MOLDED FROZEN BAR

Abstract: A process for the production of a molded aerated frozen bar which comprises preparing a mix of ingredients suitable for a frozen aerated bar, whipping the mix to obtain an aerated mix having an overrun of from 20 to 250 %, molding the aerated mix to give a molded aerated mix and freezing the molded aerated mix. Average size of air cells is less than 50 microns.

Description: MOLDED FROZEN BAR FIELD OF THE INVENTION The present invention relates to a method of preparation of a molded aerated frozen bar and to a molded aerated frozen bar obtainable thereby. BACKGROUND OF THE INVENTION Traditionally, molded aerated frozen bars are manufactured by partially freezing the ice cream mix, water ice mix or fruit juice mix in conventional batch or continuous ice cream freezers followed by pumping and filling into molds of different shapes and sizes. During the last decade, a new generation of freezers has been developed which are equipped with pre-whippers enabling the mix to be pre- aerated before being partially frozen in the freezer. The molded products are usually quiescently frozen using a cold brine system at -30° to -40°C. If desired, after demoulding, the molded products may be coated with chocolate or compound coating. Finally, the products are usually packaged and stored at about -20°C until transport and distribution. This traditional process of manufacturing molded aerated frozen bars has some limitations. For example, the partial freezing of the mix in the freezer, followed by quiescent freezing in the molds, leads to the formation of an icy texture, loss of air, as well as formation of large air cells in the product having a size range of about 110-185 microns ( Arbuckle, W.S. Ice Cream, Fourth Edition, 1986. Van Nostrand Reinhold, New York, p234). In addition, shrinkage of the products often becomes an issue. Moreover, when eating the product, a very cold feeling in the mouth is experienced. Furthermore, it is difficult to achieve more than 20% overrun in water ice products where the overrun is from 0 to 20% and usually about 5%. It is also difficult to achieve more than 80% overrun and almost impossible to achieve an overrun of 120% or higher in finished ice cream products using conventional manufacturing. Currently, there is no process that can produce very finely aerated molded frozen bars (having an average air cell size of less than 50 microns) that are smooth in texture, do not suffer from shrinkage, do not give a very cold feeling in the mouth, have a uniform appearance without large air pockets on the surface, as well as having an overrun of more than 20% for water ice products and an overrun from 80 to 250% for ice cream products. SUMMARY OF THE INVENTION We have now found that, by using a new process wherein an aged mix is aerated finely in a whipper, e.g. an Oakes commercial whipper, to a desired overrun followed by direct depositing of the aerated mass into molds, and thus eliminating the partial freezing step, the molded frozen product has a fine aerated texture, can have an unconventionally high overrun of above 20% for a water ice product and from 80 to 250% for an ice cream product, is resistant to shrinkage, has a smooth uniform air pocket free appearance, and has a creamier and warm eating quality Accordingly, the present invention provides a process for the production of a molded aerated frozen bar which comprises preparing a mix of ingredients suitable for a frozen aerated bar, whipping the mix to obtain an aerated mix having an overrun of from 20 to 250%, molding the aerated mix to give a molded aerated mix and freezing the molded aerated mix. DETAILED DESCRIPTION OF THE INVENTION The mix suitable for a frozen bar may be any conventional mix such as an ice cream mix, a water ice mix, a fruit juice mix, a frozen yoghurt mix or a sherbet mix. An ice cream mix may contain fat, non-fat milk solids, carbohydrate, a stabiliser together with water and, if desired, other conventional ingredients such as emulsifiers, mineral salts, colorants, etc. A water ice mix is made of fruit juice, sugar, and stabilizer, with or without flavouring, colour or water. A fruit juice mix is similar to a water ice mix except that additional fruit juice is added. A sherbet mix contains fruit juices, sugar, stabilizer and small amounts of milkfat and non- fat milk solids. For example, an ice cream mix may contain fat in an amount of from 3 to 18% by weight based on the total weight of the mix, non-fat milk solids in an amount of from 8 to 15% by weight based on the total weight of the mix, sugar in an amount of from 10 to 15% by weight based on the total weight of the mix, a corn sweetener in an amount of from 3 to 8% by weight based on the total weight of the mix and a stabilizer in an amount of from 0.1 to 1.0% by weight based on the total weight of the mix. The fat used may be a dairy or non-dairy fat. When the fat is a dairy fat, it may be for instance, any milk fat source such as butter oil, butter or real cream. When the fat is a non-dairy fat it may be, for instance, an edible oil or fat, preferably a vegetable oil such as coconut oil, palm kernel oil, peanut oil, olive oil, or soy bean oil, etc. The sugar used may be sucrose, glucose, fructose, lactose, dextrose or invert sugar either in the form of crystalline or liquid syrup. The