GB2599622A

GB2599622A - Vegetable noodle production

Info

Publication number: GB2599622A
Application number: GB2012339.4A
Authority: GB
Inventors: John Brace Parker Nigel; Karen Bunce Julie
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-08-07
Filing date: 2020-08-07
Publication date: 2022-04-13
Also published as: GB202012339D0

Abstract

A process for manufacturing swede noodles comprises cutting the swede into strands, immersing and heating in a temperature controlled aqueous solution of sodium percarbonate to remove the off flavours and odours. The cooked vegetables may then be rinsed in ambient water to arrest the cooking process and partially clean the product. A further rinsing stage sprays the cooked ingredients on a mesh conveyor belt. The product may be spin dried using a centrifuge drier and then packed for transport. Sodium percarbonate is used to reduce or eliminate the smell during the cooking process. The resulting noodle is a low carbohydrate, low calorie substitute for conventional noodles.

Description

Vegetable Noodle Production Introduction to the invention 01.Field of the Invention 2. This invention relates to a production process for the manufacture of a gluten-free, very low carbohydrate and low calorie substitute for cooked noodles based on wheat flour (semolina) or rice flour, which uses swede as its raw material.

3. The process has been developed primarily to produce an ambient retail product, that is 'ready-to-reheat', still within its packaging, ideally in a microwave oven, when it can substitute readily for cooked spaghetti or noodles.

4. Additionally, the process will also allow the production of chilled, food-service products, which can be deployed, in combination with other ingredients, in 'readyto-cook' or 'ready-to-reheat' meals, or as a major component of dressed salads.

5. Description of the Related Art

6. With the current obesity crisis in the developed world, where the main source of excess calorie consumption has been identified as the carbohydrate content of the diet, there is now pressure to reduce this consumption by reducing the level of this energy source in foodstuffs.

7. Carbohydrate, however, in the form of starch, as provided by whole cereals, pasta, potatoes and breads, introduces bulk to the diet and thus contributes to the satisfaction of hunger achieved by a 'full' meal.

8. The removal, therefore, of carbohydrate from the diet faces the difficulty of overcoming culturally entrenched eating habits, even among those of the populations concerned who readily acknowledge the source of the problems and support the health aims of a reduced carbohydrate consumption.

9. One way that this potential difficulty can be overcome is to replace the carbohydrate with a low calorie substitute that can provide the bulk that would otherwise be missing.

10. Swede noodles are one such product that can undertake this role.

11. In support of this potential role, raw swede noodles have the following approximate energy and carbohydrate values: composition per 100g edible portion energy value 24kcal energy value 101 kJ carbohydrate 5.0g of which; sugars 4.9g fat 0.3g 12. Furthermore, when the prepared swede noodles are cooked or re-heated, ready for consumption, these approximate values can be reduced to: composition per 100g edible portion energy value 11kcal energy value 46kJ carbohydrate 2.3g of which; sugars 2.2g protein 0.3g fat 0.4g 13. By comparison, cooked, semolina flour based spaghetti noodles have: composition per 100g edible portion energy value 157kcal energy value 657kJ carbohydrate 30.6g of which; sugars 0.6g protein 5.8g fat 0.9g while rice noodles have: composition per 100g edible portion energy value 109kcal energy value 456kJ carbohydrate 24.9g of which; sugars 0.0g protein 0.9g fat 0.2g 14. Swede noodles, when substituted for semolina based noodles, have the added benefit in that they contain no wheat gluten.

15. Swede noodles are a julienne strand-like product with cross-sectional dimensions that generally approximate to those of cooked semolina or rice flour based noodles.

16. Swede noodles are intended to be eaten cooked, either as a product in its own right or, more commonly, as a substitute for cooked. Semolina-based spaghetti or rice noodles.

17.At retail, swede noodles are intended to be purveyed as an already cooked, long shelf life, 'ready-to-reheat' product, available in microwaveable pouches.

18. Although domestically produced swede noodles, in their basic cooked state, can substitute for cooked semolina or rice flour based noodles, their principal drawback is that they will still retain their distinctive, characteristic odour and bitter flavour, rather than the relatively bland taste experience offered by the latter products.

19. Swede, Brassica napobrassica or Brassica napus var. napobrassica or Brassica napus subsp. Rapifera also known as rutabaga or Swedish turnip, is a root vegetable that was originally developed from a cross between cabbage Brassica oleracea and turnip Brassica Rapa, but now has full species recognition.

