FOOD THICKENER

Abstract: A process for producing a food thickening agent comprises the steps of providing a starch material, mixing the starch material with a fat and solidifying the mixture to form a food thickening agent. The starch material is a dried, heat treated and/or pre-cooked starch material and the fat is selected from those fats which exhibit a steep melting curve, non-polymorphic or monomorphic fats, fats which are essentially homogeneous, and fats which do not contain significant amounts of liquid fat at about 25 DEG C.

Description: FOOD THICKENER The present invention relates to processes for preparing food thickening/binding agents (for example, various types of roux/roux blanc) and to food thickening/binding agents so prepared. In particular, the invention relates to thickening/binding agents which rapidly disperse or instantize in hot liquids (when either added to the hot liquid or when the hot liquid is added thereto) , without the formation of substantial lumps. The thickeners of the invention may be formulated as a roux, simulated roux, or roux-like product. In particular, they may be formulated as a roux bianc, simulated roux blanc, or roux blanc-like product. The thickeners of the invention find application as functional food ingredients, where they may functionally replace traditional roux. They may also be used as flavour carriers (e.g. in the preparation of chocolate, vanilla, coffee etc. spreads, toppings and drinks) and as bases for dried food products. The thickeners of the invention find particular application in sauces, spreads, toppings, soups, filiings and gravies, particularly dehydrated preparations of the foregoing which are hydrated by the consumer immediately prior to use. Thus, in particularly preferred embodiments, the products of the invention are used as dehydrated bases for the thickening of sauces and other liquid/semi-liquid foodstuffs on the addition of hot liquid (e.g. hot or boiling water, fond bruπ , milk etc. ) Traditionally, roux is prepared by melting a fat (e g butter) in a pan and carefully adding flour while blending the two components The process is labour intensive and requires great skill, but produces a roux with excellent tnickenmg properties and a desirable taste and mouthfeel. However, the traditional method is not suitable for large scale commercial production and the products cannot be further processed for use in dried foodstuffs. Various methods have been proposed to produce a roux product which instantizes upon the addition of liquid without the formation of lumps. GB-A-2 1 30 467 discloses a process in which a mixture of fat and flour is heat treated, either in the presence of added water or under elevated pressure. The heated product is then cooled to form a soiid which is then grated to a powder to form an instantizable roux However, the heat treatment step makes this process relatively expensive WO-A-96 03893 discloses a process in which paniculate farinaceous material is coated with molten fat in an enclosed coating zone where a molten fat is sprayed in the form of fine droplets onto the particles while cooling them to form a fiowable particulate product. However, this coating process requires elaborate and expensive apparatus. Moreover, the process parameters are critical, so that product quality can be difficult to maintain. In contrast, the processes of the invention are relatively simple The products obtained thereby can be easily dispersed in hot liquid without substantial lump formation, and they have desirable organoleptic properties Materials other than flour and fat may be added to the product to provide a wide range of functional food ingredients or food flavours Thus, according to the present invention there 'S orovided a process for producing a food thickening agent comprising the steps of: (a) forming a free-flowing mixture of dried , heat-treated or pre-coo ed starch material and fat; and (b) solidifying to form a food thickeninc agent, wherein the starch material is present at a level of at least 40% w v\ (with respect to the fat) , for example at a starch material :f at ratio of abou: 55:45 to 65:35 (for example, at a ratio of about 60:40) . In another aspect, the invention provides a process for producing a food thickening agent comprising the steps of: (a) forming a free-flowing mixture of dried , heat-treated or pre-cooked starch material and fat (for example, at a starch materia fat ratio of about 55:45 to 65: 35, e.g. about 60:40); and (b) solidifying to form a food thickening agent, wherein the mixture in step (a) is formed in the absence of adαec water and/or the process is conducted in the absence of an intermediate cooking step between the forming step (a) and the solidifying step (b) . in another aspect, the invention provides a process for producing a food thickening agent comprising the steps of: (a) providing a starch material; (b) mixing the starch material of step (aj with a fat; and (c) solidifying the mixture to form a food thickening agent, wherein the starch material is a dried, heat-treated and/or pre-cooked starch material and the fat is selected from: (i) those fats which exhibit a steep melting curve; and/or (ii) non-polymorphic or monomorphic fats; and/or (in) those fats which are essentially homogeneous with respect to triglyceride chain length and/or crystal composition and/or degree of chemical modification (e.g. hydrogenation); and/or (iv) those fats which do not contain significant amounts of liquid fat at 20-30° C (e.g . about 25 °C) The term "pre-cooked " as used herein with respect to the starch materials for use in the invention is intended to define starch materials which have been at least partly physically and/or chemically modified by the application of heat such that changes associated with cooking have occurrec Such changes may include inter alia any or all of starch gelatinization. the generation of cooked/fried or roasted flavours (e.g . attendant on the generation of Maillard reaction products) , the inactivation of endogenous enzymes and the denaturation of proteins. Preferably, the degree of pre-cooking of the starch material is sufficient to obviate the need for an intermediate cooking step between the mixing step (a) and the solidification step (b) . Those skilled in the art will therefore be able to determine the extent of pre-cooking required empirically by routine trial and error. The "intermediate cooking step" which may be omitted according to the invention is one which involves holding the mixture at elevated temperatures and times sufficient to effect the physical and/or chemical changes in the mixture components which are associated with cooking. These include, for example, starch gelatinization, the generation of cooked/fried or roasted flavours (e.g . attendant on the generation of Maillard reaction products) , the inactivation of endogenous enzymes, the denaturation of proteins and the elimination of raw flavours and odours. It will be understood that the mixing step itself may involve heating (e.g. to melt the fat and effectively incorporate the starch therein), but this heating merely serves to functionally integrate the starch material and the fat and does not substantially cook the mixture (or any of its components) . The starch materia fat ratio may, for example, be selected from any of: 56:44; 57 :43; 58:42; 59:41 ; 61 : 39; 62:38; 63:37; 64:36. In some embodiments, relatively high concentrations of fat (greater than 50% with respect to the starch material) may be used to produce paste products (rather than powders or granules) . These find particular application in instant pastry mixes. As used herein, the term "dried " as applied to the starch material for use in the invention is intended to mean starch material in which the moisture level has been reduced, at least to some extent. Reduction in moisture content may be achieved by any convenient method , including heating. Thus, dried starch materials for use in the invention include heat-treated and/or desiccated starch materials. It should also be noted that the dried materials need not be dry in the absolute sense of containing no water: indeed, in preferred embodiments (and for practical reasons) some residual moisture is present. However, it is preferred that the moisture content of the starch material (e.g. a flour) be reduced to below 1 5%, e.g. below 1 4%, below 1 3%, below 1 1 % , below 1 0% , below 9%, below 8%, below 7%, below 6%, below 5%, below 4%, below 3%, below 2% or below 1 %. The use of dried starch materials may be critical for achieving free-flowing mixtures in which starch is present at above 40% w/w with respect to the fat (e.g. at starch:fat ratios of between 55:45 to 65:35) . In this respect, it has been found that the use of undried starch materials having relatively high moisture levels do not form free-flowing mixtures at the ratios required for the invention, but instead form semi-solid masses. As used herein, the term "free flowing mixture" is intended to embrace, inter alia, mixtures that may be manipulated and processed as substantially homogeneous liquids or slurries (e.g. pumped, sprayed, poured, spread, atomized etc.) . Thus, the free flowing mixtures of the invention may be of any viscosity (including high viscosity) , so long as they can be processed (e.g. pumped, sprayed, poured, spread, atomized etc.) as liquids. The fat for use in the invention may comprise any of a wide range of fats or oils. Preferably, the fats are selected from those which exhibit a steep melting curve, i.e. those fats in which the transition from solid to liquid states occurs over a relatively narrow temperature range (for example over a range of 1 5 ° C. 10°C, 8 °C, 6 ° C, 4 ° C or less than 4 ° C) . Solid fats exist in at least two forms: crystalline and amorphous. Crystalline fats are produced when molten fats are cooled under most conditions. When in the