corn sweetener may be the crystalline forms of refined corn sugar (dextrose and fructose), dried corn syrup (corn syrup solids), liquid corn syrup or maltodextrins. The stabilizer may be, for instance, a hydrocolloid such as agar, gelatin, gum acacia, guar gum, gum tragacanth, carrageenan and its salts, carboxymethyl cellulose, sodium alginate or propylene glycol alginate, or any mixture of stabilizers. Advantageously one or more emulsifiers may be present also. The preparation of the mix of ingredients may be carried out conventionally, by combining the ingredients with shear mixing to disperse and solubilise them into a homogeneous mass, preheating, e.g. to a temperature of from about 62° to 75°C, homogenizing, e.g. in a two stage homogenizer at a pressure of from about 500 to 3500psig in the first stage and from 0 to lOOOpsig in the second stage, more usually from 1000 to 3000psig in the first stage and from 100 to 800psig in the second stage, followed by pasteurizing the homogenized mass using, for instance either HTST or LTLT processing. After pasteurization, the mix is preferably aged by allowing to stand at a temperature of from 0° to 6°C, preferably from 1° to 5°C for from 1 to 24 hours, more usually from 2 to 18 hours and preferably from 4 to 12 hours. The mix is then colored and flavoured as needed, aerated in a mixer, e.g. an Oakes Mixer at a temperature of from 0° to 12°C, preferably from 1 to 5°C, and with a back pressure of about 20 to 80 psig, preferably from 25 to 60psig, to the desired overrun. Preferably the overrun for water ice products is from 25 to 150%, more preferably from 30 to 100% and especially from 50 to 80%. Preferably the overrun for ice cream products is from 40 to 200%, more preferably from 80 to 150% and especially from 100 to 140%. The aerated mix is then fed, preferably directly, to a mold, e.g. by pumping through a filler, and then allowed to freeze to give the frozen molded bar. The freezing may be allowed to take place quiescently at a temperature of from, for example, -25° to - 5°C, preferably from -30° to -40°C, conveniently using cold brine. The frozen molded bar may afterwards be demolded and then packaged and stored at a freezing temperature, usually at - 25°C to -35°C, preferably about -30°C. If desired, after demolding, the frozen molded bar may be coated, for instance with chocolate or compound coating, and then packaged and stored at a freezing temperature. The frozen molded bar produced by the process of the present invention may have a creamier and warm eating quality of an extruded product, and a smooth, uniform, homogeneous texture and appearance, with small air cells of an average size of less than 50 microns uniformly distributed substantially none of which are visible to the naked eye. The molded frozen bar may have a quick melt with substantially no lingering of product in the mouth, the ice crystals having a unique thin and substantially curved rod like shape and an average size of less than ice crystals in a conventionally molded aerated frozen bar after heat shock, and having improved heat shock and shrinkage resistance. To summarise, the molded aerated frozen bar produced by the process of the present invention has a texture which is smoother, creamier and has a warmer mouth feel than a conventionally molded aerated frozen bar even at lower overruns, e.g. a water ice product having an overrun of about 20% and an ice cream product having an overrun of about 50%. The present invention also provides a molded frozen bar having an overrun of 20 to 250% with small air cells uniformly distributed substantially none of which are visible to the naked eye, e.g. a water ice product having an overrun of from 20 to 150%o and an ice cream product having an overrun of from 50 to 200%. EXAMPLES The following Examples and accompanying drawings ftirther illustrate the present invention. Example 1 An ice cream mix is prepared from 8% partially hydrogenated palm kernel oil, 11% non-fat milk solids, 12% sucrose, 6% corn syrup solids (36DE) and 0.5% of a stabilizer blend containing combinations of hydrocolloids such as guar, locust bean gum, carrageenan, carboxymethyl cellulose, etc together with emulsifiers. The ingredients are mixed with agitation to disperse and solubilise them into a homogeneous mass, homogenized with a two stage homogenizer at 2000psig pressure at the first stage and 500psig pressure at the second stage, followed by HTST pasteurization. After pasteurization, the mix is aged by refrigerated storage at a temperature of 4°C for 6 hours. The aged mix is colored, flavored, and then aerated in an Oakes Mixer at a temperature of 4°C to an overrun of 130%. The aerated mix is then pumped to a mold and then allowed to freeze to give the frozen molded bar. The freezing is allowed to take place quiescently at a temperature of - 0°C using cold brine The frozen molded bar produced by the process of the present invention has the creamier and warm eating quality of an extruded product, a smooth, uniform, homogeneous texture and appearance, with small air cells of an average size of less than 50 microns uniformly distributed substantially none of which are visible to the naked eye. The molded frozen bar may have a quick melt with substantially no lingering of product in the mouth, the ice crystals have a unique