20. Swede was first recorded growing wild in Sweden by the Swiss botanist Gaspard Bauhin in 1620. It is now believed to have originated in Scandinavia or Russia and to have been broadly introduced to Britain around 1800, although it probably had a herbarium presence as early as 1669 and was described in France in 1700. Thereafter it was spread across the temperate climate areas of the British Empire and was eventually introduced to North America in the early 19th century, with reports of rutabaga crops in Illinois as early as 1817.

21. Swede contains cyanoglucosides which release cyanide and although this is subsequently detoxified into thiocyanate, it is possible for these compounds to contribute to hypothyroidism, where they inhibit thyroid iodide transport There have, however, been no reported cases of ill effects in humans from the consumption of glucosinolates from normal amounts of Brassica vegetables where their content is approximately one percent of dry matter. These compounds are responsible for the slightly bitter taste of swede.

22.The gluco inolates that contribute to the characteristic flavour and odour of prepared swede include glucocheirolin, glucobrassicanapin, glucoberteroin, gluconapoleiferin, and glucoetysolin.

23. Glucosinolates or thioglucoside-N-hydroxysulphates are a homogeneous class of naturally occurring thiosaccharidic compounds; which are modified amino acids, carrying an S-glucose functional group and a variety of different side chains.

24. Glucosinolates can be hydrolytically broken down by the endogenous plant enzyme myrosinase, when the latter is liberated for reaction by the processing of the plant tissue concerned, such as cutting, cooking or freezing.

25. Glucosinolates are not considered to be very susceptible to thermal degradation during blanching conditions but cooking will induce more thermal degradation to indole glucosinolates (38%) than in aliphatic glucosinolates (8%). Sterilisation, the most severe heat treatment, will result in significant thermal degradation of up to 73% of the total amount of glucosinolates.

26. The breakdown of glucosinolates produces 'mustard oils', a markedly pungent variety of bioactive products, including isothiocyanates, oxazolidine-2-thiones, nitriles, thiocyanate ions and indole products, which give brassicas, including swede, when processed and cooked, their strong odour and flavour.

27. To create swede noodles, that are a true substitute for semolina or rice flour based noodles, this characteristic odour and flavour requires removal.

28. Ideally, therefore, a cooked semolina or rice flour based noodles, derived from swede, will have, at consumption, the following characteristics: * a mid-to light cream in colour, * a uniform, clearly strand-like appearance, in which the individual strands have cross-sectional dimensions approximating to that of a typical cooked spaghetti or noodle strand, a moist mouth feel with individual strands being relatively firm to the bite, or describable as a/ dente, a generally bland taste, with no presence of the off-odour or off-flavour notes typical of cooked brassica vegetables.

29. With regard to the above characteristics, the texture of semolina and rice flour based noodles post cooking, in terms of firmness to the bite, or shear, is a critical quality control criterion during manufacture and it is therefore important that the texture characteristics of a substitute should be as closely comparable as possible.

30. The above can be measured using a variety of instrumentation, but the preferred equipment in this case is a Food Technology Corporation (FTC) CS-1 standard shear compression cell, which, with semolina based pasta, gives a shear reading in the range of 245.2N to 259.5N, which equates to a penetrometer hardness reading in the range of 0.85N/mm2 to 1.10N/mm2, an instrument more readily available in the processing of fresh produce.

31. With regard to achieving a bland flavour profile as one of the characteristics of semolina and rice flour based noodles, in patent GB2520486, 'Treating cauliflower with a reactive oxygen species', the inventors describe, in one of its embodiments, a method of processing fresh, raw cauliflower to remove or significantly reduce this above, brassica family associated, characteristic odour and taste.

32. The process described in patent, GB2520486, which is the one followed in the commercial production of the retail product Cauli Rice®, presents issues requiring very detailed management and are not always readily resolved.

33. In the current patent application, however, these issues are addressed with inventive solutions, the main one of which is the choice of percarbonates and in particular sodium carbonate peroxyhydrate as the active agents deployed in treating brassica vegetables to remove that plant family's associated characteristic odour and taste and thus it differs significantly from patent GB2520486 as these do not fall within its definitions of the "reactive oxygen species" identified, which includes peroxides, superoxides, ozone and hydroxyl and in that invention, "the one or more reactive oxygen species is selected from: peroxides; superoxides; and ozone and more suitably, the one or more reactive oxygen species is selected from peroxides and superoxides".

34.Typically, however, the term 'reactive oxygen species' is used in a biological context, as they are formed as natural by-products of the normal metabolism of oxygen.