crystalline state, fats may contain at least three different types of crystals: σ-crystals, β' crystals and β-crystals. The latter crystal form is classified as "high melting " and is relatively stable, while the a- and β'-crystal types are classified together as "low melting" (and are relatively unstable) . In general, fats may be classified as polymorphic or nonpolymorphic, according to the number of different crystal types that may be present after crystallisation. Polymorphic fats have two or more crystal types when in the solid state (the variety of different forms and their relative concentrations being dependent inter alia on the way in which the fat was solidified) . In contrast, solidified monomorphic (nonpolymorphic) fats are composed of essentially only one type of crystal in most circumstances. Monomorphic fats may therefore consist essentially of only one crystal type when in the solid state (in the sense that other crystal types which may be present in minor amounts do not contribute significantly to the physical properties of the fat) . Preferred according to the present invention are non-polymorphic (or monomorphic) fats. The fats for use in the invention may be essentially homogeneous with respect to triglyceride chain length and/or crystal composition (see above) and/or degree of chemical modification (e.g. hydrogenation). Homogeneity with respect to any or all of these parameters may confer a desirable steep melting curve (see above) on the solid fat Preτerably, the fats for use in the present invention do not contain significant amounts of liquid fat at 20-30°C (e.g about 25 °C) . Fats having a slip melting point in the range 30° C-55 ° C (e.g. 35-50°C) may be used, and in a preferred embodiments a fat having a slip melting point of below about 50 °C (e.g about 46 °C) is used. Preferably, the mixture in step (a) is formed in the absence of added water, i.e. without the addition of supplementary water to the mix It will be understood that some residual moisture will in practice always be present in the starch material: the absence of "added" water in this context therefore means avoiding adding water as a separate ingredient at levels sufficient to significantly increase the viscosity of the mixture. Thus, low inclusion levels may be acceptable (for example, flavourings or colouring agents may be added in the form of aqueous solutions or suspensions at this stage) . The avoidance of adding water at this stage has the advantage of improving the flow characteristics of the mixture and facilitates the formulation of the starch:fat ratios of the invention. The process of the invention is advantageously conducted in the absence of an intermediate cooking step between the forming step (a) and the solidifying step (b) . This significantly reduces costs The process of the invention preferably consists essentially of the steps of. (a) forming a free-flowing mixture of starch material and fat at a ratio of 55 45 to 65: 35 (for example, at a ratio of about 60:40); followed by (b) solidifying the mixture to form a food thickening agent The starch material for use in the invention may be any suitable starch-containing material. Preferably, the starch materials for use in the invention comprise greater than 70% starch, preferably greater than 80% starch. The starch material may further comprise protein (e.g. casein) . The use of protein (such a milk protein or casein) improves the organoleptic properties of the thickening product, and also its dispersability. Other functional additives may also be used, for example lecithin. Lecithin has been found to improve dispersibility in certain formulations. The starch material preferably: (a) is pre-dried, pre-cooked or heat treated; and/or (b) has a moisture content of below 10% (for example, below 8%, e.g. below 4%, e.g. below 1 %) ; (c) has low (e.g. substantially no) enzyme (e.g. lipase) activity. Particularly preferred for use as starch materials in the invention are flours or other farinaceous materials. For example, the starch material may be any of: (a) a classified flour; and/or (b) an enzyme-inactivated flour; and/or (c) a pre-cooked, heat-treated or dried flour; (d) a pre-gelatinized flour; and/or (e) a heat-treated flour having up to about 40% pre-gelatinization as measured by loss of birefringence; and/or (f) a heat-treated flour having up to about 5 % pre-gelatinization as measured by differential scanning calorimetry; and/or (g) a flour selected to have low enzyme activity; and/or (h) a flour having low lipase activity, and/or (i) a synthetic flour/flour substitute/flour mimetic, or combinations thereof. The terms "synthetic flour", "flour substitute" and "flour mimetic" are used herein to define a composition which has been formulated from separate functional ingredients to produce a composition which is substantially duplicative of the composition and/or function of a flour derived from milled cereal. Syntnetic flours for use in the