moisture level of the chicory cubes and powder was maintained below 8 % by passing hot and dry air through the conveying section of the mill to avoid the lump formation in chicory powder. After size reduction, the sorting of the ground chicory powder was done by vibro shifter with mesh size 20 and 40. The same material is then packed in polybags (50 Kg) and used as source of inulin fiber for the application in food and feed industry. The inulin content of the sun- dried chicory root powder was analysed as described above in Example 1. The results of analysis indicated inulin content > 65 % on dry basis (db).

[0063] Table 3: HPLC analysis of dry chicory roots for inulin content and other sugar composition on dry basis (db)

[0064] Example 3: Manufacturing of partially pure inulin (inulin 80-85%) from sun-dried chicory roots for food and feed application

[0065] The 100 Kg of the sun-dried chicory cubes of size between 5 mm to 25 mm were further cut in to 1 to 3 mm size by grinding with electrically driven multi mill or AMG-1 hammer mill. While grinding the moisture level of the chicory cubes and powder was maintained below 8 % by passing hot and dry air through the conveying section of the mill to avoid the lump formation in chicory powder. After size reduction, the sorting of the ground chicory powder was done by vibro shifter with sieve size 3 mm to retain the larger particles to avoid oversized material. The particle size of the dry chicory is important to increase the extraction efficiency to >70%. Chicory root powder with particle size of 1-3 was extracted in hot water at 80 °C temperature for 2-4 hours in an agitated jacketed tank reactor / diffuser 1.5 KL, with 30 RPM agitation speed. The hot water quantity utilized for the diffusion of inulin from sun-dried chicory roots was in the ratio of 1:7 on the weight by volume basis. After extraction is completed, the whole chicory extract was filter through press filter. The finely filtered extract of the sun-dried chicory roots was then treated with lime (Ca(OH)2 (5%)) and phosphoric acid (H3PO4) (85%). The solution of lime was added in the extract and pH was raised to 11, subsequently concentrated phosphoric acid or CO2 gas (99.99% purity) was added to bring down the pH of the solution to 6.5. This treatment leads to the formation of calcium phosphate Cas(PO)4 precipitate or calcium carbonate (CaCCE) precipitate, which traps the denatured proteins, precipitated organic and inorganic salt impurities, suspended particles, etc. Before addition of lime, temperature of the solution was raised to 70 °C, and reaction was completed within 5 minutes. The precipitated calcium phosphate or calcium carbonate along with trapped impurities were removed by decantation at 4000 g force in a decanter separator followed by high-speed centrifugation at 7000 g. Further, the partially purified dry chicory extract was concentrated in evaporator to brix value of 30% and spray dried to produce inulin powder of purity 85%. The spray drying was carried out at 180 °C temperature. During spray drying the absolute humidity of air was maintained at 7 gram / Kg to produce free flowing inulin powder. The analysis of inulin content in spray dried powder by HPLC method (as mentioned in Example no. 1) indicated purity of 80 - 85 % on dry basis (db) based on initial inulin content in sun-dried chicory roots, time and temperature of extraction. The same powder can be used as a source of purified Inulin in food and feed applications. AMG-1

[0066] Table 4: Efficiency of extraction of sun-dried chicory roots with respect to time and temperature of extraction Example 4: Manufacturing of standard grade inulin from sun-dried chicory roots for food and feed applications AMG-1

