FR2539587A1 - Process for the preparation of saccharified cereals using the enzymes arising from whole cereal grains and cereals obtained by this process - Google Patents

Abstract

Process for the production of an entirely natural, enzymatically saccharified cereal arising from the whole grain. It consists in milling and separating the whole grain in order to produce a bran fraction, an endosperm fraction and a germ fraction. The germ fraction is treated by toasting and milling and preferably by removing the bran before toasting. The bran fraction and the bran optionally separated from the milled germ are modified in order to increase their functionality either by high-temperature extrusion, under high pressure, or by milling to a particle size of 5 to 100 <0>m. The endosperm fraction is crudely milled, brought to the form of a solid/liquid mixture, cooked and then hydrolysed enzymatically. The final stage consists in recombining the treated fractions in order to form a cereal pulp which is subjected to a later treatment in order to produce a ready-to-eat breakfast cereal. If desired, the cereal pulp can be malted and then have added to it from 1 to 15 % of the whole grain.

Description

Process for the preparation of cereals saccharified by enzymes originating from whole cereal grains and cereals obtained by this process.

The present invention relates to a novel breakfast cereal and a method for its preparation. It relates more particularly to a sugary cereal, entirely natural, saccharified by enzymes, with a high fiber content, originating from a whole cereal grain.

Methods involving the enzymatic hydrolysis of starch to form monosaccharides, disaccharides, trisaccharides and oligosaccharides are known to those in the food industry.

U.S. Patent 4,254,150 issued to Fritze et al. Entitled "Process for the Production of Cereal Food" describes a process for saccharifying the starch contained in the cereal to form dextrose by enzymatic degradation of starch in the cereal. the cereal grain. In this enzymatic process, all the substances in the cereal, both those containing starch and those without starch are processed together. It is argued that the food produced in accordance with this invention has a satisfactory flavor and that the dextrose it contains is taken up directly as sugar by the body.

Although such a process saccharifies the starch contained in the cereal kernel, it is difficult to produce a cereal paw with sufficient functionality because the starch which has been saccharified is no longer present in sufficient quantity to provide properties. typical of matrix formation brought on by the endosperm.

U.S. Patent 4,282,319, issued to Conrad, describes a process for preparing enzymatically hydrolyzed protein and starch products in situ from whole grain, comprising crushing the grain, enzymatically treating the crushed grain first with an endopeptidase to convert substantially all of the water soluble proteins into peptides and to subject the rest of the crushed grain to enzymatic starch hydrolysis and preferably to separate the bran when the above treatments are completed.

U.S. Patent 2,289,416 issued to Fine et al.

describes a process for preparing a cereal from the whole grain comprising breaking the bran husk of the grain, gelatinizing the starch and then treating the gelatinized starch with a starch-breaking enzyme to process most of the starch. starch in dextrin and in sugars. When processing is complete (in about 2 hrs at 60-700c), the processed grain is heated to inactivate the enzyme, dried, diluted and processed to produce a toasted product in flakes, fragments, or any other desired form.

One of the aims of the invention is therefore to hydrolyze the polysaccharides and starches present in the cereal grain in order to achieve significant sweetening of the final cereal product. Another object of the invention is a process for obtaining a self-sweetened food product, in particular a ready-to-eat breakfast cereal without the addition of sugars.

One of the aims of the present invention is also to increase the absorption of moisture, the organoleptic qualities, the palatability and the texturing properties of the constituent bran of the cereal grain to replace the lost endosperm matrix-forming properties. under the effect of the in situ transformation of starch. Likewise, the protein component present in the germ fraction of the whole grain, after functional modification, is used in the present invention to form a matrix for the grain syrup resulting from the saccharification of starch.

Another object of the invention is to provide a ready-to-eat cereal product containing an increased level of dietary fiber compared to ordinary breakfast cereals.

The present invention involves a novel process for producing an all-natural, enzyme-saccharified, sweetened cereal derived from a whole cereal kernel.