invention therefore include mixtures of starcn and proteιn(s) , for example at a ratio of about 70-95% starch to 5-30% proteιn(s). The term ' pre-cooked flour" (often referred to as "neat treated" flour) is a term of art, and defines those flours which have been subject to a heat treatment (e.g. steaming and/or dry heating and/or roasting) which may inter alia generate Maillard reaction products, at least partially gelatinize starch and/or inactivate endogenous enzymes (e.g. Iipases) . Such flours may (or may not) also be dried. The use of such flours improves the organoleptic qualities and/or colour of the thickener, and improves its shelf-life (oy reducing spoiling mediated vie enzyme activity) . Classified flours have relatively high levels of starch, and this improves the colour and instantiation properties of the product. The starch material for use in the invention may also comprise (or consist essentially of) enzyme-modified flours (such as for example the products described in WO 95/27407, the contents of which are incorporated herein by reference). Such enzyme modified farinaceous materials find particular utility in the preparation of low fat food thickeners in which relatively high concentrations of starch material are used relative to fat (for example, greater than 60, 65 or 70% starch material with respect to fat) . The food thickening agent may be of any type, providing that at least some thickening functionality is exhibited. Preferably, the agents of the invention are selected from: (a) a roux- (e.g. roux blanc-) like product; (b) a roux (e.g. roux blanc) substitute or mimetic; (c) a binding agent; (d) a sauce, spread, topping, soup, filling and grav\ Dase. " Tne invention also contemplates a food thickening agent obtainable by (or ootained by) the process of the invention, as well as a foodstuff comprising such thickening agents. Preferred foodstuffs include dried food bases, particularly those for use in sauces, spreads, toppings, soups, fillings and gravies. in yet another aspect of the invention, there is provided process for preparing a roux powder, comprising the steps of: (a) forming a liquid mixture of fat and flour; (b) atomizing the liquid mixture, for example in a chamber; and (c) cooling the atomized mixture to form a roux powder. As the flour and fat are mixed prior to atomization a consistent ratio of flour to fat is achieved in the powder. The size of the particles can be controlled simply by the size of droplets formed upon atomization. There is no need for a heat treatment stage, rather it is just necessary to maintain the slurry mixture as a fluid for spraying into the chamber. Normally step a) comprises melting the fat then mixing in the flour, preferably until the mixture is homogenous. Advantageously, step c) includes collecting the atomized mixture on a conveyor belt system or a fluid bed cooler. This reduces compaction and balling of the product. The fluid bed cooler can be used advantageously to rapidly cool the atomized mixture to form the roux powder. The temperature of the mixture immediately prior to atomization is advantageously controlled to fall within the range 0-40, for example 0-20, e.g. 5- 1 5 or 10-40°C above the solidification point of the mixture, preferably 1 0°C to 35 °C higher. This allows good atomization of the mixture whilst facilitating speedy cooling of the atomized mixture to form the solid roux powαer Advantageously, step c) comprises setting the ambient temperature in the chamber to less than the solidification point of the mixture. The ambient temperature in the chamber wili normally be controlled, for example by pumping a cooling fluid into the chamber Often air will be used as the cooling fluid and the temperature of the air when inlet into the chamber will be predetermined so that the ambient temperature in the chamber allows the atomized mixture to cool sufficiently to form the roux powder whilst in the chamber. For example, where the fat has a slip melting point of around 40°C, the inlet air is typically set to a temperature of 5 to 1 0°C However, the precise physical conditions will depend on the solidification point of the mixture, the slip melting point of the fat, and also upon the cooling characteristics of the mixture The skilled person can determine the cooling characteristics of the mixture and set the inlet temperature accordingly. Alternatively, it may be advantageous to use a different atmosphere in the chamber depending upon the constituents of the mixture For example, it is preferred for some mixtures to use a nitrogen atmosphere generated from liquid nitrogen, which results in an inlet temperature of approximately -1 96°C. This allows rapid cooling of the atomized mixture in the chamber. Other gases and other temperatures could also be employed. As described above, the nature of the fat can have a great influence on the characteristics of the roux powder. As the roux powder is generally used in food preparation, the fat is consequently an edible fat and presently it is preferred to be a vegetable fat such as a pastry fat, including fats with a slip melting point of about 37 °C with about 1 6% water content to 1 00% fat Currently preferred fats include cocoa butter compatible fats with a slip . 