the ability to generate small consistent bubbles within an extrusion system or in baking dough has always been a limiting factor among the processing engineers within various fields of food manufacturing . however , with new advanced technology , this task has become easy and reliable but with one speculation , which is to incorporate the bubbles within the plasticizer agent before it is injected into the extruder or incorporated into the dough . this technique makes the production of micro bubbles more reliable within a more liquid phase of the recipe and thus more dependable for consistency . this invention utilizes the cooking extrusion process and , to a lesser degree , the baking process to produce high protein , high fiber , low carbohydrate , snacks and cereals with low bulk density and light crunchy texture . since high temperature extrusion under this condition utilizes the lower end of processing temperatures of about 200 ° f . to about 285 ° f ., the high protein dough is not affected by runaway reactions , yet the expansion force exists within the plasticizer to produce a lighter texture product . it is able to provide conditions and energy required for the high protein dough mixture to go through a glass transition temperature and denaturation phase , before reaching the texturization temperature . this process is further assisted by the injection of gas - incorporated water inside the dough as a source of plasticizer . the gas - incorporated water provides the micro bubbles , which are required to evenly distribute the gas within the dough . at the point of exit , where the pressure is released , the gasses trapped within the dough will cause the semi - cooked dough to expand and generate textures that are light in crunch . this process also allows the final product t have a low bulk density , which is so desired by the snack and cereal industry using a high protein low carbohydrate recipe . similar reaction with lower results can be realized in baking processes where the dough containing high protein and low carbohydrate is formed using a highly charged plasticizer with gases such as co 2 . this process allows the various components of the recipe to hydrate as well as distribute the micro bubbles within its matrix captured under the strength of the crosslinking components of the dough . when this dough is formed and heated , the leavening agents begin to expand the dough , the gases within the micro - bubble of the dough also begin to expand , and the dough tends to increase in size and produce a lower bulk density than if the gas was not used . we have been able to demonstrate up to 28 % increase in volume by using a highly charged plasticizer in a high protein dough . incorporating gases within the extrusion system has been done for various processes . however , the major difficulty in this component of extrusion process has always been the ability of controlling the bubble size of the gas within the dough matrix so that at the time of exit from the die , the expansion of the dough can be uniform and consistent . the utilization of gas incorporation into the plasticizing agent combined with dough containing a high protein profile makes this process viable and the only option for the manufacturing of high protein cereals and snacks . while food ingredients such as high - protein ingredients increase the health benefits of the food products that contain the ingredients , the high - protein ingredients tend to increase the density of the food products . the increased density of the food products may make it difficult for persons to chew such food products . various techniques have been used to reduce the density of food products such that the healthful benefits may be enjoyed while the food products have a desired texture when chewed . one technique to reduce the density of the food products is to use a chemical leavening agent such as yeast or baking powder . these chemical leavening agents cause the production of a gas such as co 2 during the process of preparing the food product . however , the expansion and activation of yeast is limited based upon a variety of factors such as time , temperature , amount of water and sugar to initiate growth of the yeast . for a chemical reaction using baking powder , the reaction of basic and acidic ingredients causes the formation of co 2 . the amount of expansion produced by chemical leavening agents depends significantly upon the cooking time and temperature . the relatively short heating time in typical extruders precludes the use of chemical leavening agents because the chemical leavening agents do not have sufficient time to produce a desired level of expansion . additionally , the chemical leavening agents do not perform well when used with food products that have a protein concentration of more than about 20 percent by weight . the protein generates a great deal of internal force within the dough , which reduces the possibility of gases formed by the chemical leavening agents to allow expansion to produce a significant expansion within the matrix . the high protein food products thereby have a harder texture . it is also known that gas may be introduced into a food product by adding a foaming agent to the food product during the preparation process and then subjecting the food product to a high - speed blending process , which causes air to be drawn into the food product . this process produces significantly different size air bubbles to be provided in the food product compared to the air bubbles that are produced using the gas infused plasticizer , which is discussed in more detail below . because of the preceding differences , persons of ordinary skill in the art would not view these two techniques as being similar or producing similar results . gas infused plasticizers may use a variety of easily volatile gases . for producing a variety of food products , the gases should be volatile at room temperature . for other embodiments , the gases should become volatile at temperatures of between about 45 and 95 ° c . the gases should also be food grade since the gases are being incorporated into food products that are intended for consumption . examples of suitable gases include co 2 , air , peroxide , alcohols and ethers . however , a person of skill in the art will appreciate that other gases may be used in conjunction with the concepts of the current invention . the concentration of the gas that is infused into the plasticizer may be provided at a concentration of up to about 40 percent by weight . in other embodiments , the concentration of gas infused in the plasticizer is between about 0 . 