The starting material for this process is the whole cereal kernel which is then crushed and separated to produce a bran fraction, an endosperm fraction and a germ fraction. If desired, the cereal grain fractions can be obtained from suppliers and used in the proportion found in the whole cereal grain and processed in accordance with the invention. The three components undergo separate treatments and are recombined to form a cereal paste such that all three fractions are present in the same ratio as in the starting whole grain.

The seed fraction which contains a high level of high quality protein but which also contains a predominant amount of bran and oil is roasted and ground to achieve optimum matrix behavior and storage stability. The germ is roasted at 110-1600C, preferably 130-1550C 'for 15-175 minutes, preferably 20-30 minutes, then the roasted germ is ground to an average particle size of 0.25-2.0 millimeters . If crushed too finely, the bran-free sprout will develop secondary flavors.

If desired, before the germ is roasted, any bran which may be found there is separated (for example by air grading) and combined with the bran fraction of the cereal grain.

The bran fraction alone or in combination with the bran separated from the ground germ (if this optional embodiment is used) must be processed to improve its functionality. Hiodification of bran is essential to the invention because if most of the endosperm containing starch is saccharified, then another ingredient must replace starch as the matrix of the cereal. The sound modification operation will produce a sound which is functional and has improved texturing properties. Likewise, the altered sound will not give the sandy mouth feel of conventional bran-containing cereals.

The process of modifying the are involves extrusion modification and / or grinding modification to a particle size of 5 to 100 µm, preferably 20 to 60 µm. The extrusion modification involves forming a bran and water feedstock having a bran to water ratio of 5.5: 1 to 10: 1 and extruding the feedstock in a dual extruder. screw rotating in the opposite direction under high pressure, at high temperature, with sufficient shear to produce a sound which will be more easily crushed. The modified bran is then ground, preferably in a conventional food grinder.

The endosperm fraction, which consists mainly of starch, is ground to a particle size of less than 2 mm to achieve optimum penetration of water, heat and enzyme. The ground endosperm, 15 to 60% by weight in a slurry, is cooked by any suitable means until substantially all of the starch is gelatinized, then enzymatically hydrolyzed to form soluble saccharides.

From 15 to 75 t by weight of the endosperm are enzymatically hydrolyzed, preferably from 50 to 60.%. The soluble saccharide produced is preferably glucose. The endosperm fraction is enzymatically saccharified until a degree of sweetening of 7.5 parts sucrose equivalent to 50 parts sucrose equivalent is present in the final breakfast cereal product, as consumed. . The endosperm fraction is preferably enzymatically saccharified until a degree of sweetening of 10 parts sucrose equivalent to 45 parts sucrose equivalent is present, and more preferably until a degree of sweetness is present. A sweetening of 35 to 40 parts of sucrose equivalent is present in the final breakfast cereal product, as consumed.

The endosperm fraction, after grinding, can be cooked in many different ways to achieve significant gelatinization of the starch therein.

The gelatinization of the starch of the endosperm fraction can be accomplished by injecting steam into a nozzle cooker at 140-1650C in the presence of a thermally stable α-amylase for a period of 1 to 60 seconds.

Starch gelatinization can also be accomplished by cooking in a pressure chamber such as an autoclave or rotary cooker at 100-1400C for 5 to 60 minutes with or without the addition of a thermally stable α-amylase. The dry endosperm starch can also be brought in slurry form and gelatinized by heating to 110-1600C in an extruder and then further diluted to give an endosperm concentration by weight of 15 to 60% by weight before enzymatic hydrolysis. .

A cereal paste is then prepared by combining the processed ingredients, namely the roasted germ, the modified bran and the enzymatically hydrolyzed endosperm, so that the dough contains the levels of protein, fiber and digestible carbohydrates. whole grain. The cereal dough can be further processed using conventional breakfast cereal manufacturing techniques to obtain a ready-to-eat breakfast cereal.