35.With reference to the above, peroxide is defined as any class of chemical compound containing two oxygen atoms linked together by a single covalent bond, or produces the anion 022-, with typical examples being hydrogen peroxide (F1202)! sodium peroxide (Na202), calcium peroxide (Ca02) and barium peroxide (Ba02).

36. Two further categories of peroxides also exist, in which one or both of the oxygen atoms are covalently linked to atoms other than hydrogen, where one is represented by cumene hydroperoxide, a polymerization initiator with the other category represented by i-ammonium peroxydisulphate, also used as an initiator.

37. Again with reference to the above, a superoxide is defined as a compound, which contains the highly reactive oxygen radical or anion 02-.

38. In the present invention, the process relates, in particular, to the production of a gluten-free, low carbohydrate and low calorie content substitute for cooked semolina or rice flour based noodles, derived from swede as the raw material.

39. The technology involved, however, could be applied to unrelated fresh produce species, such as members of both the beet family, Betoideae, including mangolds Beta vulgaris subsp. vulgar-is, and the squash family, Cucurbitaceae, including pumpkins Cucurbita pepo, C. moschata and amaxima which when produced as semolina-based or rice noodles, the removal of distinctive flavour compounds would be of benefit.

40. In the process of the present invention, the principal focus, with regard to the sourced raw material, is on those varieties of swede, found among the annual cultivars grown in Europe and North America.

41. In the process of the present invention, the first stage is that of basic preparation, which involves the conventional abrasive peeling of the pre-trimmed root of the swede to fully remove the skin and any surface wound areas.

42. The second stage in the operation is the washing of the peeled roots to remove any remaining field soiling and surface debris post-peeling.

43. The above operation is carried out in a flume washer, with programmed water flows to create both sufficient agitation for effective cleaning and an adequate contact time for the product within of the flume, at the end of which is a perforated, vibratory discharge conveyor for surface water removal.

44. In the process of the present invention, the third stage is that of product size reduction, which involves the mechanical cutting of the swede root into regular julienne strands across a range of predetermined, profile dimensions.

45. In the present invention, the mechanical cutting of the prepared swede root is undertaken with a shredder, such as the Urschel CC-D or FAM Centris 315 or 400 machines, in which the knife assembly is operating in two different planes.

46. In one embodiment of the process, within the knife assembly, blades are arranged in two planes at right angles to each other, in order to produce a julienne strand with a rectangular cross-section with dimensions in the range of 2.5mm x 2.5mm to 3.5mm x 3.5mm.

47. In the preferred embodiment of the process, however, within the knife assembly, blades are arranged at 60° to each other to create a julienne strand with an a diamond shaped cross section formed from two equilateral triangles, providing a maximum cross-section width of 3.2mm, with sides of 3.2mm.

48. With the selection of either of the above knife assemblies, the julienne strand length is determined by the dimensions of the prepared swede root storage tissue presented, although these should be of a size to ensure that at least 75%, by weight, of the strands produced will exceed 125mm.

49. In the process of the present invention, the fourth stage is that of treatment, in which the julienne strand swede is exposed to an aqueous solution of a percarbonate at a predetermined concentration, temperature and contact time, in order to both significantly inhibit the development of glucosinolate byproducts from the hydrolysis reaction with the enzyme myrosinase and then oxidatively disable both those compounds, which may have already been formed due to consequential tissue damage during the size reduction stage.

50. In one embodiment of the present invention, the particular percarbonate selected for the treatment stage is sodium percarbonate, also known as sodium carbonate peroxyhrate (Na2CO3.3/2H20), for which the reaction equation in qaueous solution is shown below: -H20 Na2CO3.3/2H20 4 Na2CO3 + 3/2H202 4 Na2CO3 + 3/2H20 + 3/402 sodium carbonate sodium peroxyhydrate carbonate 51. In the present invention, the treatment stage involves the transfer of the freshly prepared julienne strand swede into a stainless steel basket, the latter having a high density pattern of perforations, each with a diameter of 1.75mm, over a significant percentage of its surface area.

52. The above stainless steel basket, with its load of freshly prepared julienne strand swede, at a predetermined weight, is then lowered into an immersion tank containing an aqueous solution of sodium percarbonate, at both a predetermined concentration and a thermostatically controlled temperature, where the weight/volume ratio of the product to the immersion solution is in a ratio of 1:5.

53.The above operation is executed rapidly, in order to allow all of the freshly prepared julienne strand swede to be fully immersed within a very short time frame, assisted by a continuous, pumped circulation to facilitate uniform contact and temperature distribution.

54. In aqueous solution, sodium percarbonate reacts as shown in the above equation, producing both sodium carbonate and oxygen as final reaction products.