5 and 38 percent by weight . in certain embodiments , the concentration of gas infused into the plasticizer is between about 12 and 25 percent by weight . the plasticizer used to infuse the gas within them should be imitable with the dough being prepared . by this , it is meant that the plasticizer does not increase or decrease the ph of the dough by more than about 2 . 5 . in certain embodiments , the change of ph of the dough caused by the plasticizer is less than about 1 . 0 . care must be taken when selecting the level of gas that is introduced into the dough because using an excess amount of gas or using an incompatible plasticizer may result in burning the high protein matrix during cooking such a result would decrease the quality of the food product such that consumption would not be desired . liquid plasticizers are typically used at a concentration of between about 10 and 30 percent by weight when extrusion is used and between about 30 and 45 percent by weight when baking is used . in certain embodiments , the air cells produced by the techniques of this invention are between about 2 and 3 , 000 microns . in other embodiments , the air cells range in size from 2 to about 1 , 000 microns . once the gas is infused into the plasticizer and the gas - infused plasticizer is mixed with the raw powder to form the dough , the gas is well mixed within the high protein matrix to form a well developed dough . such a process allows a very good distribution of gas in micro forms to all aspects of the dough matrix . when the gas is exposed to the high pressure and high temperature within the extruder , the gas tends to expand to a point where it forms smaller chambers of expansion , which are called air bubbles . the process creates micro bubbles at the cross - section of the end product resulting in a light textured end product . there may be some bleeding of one gas cell to another to form larger cells or air bubbles . on average , the cell formations are much smaller than they would be if a chemical leavening agent was used . good control of the amount and the size of the air bubble and its uniform distribution in molecular level directly affects the texture of the finished product regardless of how strong a matrix or how high a protein level it is dispersed in . the quantity of gases is also relevant to the textural changes . the smaller , more uniform and abundant the air bubbles within the high protein matrix will result both in the extrusion and baking processes to lighter textured end product and will give a better mouthfeel similar to starch - based matrices , which is the common standard of public reference in cereals and snacks . to further develop the dough so that the stretchability and expansion can be further realized during the exit from the die of the cooking extruder , we were able to use some hydrocolloids such as gums , fiber gums , and gelatins within the dough to add to the strength of the high protein dough and provide the weakening of the matrix so that the gas can expand and allow the product to form a light texture . two major sources of protein were utilized during our studies , one being the protein from legumes such as soya isolate and the second was whey protein isolate . the type of gums and hydrocolloids used were the gum arabic , xanthan gum , pre - gelled corn starch , pre - gelled potato , and tapioca starch , as well as number of other sources of ingredients , which provide stretch ability and matrix building capacity to the dough . under all conditions the gas - infused plasticizers tend to reduce the bulk density of the product with no side effects such as off flavor or taste by about 30 % to about 50 %. the final textural acceptability of the finished product was improved by about 2 to 3 times the normal condition if this process was not adopted . since high temperatures are avoided using this technique , the utilization of proteins from sources that contain reducing sugars , such as whey , which were not previously possible , can be achieved . the low temperatures , while denaturing the proteins , stay far below the texturization point of the proteins , thus allowing the dough to be fully developed using the hydrating force of the protein matrix and other dough developing compounds of the dough such as hydrocolloid soluble fibers and gelling agents , such as variations of cmc ( carboxymethyl cellulose ), all at lower temperatures but containing a highly gas infused matrix . this matrix readily expands under slight heating of the dough and during the release of pressure at the die of an extrusion system . to fully verify the effects of gas infused dough during the cooking extrusion and baking , we tested the following protein sources at various levels of concentration with tap water as well as with highly charged water with co 2 . from the above findings , it is evident that the addition of gas to the dough will result in higher expansion ratio and thus lower bulk density . the raw ingredients are mixed in a form of flour to a substantially homogenized mixture . the mixture is then introduced to a chamber where it is mixed with steam or moisture . the mixture is then introduced to the feeding zone of the cooking extruder such as twin - screw extruder . carbonated or gas infused water is injected into the extruder . with low carbohydrate , high protein flour , about 2 to about 2 . 