An optional variation of the process involves malting an amount of whole grain equivalent to 1-15% of the starting material, grinding the malted grain to the consistency of flour and combining the malted grain flour with the processed grain fractions. The bran is preferably separated from the ground malted grain before adding the malted grain to the cereal paste. The bran which is separated is added to the bran fraction of the cereal kernel to be processed therewith. The best results are obtained by adding malt flour to the saccharified endosperm, bran and germ before formation of the final cereal dough product.

In food applications where the oil contained in the seed fraction is undesirable in the final product, for example in a cereal intended to be substantially fat free, the oil contained in the seed fraction can be separated by extraction. in a solvent or by expelling before roasting.

The germ can also be separated from the bran fragments, preferably by air grading, and the germ particles having all of their fat are then beaten, dehydrated and / or roasted. This treatment, by basically keeping the oil droplets in the natural environment of the cell, encapsulated by the cellular material which contains desirable natural antioxidants, can lead to germ particles having all their fat, endowed with stability in the cell. proper storage in the finished cereal product.

The protein in the germ fraction is a useful, functional ingredient that replaces some of the lost functional properties attributable to starch. The protein exerts its role in promoting texture by matrixing with the endosperm syrup.

The mastering of the protein with the syrup is best when the oil present in the germ has been removed before the cereal paste is formed.

Although hydrolysis of polysaccharides can be achieved by enzymes and various methods, the preferred method is to treat 1 to 4 hours of cooked and uncooked endosperm fractions of beans to 18 to 55% solids. Preferred is a dual enzymatic reaction involving bacterial α-amylase together with fungal glycoamylase.

The operation is carried out at a pH of 4.5 to 6.0, preferably 4.8 to 5.2 in a temperature range of from about 40 to 750C, preferably from -55 to 76qu.

The sweetness can be varied by adjusting either the solids concentration1 or the amount of saccharide incorporated into the final cereal paste. In addition, the total sweetness of the cereal product can be regulated, but by limiting the enzymatic action. on the endosperm starch, or by not saccharifying an aliquot of the endosperm fraction.

It is undesirable to separate the sweet liquid obtained by hydrolysis from the endosperm fraction from the residual solids. The structure of the residual unreacted endosperm, if not physically disrupted by the separation, is beneficial in that it aids in the formation of the matrix. Other advantages of the process include the fact that the transformation takes place quite quickly and the reaction takes place in a single vessel.

Suitable cereal grains which can be used in the invention include malus, wheat, oats, barley, buckwheat, rye, rice, sorghum, and millet.

As the endosperm contains more than 95% of the starch present in the whole grain, it is the only fraction of the whole grain that undergoes an enzymatic treatment. As the level of the starch component in the malted grain is low, it is generally not considered economically advantageous to subject the malt flour to an enzymatic treatment. However, malt flour could further be added to the endosperm before gelatinization and saccharification to convert the residual starch present in malt flour into sugar. It is undesirable to enzymatically treat the germ or fiber fraction, since secondary flavors may develop. The process of the invention will not produce any secondary flavors, since the enzymatic saccharification of the endosperm is carried out separately.

To obtain an optimum quality product, certain food ingredients which have not necessarily been processed to improve sweetness or fibrous functionality, i.e. cereal products such as oatmeal or buckwheat, can be added to improve flavor or texture, or to facilitate processing.

Other untreated ingredients, such as nuts, grapes, honey etc. .,. can also be incorporated to increase the appeal of the product.

Although the process of the first invention is expected to have its most important application in the field of the production of ready-to-eat breakfast cereals, logical applications of the product other than breakfast cereals include but are not limited to snack foods, baby foods, main meal items, side dishes, desserts, cake ingredients, and animal or baby food ingredients. animals.

The processed ingredients which constitute the cereal dough can be subjected to further processing by typical breakfast cereal manufacturing techniques, singly, in groups or sequentially to obtain a ready-to-eat cereal product which can be placed on the market. In a simple and convenient way, the processed ingredients (modified bran, germ, malt and saccharified endosperm) were combined and dried / roasted on steam drying cylinders at moderate temperature (around 1500C). This stage of the process results in the thick slurry of the combined materials in the form of a malted cereal material, of a pleasant taste, crisp to the bite. Consumed with milk, the flaked cereal as supplied by the drying cylinders retain a remarkable crispness in the fluid. Considering its high content of simple sugars, this is surprising and unexpected, and turned out to be due to the presence of the modified bran fibers, without which the cereal would have quickly assumed a soft texture which would have quickly disintegrated in the grain. milk.