[0067] The 100 Kg of the sun-dried chicory cubes of size between 1-3 mm were extracted with 700 Liters of water as mentioned in Example no. 3. The finely filtered extract of the sun-dried chicory roots was then treated with lime (Ca(OH)2 (5%)) and phosphoric acid (H3PO4) (85%). The solution of lime was added in the extract and pH was raised to 11, subsequently concentrated phosphoric acid was added to bring down the pH of the solution to 6.5, the reaction was performed at 70 °C within 5 minutes. The precipitated calcium phosphate was Ca3(PO)4, was removed by decantation at 4000 g force in a decanter separator followed by highspeed centrifugation at 7000 g. The clean supernatant with total dissolved solid content of 8.5 % was further purified to remove the unwanted impurities like phenolic compounds, mono and disaccharides, mineral, and colour impurities by the nanofiltration (membrane filtration) technique. The filtration was carried out with 600 - 700 Dalton polymeric membranes, sulfonated poly ethersulfone. The nanofiltration was done at 70 °C to remove smaller molecular weight impurities like glucose, fructose, sucrose, minerals, and colour impurities and retain the higher chain length inulin (DP 3-60) in the retentate. By this technique 50 % of the mineral, colour and organic impurities were removed and purity of the inulin was also improved up to 88-90 % based on the rejection % of the impurities. The total dissolved solids in the retentate were build up to 18 %. The same retentate liquid was further subjected to resin treatment to remove minerals, and colour impurities. The resin treatment was performed with anionic and cationic resin columns. Three types of resins in the ionic form C1-, H+ and OH were used to remove both colour and inorganic impurities. Operations of resin columns were specifically carried out at temperatures of 60 °C, with column size of 50 L. The columns were connected in following sequence (in series); Strong Base Anion — — > Strong Base Anion - > Strong Acid Cation - >Strong Base Anion -

[0068] — > Strong Acid Cation - > Week Base Anion, followed by mixed bed polishing with Strong Acid Cation - > Strong Base Anion, resins. The operation flow rate of the columns was maintained at 5 bed volume per hour. The above configuration of resin column was designed such a way that it reduces the 6000 ICUMSA colour of the chicory extract to less than 10 ICUMSA as well as AMG-1 the conductivity of extract was reduced from 5000 micro Simens to 50 micro Simens. Further, the resin treated chicory extract was concentrated in evaporator to brix value of 30% and spray dried to produce inulin powder of purity 90%. The spray drying was carried out at 180 °C temperature. During spray drying the absolute humidity of air in the dryer was maintained at 7 gram / Kg to produce free flowing inulin powder. The analysis of inulin content in spray dried powder by HPLC method (as mentioned in Example no. 1) indicated purity of 90 % on dry basis (db). The same powder can be used as a source of purified inulin in food applications.

[0069] Table 5: Analysis of inulin for its purity and degree of polymerization by HPAEC-PAD method

[0070] Example 5: Manufacturing of highly pure grade Inulin from sun-dried chicory roots for food and feed applications

[0071] The 100 Kg of the sun-dried chicory cubes of size between 1-3 mm were extracted as mentioned in Example no. 3. The finely filtered extract of the sun- dried chicory roots was then treated with lime (Ca(OH)2 (5%)) and phosphoric acid (H3PO4) (85%). The precipitated calcium phosphate was Ca3(PO)4, was removed by decantation at 4000 g force in a decanter separator followed by highspeed centrifugation at 7000 g. The clean supernatant with total dissolved solid content of 8.5 % was further purified to remove the unwanted impurities like phenolic compounds, mono and disaccharides, mineral, and colour impurities by the Nanofiltration (NF) (membrane filtration) technique. The NF filtration was carried out with 600 - 700 Dalton cutoff polymeric membranes, sulfonated polyethersulfone. The nanofiltration was done at 70 °C to remove smaller molecular weight impurities like glucose, fructose, sucrose, mineral, colour AMG-1 impurities and retain the higher chain length inulin (DP 3-60) in the retentate. The total dissolved solids in the retentate were build up to 18 %. After it, the same retentate liquid was subjected to resin treatment to remove minerals, and colour impurities as mentioned in Example no. 3. To produce high pure inulin, the above resin treated clean chicory extract was further subjected to nanofiltration-2 treatment. NF was performed with 300 -500 Daltons cutoff polymeric membrane, sulfonated poly ethersulfone. The operations were performed at 70 °C to remove smaller molecular weight impurities like glucose, fructose and sucrose and increase the overall purity of the inulin to 93%. The same purified inulin was further subjected to diafiltration operations. Diafiltration was carried by addition of 150 L of demineralized water (DM) in retentate solution. After addition of water the overall dissolved solid were diluted to 12 %. The membrane filtration was continued with same 300 -500 Daltons cutoff polymeric membrane, sulfonated polyethersulfone. The concentrations of the dissolved solids at retentate side were enhanced again to 25 % and at the same time the purity of inulin was increased to 95 %. Further, the concentrated 25 brix inulin solution was evaporated at 80 °C up to 30 brix and spray dried at 180 °C temperature to produce inulin powder with purity 95 %. During spray drying the absolute humidity of the air was maintained at 7 gram / Kg to produce free flowing inulin powder. The analysis of inulin content in spray dried powder by HPLC-RI and HPAEC-PAD method (as mentioned in Example no. 1) indicated purity of 95.34 % on dry basis (db). The average DP value of the final purified inulin was retained to >13. The overall yield of the purified inulin obtained after final spray drying step was 55% of dry chicory weight. The same inulin can be used as a source of dietary fiber in the functional food applications.