2 melting point of about 37 ° C and 74 % solid fat measured at 20°C, and fat with a slip melting point of 46 °C and 90% solid at 20 ° C The most preferred fats are fractionated, partially hydrogenated , refined vegetable fats of non-lauπc origin with preferably a slip melting point of about 46 °C-50 ° C (e.g. about 48 %) and 95 % solid fat at 20°C. The choice of flour also influences the nature of the roux powder significantly. Normal flours contain over 1 0% moisture, typically in the range of 1 2 to 14% moisture. For the present invention, it has been found that flours with reduced moisture content form a superior roux powder, for example flours with less than 8% moisture. Pre-gelatinized flours are suitable for the process of the present invention, but as these pre-gelatinized flours are considerably more expensive than other flours and tend to be more viscous, they limit the amount of flour that can be added to the slurry Thus, the use of pre-gelatinized flour is not presently preferred . Flours which are "heat-treated" provided a high quality roux powder and these flours are less expensive than pre-gelatinized flours and can be added to the fat in quantities of at leat 60% by weight, and, for these reasons, heat-treated flours are preferred for the present invention. In particular, heat-treated flours having a moisture content of about 4% are advantageously used in the present invention. Classified flours have a high, fine starch content (due to removal of heavier bran content and some protein) have been found to be particularly suitable for the present invention and it is most preferred to use heat-treated, classified flours such as Viceroy 4% produced by Spillers Milling . It is particularly preferred to use heat-treated flours with up to about 5% pre-gelatinisation as measured by differential scanning caloπmetry. It has been found that improved whiteness of the product and thickening of the properties of the product can be obtained by using small amounts of rice starch in the mixture. It is presently preferred to use up to 5% rice starch by weight. The present invention will now be described , with reference to the accompanving drawings in which:- Figure 1 shows a flow diagram illustrating a preferred embodiment of the present invention, which is now described below: Normally the fat is melted prior to mixing with the flour. Any technique known in the art can be used for melting the fat, such asrteam jacketed vessels when the fat is liquified . The fat will normally be liquified at a temperature somewhat in excess of the fat solidification point to allow good flowability. Normally vegetable oils will be used as the base of the fat, such as hydrogenated vegetable fat, pastry fat or fats with a slip melting point of about 37 °C with about 1 6% water content to 1 00% fat. Currently preferred fats include cocoa butter compatible fats with a slip melting point of about 37 °C and 74% solid fat measured at 20° C, and fat with a slip melting point 46 °C and 90% solid at 20°C. The most preferred fats are fractionated, partially hydrogenated, refined vegetable fats of non-lauric origin with preferably a slip melting point of about 46 °C and 95% solid fat at 20° C. If a steam jacketed vessel is used to melt the fat, this can be provided with a mixing tank and the flour may be introduced for mixing into the liquid fat in the mixing tank. Normally, over 50% by weight of flour is added to the mixture, preferably about 60% by weight. Normally, the flour is added unheated and causes a consequential drop in the temperature in the contents of the tank. The temperature of the formed mixture should remain higher than the solidification point of the mixture and high enough so that the mixture can be easily pumped. As mentioned above, the type of flour used in the mixture has an important effect on the properties of the resulting roux powder. Normally, flours have more than 10% moisture content; in the present invention it is preferred to use flours with reduced moisture content, preferably about 4% moisture content Various pre-gelatinized flours could be jsed in the present invention but these are commercially not preferred due to tne expense of the flour and the relatively low amount which can be addeo to the mixture It is preferreα to use heat-treated flours which may show up to 40% starch gelatisation, for example between 20% and 40% starcr, gelatmisation as measured by birefringence. It is currently preferred to measure the degree of gelatmisation by differential scanning caloπmetry which has initially shown that only up to about 5% gelatmisation for heat treated flours. It is presently preferred to use fiours