SWEETENED EXTRUDED FOOD PRODUCTS

Abstract: A sweetened extruded food product based on a vegetable material containing sweetener incorporated before extrusion, is formulated so that the sweetener comprises a significant proportion of sucralose. In particular, the sucralose provides at least 50 %, preferably at least 75 % of the sweetness.

Description: Sweetened Extruded Food Products This invention relates to the production of sweetened extruded food products such as breakfast cereals and snack foods containing the high intensity sweetener sucralose (I, 6-dichloro-l, 6-dideoxy-β-D-fructofuranosyl 4-chloro-4-deoxy-(α-D-galactopyranoside). The use of sucralose as a high intensity sweetener in sweetening compositions, ingestible products and oral compositions is disclosed in British Patent No. 1,544,167. By an "extruded food product" we mean a cooked, extruded food product based on edible vegetable materials comprising or derived from cereals, legumes, tubers, nuts, and the like, and mixtures thereof. The term includes human foods and animal feeds and further includes both finished food products and also food ingredients such as textured vegetable protein products. By a "breakfast cereal" there is meant an extruded food product based on cereals such as corn, wheat and oats, and mixtures thereof, usually eaten with milk, for example corn flakes. By a "snack food" there is meant a ready to eat extruded food product based on edible vegetable materials as mentioned above, such as a flavoured cereal snack or potato sticks. Conventional sweetened extruded food products such as breakfast cereals and snack foods often have a high sugar content, comprising a wide variety of monosaccharides and disaccharides including sucrose, high fructose corn syrups (HFCS), dextrose, fructose, maltose, lactose and mixtures thereof. The sugar is important as a source of sweetness, bulk and texture as well as enhancing the flavour of such foods and providing an easily digestible source of energy. The sugar may be incorporated in the extruded product and/or may be coated thereon. There is considerable interest in foodstuffs with a reduced sugar content amongst consumers who wish to reduce their intake of sugars and to consume a higher proportion of carbohydrates in the form of starch and dietary fibre. Other consumers, such as diabetics, require sugar-free foods. One way in which manufacturers have responded to the desire for foods with a reduced sugar content has been to replace some or all of the sugar with a high intensity sweetener. Generally this has proved difficult for products such as breakfast cereals and snack foods which traditionally depend upon sugars to provide properties such as bulk, texture, viscosity and flavour enhancement, as well as sweetness. Hitherto, high intensity sweeteners have not been incorporated during the manufacture of sweetened extruded food products, in part because of their instability to high temperatures during cooking (particularly aspartame) or their poor quality of sweetness compared to sugars (for example, saccharin), and in part because they do not provide the desired bulk, texture and flavour which sugars impart to the products. Sucralose differs from other available high intensity sweeteners in having both a clean, sweet taste and a high degree of stability when used in the production of high temperature processed products ( R Jenner, Lindsey Bagley and C R Heath, in Food Technology International 1989, Sterling Publications Ltd). Further, sucralose is remarkably stable when incorporated in processed foods. We have now found that highly acceptable breakfast cereals and snack foods can be produced by using sucralose to provide some or all of the sweetness formerly provided by sucrose and other sugars. The sweetness of sucralose in these products varies from about 180 to 400 times that of sucrose depending upon the concentration at which it is used and the nature of the other ingredients, and the quality of the sweetness imparted by sucralose is similar to that of sucrose. Further, sucralose can be incorporated at levels which provide sufficient sweetness without the need for a sugar coating. Still further, the use of sucralose in extruded food products has unexpected advantages with respect to processing and to the physical properties of the products. Conventional sweetened extruded food products are produced using cooking extruders such as the Wenger TX-series (Wenger Manufacturing, Inc., Sabetha, Kansas, USA) and the Baker-Perkins MPF50 (APV Baker, Peterborough, England). In this process a mixture of ingredients comprising the edible vegetable material, often in the form of a flour, water and