The heat, (e.g. from steam drying cylinders) helped to develop an attractive composite flavor in which the intrinsic cereal flavor, especially in the bran, nutty flavor of the sprout, sweetness and flavor of The saccharified endosperm and the toasted flavor of the malting are combined into a pleasant and potent flavor level.

The recombinant, transformed grain constituents which constitute the cereal paste can be transformed into a ready-to-eat cereal by other conventional routes comprising, without limitation, the following processes 1) - Partial drying of the materials of the combined ingredients until pasty consistency - shaping, extruding the material into granules on equipment such as Buhler or Ambretti extruders, drying the granules at an even lower humidity level, flaking the granules (e.g. on a non-differential fluff mill) and roasting the flakes to give them a pleasant flavor.

2) - Reduction of the moisture content of the material to a pasty consistency, and shaping into selected shapes on a cookie cutting machine using known techniques, then roasting of the particles.

3) - It is even possible if the total transformation of the starch of the grain to obtain the sweetness is not necessary, to recombine an endosperm or a starch fraction from the non-saccharified part of the grain to the processed grain fractions, and to expand the material by one of the known techniques.

The following nonlimiting examples are given by way of illustration of the invention.

Example 1.

A cereal is prepared all but by the following process. The corn of maSs is divided into two portions, the largest (95%) is coarsely ground and separated into endosperm, germ and its primary fractions. The other portion, 5%, is malted as will be described below in the example. The endosperm fraction (the size of brewer's oatmeal, 2 mm in diameter) is made up as a 20% W / W aqueous slurry and cooked at 1210C for 30 minutes. Part of the cooked endosperm is saccharified as follows. The pH is adjusted to 5.0 with 3N HCl, the Ca + level of the solution is brought to 330 ppm and the temperature is adjusted to 600 C. Then α-amylase, Novc Termamyl T-60 (1, 6 ml / kg endosperm) and Miles Diazyme L-100 glucoamylase (6.6 ml / kg endosperm) to the stirred porridge. After 2 hours of reaction, 65% of the weight of the endosperm has been converted into glucose.

The germ fraction undergoes classification in the air to separate the sound. The bran-free germ fraction, the oil content of which is intact, is roasted at 1500C for 30 minutes and crushed using a 10 US Standard sieve.
(i.e. approximately 2.0 mm).

The primary sound fraction and the sound removed from the seed fraction are modified by extrusion in a twin screw extruder rotating in the opposite direction Welding
Engineers, under the following conditions: feed flow 91 kg / h, water flow 8 kg / h, screw rotation speed 275 rpm, 50 A, 20 HP, temp. ailments. of the barrel 1650C, pressure approximately 1380 kPa and water: bran ratio in the feed 7: 1. The extrudate obtained is ground in a HomoloSd Fitzmill.

MaVs malt is prepared by the following malting process. A thin layer of corn kernels is placed on wire mesh sieves. Two stages of the sieves are introduced into a closed dark chamber with air flow.

The maVs is germinated in the chamber with a spray of water at 240C for two seconds every five minutes through a wide angle nozzle. The maSs is harvested after 72 hours of germination. At this time, the germinated corn has sprouts and roots of 3.8-5.1 cm.

Sprouted corn contains 2.6% (on a dry weight basis) reducing sugar, while non-germinated corn contains only 0.7%. The germinated corn is dried in an air oven at 1400C for 45 minutes. The drying operation brings the reducing sugar content to 8-9% and develops an excellent malt flavor. The dried mail is ground to a particle size of 0.83 mm.