produced by Spillers Milling such as REGENT 4% (TM) (dried and heat treated) or VICEROY 4% (TM) (dried, heat treated and classified) . For example, VICEROY 4% (TM) shows from 0% to 5% pre-gelatmisation when measured on a SETARAM differential scanning calirometer operating in the range of 25 ° C to 1 20° C, increasing at 1 °C per minute; this allows measurement of the enthalpy of starch gelatmisation. Another feature of these flours which make them particularly suitable for the present invention is the reduced lipase activity of these fiours. Flours with low lipase activity improve the final product by minimising the oxidative rancidity and, thus, increase the shelf-life of the roux powder. Generally, flours with low enzyme activity will be used in the present invention. Further functionality may be introduced into the flour for particular applications Up to 5% starch may also be added into the mixture. This can improve the whiteness and thickening properties of the roux powder. Other additives could also be included in the mixture, such as colourings, flavourings, enzymes, proteins (such as milk proteins) , etc may be included to impart particular features into the roux powder The liquid mixture will be made substantially homogenous in order to form a good quality roux powder. The temperature of the mixture will be kept above the melting point of the mixture in order to allow easy transfer of the mixture from the mixing tank to the atomizer or spray head. In order to reduce tnε solidification of the mixture when being transferred; the temperature will normally be several degrees centigrade higher than the solidification ooint of the mixture, but the temperature will be kept as low as possible for the reasons explained hereinafter. Normally, pipes, etc. through which the liquid mixture must pass will be insulated to ensure minimum heat loss from the liquid mixture. Alternatively, the pipes may be heat traced or be steam jacketed. The liαuid mixture is emitted from the atomizer or spray head as a stream of droplets into the chamber of a spray chilling apparatus. The ambient temperature within the chamber will be maintained significantly below the solidification point of the liquid mixture and so that the droplets of the mixture will tend to solidify in the chamber. The degree of solidification of the mixture depends upon the ambient temperature of the chamber, the residence time of the droplets in the chamber and the initial temperature of the droplets when entering the chamber. Thus, if the initial temperature of the droplets is too high not all the droplets will solidify in the chamber unless the ambient temperature is set considerably lower than the melting point of the mixture and/or the residence time in the chamber is increased. Of course, adopting either of the latter two procedures can increase the cost of the process. As mentioned above, the fat can be selected to have suitable solidifying characteristics and temperatures. If, for example, the fat has 95% solid content at 20°C, then if the ambient temperature of the chamber is from 1 0 to 1 5 °C the majority of the droplets will solidify in the cooling chamber. In one embodiment, the cooling chamber is supplied with a cooling fluid, for example cooling air. The temperature of the cooling air will be less than the desired ambient temperature to counteract the hot liquid mixture entering tne chamber The cooling fluid can be directed against the stream of droolets to increase the residence time in the chamber The cooling fluid may alternatively or additionally be pumped into the chamber from the region of the atomizer. Whilst air is commonly used as the cooling fluid due to its ready availability, other fluids can also be used. For example, the cooling fluid may be nitrogen which is passed into the chamber just as the nitrogen has been allowed to boil, thus being at approximately - 1 96°C Clearly, this provides a much greater temperature gradient within the chamber allowing rapid cooling of the droplets. It has been found that a particularly high quality roux powder can be formed by using such sharp temperature gradients The solidified droplets will collect at the bottom of the chamber assuming that the droplets are allowed to fall under the action of gravity and this embodiment is known generally in the art as spray chilling. The bottom of the chamber is provided with a collector, such as a fluid bed cooler. As the liαuid mixture is solidified from fine droplets of the liquid mixture, the solid is in the form of a fine powder and so further processing of the roux powder is not required. The powder may be transferred, possibly by a cyclone, to a bagging apparatus to be bagged. In an alternative embodiment, the technique of spray drying is used where the slurry mixture is atomized in the chamber and collected on a collector. Normally, the collector is a fluid bed cooler (or other collector) arranged to rapidly cool the atomized mixture to form the roux powder. Again, the powder will normally be transferred to a bagging apparatus for bagging The skilled person can set the required physical conditions in the apparatus depending upon the nature of the fat, flour and other ingredients. Routine trial and error can be used to determine these characteristics as is normal in the art. SUBSTITUTE SHEE I (RULE 26)