55. Sodium carbonate in aqueous solution reacts with water to form sodium hydroxide, a strong base and carbonic acid, a weak acid, as shown in the example equation below: Na2 03 + H20 4 NaOH + H2003 sodium water sodium carbonic carbonate hydroxide acid 56. The above reaction allows sodium carbonate to act in the same way as does sodium bicarbonate, when the latter is deployed to soften' vegetable material during processing, by increasing the permeability of both cell walls and cell membranes within the cell structure of the swede julienne strands, thus promoting the improved permeation of the plant tissue by the oxygen generated during the reaction of sodium percarbonate within the aqueous immersion solution.

57. The above, improved permeability the swede cell structure to oxygen allows a greater efficacy of the reactions, not only between the oxygen and the glucosinolates themselves but also the reaction products from the latter's hydrolytic reactions with the enzyme myrosinase, resulting in a greater oxidative disabling of these compounds than would have hitherto taken place.

58. In the present invention, the above process, unlike the process described in patent GB2520486, does not require a separate 'softening' stage, the elimination of which, in itself, can be considered an innovative step and in commercial operation increases throughput and delivers consequent production economies.

59. The removal of the requirement for a separate 'softening' stage is a result of the selection of percarbonates, in particular sodium percarconate, not only as an source of process oxygen but also as a source of soluble carbonates to promote cell membrane permeability to dissolved oxygen.

60. The deployment of those reactive oxygen species referred to in patent GB2520486, if not impossible, would be highly impractical to substitute for sodium percarbonate in the above treatment process as their reactivity at the temperature range required would be extremely difficult to manage effectively.

61. In the present invention, the treatment stage, by pre-determined and programmed variations, at any point in the process, of the following: * the concentration of sodium percarbonate in solution, * the rate of increase or decrease in immersion solution temperature, * the maximum temperature of the immersion solution, * the contact time of the above, can, from the julienne strand swede within the immersion solution, provide for the production of several products, each suitable for a different retail or food service market niche.

62. In the present invention, the treatment stage is ended by the rapid transfer of the now par-cooked, or cooked and treated, julienne strand swede to a fifth stage; a cooling and initial rinsing stage, designed to both arrest the cooking process and remove any surface residues of sodium percarbonate and its reaction products.

63. The above residues of sodium percarbonate and its reaction products, unlike the the reactive oxygen species, hydrogen peroxide, deployed in the treatment step referred to in patent GB2520486, leave no attributable, detectable odour or taste taint in the finished product at retail.

64.T1:e tea men:stage s executed IDY raising the perforated, stainless steel basket, from the treatment solution, allowing a 60sec drainage interval and then tipping its contents into a second tank, of double the volume the treatment tank and containing mains water, at 12°C to 15°C, with a continuous, pumped circulation, designed to facilitate a uniform contact and temperature distribution.

65. In the present invention, the cooling and initial rinsing stage, after a predetermined contact time of 5 minutes, is ended by a pumped discharge of the now par-cooked or cooked, treated, cooled and rinsed julienne strand swede, for the sixth stage of the process, on to a conveyor with a fine mesh belt where it is automatically spread to produce a uniform layer with a depth of approximately lOmm, over which is positioned a series of nozzles delivering a second and final rinse of mains water, again at 12°C to 15°C, delivered as a coarse spray at an approximate rate of 2 litre of water per 1kg of product.

66. After this second and final rinse, the above conveyor, with a fine mesh belt, allows the julienne strand swede to free drain before a discharged transfer to the seventh stage of the process, which is that of centrifuge drying, with predetermined product loading, ramp and maximum rpm settings, where only the free water, in direct contact with the surface of the individual julienne strands of swede, is removed.

67. With the process as described in patent GB2520486, the cooling and rinsing stage in commercial production requires a minimum of 45 minutes and the product leaving this stage still retains both odour and flavour taints attributable either to residual hydrogen peroxide, which has not been fully challenged by the processed vegetable substrate, or its reaction products, which are not always possible to remove by additional rinsing stages; a situation avoided with the treatment stage process described in the present invention, where the latter can be considered as an inventive step.

68. With the current invention, in addition to the absence of odour or taste taints in the product thus processed, the considerable reduction in the contact time required and consequent beneficial effect on production output and economy due to the deployment of sodium percarbonate, as opposed to the "active oxygen species" deployed in patent GB2520486, can also be considered as an inventive step.