5 times the water may be needed . the extruder then mixes the components together to generate dough under pressure , which is kneaded to a substantially homogenous state . the dough is then conveyed to a high pressure and shear zone within the extruder . in this zone , the dough temperature is raised to about 250 to about 350 ° f . the high sheared and pressured dough with micro bubbles of the gas imbedded within its matrix is well distributed within its heated dough and is then introduced to the die area of the extruder . by this time the dough temperature may be between about 250 to about 350 ° f . and the water vapors and the gas is under pressures of over about 1 , 000 psi . the pressurized and gas infused dough is then pushed through a die opening resulting in formation of a shape and release of pressure to the atmosphere . the gas and vapor within the dough matrix expands while conforming to the die shape . the expanded product is then cut either at the die or formed into a ribbon and cut later by a rotary cutter to form the final product . the cut pieces are then transferred to a toaster or drier to further develop the product taste and texture . the finished puffed product is then cooled to room temperature and is ready to be consumed . alternatively , the food product may be produced using a baking process as set forth below . the raw ingredients are mixed in a form of flour to a substantially homogenized mixture . to the mixture of flour , the highly charged plasticizing agent is introduced and mixed rapidly . the temperature of the plasticizing agent can be in the range of conventional room temperature . dough is formed with the infused gas in a substantially homogenous format initiating the leavening agents either chemical or natural . the gas infused dough is then placed in formers to produce and form the food particulate . the formed dough is then cut to the appropriate shape and size . the cut pieces are then introduced into a 5 % sodium hydroxide solution to produce pretzels or sprayed with acidic solution to produce shiny surface . the coated pieces are then to form a very fast rising dough under conventional baking conditions . the liquid treated surface of the dough is then sprinkled with various products nuts , sesame , or rock salts to give a specific taste to the final product . the baked dough is then dried to a final moisture content of about 2 to about 3 % and is then cooled to room temperature where the food product is ready for consumption . the above outlined process can be used for the making of high protein cookies pretzels crackers and bread sticks as well as number of other food products . this technique although simple in application is able to generate great results in lowering the bulk density of the food product and most effectively can be used in the formulations which contain high protein and high fiber components which prevents the formed matrix from expanding . this art used in the processing and baking of food articles is unique in its form and application due to the ability of gas infused plasticizer such as water which is needed in the making of a dough both for extrusion cooking as well as baking of pretzels and other food articles . the gas infused plasticizer such as water infused with co 2 at concentration values ranging from about 0 . 5 to about 38 percent of the volume of the plasticizer added to the flour will result in expansion of the food item to increase its total volume by almost 50 percent or more during processing and cooking and baking . its most useful application is in the field of high protein low carbohydrate products , which have problems with light texture and good mouth feel . this process is able to lighten the texture of the food item as well as reduce the bulk density and textural profile . the gas infused plasticizer can be used in recipes with protein levels ranging from about 2 to about 75 percent from sources like legume proteins , cereal proteins , whey and milk proteins as well as egg and other sources the recipe may also contain fiber in concentration from about 0 . 1 to about 18 percent from various sources , and starch from various tubular and cereal and corn sources as well as sugars and minerals and vitamins . use of nucleotides and other sources of amino acids in the recipe also can be improved in functionality using this processing outline . it is contemplated that features disclosed in this application , as well as those described in the above applications incorporated by reference , can be mixed and matched to suit particular circumstances . various other modifications and changes will be apparent to those of ordinary skill .
the present invention relates to a method or processing technique as well as the product achieved there from for the manufacturing of high protein , high fiber , low carbohydrate snacks , cereals , and food items in which the end product will demonstrate low bulk density and / or a light crunchy texture . the product may be made up of mixtures of various sources of proteins such as milk protein , whey protein , soya protein , meat protein mixed with various portions of grains and hydrocolloids and processed in such manner where the product , utilizing the incorporation of various gasses into the plasticizing agent and then distributed within the matrix under low or high pressure such as cooking extrusion or forming extruder for the purpose of expanding the matrix of the food when exiting the die and the pressure is released . during the baking process , such expansion takes place when the gas infused plasticizer is distributed within the dough and further expands within the dough as it is being baked . the presence of heat further assists in the expansion of the dough by turning water into steam within the dough and expanding the gas within the plasticizer , thus resulting in the expansion of the food particle resulting in final very light crunchy texture product thus achieving a very low bulk density .