[0072] Figure 3 is a graphical representation showing HPLC -RI chromatograph of the purified inulin (95% purity).

[0073] Table 6: Analysis of purified inulin with HPLC-RI detection method AMG-1

[0074] Figure 4 is a graphical representation showing HPAC-PAD fingerprinting of purified inulin (95% purity).

[0075] Table 7: Analysis of spray dried powder for its inulin content, purity, mineral composition, and color

[0076] Example 6: Manufacturing of highly pure grade oligofructose from sun-dried chicory roots for prebiotic and dietary fiber applications The 100 Kg of the sun-dried chicory cubes of size between 1-3 mm were extracted as mentioned in Example no. 3. The finely filtered extract of the sun- dried chicory roots was then treated with endo-acting enzyme inulinase (EC 3.2.1.7). The 0.2 IU of enzyme was added per litres of retentate and reaction was allowed to carried out at 50 °C for 12 hours in a reactor at 30 rpm agitation speed. Reaction was terminated by heating the reaction mixture at 70 °C and whole mixture was treated with lime (Ca(OH)2 (5%)) and phosphoric acid (H3PO4) (85%). The precipitated calcium phosphate (Ca (PO)4) was removed by decantation at 4000 g force in a decanter separator followed by high-speed AMG-1 centrifugation at 7000 g. The clean supernatant with total dissolved solid content of 8.5-9.5 % was further purified to remove the unwanted impurities like phenolic compounds, mono and disaccharides, mineral, and colour impurities by the Nanofiltration (NF) (membrane filtration) technique. The NF filtration was carried out with 150-300 Dalton cutoff polymeric membranes, sulfonated polyethersulfone. The nanofiltration was done at 50 °C to remove small molecular weight impurities like glucose, fructose, mineral, colour impurities and retain the medium chain length oligofructose (DP 2-7) in the retentate. The total dissolved solids in the retentate were build up to 23 %. Thereafter, the same retentate liquid was subjected to treatment with polymeric anionic and cationic resins to remove minerals, and colour impurities as mentioned in Example no. 3. The high pure oligofructose solution was then concentrated in multiple effect evaporator at 80 °C up to 50 brix and spray dried at 180 °C temperature to produce oligofructose powder with purity > 95 %. During spray drying the absolute humidity of the air was maintained at 7 gram / Kg to produce free flowing oligofructose powder. The analysis of oligofructose content in spray dried powder was done by HPLC-RI method (as mentioned in Example no. 1) indicated purity of > 95.0 % on dry basis (db). The average DP value of the final purified oligofructose was > 4.

