Abstract
Cereal grain is pretreated before milling, by selectively removing a first fraction of husk components of the cereal, wherein the first fraction includes the outer husk components of the dampened cereal, and wherein 0.2 to 2% by weight of the cereal is removed, then dampening and conditioning the cereal, then selectively removing a second fraction of husk components of the cereal, wherein the second fraction substantially contains dietary fibers of the dampened cereal. The method makes it possible to efficiently obtain contamination-free total dietary fibers. An apparatus for carrying out the method, and advantageous uses of the total dietary fibers are also described.
Claims
1. A method of supplementing foodstuffs selected from the group consisting of baked goods, cereals, snacks, drinks, milk products, food supplements and diet foods, said method comprising adding dietary fibers to the foodstuff, and the dietary fibers being obtained by a method for pretreating grain before milling, the method comprising the following steps: a) providing cereals; b) optionally: dampening and conditioning the cereal; c) selectively removing a first fraction of husk components of the cereal as per step a) or of the cereal obtained from step b), wherein said first fraction substantially comprises the outer husk components of the dampened cereal, and 0.2 to 2% by weight of the cereal is removed; d) dampening and conditioning the cereal obtained from step c); and e) selectively removing a second fraction of husk components of the cereal obtained from step d) to provide a treated cereal separate from said second fraction, wherein said second fraction substantially contains dietary fibers of the dampened cereal.
2. A method of supplementing foodstuffs selected from the group consisting of baked goods, cereals, snacks, drinks, milk products, food supplements and diet foods, said method comprising adding dietary fibers to the foodstuff, and the dietary fibers being obtained by a method for pretreating grain before milling, the method comprising: a) providing cereals; b) dampening and conditioning the cereal; c) selectively removing a first fraction of husk components of the cereal as per step a) or of the cereal obtained from step b), wherein said first fraction substantially comprises the outer husk components of the dampened cereal, and 0.2 to 2% by weight of the cereal is removed; d) dampening and conditioning the cereal obtained from step c); and e) selectively removing a second fraction of husk components of the cereal obtained from step d) to provide a treated cereal separate from said second fraction, wherein said second fraction substantially contains dietary fibers of the dampened cereal.
Description
(1) The invention is explained below with reference to exemplary embodiments and figures without restricting the subject matter of the invention to said embodiments. In the figures:
(2) FIG. 1 shows a flow diagram of a variant for carrying out the method;
(3) FIG. 2 shows a longitudinal section of a light peeler;
(4) FIG. 3 shows a cross section of a light peeler;
(5) FIG. 4 shows a longitudinal section of a peeler;
(6) FIG. 5 shows a cross section of a peeler;
(7) FIG. 6 shows a longitudinal section (on the left) and cross section (on the right) of a dampener turbolizer;
(8) FIG. 7 shows a cross section of a dampening and retaining screw conveyor.
(9) In the flow diagram in FIG. 1 of a variant for carrying out the method, cereal having a defined grinding moisture is supplied from a tempering bin (not shown) to the process. The cereal first of all passes through a magnet 1 for sorting out metallic parts. The cereal is subsequently supplied to a dampener turbolizer 2 which has a water supply 3 for dampening the cereal. The dampener turbolizer 2 is explained in more detail in the description of FIG. 6. The dampened cereal is subsequently supplied to a first device for treatment of the surface of the cereal by peeling, namely a “light peeler” 4; the latter is explained in more detail in conjunction with FIG. 2 and FIG. 3. However, instead of a light peeler, a peeler 12 may also be used; the latter is explained in more detail in conjunction with FIGS. 4 and 5. The fiber fraction leaving the light peeler 4 (or peeler 12) can be supplied for a further use (not illustrated). The cereal fraction is conducted through an aspiration passage 5. The loose parts which were not removed by the screen jacket of the light peeler are sucked off here. The cereal is then supplied to a depot 6 in which it can be temporarily stored in order to compensate for different capacities of the individual process steps. It can be ensured by means of a pair of scales 7 that defined quantities of cereal are supplied to the subsequent process stages, which is essential in particular for the later dampening. The cereal is dampened and at the same time conveyed in a dampening screw conveyor 8; the dampening screw conveyor 8 is fed with water via a water supply 9. The dampened cereal is subsequently conditioned again in a retaining screw conveyor 10. The construction of the dampening screw conveyor 8 and retaining screw conveyor 10 is identical except for the water supply and is explained in more detail in conjunction with FIG. 7. The dampened cereal is again guided past a magnet 11 in order to sort out any metallic contamination. The cereal is subsequently supplied to a second device for treatment of the surface of the cereal by peeling, in this case to a peeler 12; the latter is explained in more detail in conjunction with FIG. 4 and FIG. 5. However, in this method step, a light peeler 4 can alternatively also be used if a more gentle treatment with less abrasion of husk material is desired. The fiber fraction leaving the peeler 12 can be supplied for a further use (not illustrated). The cereal passes through a further aspiration passage 13 and a further magnet 14 and is subsequently supplied to the grinding process.
(10) FIG. 2 and FIG. 3 illustrate the light peeler 4 in more detail. The cereal is supplied to the light peeler 4 via a product inlet 15 and passes to a feed screw 20. The light peeler 4 has a stator 19 and a rotor 25. A treatment space 18 for the cereal is formed between the rotor 25 and stator 19 and also screen plates 27 (FIG. 3). The distance between the rotor 25 and stator 19 can be reduced at the top and bottom by putting the segments 41 thereunder in order to obtain a more intensive treatment of the process product. The distance between the screen plates 27 and rotor 25 can likewise be adjusted; a greater distance is associated with a more gentle treatment of the process product. The rotor 25 has a hollow shaft 26 which is driven via a motor 23. The hollow shaft has air openings 24 via which air can be supplied to the treatment space 18. By regulation of the backing-up devices 21 and 22, the intensity of the treatment in the treatment space 18 can be regulated by the backing-up pressure of the cereal in the light peeler 4 being adjusted. The fiber fraction leaves the light peeler 4 via the outlet 16; the treated cereal leaves the light peeler 4 via the outlet 17.
