METHOD OF TREATING A FEED MATERIAL

Abstract

The present invention relates to a method of treating a raw feed material, the method comprising a grinding step, an enzymatic treatment step, and a drying step, wherein the raw feed material is ground to obtain a meal in the grinding step, water is added and mixed into the meal to obtain a mixture, which is then subjected to an enzymatic treatment step with an enzyme preparation, to obtain an enzymatically treated mixture. The enzymatically treated mixture is dried in the drying step. The grinding process is adjusted in such way as to deliver a meal that has a particle size, measured as d50, between ≥100 μm and ≤1000 μm, whereas water is added to achieve a total water content of between ≥15% w/w and ≤40% w/w.

Claims

1. A method of treating a raw feed material, the method comprising a grinding step, an enzymatic treatment step, and a drying step, wherein a) the raw feed material is ground to a obtain a meal in the grinding step, b) water is added and mixed into the meal to obtain a mixture, which is then subjected to an enzymatic treatment step with an enzyme preparation, to obtain an enzymatically treated mixture, and c) the enzymatically treated mixture is dried in the drying step, and wherein further in step a), the grinding process is adjusted in such way as to deliver a meal that has a particle size, measured as d50, between ≥100 μm and ≤1000 μm in step b), water is added to achieve a total water content of between ≥15% w/w and ≤40% w/w

2. The method according to claim 1, wherein, in step b) water is added to the meal to obtain a resulting water activity of ≥0.8.

3. The method according to claim 1, which method further comprises at least one step selected from the group consisting of: at least one analysis step for determining key parameters of the raw feed material or an intermediate material, and/or a hydrothermal treatment step to degrade fibres comprised in the raw feed material or an intermediate material.

4. The method according to any of the aforementioned claims, wherein the drying step serves to reduce the total water content of the feed material thus treated to ≤8% w/w.

5. The method according to any of the aforementioned claims, wherein the grinding step is performed with a hammer mill or a ball mill.

6. The method according to any one of the aforementioned claims, wherein the enzymatic treatment step is performed in one or more batch reactors.

7. The method according to claim 6, wherein multiple batch reactors are operated in a time-displaced manner.

8. The method according to any of the aforementioned claims, wherein the drying step serves to denaturate the enzymes added to the feed material.

9. The method according to any of the aforementioned claims, wherein the analysis step serves to determine at least one parameter selected from the group consisting of: digestible protein content, water activity, total water content, fibre content, and/or content of antinutritional factors.

10. The method according to any of the aforementioned claims, wherein the one or more enzymes added to the feed material are selected from the group consisting of: protease phytase, and/or carbohydrase (cellulase, hemicellulose, alpha-galactosidase)

11. The method according to any of the aforementioned claims, wherein the one or more enzymes added to the feed material are capable of degrading, digesting or hydrolyzing one or more anti nutritional factors (ANF).

12. The method according to any of the aforementioned claims, wherein one or more enzymes, and their dosage are selected according to the outcome of the analysis step.

13. The method according to any of the aforementioned claims, wherein the raw feed material is at least one selected from the group consisting of: soy bean meal, corn, rapeseed, sun flower meal, barley, wheat, and/or DDGS (dried distillers grains with solubles).

14. The method according to any of the aforementioned claims, wherein for mixing water into the meal a mixer is used which combines a shaft paddle mixer and a lump breaker.

15. A feed material treated with a process according to any of the aforementioned claims.

16. A feedstuff comprising a feed material according to claim 15.

17. The feedstuff according to claim 16, which is provided as at least one of pellets powder, and/or meal.

18. A system for carrying out the method according to any of the aforementioned claims, said system comprising a mill to grind a raw feed material to obtain a meal, a water supply to add water to the meal, a mixer for mixing water into the meal, an enzyme supply to add an enzyme preparation to the watered meal, a fermenter for the enzymatic treatment of the thus treated watered meal, and a dryer to dry the enzymatically treated meal.

19. The system according to claim 18, which system further comprises at least one device selected from the group consisting of: an analysis unit for determining key parameters of the feed material, and/or a hydrothermal treatment unit capable to degrade fibres comprised in the feed material or the meal obtained therefrom.

20. A feedmill comprising a system according to any of claims 18-19.

Description

SHORT DESCRIPTION OF THE FIGURES

[0169] FIG. 1 shows the relationship between water activity and enzyme activity. Generally, the higher the water activity, the better the enzyme activity is.

[0170] This means, from this point of view, one would have an incentive to increase the water activity to a value as high as possible to obtain a maximum possible substrate conversion. However, in the present context, energy consumption considerations play an important role, because drying an aqueous slurry comprising a feed meal is an energy intensive process. From this point of view, one would have the incentive to add only small amounts of water to the feed meal, to keep the total water content low, and hence reduce subsequent drying costs.