69. The julienne strand swede, once it has been centrifuge dried, can now be regarded as swede noodles and is in a condition suitable for retail or food service packing, the eighth and final stage of the process, the format of which will be dependent on the regime selected for the treatment stage required to produce the textural and organoleptic qualities demanded by the specific market sector that has been targeted.

70. In the present invention, although the focus, with regard to raw materials for the manufacture of a substitute for cooked semolina or rice flour based noodles, has been on swede cultivars from Europe and North America, the seasonal availability of varieties within these cultivars lead, fortunately, only to minor variations in the texture and flavour as well as glucosinolate content of the swede root, which require no significant adjustments to the manufacturing process.

71. In the preferred embodiment of the present invention, described by way of example only, are the parameters for the treatment stage, which require to be observed in order to produce julienne strand swede, par-cooked under a regime with: * a prepared product at a process introduction temperature of 12°C to 15°C, * an immersion treatment with a predetermined concentration of sodium percarbonate in an aqueous treatment solution of between 0.5% and 1.5% w/v, * an immersion treatment with a pre-determined controlled temperature, at product reception, of 50°C, * a rapid introduction of the prepared product to the above immersion treatment at a weight to volume ratio of 1:5, * a predetermined final, end-of-treatment, immersion solution temperature of between 50°C and 55°C, * a pre-determined, controlled rise from the immediate, post-reception, equilibrium immersion solution temperature, of between 40°C and 45°C, to the above final temperature, with a ramp duration of between 10 minutes and 15 minutes, * a predetermined contact time at the final, end-of-treatment, immersion solution temperature, of between 150 seconds and 300 seconds, which, when discharged, cooled, rinsed, dried and, then packed and sealed in a conventional, gusseted retort pouch, will allow it to withstand a subsequent thermal process sterilisation at 116°C to 118°C and still retain, over a shelf life of twelve months, its required appearance and organoleptic characteristics at retail.

72. The above sterilisation temperatures require that the predetermined, immersion solution temperature at product reception of 50°C and the end-of-treatment, immersion solution temperature of between 50°C and 55°C are closely observed to ensure that the product does not become overcooked during the thermal process and consequently become visually and organoleptically unacceptable at retail.

73. In this latter regard, the julienne swede strands, at the end of the above treatment process, must be sufficiently firm in texture to withstand the thermal process and still be al dente to the bite, with a shear reading in the range of 245.2N to 259.5N, or a penetrometer hardness in the range of 0.85N/mm2 to 1.1oN/mm2 74. In order to meet the above textural criteria, post thermal process, the julienne strand swede, at the end of the seventh process stage, will require a texture with a firmness, as measured by the FTC CS-1 standard shear compression cell, in the range of 255.0N to 260.0N, or a penetrometer hardness reading in the range of 2.50N/mm2 to 2.90N/mm2.

75. In another embodiment of the present invention, described by way of example only, are the parameters for the treatment stages, which are required to be observed to produce julienne strand swede, par-cooked under a regime with: * a prepared product at a process introduction temperature of 12°C to 15°C, * an immersion treatment with a predetermined concentration of sodium percarbonate in aqueous solution of between 0.5% and 1.5% w/v, * an immersion treatment with a pre-determined, controlled temperature at product reception of 50°C, * a rapid introduction of the prepared product to the above immersion solution at a weight to volume ratio of 1:5, * a predetermined final, end-of-treatment, immersion solution temperature of between 85°C and 90°C, * a pre-determined, controlled rise from the immediate, post-reception, equilibrium immersion solution temperature of 50°C, to the above final temperature, with a ramp duration of between 20 minutes and 25 minutes, * a predetermined contact time at the final, end-of-treatment, immersion solution temperature of between 360 seconds and 390 seconds, which, when discharged, cooled, rinsed, dried and then individually quick frozen before packing into a bag of a suitable polymer material, will retain its required appearance and organoleptic characteristics as a substitute for cooked semolina or rice flour based noodles, under frozen storage, distribution and subsequent retail display conditions, with a shelf life of at least six months, as a product requiring either reheating or some further cooking.