sugar, is cooked in the extruder at a temperature of about 35-120 * C and is then extruded as pellets or other shaped pieces, allowed to cool and settle for a few minutes and dried to the desired moisture content at temperatures ranging from about 100-180 * C. When high levels of sugar are used e. g. around 12% to 15%, the sugar can interfere with gelatiπisation of the flour and this causes the extruded pellets to clump and stick together. This problem may be exacerbated by the inclusion of other ingredients such as malt syrup which is commonly used as a flavouring. Thus, in order to provide the desired level of sweetness it is often necessary to include less sugar and to coat the product with additional sugar. Higher levels of sugar can be incorporated in bran-based products, up to about 18%, to improve palatability, but the products are rather heavy textured. We have now found that the extrusion process can be operated to produce products with a reduced sugar content by replacing some or all of the sugar with an appropriate amount of sucralose. Unexpectedly, we have found that this does not require special reformulation of the product to replace the bulk and texture formerly provided by the sugar, and highly acceptable products are obtained by simply increasing the content of the cereal or other vegetable material. It seems possible that the special organoleptiσ properties of sucralose which confer a quality of sweetness similar to that of sucrose, may also influence the sensory perception of texture or "mouthfeel" so that the product is as palatable as one made with sugar. Unlike sugar, sucralose does not interfere with gelatinis tion and it is possible to incorporate sucralose in the products at levels which provide sufficient sweetness without the need for a coating of sugar or other sweetener. Further, reduction of the sugar content to less than about 12% avoids the problem of undue stickiness and clumping of the extruded product. Another unexpected advantage of using sucralose to sweeten extruded food products is that the products often retain their crispness longer than those sweetened with sugar. This is particularly advantageous in the case of sucralose sweetened breakfast cereals such as corn flakes which retain their crispness longer when immersed in milk than do the conventional sugar sweetened products, particularly those with a relatively high sugar content. A further unexpected advantage of using sucralose to sweeten extruded food products is that sucralose sweetened products often exhibit a greater volume expansion during extrusion and have a lower bulk density than sucrose sweetened products. This is particularly noticeable for products based on dense materials with a high fibre content, such as bran, although other products such as potato sticks can benefit from the enhanced expansion. Thus sucralose sweetened bran rods had a much lighter texture than the sucrose sweetened counterparts and were much more palatable. Thus, for example, products may be obtained having a bulk density of from 75% down to about 45% of that obtained using an all-sugar sweetener. The advantages of using sucralose to sweeten extruded food products are greatest when it is used to replace a relatively high proportion of the conventional sugar sweetener. Satisfactory products can be made by replacing at least about half of the sugar with sucralose but in general we prefer to replace at least 75% of the sugar with sucralose: that is to say, the sweetness contribution of the sucralose should preferably be at least 50%, especially at least 75% of the total sweetness. Thus, according to the present invention, we provide a sweetened extruded food product based on a vegetable material containing sweetener' incorporated before extrusion, characterised in that the sweetener comprises a significant proporation of sucralose. According to a further feature of the present invention we provide a process for manufacturing sweetened extruded food products by cooking a mixture of vegetable material (for example material comprising or derived from cereals, legumes, tubers, nuts, and the like, or mixtures thereof), water and sucralose, extruding the cooked mixture as pellets or other shaped pieces and drying them to the desired moisture content. Other ingredients such as sugars, malt syrup, flavourings and salt can be incorporated during the cooking step and the product may be flaked and/or toasted to provide a crisp product with a distinctive flavour. The sucralose may be mixed with the other ingredients prior to processing in the extruder or may be diluted with water to the desired concentration and fed into the extruder through a