A ready-to-eat breakfast cereal is prepared by combining the saccharified endosperm and the cooked endosperm to give the desired sweetness, adding the germ and bran malt fractions, then drying the porridge on steam cylinders at 1490C to 4 revolutions / min. The final dry weight composition of the flakes is 73.5 t of endosperm (of which at least 37% is a saccharified endosperm fraction), 10.5% of its extruded fraction, 10.5% of roasted germ fraction with all its fat, 5% corn malt and 0.5% salt.

Example 2.

Wheat flour (the endosperm fraction of the wheat grain) is purchased from a seed producer and saccharified by the method set forth in Example 1. On analysis, 53% by weight of the wheat is found. endosperm are saccharified and transformed into glucose. Wheat bran was purchased from International Multifoods and ground to an average particle size of 60 µm using the apparatus and procedure described in Example 1.

A ground wheat germ, degreased with solvents, is purchased from Vitamins, Inc. This represents the germ fraction from which the oil has been removed prior to roasting and grinding of the germ. Wheat malt is bought from the National
Melting Corporation. The saccharified endosperm, the wheat bran crushed at 60 vm, the wheat germ defatted with solvents and the wheat malt are combined to form a cereal paste. The cereal paste obtained from these contains the same proportion of each of the fractions of the cereal grains (or hydrolyzed products obtained from them) as in the whole wheat grain (except for the oil that has been removed from the germ).

A small amount of salt is added to the cereal paste.

Cereal flakes are prepared on steam cylinders as in Example 1 and the finished product, a ready-to-eat breakfast cereal1 contains approximately 79% wheat germ defatted with saccharified solvents, 5% wheat malt and 0.5% salt.

Claims (25)