76. In a further embodiment of the present invention, described by way of example only, are the parameters for the treatment stage, which are observed to produce julienne strand swede, fully cooked under a regime with: * a prepared product at a process introduction temperature of 12°C to 15°C, * an immersion treatment with a predetermined concentration of sodium percarbonate in aqueous solution of between 0.5% and 1.5% w/v, * an immersion treatment with a pre-determined controlled temperature at product reception of 50°C, * a rapid introduction of the prepared product to the above immersion solution at a weight to volume ratio of 1:5, * a predetermined final, end-of-treatment, immersion solution temperature of between 90°C and 95°C, * a pre-determined, controlled rise from the immediate, post-reception equilibrium immersion solution temperature of between 40°C and 45°C, to the above final temperature, with a ramp duration of between 24 minutes and 28 minutes, * a predetermined contact time at the final, end of treatment, immersion solution temperature of between 180 seconds and 360 seconds, which, when discharged cooled, rinsed and dried, will retain its required appearance and organoleptic characteristics as a substitute for cooked semolina or rice flour based noodle, in chilled, retail dressed salads, ready-to-eat and ready-to-reheat recipe dishes, with shelf lives of between 7 days and 12 days.

Summary of the Invention

77.The process in the present invention is a method for the manufacture of a gluten-free, very low carbohydrate content and low calorie substitute, as a retail product, for cooked semolina or rice flour based noodles, using swede root as the raw material, whereby the latter is converted into a cream coloured, strand-like product, which retains its texture at the point of consumption and thus be comparable to the conventional noodles to be substituted for, in providing a 'mouth-feel' that is both moist and definably firm to the bite or "al dente" but is pleasantly bland in odour and flavour, having none of the off-odour and bitter off-taste notes typically associated with the glucosinolate content of brassicas, which are oxidatively removed by a treatment process deploying percarbonates as the oxygen source, with sodium percarbonate as the preferred active agent.

78. The raw material source for the process is those varieties of swede found among the annual cultivars grown in Europe and North America.

79. The process, in order to produce the substitute for cooked, semolina and rice flour based noodles with the characteristics described above, requires a number of stages.

80.The first stage is basic preparation, in which the whole, harvested, trimmed swede root is peeled mechanically by a conventional abrasive peeler in order to remove leaf bases, wound sites and the epidermal layers to expose the storage tissue (flesh).

81. The second stage is the removal, by washing, of extraneous particulate matter and field soiling, during which the peeled roots are transferred to a flume washer, with programmed water flows designed to create both sufficient agitation for effective cleaning and the controlled movement of the product along the length of the flume to provide a predetermined contact time, at the end of which is a perforated, vibratory discharge conveyor for surface water extraction.

82. The third stage is product size reduction, which involves the mechanical cutting of the swede root into julienne strands having a range of predetermined, profile dimensions.

83. In the present invention, the knife assembly deployed for the above is operating in one of two different cutting plane arrangements.

84. In the case of the first, the blades are arranged in two planes at right angles to each other, in order to produce a julienne strand with a rectangular cross-section with dimensions in the range of 2.5mm x 2.5mm to 3.5mm x 3.5mm.

85. In the case of the second and preferred embodiment, the blades are arranged at 60° to each other in order to create a julienne strand with an a diamond-shaped cross section formed from two equilateral triangles, providing a maximum cross-sectional width of 3.2mm, with sides of 3.2mm.

86. The fourth stage is the treatment of the swede julienne strands, in which the product is exposed to an aqueous solution of a percarbonate at predetermined concentrations, temperatures and contact times, in order to both significantly inhibit the development of glucosinolate byproducts resulting from the hydrolysis reaction with the enzyme myrosinase and then oxidatively disable those compounds, which may have already been formed due to consequential tissue damage during the size reduction stage.

87. In the preferred embodiment of the present invention, the percarbonate selected for the fourth and treatment stage, is sodium percarbonate (Na2CO3.3/2H20), in which the reaction in aqaueous solution produces, as final reaction products, both sodium carbonate and oxygen.

88. In the same embodiment, the above reaction product, sodium carbonate, in the intimate presence of the swede julienne strands, produces a sodium acid salt and carbon dioxide.

89. In the same embodiment, the above reaction allows sodium carbonate to act in the same way as sodium bicarbonate, when the latter is deployed to 'soften' vegetables during processing, by increasing the permeability of cell membranes within the cell structure of the swede julienne strands.

90. In the same embodiment, the above increased permeability of the cell structure within the swede julienne strands promotes the penetration of this plant tissue by the oxygen, generated during the reaction of sodium percarbonate within the aqueous, immersion solution, increasing its efficacy in the oxidative disabling of the odour and taste compounds associated with glucosinolates and their hydrolytic reaction products with the endogenous enzyme myrosinase.

91. In the present invention, the treatment stage involves the transfer of a predetermined weight of the swede julienne strands into a stainless steel basket, the latter having a high density pattern of perforations, each with a diameter of 1.75mm, over a significant percentage of its surface area.