(11) The peeler 12 is illustrated in more detail in FIG. 4 and FIG. 5. Parts having substantially the same function are referred to with the same reference numbers as in the light peeler 4. The cereal is supplied to the peeler 12 via a product inlet 15 and passes to a feed worm 20. The peeler 12 has a stator 19 and a rotor 25. A treatment space 18 for the cereal is formed between the rotor 25 and stator 19 and also screen plates 27 (FIG. 5). The distance between the rotor 25 and stator 19 can be reduced at the top and bottom by putting the segments 41 thereunder in order therefore to obtain a more intensive treatment of the process product. The distance between the screen plates 27 and the rotor 25 can likewise be adjusted; a larger distance is associated with a more gentle treatment of the process product. The rotor 25 has a hollow shaft 26 which is driven via a motor 23. The hollow shaft has air openings 24 via which air can be supplied to the treatment space 18 by means of a ventilator 28, as a result of which the severing of the husk fraction can be made easier and completed. The treatment space 18, which is narrower in the peeler 12 in comparison to the light peeler 4, also intensifies the treatment of the cereal (cf. FIG. 3). By regulating the backing-up devices 21 and 22, the intensity of the treatment in the treatment space 18 can be regulated by the backing-up pressure of the cereal in the peeler 12 being adjusted. The fiber fraction leaves the peeler 12 via the outlet 16; the treated cereal leaves the peeler 12 via the outlet 17.
(12) FIG. 6 shows the dampener turbolizer 2 in detail. The cereal is supplied to the dampener turbolizer 2 via the product inlet 34 and is conducted through the dampener turbolizer in a helical direction (indicated by the arrow line in the interior of the dampener turbolizer 2). Water is supplied to the interior of the dampener turbolizer 2 in a metered manner via a water feed (not shown in detail). An upper shaft 30 and a lower shaft 31 are arranged in the interior of the dampener turbolizer 2; paddles 32 and 33 are provided on said rotating shafts in such a geometry and arrangement that the above-described, helical conveying movement is achieved. The shafts 30 and 31 are driven via a common motor 29. The dampened cereal leaves the dampener turbolizer via the product outlet 35.
(13) FIG. 7 shows a retaining screw conveyor 10 in detail. The cereal is supplied to the retaining screw conveyor via a product inlet 36. A shaft 38 on which paddles 40 are provided in such a geometry and arrangement that a conveyor movement is achieved is arranged in the interior of the retaining screw conveyor 10. The cereal leaves the retaining screw conveyor via the product outlet 37. The shaft 38 is driven by the motor 39. A dampening screw conveyor (not shown in detail) can be formed in an analogous manner, but with a water supply preferably being provided in the front part of the interior in the product flow direction.
(14) The following results were obtained (by way of example) with the method according to the invention:
(15) Swiss quality wheat with a storage moisture of 12.6% by weight and an ash content of 1.83% with reference to the dry substance was used as the cereal. Prior to the experiment, the wheat was dampened to a moisture content of approximately 16% by weight. The subsequent tempering time prior to the experiment lasted 18 h.
(16) A dampener turbolizer 2 was used for the dampening. The treatments of the surface were carried out using a peeler 12 (MHXM-W; Buhler AG).
(17) The peeler 12 was always operated at the following settings: Product input rate: 3 t/h Rotational speed of the rotor: 335 rpm Screen perforation: 1.1 mm×12 mm Distance of rotor from segment 41: 13 mm Distance of rotor from screen: 8 mm.
(18) Prior to each surface treatment in the peeler 12, dampening took place in the dampener turbolizer (below: experiments 1 to 4), with a flow time through the dampener turbolizer of approximately 0.3 minute, and with the following quantities of water supplied for the dampening: Experiment 1: 0.2% by weight Experiment 2: 0.4% by weight Experiment 3: 0.6% by weight Experiment 4: 1.4% by weight
(19) Subsequently, a further husk fraction was separated off after dampening in a dampening screw conveyor followed by a retaining screw conveyor (below: experiment 5). This dampening required 2% by weight of water to be supplied, with a retaining and conditioning time in the dampening screw conveyor and the retaining screw conveyor of a total of 3 minutes prior to entry into the peeler 12.
(20) The fractions obtained in experiments 1-5 were characterized as follows:
(21) TABLE-US-00001 Experiment # 1 2 3 4 5 Isolated fraction in % 0.36 0.43 0.50 1.76 1.4 by weight of the total grain used Ash 1.90 1.81 1.86 2.11 3.37 Total dietary fibers in 88.0 86.5 85.1 86.4 61.2 % by weight Starch in % by weight 2.99 4.09 4.09 2.08 12.8
(22) It is apparent from the above results that, with the method according to invention and with the use of a plant according to the invention, husk components of the cereal can be selectively isolated and successively severed without the endosperm being significantly damaged. Damage to the endosperm can at most be assumed only in fraction 5, since the starch content here has after all risen to 12.8% by weight. Nevertheless, this fraction can still also be used, since it still also contains 61.2% by weight of total dietary fibers—i.e. primarily contains the latter.
(23) With the fraction according to experiment 1, essentially all of the contaminations have already been removed. Therefore, combining the fractions according to experiments 2 to 4 (if appropriate also including the fraction according to experiment 5, see above) results in a highly pure total dietary fiber fraction which can be supplied for further use in foodstuffs.