Method for preparing a ready-to-eat, enzyme-saccharified cereal from a whole cereal kernel, characterized in that it consists of: (a) crushing and separating a whole cereal kernel to produce a germ fraction , a bran fraction and an endosperm fraction (b) treat the germ fraction (1) roasting the germ fraction, and (2) grinding the roasted germ to a particle size of 0.25 to 2.0 millimeters (c) modifying the bran fraction (d) treating the endosperm fraction (1) grinding it to a particle size of less than 2 mm, (2) forming a slurry containing 15 to 60% by weight of this ground endosperm, (3) cooking the ground endosperm until substantially all of the starch is gelatinized, and (4) by enzymatically hydrolyzing 15-75% by weight of this endosperm to form soluble saccharides such that the ready-to-eat cereal has a sweetness corresponding to 7.5-50 parts of which valent-sucrose (e) recombine the ground, roasted germ from step (b) (2), the modified bran from step (c) and the enzymatically hydrolyzed endosperm from step (d) (4) to form a cereal paste containing the same levels of protein, fiber and digestible carbohydrates as whole grain; (f) preparing the ready-to-eat cereal from this cereal paste. 2. A method according to claim 1, characterized in that the sound is modified in step (c) to improve its functionality by extrusion at high temperature, under high pressure, in a twin screw extruder rotating in the opposite direction. 3. Method according to claim 1, characterized in that the bran is modified in step (c) to improve its functionality by grinding this fraction of bran to a particle size of 5 to 100 vm. 4. Method according to claim 1, characterized in that the whole grain is corn, wheat, oats, barley, rye, buckwheat, rice, sorghum or millet. 5. The method of claim 1 further comprising the steps of (a) malting an amount of the whole grain equivalent to 1 to 15% of the whole cereal kernel (b) grinding the malted kernel to the consistency of flour, and (c) adding this malted grain flour to the cereal dough according to claim 1, step (e). 6. Process according to claim 1, characterized in that the enzymatic hydrolysis of the endosperm comprises a treatment process by which the endosperm at a solids content of 18 to 55% is simultaneously subjected to the enzymatic action of. an α-amylase and a fungal glucoamylase at a pH of 4.5 to 6 at a temperature of 40 to 750C for 1 to 4 hours. 7. The method of claim 6, characterized in that the pH is 4.8 to 5.2 and the temperature from 550 to 700C. 8. Method according to claim 1, characterized in that the oil contained in the seed fraction is separated by extraction or expulsion before roasting. 9.Procédé claimed in claim 1, characterized in that the seed fraction is roasted at a temperature of 1100 to 1600C for 15 to 175 minutes. 10. The method of claim 1, characterized in that the seed fraction is first subjected to a bran separation treatment before roasting, this bran being further added to the bran fraction of claim 1 step (c) for be treated with it. 11. The method of claim 5, characterized in that the bran is separated from the malted grain crushed before the addition of the malted gratin to the cereal paste, this bran being further added to the bran fraction of claim 1 , step (c) to be processed therewith. 12. The method of claim 1, characterized in that the ready-to-eat cereal has a sweetness corresponding to 10-45 parts of slow-sucrose equiva. 13. A method according to claim 3, characterized in that this bran fraction is ground to a particle size of 20 to 60 µm. (4) enzymatically hydrolyzing from 15 to 75% by weight of this endosperm to form soluble saccharides such that the ready-to-eat cereal has a sweetness corresponding to 7.5-50 parts of sucrose equivalent; (d) recombining the crushed, roasted germ from step (a) (2), the modified bran from step (b) and the enzymatically hydrolyzed endosperm from step (c) (4) to form a paste cereal containing the same levels of protein, fiber and digestible carbohydrates as whole grain, (e) prepare a ready-to-eat breakfast cereal from this cereal paw (3) cooking the endosperm-crushed until substantially all of the starch is gelatinized, and (2) forming a slurry containing 15 to 60 t by weight of this ground endosperm, (1) grinding to a particle size of less than 2 millimeters, (c) treat the endosperm fraction by (b) modify the fraction sound (2) grinding the roasted germ to a particle size of 0.25 to 2.0 millimeters (1) roasting the germ fraction, and (a) treat the germ fraction 14. Process for preparing a ready-to-eat enzyme saccharified cereal obtained from whole cereal grain fractions, these fractions comprising a germ fraction, a bran fraction and an endosperm fraction, all these fractions originating from a cereal grain and these fractions being present in the same proportions as in the whole cereal grain, this process consisting of 15. The method of claim 14, characterized in that the sound is modified in step (b) to improve its functionality by extrusion at high temperature, under high pressure, in a twin screw extrusion rotating in the opposite direction. . 16. The method of claim 14, characterized in that the bran is modified in step (b) to improve its functionality by grinding this fraction of bran to a particle size of 5 to 100 vmo. 17. The method of claim 14 characterized in that the whole grain is corn, wheat, oats, barley, rye, buckwheat, rice, sorghum or millet. 18. The method of claim 14, characterized in that it further comprises the steps of (a) malting an amount of the whole grain fractions equivalent to 1-15% of the whole grain grain (b) grinding the malted grain to a flour consistency and (c) adding this malted grain flour to the cereal dough of claim 14, step (d). 19. A process according to claim 14, characterized in that the enzymatic hydrolysis of the endosperm comprises a treatment process whereby the endosperm has a solids content of 18 to 55% is simultaneously subjected to the enzymatic action. of an α-amylase and a fungal gluco-amylase has a pH of 4.5 to 6 at a temperature of 40 to 75 ° C for 1 to 4 hours. 20. The method of claim 19, characterized in that the pH is 4.8 to 5.2 and the temperature of 55 * to 700C, 21. The method of claim 14, characterized in that the oil contained in the seed fraction is separated by extraction or expulsion before roasting. 22. The method of claim 14, characterized in that the seed fraction is roasted at a temperature of 1100C to 1600C for 15 to 175 minutes. 23. The method of claim 14, characterized in that the seed fraction is first treated by separating the bran from this fraction before roasting, this bran being further added to the bran fraction of claim 14 step (b) for be treated with it. 24. The method of claim 18, characterized in that the bran is separated from the ground malted grain before the addition of the malted grain to the cereal paste, this bran being further added to the bran fraction of claim 14 step (b ) to be treated with it. 25. The method of claim 14, characterized in that the ready-to-eat cereal has a sweetness corresponding to 10-45 parts of sucrose equivalent.