separate inlet to that used for the other ingredients. The process can be used to make a wide range of sweetened extruded food products including breakfast cereals and snack foods. Thus, according to a further embodiment of the present invention, we provide sweetened extruded food products containing sucralose. These products have a reduced-sugar content compared to conventional products of the same type and can be made to contain no added sugar. The sucralose content may vary from about 0.01% to 0.2% by weight, depending upon the desired level of sweetness and the amount of sugar replaced. Thus, the concentration of sucralose required to produce a sweetness equivalent to 6% sucrose is about 0.02% to 0.03% and the concentration required to provide a sweetness equivalent to 18% sucrose is about 0.08% to 0.10%. Higher concentrations of sucralose up to about 0.2% are required to provide the levels of sweetness equivalent to those of some products with an additional sugar coating, e.g. "frosted" corn flakes. Sucralose concentrations for partial replacement of sugar over the full range of products will vary from 0.01% to 0.10% for 50% replacement and from 0.015% to 0.150% for 75% replacement. The invention is illustrated by the following Examples. Example 1. Flaked breakfast cereal Three types of product were made, using maize flour; one comprising flour and water, without any sweetener (A); one comprising flour, sugar and water, the sugar being pre-blended with the flour (B); and one comprising flour, water and sucralose, the sucralose being added as an aqueous solution (C). Maize flour (A and C), or maize flour plus sugar at 12% on a dry weight basis (B), in each case containing 12.9% moisture, was fed into the barrel of a Baker-Perkins MPF50, 25 twin screw extruder fitted with two 4mm diameter dies and heated to a constant temperature -of 120 * C, at 41 Kg/h, and moved along by the screws at a constant speed of 220 rev/min. As the mixture of ingredients passed along the barrel, additional water was added (at 8.2 1/h for A and B; and 5.8 1/h. for C) to produce a slurry containing 27% moisture, and the partially cooked product was extruded as pellets after a retention time of about 45 seconds. For C, an aqueous solution of sucralose (0.5% w/v) was added through a separate inlet, at 2.5 1/h, to provide the required sweetness, equivalent to 12% sugar. The moisture content prior to extrusion was 27.42% for A and B, and 27.55% for C. The sucralose content of C was 0.035% dry weight basis. The extruded pellets were collected and fed through an 8 inch flaking roll to produce flakes. The flakes were toasted in an oven at 170"C for 12 minutes. After cooling to ambient temperature, the finished product was packed in cartons. Samples of products A (flour and water) and C (flour, water and sucralose) were ground to a fine powder with a pestle and mortar. Powdered material of product A was spiked with sucralose by mixing with an aqueous solution of sucralose to give a concentration of 0.032% sucralose on a dry weight basis and freeze drying to remove the water. Sucralose was extracted from samples of the powdered material by adding boiling water and shaking for 10 minutes. The aqueous extract was then concentrated and analysed by HPLC. Analysis of spiked samples of product A indicated that the recovery of sucralose was 93.7% on average (seven replicates; coefficient of variation ±4.8%). Applying this mean recovery factor to the results of the analysis of product C, it was estimated that the sucralose content varied from 0.034% to 0.038%, with a mean value of 0.0365% (four replicates; coefficient of variation ±4.7%). The difference between this value and the original sucralose content of 0.035%, is statistically insignificant (p=0.05). Both products B and C were found to have a similarly pleasant sweetness and texture. Example 2. Sucralose sweetened corn flakes Ingredients (% by weight): Fine corn meal* 97.76 Salt 1.47 Sucralose LC25** 0.22 N&A Grain Flavour LDF 264388 + 0.50 N&A Grain Flavour LDF 264389 + 0.25 * Dry-milled maize, particle size 0.3-0.17 mm ** Sucralose liquid concentrate (25% w/w); Haarmann & Reimer Preparation: 1. Mix together all ingredients except sucralose. 2. Mix sucralose with water to desired concentration. 3. Feed mixture of ingredients and sucralose into extruder (Wenger TX80) through separate inlets and extrude at 96"C and 3.45 MPa (500 psi) as beads. 4. Pass beads through flaking roll. 5. Dry for 5 minutes at 182 * C to moisture content of about 3%. Example 3 Corn flakes sweetened with sucralose and/or sucrose Ingredients (% by weight): Fine corn meal 97.56 91.67 85.78 Salt 1.47 1.47 1.47 Sucralose LC25 0.22 0.11 Sucrose - 6.00 12.00 N&A Grain Flavour LDF 264388* 0.50 0.50 0.50 N&A Grain Flavour LDF 264389 + 0.25 0.25 0.25 Haarmann & Reimer Preparation: 1. Mix together all ingredients except sucralose. 