Claims: CLAIMS 1 . A process for producing a food thickening agent comprising the steps of: (a) providing a starch material; (b) mixing the starch material of step (a) with a fat; and (c) solidifying the mixture to form a food thickening agent, wherein the starch material is a dried, heat-treated and/or pre-cooked starch material and the fat is selected from: (i) those fats which exhibit a steep melting curve; and/or (ii) non-polymorphic or monomorphic fats; and/or (iii) those fats which are essentially homogeneous with respect to triglyceride chain length and/or crystal composition and/or degree of chemical modification (e.g. hydrogenation); and/or (iv) those fats which do not contain significant amounts of liquid fat at 20-30°C (e.g. about 25 °C) . 2. A process for producing a food thickening agent comprising the steps of: (a) forming a free-flowing mixture of dried, heat-treated and/or pre-cooked starch material and fat; and (b) solidifying to form a food thickening agent, wherein the starch material is present at a level of at least 40% w/w (with respect to the fat), for example at a starch mateπakfat ratio of about 55:45 to 65:35 (for example, at a ratio of about 60:40) . 3 A process for producing a food thickening agent comprising the steps of: (a) forming a mixture (e.g. a free flowing mixture) of dried, heat-treated and/or precooked starch material and fat (for example, at a starch materiakfat ratio of about 55:45 to 65: 35, e.g. about 60:40) ; and (b) solidifying to form a food thickening agent, wherein the mixture in step (a) is formed in the absence of added water and/or the process is conducted in the absence of an intermediate cooking step between the forming step (a) and the solidifying step (b) . 4. The process of claim 2, wherein the mixture in step (a) is formed in the absence of added water and/or the process is conducted in the absence of an intermediate cooking step between the forming step (a) and the solidifying step (b) . 5. The process of any one of the preceding claims which consists (or consists essentially of) the steps of: (a) forming the mixture of starch material and fat (for example at a ratio of about 55:45 to 65: 35, e.g. at a ratio of about 60:40); followed by (b) solidifying the mixture to form a food thickening agent. 6. The process of any one of the preceding claims wherein the solidifying step comprises: (a) cooling; and/or (b) spray chilling to form a food thickening powder (e.g. by atomizing the mixture in a chamber and cooling the atomized mixture to form a powder); and/or (c) disc pastellation; and/or (d) drum flaking; and/or (e) cryomilling; and/or (f) extrusion, optionally further comprising the step of size-reducing, grating or comminuting the solidified material. 7. The process of any one of the preceding claims wherein the starch material is (a) pre-dπed, pre-cooked or heat treated, and/or (b) has a moisture content of below 1 6% (for example, below 1 5%, e.g below 14%, below 1 3%, below 1 1 %, oelow 10%, below 9%, below 8%, below 7 % , below 6%, below 5%, below 4%, below 3%, below 2% or beiow 1 %); (c) has low (e.g. substantially no) enzyme (e.g. lipase) activity, and/or (d) is a flour or farinaceous material, and/or (e) comprises protein (e.g. casein) 8. The process of claim 7(d) wherein the flour is (a) a classified flour, and/or (b) an enzyme-inactivated flour; and/or (c) a pre-cooked, heat-treated or dried flour; (d) a pre-gelatinized flour; and/or (e) a heat-treated flour having up to about 40% pre-gelatinization as measured by loss of birefringence; and/or (f) a heat-treated flour having up to about 5% pre-gelatinization as measured by differential scanning caloπmetry; and/or (g) a flour selected to have low enzyme activity; and/or (h) a flour having low lipase activity, and/or (i) a synthetic flour/flour substitute/flour mimetic 9. The process of any one of the preceding claims wherein the free-flowing mixture is a substantially homogeneous liquid and/or can be processed (e.g. pumped and/or sprayed and/or poured and/or spread and/or atomized etc.) as a liquid. 10. The process of any one of the preceding claims wherein the food thickening agent is selected from: (a) a roux- (e.g. roux blanc-) like product (e.g. a low or reduced fat Droαuct) (b) a roux (e.g. roux blanc) substitute or mimetic (e.g. a low or reduced fat substitute or mimetic); (c) a Dinding agent; (d) ε sauce, spread, topping, soup, filling and gravy base. 1 1 . A food thickening agent obtainable by (or obtained by) the process of any one of the preceding claims. 