thin and substantially curved rod like shape and an average size of less than ice crystals in a conventionally molded aerated ice cream bar after heat shock, and have improved heat shock and shrinkage resistance. In the accompanying drawings, Figure 1 illustrates ice crystals in a conventionally molded aerated ice cream bar after heat shock and Figure 2 illustrates ice crystals in a molded aerated ice cream bar made by the process of the present invention after heat shock. The frozen molded bar is demolded and then coated with chocolate crunch bar at 35°C, packaged and stored at -20°C. Example 2 A water ice mix is prepared from 23% sucrose, 7% corn syrup solids (36 DE) and 0.6% stabilizer blend containing combinations of hydrocolloids, such as guar, locust bean gum, pectin, carboxymethyl cellulose, gelatin, microcrystalline cellulose, hydrolyzed soy or milk proteins, etc. with or without emulsifiers. The ingredients are mixed with agitation to disperse and solubilise them into a homogeneous mass in water, homogenized with a two stage homogenizer at 1500psig pressure at the first stage and 500psig pressure at the second stage, followed by HTST pasteurization. After pasteurization, the mix is aged by refrigerated storage at a temperature of 4°C for 6 hours. The aged mix is colored, flavored, acidified (e.g. adding citric acid solution), and then aerated in an Oakes Mixer at a temperature of 4°C to an overrun of 60%. The aerated mix is then pumped to a mold and then allowed to freeze to give the frozen molded bar. The freezing is allowed to take place quiescently at a temperature of -40°C using cold brine The frozen molded bar produced by the process of the present invention has the creamier and warm eating quality of an extruded product, a smooth, uniform, homogeneous texture and appearance, substantially none of which are visible to the naked eye. The molded frozen bar has a quick melt with substantially no lingering of product in the mouth. The frozen molded bar is demolded and then packaged and stored at -20°C.

Claims: CLAIMS 1. A process for the production of a molded aerated frozen bar which comprises preparing a mix of ingredients suitable for a frozen aerated bar, whipping the mix to obtain an aerated mix having an overrun of 20 to 250%, molding the aerated mix to give a molded aerated mix and freezing the molded aerated mix. 2. A process according to claim 1 wherein the mix suitable for the frozen bar is an ice cream mix, a water ice mix, a fruit juice mix, a frozen yoghurt mix or a sherbet mix. 3. A process according to claim 1 wherein the preparation of the mix of ingredients is carried out by combining the ingredients with shear mixing to disperse and solubilise them into a homogeneous mass, homogenizing in a two stage homogenizer at a pressure of from about 500 to 3500psig in the first stage and from 0 to lOOOpsig in the second stage, followed by pasteurizing the homogenized mass. 4. A process according to claim 3 wherein, after pasteurization, the mix is aged by refrigerated storage at a temperature of from 0° to 6°C for from 1 to 24 hours. 5. A process according to claim 1 wherein the mix is colored, flavored and then aerated in a mixer at a temperature of from 0° to 12°C to the desired overrun. 6. A process according to claim 1 wherein the overrun for water ice products is from 25 to 150% 7. A process according to claim 1 wherein the overrun for ice cream products is from 40 to 200%. 8. A process according to claim 1 wherein the aerated mix is directly fed to a mold, and then allowed to freeze to give the frozen molded bar. 9. A process according to claim 1 wherein the freezing is allowed to take place quiescently at a temperature of from -25° to -45°C. 10. A process according to claim 1 wherein the molded aerated frozen bar. is afterwards demolded and then packaged and stored at a freezing temperature. 11. A process according to claim 1 wherein the molded aerated frozen bar is afterwards demolded and then coated and then packaged and stored at a freezing temperature. 12. A process according to either claim 10 or claim 11 wherein the freezing temperature is from -25° to -35°C. 13. A molded aerated frozen bar having an overrun of from 20 to 250% with small air cells having an average size of less than 50 microns uniformly distributed substantially none of which are visible to the naked eye. 14. A molded aerated frozen bar according to claim 13 which is a water ice product having an overrun of from 25 to 150%. 15. A molded aerated frozen bar according to claim 13 which is an ice cream product having an overrun of from 40 to 200% 16. A molded aerated frozen bar having a smooth texture similar to an extruded bar, warm eating quality and quick melt with substantially no lingering of product in the mouth. 17. A molded bar having a unique thin and substantially curved rod like shape and an average size of less than ice crystals in a conventionally molded aerated ice cream bar after heat shock, and having improved heat shock and shrinkage resistance.

Inventors: SHARKASI TAWFIK YOUSEF, VAGHELA MADANSINH, SHARKASI, TAWFIK, YOUSEF, VAGHELA, MADANSINH
Applicants: NESTLE SA, SHARKASI TAWFIK YOUSEF, VAGHELA MADANSINH, SHARKASI, TAWFIK, YOUSEF, SOCIETE DES PRODUITS NESTLE S.A., VAGHELA, MADANSINH
Application year: 1999
Main classification: A23G9
IPC codes: A23G9