2. Mix sucralose with water to desired concentration. 3. Feed mixture of ingredients and sucralose into extruder (Wenger TX80) through separate inlets and extrude at 96'C and 3.45 MPa (500 psi) as beads. 4. Pass beads through flaking roll. 5. Dry for 5 minutes at 182'C to moisture content of about 3%. The cornflakes sweetened with sucralose and with sucralose plus sucrose were rated as sweeter than those sweetened with sucrose, but the flavour and overall liking of the products were rated the same for all three products. The sucralose sweetened cornflakes were crisper than those sweetened with sucrose. Example 4 Multi-grain flakes with banana flavour Ingredients (% by weight): Whole cut wheat 40.00 Brown rice flour 31.58 Fine corn meal 20.00 Corn bran 6.50 Salt 1.50 Sucralose LC25 0.22 Banana flavour #75420-33 (Givaudan (Canada) Inc. ) 0.20 Preparation: 1. Mix together all ingredients except sucralose. 2. Mix sucralose with water to desired concentration. 3. Feed mixture of ingredients and sucralose into extruder (Wenger TX80) through separate inlets and extrude at 96'C and 3.45 MPa (500 psi). 4. Pass extruded beads through flaking roll. 5. Dry for 5 minutes at 182'C to moisture content of less than 3%. Example 5 "Fruity Loop" extruded breakfast cereal Ingredients (% by weight): Corn flour Wheat flour Oat groat flour Salt Corn oil Sucralose LC25 Citric acid Flavour (Haar ann & Reimer) Colouring a = lemon #264292; yellow #5; b = orange #264051; yellow #5/red #40 (2:1); c = strawberry #US 64703; red #40. Preparation: 1. Mix together all ingredients except sucralose. 2. Mix sucralose with water to desired concentration. 3. Feed mixture of ingredients and sucralose into extruder (Wenger TX80) through separate inlets and extrude at 93 * C and 6.9 MPa (1000 psi). 4. Form into ring shapes. 5. Dry for 10 minutes at 1160'C to moisture content of less than 1%. 6. Mix lemon, orange and strawberry loops in equal proportions. The quality of the fruity loop product was compared with that of a conventionally sweetened, commercially available product, "Kellogg' s Froot Loops", containing sucrose incorporated in the cereal matrix (8%) and coated on the loops (about 50% by weight), by 15 taste panelists. The panelists found that the Kellogg' s Froot Loops were sweeter than the sucralose-sweetened product, due to the rather heavy coating of sucrose, but the flavour, texture and overall liking of the products were similar. Example 6 Cookie-flavoured snack food Ingredients (% by weight) Corn flour 21.50 Barley flour 21.73 Wheat flour 31.96 Oat flour 22.48 Salt 1.50 Corn oil 0.50 Bakery flavour (Givaudan 70187) 0.11 Sucralose LC25 0.22 Preparation: 1. Mix together all ingredients except sucralose. 2. Mix sucralose with water to desired concentration. 3. Feed mixture of ingredients and sucralose into extruder (Wenger TX80) fitted with disc-shaped die through separate inlets and extrude at 118'C and 2.76 MPa (400 psi). 4. Dry for 10 minutes at 116"C to moisture content of less than 1%. Example 7 Apple Cinnamon Flavoured Snack Ingredients (% by weight): Corn flour 21.45 Barley flour 21.66 Wheat flour 31.87 Oat flour 22.41 Salt 1.49 Corn oil 0.50 Apple Cinnamon flavour (Haar an & Reimer) 0.40 Sucralose LC25 0.22 Preparation: 1. Mix together all ingredients except sucralose. 2. Mix sucralose with water to desired concentration. 3. Feed mixture of ingredients and sucralose into extruder (Wenger TX80) fitted with disc-shaped die through separate inlets and extrude at 118 * C and 2.76 MPa (400 psi). 4. Dry for 10 minutes at 116 * C to moisture content of less than 1%. Example 8 Chocolate Flavoured Snack Ingredients (% by weight): Corn flour 40.32 Wheat flour 29.82 Oat flour 20.97 . Salt 1.40 Corn oil 0.47 Cocoa Powder 6.52 Caramel Cream flavour 0.28 Sucralose LC25 0.22 Preparation: 1. Mix together all ingredients except sucralose. 2. Mix sucralose with water to desired concentration. 3. Feed mixture of ingredients and sucralose into extruder (Wenger TX80) fitted with disc-shaped die through separate inlets and extrude at 118 * C and 2.76 MPa (400 psi). 4. Dry for 10 minutes at 116 * C to moisture content of less than 1%. Example 9 Cornflakes sweetened with sucrose, HFCS, dextrose or sucralose Ingredients (% by weight): B D + concentrated glyceryl monostearates (Eastman Chemical Products, Inc. , Kingsport, Tennessee) Preparation: 1. Mix together all ingredients except sucralose. 2. mix sucralose with water to desired concentration. 