92. The above stainless steel basket, with its load of swede julienne strands, is then lowered into a tank containing an aqueous solution of sodium percarbonate at both a predetermined concentration and thermostatically controlled temperature, where the volume ratio of the product to the immersion solution is in a ratio of 1:5.

93.The above operation is executed rapidly, in order to allow all of the swede julienne strands to be fully immersed within a very short time frame, assisted by a continuous, pumped circulation; the latter to facilitate uniform contact and temperature distribution.

94. In the present invention, the treatment stage can provide for the production of several swede julienne strand products, each specifically suited to different retail or food service market niches, by pre-determined and programmed regime variations, at any point in the process, of the following: * the concentration of sodium percarbonate in the immersion solution, * the rate of increase or decrease in immersion solution temperature, * the maximum temperature of the immersion solution, * the contact times at each of the above.

95. In the present invention, the treatment stage is ended by the rapid transfer of the now par-cooked or cooked and treated swede julienne strands to a fifth, cooling and initial rinsing stage, designed to both immediately arrest the cooking process and remove any residues of sodium percarbonate and its reaction products.

96 The above transfer is effected by raising the perforated, stainless steel basket out of the treatment tank and tipping its contents into a second tank, of an equal volume to that of the treatment tank and containing mains water at ambient temperature, with a continuous, pumped circulation to facilitate a uniform contact and temperature distribution.

97. In the present invention, the cooling and initial rinsing stage, after a predetermined contact time, is ended by a pumped discharge transfer of the par-cooked or cooked, treated, cooled and rinsed swede julienne strands to the sixth process stage.

98. In the present invention, the sixth, or second rinse stage, involves the reception of the transferred swede julienne strands on to a conveyor, fitted with a fine mesh belt, where it is automatically spread to form a uniform layer, with a depth of approximately lOmm, over which is positioned a series of nozzles delivering, as a coarse spray or drench, mains water at an approximate combined rate of 2 litres per 1kg of product.

99. The above conveyor, after the second rinse, allows the swede julienne strands to free drain before a discharged transfer to the seventh stage of the process, which is that of centrifuge drying, with predetermined load weight, ramp and maximum rpm settings, where only the free water in direct contact with the surface of the individual julienne strands of swede is removed.

100. Once it has been centrifuge dried, the par-cooked or cooked, treated, cooled, rinsed and dried, swede julienne strands can now be regarded as swede noodles and are therefore in a condition suitable for the eighth stage of the process, which is that of retail or food service packing, where the format of the packaging employed will be dependent on the regime selected at the treatment stage, the consequent textural and organoleptic qualities created and the specific market sector that these have been targeted at.

101. In the embodiment, in which the swede noodles are targeted at the retail grocery market, as a microwave-ovened, 'ready-to-reheat' product, with an ambient distribution and display and a 12 month shelf life, they are packed and sealed into a conventional, gusseted retort pouch and subjected to a thermal process operating at 116°C to 118°C.

102. In the embodiment, in which the swede noodles are targeted at both the retail grocery and food service markets as a frozen, 'ready-to-cook' product, with an 18 month shelf life, the swede noodles will be subject to an IQF treatment before packing into a bag of an unperforated, suitable, polymer material.

103. In the embodiment, in which the swede noodles are targeted at the food service or ingredient supply markets as a cooked semolina or rice flour noodle substitute ingredient or a component in chilled, retail dressed salsds, ready-to-eat and ready-to-reheat recipe dishes, with shelf lives of between 7 days and 12 days.