[0077] Table 8: The analysis of oligofructose content in purified spray dried powder by HPLC-RI method AMG-1

[0078] Example 7: Manufacturing of partially hydrolyzed inulin from sun-dried chicory roots for prebiotic and dietary fiber applications

[0079] The 100 Kg of the sun-dried chicory cubes of size between 1-3 mm were extracted as mentioned in Example no. 3. The finely filtered extract of the sun- dried chicory roots was then treated with endo-acting enzyme inulinase (EC 3.2.1.7). The 0.1 IU of enzyme was added per litres of retentate and reaction was allowed to carried out at 50 °C for 4 hours in a reactor at 30 rpm agitation speed. Reaction was terminated by heating the reaction mixture at 70 °C and whole mixture was treated with lime (Ca(OH)2 (5%)) and phosphoric acid (H3PO4) (85%). The precipitated calcium phosphate (Ca3(PO)4) was removed by decantation at 4000 g force in a decanter separator followed by high-speed centrifugation at 7000 g. The clean supernatant with total dissolved solid content of 8.5-9.5 % was further purified to remove the unwanted impurities like phenolic compounds, mono and disaccharides, mineral, and colour impurities by the Nanofiltration (NF) (membrane filtration) technique. The NF filtration was carried out with 300-500 Dalton cutoff polymeric membranes, sulfonated polyethersulfone. The nanofiltration was done at 50 °C to remove small molecular weight impurities like glucose, fructose, mineral, colour impurities and retain the medium chain length inulin (DP2-20) in the retentate. The total dissolved solids in the retentate were build up to 23 %. Thereafter, the same retentate liquid was subjected to treatment with polymeric anionic and cationic resins to remove minerals, and colour impurities as mentioned in Example no. 3. The high pure inulin solution was then concentrated in multiple effect evaporator at 80 °C up to 40 brix and spray dried at 180 °C temperature to produce oligofructose powder with purity > 95 %. During spray drying the absolute humidity of the air was maintained at 7 gram / Kg to produce free flowing oligofructose powder. The analysis of oligofructose content in spray dried powder was done by HPLC-RI method (as mentioned in Example no. 1) indicated purity of > 95.0 % on dry basis (db). The average DP value of the final purified oligofructose was > 8. AMG-1

[0080] ADVANTAGES OF THE INVENTION

[0081] 1. The method of the present invention facilitates inulin manufacturing carried out throughout the year without the limitations of harvesting and processing time of fresh chicory roots (60-90 days), as sun-dried chicory can be stored for 12 to 15 months without the degradation of its inulin content and average chain length (DP) of the inulin.

[0082] 2. The method of the present invention utilizes the nanofiltration step to improve the purity of inulin and does not require the tedious chromatographic separation step as used in the prior art.

[0083] 3. The method of the present invention does not require the conventional carbon treatment step used to remove color impurities. Instead, in the method of the present invention color impurities after the extraction of sun-dried chicory roots are removed by the sequential clarification and purification steps, particularly lime and phosphotation, nanofiltration with 600 to 700 Dalton polymeric membranes and uniquely designed resin treatment step.

[0084] 4. The method of the present invention provides the most sustainable way of manufacturing of chicory root powder and purified inulin powder as the overall processing equipment and utility equipment sizes are brought down and hence the capital cost.

[0085] 5. The present invention provided economical and industrially feasible method of extraction of sun-dried chicory roots and subsequent purification of its active component i.e., inulin, without losing its functionality i.e. DP value (degree of polymerization).

[0086] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to AMG-1 thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the scope of the present invention.

Claims

I claim:

1. A method of producing inulin and intermediate derivatives thereof from sun-dried chicory roots, the method comprising: washing fresh chicory roots, and dicing the washed chicory roots into cubes of 5 mm to 40 mm size; sun-drying the diced cubes for 48 to 72 hours to achieve a moisture content of 5-8 % w / w; storing the sun-dried diced cubes, and preparing a dried chicory root powder therefrom; extracting inulin from the dried chicory root powder using hot water; fdtering a chicory extract through a rotary filter followed by screw press equipment for maximum dewatering of an extracted chicory cake followed by a fine filtration with a press filter having a cloth pore size of 5 micron; evaporating a press filtered chicory extract in a vacuum evaporator; clarifying a clear extracted chicory liquid to remove impurities; concentrating a partially purified dry chicory extract in the evaporator; purifying the clarified chicory extract to remove the impurities by a membrane filtration using nanofiltration; treating a purified inulin retentate / concentrate generated after the membrane filtration step with a series of anionic and cationic resins at a temperature of 40 to 60 °C to remove color and reduce conductivity; and concentrating the resin treated extract in a vacuum evaporator to obtain inulin powder with inulin content in the range of 85 to 90 %.

2. The method as claimed in claim 1, wherein sun-dried chicory roots are stored into 5 mm to 25 mm cube sizes by sieving through vibro shifter with mesh size of 4 for 12-15 months without reduction of inulin content and maintaining an average degree of polymerization (DP) of 10-13.

3. The method as claimed in claim 1, wherein the sun-dried chicory roots after drying attend the cube size of 2 to 25 mm and contains inulin on the dry basis (db) in the range of 50 % to 65 %, reducing sugar content in the range of 5% to 15 % on dry basis and moisture content in the range of 5%-8%.

4. The method as claimed in claim 1, wherein preparing the dried chicory root powder includes reducing the size of the sun-dried cubes of size between 5 mm to 25 mm using a multi mill or hammer mill to obtain a particle size of 3 mm to 5 mm, and 1 mm to 3 mm.

5. The method as claimed in claim 1, wherein inulin is extracted by contacting the dried chicory root powder with hot water at a temperature of 60 °C to 80 °C for 1 to 3 hours, and at 40 °C to 50 °C for 2 to 5 hours in an agitated jacketed tank reactor / diffuser, wherein the hot water quantity used is in the ratio of 1 :6 to 1 : 10 on the weight by volume basis.

6. The method as claimed in claim 1, wherein the press filtered chicory extract is evaporated at 60 °C -80 °C in a double effect evaporator under vacuum to produce concentrated extract of brix 20-30 % which is spray dried subsequently in a dryer at 180 °C temperature with controlled moisture content in the dryer to produce a free-flowing inulin powder of purity between 80 %to 85 %.

7. The method as claimed in claim 1, wherein the extract is clarified by, raising extract pH to 11 by addition of lime, wherein temperature is kept at 70 °C, and lowering pH of extract to 6.5 using phosphoric acid or carbon dioxide to precipitate calcium phosphate or calcium carbonate, wherein the precipitated calcium phosphate or calcium carbonate along with trapped impurities are removed by decantation at 4000 g followed by centrifugation at 7000 g.AMG-18. The method as claimed in claim 1, wherein the nanofiltration is carried out with a sulfonated polyethersulfone polymeric membrane having a cutoff of 300 to 1000 Dalton at 50 °C to 70 °C to remove Mono and Disaccharides into a permeate and retain the large molecular weight inulin (DP 3-60) in the retentate.

9. The method as claimed in claim 1, wherein the purified inulin solution recovered after resin treatment is subjected to, second stage membrane filtration and diafiltration operations with a sulfonated polyethersulfone polymeric membrane having a cutoff of 300 to 1000 Dalton at 50 to 70 °C to remove Mono and Disaccharides into the permeate, and retain the higher chain length inulin (DP 3-60) in the retentate thereby achieving a product concentration of 23% to 25%, and concentrating the concentrated and purified inulin in a vacuum evaporator to the brix value of 30 to 35 % followed by spray drying to produce purified inulin powder with purity ranges between 93 to 98 %.

10. The method as claimed in claim 1, wherein the press filtered chicory extract is treated with enzyme endo-inulinase at 50 °C followed by clarification with lime treatment, decolorization and demineralization with resin treatment, and purification by nanofiltration with 150-300 and 300-500 Dalton sulfonated polyethersulfone membranes to produce spray dried oligofructose and partially hydrolyzed inulin.

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