3. Feed mixture of ingredients and sucralose into extruder (Wenger TX80) fitted with disc-shaped die through separate inlets and extrude at 118 * C and 2.76 MPa (400 psi). 4. Dry for 10 minutes at 116"C to moisture content of about 3%. Product D (sucralose) was rated as sweeter than products A (sucrose), B (HFCS) and C (dextrose) but all four products were rated similarly for overall flavour and texture. Exam le 10 Potato sticks sweetened with sucralose Preparation: 1.1 Product A: Mix together sucralose, corn meal and water, then add potato flour. 1.2 Product B: Mix together corn meal and water, then add potato flour and sucrose. 2. Feed mixture of ingredients into extruder (Wenger TX52) and extrude at 102 * C (sucralose) or 114 * C (sucrose) and 10.34 MPa (1500 psi) (sucralose) or 7.6 MPa (1100 psi) (sucrose), passing through belt cutter to divide into sticks. 3. Dry for 10 minutes at 116"C to moisture content of about 3%. The sucralose sweetened potato sticks (A) were much lighter textured, with a density of 0.098 g/ml, than the sucrose sweetened product (B) which had a density of 0.206 g/ml. Exam le 11 Soy snack sweetened with sucralose or 1. Mix together ingredients. 2. Peed mixture of ingredients into extruder (Wenger TX52) and extrude at 116'C and 4.14 MPa (600 psi), passing through belt cutter to divide into sticks. 3. Dry for 10 minutes at 116 * C to moisture content of about 4%. Exam le 12 Bran buds breakfast cereal sweetened with Preparation: 1. Mix together ingredients. 2. Feed mixture of ingredients into extruder (Wenger TX80) and extrude at 93 * C and 3.45 MPa (500 psi) as beads. 3. Dry for 5 minutes at 154"C to moisture content of about 0.5%. The sucralose sweetened bran buds (B and C) showed a greater expansion of volume than the sucrose sweetened product (A) and had a lighter texture. The densities of the products (g/ml) were: A, 0.145; B, 0.112; C, 0.105. Example 13 Texturised vegetable protein sweetened with sucralose Ingredients (% by weight) Defatted soy flour 99.55 Sucralose LC25 0.45 Preparation: 1. Mix together ingredients. 2. Feed mixture of ingredients into extruder (Wenger TX20) and extrude at 68'C and 3.45 MPa (500 psi), as pellets. 3. Dry for 5 minutes at 104"C to moisture content of about 3%. Example 14 Moist petfood sweetened with sucrose (A) or sucrose (B) Ingredients (% by weight) A B Yellow corn Wheat grains Rice grains Vitamin mix Brewers yeast Corn gluten meal Soybean meal Poultry meal Salt and trace minerals Colouring Red #40 Potassium sorbate Phosphoric acid Clycerine Sucrose Sucralose LC25 - 0.08 Preparation: 1. Mix together ingredients. 2. Feed mixture of ingredients into extruder (Wenger TX20) and extrude at 37"C and 2.76 MPa (400 psi), as pellets. 3. Dry to moisture content of about 30%.

Claims: CLAIMS 1. A sweetened extruded food product based on a vegetable material containing sweetener incorporated before extrusion, characterised in that the sweetener comprises a significant proportion of sucralose. 2. A food product according to Claim 1, in which the sucralose provides at least 50% of the total sweetness. 3. A food product according to Claim 2, in which the sucralose provides at least 75% of the sweetness. 4. A food product according to Claim 1, in which the sucralose content is from 0.01% to 0.2% by weight. 5. A food product according to Claim 3, having a bulk density of from 45 to 75% that of an equivalent product using an all-sugar sweetener. 6. A process for manufacturing a sweetened extruded food product comprising cooking a mixture of vegetable material, water and sweetener, extruding the cooked mixture as pellets or other shaped pieces and, where necessary, drying them to a desired moisture content, characterised in that the sweetener comprises a significant proportion of sucralose. 7. A process according to Claim 6, in which the sucralose provides at least 50% of the sweetness provided by the sweetener. 8. A process according to Claim 7, in which the sucralose provides at least 75% of the sweetness provided by the sweetener. 9. A process according to Claim 6, in which the sucralose content in the product is from 0.01% to 0.2% by weight.

Inventors: DENHARTOG LISA, HEATH CHRISTOPHER ROBIN, KETELSEN SANDRA MILLS, MELEGA VALERIE, MILLER GARY ALLEN, ZANNONI JOSEPH MICHAEL, DENHARTOG, LISA, HEATH, CHRISTOPHER, ROBIN, KETELSEN, SANDRA, MILLS, MELEGA, VALERIE, MILLER, GARY, ALLEN, ZANNONI, JOSEPH, MICHAEL
Applicants: DENHARTOG LISA, HEATH CHRISTOPHER ROBIN, KETELSEN SANDRA MILLS, MELEGA VALERIE, MILLER GARY ALLEN, TATE & LYLE PLC, ZANNONI JOSEPH MICHAEL, TATE & LYLE PUBLIC LIMITED COMPANY
Application year: 1993
Main classification: A23L1
IPC codes: A23J3, A23K1, A23L1