Claims

Claims 1 The process for the manufacture of a gluten-free, very low carbohydrate content and low calorie substitute for cooked semolina or rice flour based noodles, as a retail product, using swede root storage tissue as the raw material, whereby the latter is converted into a strand-like product, which, to be comparable to the products it is substituting for, retains a texture and taste at the point of consumption, that are respectively of a defined moderate firmness to the bite, moist and pleasantly bland in odour and taste, having none of the off-odour and bitter off-flavour notes typically associated with the glucosinolate content of brassicas, which are oxidatively removed by a treatment process deploying percarbonates as the oxygen source, with sodium percarbonate as the preferred active agent.
2 The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 1, wherein the raw material is swede, principally sourced from those varieties typically found among the annual cultivars grown in Europe and North America.
3 The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 1, wherein the swede root storage tissue is converted into a strand-like product during a sequence of process stages, the first being that of basic preparation, where the swede root is peeled to remove all leaf bases, wound sites and epidermal layers in order to expose the storage tissue.
4 The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 1, wherein the swede root storage flesh is converted into a strand-like product during a sequence of stages, the second being that of washing, during which the peeled swede roots are passed through a flume washer with sufficient agitation to remove extraneous matter and field soiling, before being allowed to drain on a perforated, vibratory discharge conveyor.
The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 1, wherein the swede root storage tissue is converted into a strand-like product during a sequence of stages, the third being that of mechanical, size reduction during which the peeled, washed and drained swede roots are mechanically shredded into julienne strands of the nominal profile dimensions of 2.mm x 2.5mm to 3.5mm x 3.5mm.
6. The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 1, wherein the swede root storage tissue is converted into a strand-like product during a sequence of stages, the fourth being that of a heated, immersion treatment, in which percarbonate, in aqueous solution, is the primary active agent in the oxidative disablement of the undesirable odour and taste compounds, typical of processed brassicas and released by glucosinolates and their myrosinase initiated, hydrolytic reaction products.
7 The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 6, wherein sodium percarbonate in aqueous solution produces the final reaction products sodium carbonate and oxygen.
8 The process for the manufacture of a cooked semolina or rice flour based noodle substitute of a rice substitute according to claim 7, wherein sodium carbonate, in the intimate presence of par-cooked swede julienne strands, reacts, in aqueous solution, to form sodium hydroxide and carbonic acid, enabling sodium carbonate to act in the similar way as does sodium bicarbonate, when the latter is deployed to 'soften' vegetables during processing, by increasing the permeability of both of the cell walls and cell membranes within the cell structure of the swede julienne strand.
9 The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 7, wherein oxygen generated in the intimate presence of swede julienne strands, in which the permeability of cell walls and cell membranes within the cell structure of the swede julienne strands has been significantly increased by the reaction products of sodium carbonate in aqueous solution, is able to penetrate the swede root tissue more readily, thus increasing its efficacy in the oxidative disabling of the undesirable odour and taste compounds associated with glucosinolates and their hydrolytic reaction products with the endogenous enzyme myrosinase.
10. The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 1, wherein the swede root storage tissue is converted into a strand-like product during a sequence of stages, the fourth being that of a thermostatically-controlled, heated, immersion treatment, the predetermined control of the parameters of which, namely temperature, sodium percarbonate concentration and respective contact times, will enable, by means of this single stage, the production of a range of retail products, in which cooked semolina or rice flour based noodles are substituted for, as appropriate, by par-cooked or fully cooked variations of the treated, swede julienne strands.
11. The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claims 1 and 10, wherein the swede root storage tissue is converted into a strand-like product during a sequence of stages and at the end of the treatment process carried out in the fourth stage, the swede julienne strands are sufficiently firm in texture to withstand the subsequent thermal process and still be a/ dente to the bite, which equates to a textural firmness, measured by the FTC CS-1 standard shear compression cell, in the range of 245.2N to 259.5N, or a penetrometer hardness in the range of 0.85N/mm2 to 1.1oN/mm2 and in order to achieve this will require, at the end of the fourth stage, strands having a texture with a firmness, as measured by the standard shear compression cell, in the range of 255.0N to 260.0N, or a penetrometer hardness reading in the range of 2.50N/mm2 to 2.90N/mm2
12 The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 1, wherein the swede root storage tissue is converted into a strand-like product during a sequence of stages, the fifth being that of cooling and initial rinsing, in which the treated and now par-cooked or cooked and treated, swede julienne strands are transferred rapidly to an ambient, mains water immersion to immediately arrest the coking process and effect the initial, rinsed removal of any residues of the processing aid, sodium percarbonate and its reaction products.
13 The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 1, wherein the swede root storage tissue is converted into a strand-like product during a sequence of stages, the sixth being that of the second rinse stage, which involves the transfer of the now par-cooked or cooked, treated, cooled, rinsed swede julienne strands to a conveyor, fitted with a fine mesh belt, where it is subjected to a saturating spray or drench of ambient mains water before being allowed to free drain, now without any odour or taste taints attributable to the processing aid, sodium percarbonate or its reaction products.
14. The process for the manufacture of a cooked semolina or rice flour based noodle substitute according to claim 1, wherein the swede root storage tissue is converted into a strand-like product during a sequence of stages, the seventh being that of centrifuge drying, where only the free water in direct contact with the surface of the individual julienne strands of swede is removed.The process for the manufacture of a semolina or rice flour based noodle substitute according to claim 1, wherein the swede root storage tissue is converted into a strand-like product during a sequence of stages, the eighth and final stage being that of retail or food service packing, where the format of the packaging will be dependent on the regime selected at the treatment stage, the consequent textural qualities created and the specific market sector that these have been targeted at.