12. A foodstuff comprising the thickening agent of claim 1 0 (e.g. a sauce, spread, topping, soup, instant pastry mix, filling or gravy base) . 1 3. The foodstuff of claim 1 2 which is dispersed in a liquid (e.g. in water, milk or fond brun) . 14. A process for preparing a roux powder, comprising the steps of: (a) forming a liquid mixture of fat and flour; (b) atomizing the liquid mixture, for example in a chamber; and (c) cooling the atomized mixture to form a roux powder. 1 5. The process of claim 1 4 wherein step (a) comprises melting the fat and then mixing in the flour. 1 6. The process of claim 1 4 or claim 1 5 wherein the mixture is mixed until substantially homogeneous. 1 7. The process according to claim 6(b) or any one of claims 1 4- 1 6 further including the step (d) comprising collecting the roux powder on a conveyor belt system or a fluid bed cooler. 18. The process of any one of the preceding claims wherein the temperature of the mixture (e .g . immediately prior to atomization) is controlled, for example to fall in the range 0-40, for example 0-20, e.g. 5- 1 5 or 1 0-40°C above the slip melting point of the fat (e.g . 1 0-35 ° C above the slip melting point) . 1 9. The process of ciaim 6(b) or any one of claims 1 4-1 8 wherein the cooling step comprises setting the ambient temperature in the chamber to less than the solidification point of the mixture. 20. The process of claim 6(b) or any one of claims 14- 1 9 wherein the ambient temperature in the chamber is controlled, for example by pumping a cooling fluid into the chamber. 21 . The process of claim 1 9 or 20 wherein air at a predetermined temperature is used as the cooling fluid and preferably the predetermined temperature of the air when let into the chamber is set so that the ambient temperature in the chamber allows the atomized mixture to cool sufficiently to form the roux powder whilst in the chamber. 22. The process of claim 1 9 or claim 20 wherein nitrogen gas boiling from liquid nitrogen (i.e. with a temperature of about - 1 96°C) is used as the cooling fluid and preferably the temperature of the nitrogen gas when let into the chamber is set so that the ambient temperature in the chamber allows the atomized mixture to cool sufficiently to form the roux powder whilst in the chamber. 23. The process of any one of the preceding claims further comprising the preliminary step of determining the cooling characteristics of the mixture and the subsequent step of setting the inlet temperature and/or other physical conditions in the chamber so that substantially all the atomized mixture solidifies in the chamber. 24. The process according to any one of the preceding claims wherein the fat is selected from edible fats, for example a vegetable fat, e.g. a pastry fat. 25. The process of any one of the preceding claims, wherein the fat is selected from: (i) fats with a slip melting point of about 37 °C with about 1 6% water content to 100% fat; (ii) cocoa butter compatible fats with a slip melting point of about 37 °C and 74% solid fat measured at 20°C; (iii) fats with a slip melting point of about 46°C and 90% solid at 20°C; (iv) fats fractionated, partially hydrogenated, refined vegetable fats of non-lauric origin with preferably a slip melting point of about 45-50°C (e.g. about 46/48 °C) and 95% solid fat at 20°C; and (v) fats with substantially similar characteristics. 26. The process of any one of the preceding claims wherein the flour is selected from flours having a reduced moisture content, for example flours with less than 8% moisture (e.g. about 4% moisture) . 27. The process of any one of the preceding claims wherein the flour is selected from: (a) pre-gelatinized flours; or preferably (b) either: (i) heat treated flours having up to about 40% pre-gelatinization as measured by loss of birefringence, or (ii) heat-treated flours having up to about 5% pre-gelatinization as measured by differential scanning calorimetry. 28. The process according to any one of the preceding claims wherein the flour is selected to have low enzyme activity. 29. The process of claim 28, wherein the flour has low lipase activity. 30. The process according any one of the preceding claims, wherein the flour is a classified flour. 31 . The process of any one of the preceding claims wherein a small amount of rice starch is included in the mixture, for example up to 5% by weight of rice starch. 32. The process of any one of the preceding claims wherein the ratio of flour to fat is: 60% flour: 40% fat. 33. A roux powder producible by the process of any one of the preceding claims.

Inventors: CLENSHAW MIKE, FROST MATTHEW JONATHAN, THORPE CATHERINE, WINKCUP JENNIFER, CLENSHAW, MIKE, FROST, MATTHEW, JONATHAN, THORPE, CATHERINE, WINKCUP, JENNIFER
Applicants: CLENSHAW MIKE, DALGETY PLC, FROST MATTHEW JONATHAN, THORPE CATHERINE, WINKCUP JENNIFER, CLENSHAW, MIKE, FROST, MATTHEW, JONATHAN, THORPE, CATHERINE, WINKCUP, JENNIFER
Application year: 1997
Main classification: A23L1
IPC codes: A23L1, A23P1