[0171] FIG. 1B shows the relationship between water activity and total water content of a slurry comprising a meal of a water absorbing feed material. It can be seen that said relationship relies on a saturation curve. Once the water absorbing meal is saturated, the water activity remains stable, because further added water is no longer soaked up by the meal.

[0172] FIG. 1C shows such saturation curve in an experiment with a more finely ground meal. The inventors have now shown that the ratio between the total water content and water activity depends on the milling grade of the grinding process. The finer the resulting meal is, the more water it absorbs, hence the water activity saturation curve is shifted to the right, as indicated by the arrow in FIG. 1C.

[0173] FIG. 2A shows a schematic illustration of the first two steps of the process, i.e., the grinding step and the enzymatic treatment step. FIG. 2B shows a schematic illustration of the follow-on step of the process, i.e., the drying step.

[0174] FIG. 3 shows the composition % DM and non-starch polysaccharides (NSP) species in different crops, as shown in the following tables:

TABLE-US-00003 TABLE 1 Composition of maize, wheat and soybean meal (% DM) (from Graham and Aman 2014) Analytical component Soybean (% DM) Maize Wheat meal Ash 1.4 1.7 6.6 Crude protein 9.1 11.0 53.3 Crude fat 4.6 2.4 2.8 Sugars 2.6 3.5 3.5 Oligosaecharides 0.3 0.2 5.3 ructans 0..6 1.8 0.9 Starch 69.0 66.5 0 Crude fibre 2.3 Acid deterent fibre 2.5 3.4 4.9 Neutral detergent fibre 9.2 10.0 8.4 Non-starch polysaccharides + 10.0 + 0.8 11.0 + 1.0 20.8 + 1.0 lignin Non-starch polysaccharides rhamnose Tr Tr 0.7 arabinose 2.3 2.7 2.3 xylose 3.1 3.9 1.5 mannose Tr Tr 1.4 galactose 0.5 0.2 5.3 glucose 3.4 3.7 6.0 uronie acids 0.7 0.5 3.8

TABLE-US-00004 TABLE 2 The types and levels on non-starch polysaccharides present in some cereals grains and their by-products (% DM) (from Englyst (1989) Cereal Arabinoxylan β-glucan Cellulose Mannose Galactose Uronic acid Total Wheat.sup.A Soluble 1.8 0.4 — t 0.2 t 2.4 Insoluble 6.3 0.4 2.0 t 0.1 0.2 9.0 Barley.sup.A Soluble 0.8 3.6 — t 0.1 t 4.5 insoluble 7.1 0.7 3.9 0.2 0.1 0.2 12.2  Rye.sup.A Soluble 3.4 0.9 — 0.1 0.1 0.1 4.6 Insoluble 5.5 1.1 1.5 0.2 0.2 0.1 8.6 Oats.sup.A Soluble 0.8 2.8 — t 0.1 0.1 3.8 Insoluble 14.7  — 10.1  0.2 0.1 1 24.5  Triticale.sup.B Soluble 1.3 0.2 —  0.02 0.1 0.1 1.7 insoluble 9.5 1.5 2.5 0.6 0.4 0.1 14.6  Sorghum.sup.B Soluble 0.1 0.1 — t t 1 0.2 Insoluble 2.0 0.1 2.2 0.1  0.15 t 4.6 Corn.sup.B Soluble 0.1 t — t t t 0.1 insoluble 5.1 — 2.0 0.2 0.6 t 8.0 Rice (pealed).sup.B Soluble t 0.1 — t 0.1 0.1 0.3 Insoluble 0.2 — 0.3 t t t 0.5 Wheat pollard.sup.A Soluble 1.1 0.4 — t 0.1 0.1 1.7 insoluble 20.8  — 10.7  0.4 0.7 1.0 33.6  Wheat bran.sup.B Soluble 2.6 0.2 — t 0.1 0.3 3.2 insoluble 26.0  — 10.8  0.1 0.6 0.9 38.4  Rice bran (defatted).sup.B Soluble 0.2 t — t 0.2 t 0.5 Insoluble 8.3 — 11.2  0.4 1.0 0.4 21.3 

[0175] FIG. 4 shows the relationship between particle size (PSD, determined as d50 [μm] with respective sieves, as described elsewhere herein) and energy consumption (kWh/t) in the milling process, as obtained in a vertical Hammer mill with a 22 KW electric motor. It can be seen that with particle sizes of smaller than 230 μm, the energy consumption increases drastically. FIG. 4 shows also that with smaller particle size, also the hourly capacity of the mill is reduced. The raw data are as follows:

TABLE-US-00005 Sieve mesh Energy Capacity d50 size mm Consumption kWh/t ton/h 160 0.4 20.78 0.9 230 0.6 14.38 1.3 260 0.8 11.69 1.6 280 1 9.35 2 295 1.25 7.48 2.5 300 1.5 6.23 3 340 2 4.56 4.1 400 2.5 4.07 4.6 440 3 3.74 5 480 4 3.34 5.6

[0176] FIG. 5 shows the results of FIG. 4 (bar graphs), plus also the obtained water activity with different water contents. aW20 is the resulting water activity at a total water content of 20% w/w, aW50 is the resulting water activity at a total water content of 50%, and so forth. aW has been determined with a AWTherm lab analyzer (Rotronic AG, CH). It can be seen that at a total water content of 20% w/w, the water activity is quite independet from the milling grade, oscillating around 0.8.

[0177] FIG. 6 shows the relationship between total water content (% w/w) and water activity in corn meal and soy bean meal (SBM). Particle size was determined by a sieve having 1 mm screen size (D90<600 μm).

[0178] FIG. 7 shows the relationship between total energy costs (for milling and drying) in soy bean meal (SBM). It is clearly visible that a total water content of 30% w/W or higher escalates the energy costs, mainly because of the increased energy demand for drying. Drying has been performed in a convective dryer.

[0179] Product Final moisture level was 10%/w, with a capacity of 15 t/h. The energy consumption was calculated per ton of dried product, as shown in the table below

TABLE-US-00006 Inlet dryer moisture level % E.Consumpt. kWh/t 20 113 25 180 30 257 40 450

[0180] FIG. 8 shows that, for obtaining a homogeneous mixing result prior to the fermentation, a moisture content in the meal is decisive. In the experiments, underlying FIG. 8, a meal comprising soybean and corn ground on a hammer mill with 1 mm screen size was used. Water was added to achieve a total water content of 10, 20, 30, 40 and 50% w/w. After mixing for 5 minutes in a 1000 l Single shaft paddle mixer with chopper knifes, an homogeneity test was done using the Chloride Titrator method with an NaCl marker added in concentration of 0.3% of the dry meal. The results are presented as the coefficient of variation (CV), with a CV of <10 representing an excellent mixing result/high homogeneity, and a CV or >20 representing a poor mixing result/low homogeneity. CV relates the standard deviation to the mean in the form of a percentage. Therefore, the CV is an effective tool for describing the variability present in the sample population.

[0181] The methodology is described in, inter alia, Fahrenholz and Stark, 2014, Herrman and Behnke, 1994. Traylor et al. 1994, Wicker and Poole, 1991 and Wilcox and Unruh, 1986, the contents of which are incorporated herein by reference for enablement purposes. The results show that a conventional mixer cannot handle meals with a total water content of higher than about 8% w/w. For meals comprising a water content of about 20% or higher, a custom made mixer was used that combines a single or twin shaft paddle mixer and a lump breaker, the latter comprising tulip knifes or high speed choppers.

[0182] FIG. 9 shows a mixer that can be used in the process according to the present invention due to its capability to obtain better homogeneity results in meal-water mixtures having a water content of >10% w/w., than a conventional shaft paddle mixer. The mixer of FIG. 9 is disclosed in EP publication EP3573744.

[0183] The mixer comprises a mixing chamber comprising a de-agglomerator (10) with a de-agglomeration shaft (11) with de-agglomeration means (12a, 12b, . . . ), a mixer (20) with a mixer shaft (21) with two or more mixing paddles (22a, 22b, . . . 23a, 23b, . . . , 24a, 24b, . . . ), arranged for mixing and impelling particles and powders in an upstream direction (u) towards the de-agglomerator (20).

[0184] The de-agglomeration shaft (11) is arranged above, and in parallel with said mixer shaft (21). The mixing chamber (1) further comprises a first portion (la) of said mixing chamber (1) having an inner profile adjacent and curved about an upper part of said de-agglomerator (10) and arranged to guide particles and powders impelled by said two or more mixing paddles (22a, 22b, . . . 23a, 23b, . . . , 24a, 24b, . . . ) over said de-agglomeration shaft (11). The mixer further comprises one or more spray means (30) arranged adjacent, above, and at a downstream particle flow side of said de-agglomerator (10), for providing a liquid spray (31) into a downstream flow from said mixing chamber (1).

REFERENCES

[0185] Ramos M., Carabanio R., Boisen S., 1992. An in vitro method for estimating digestibility in rabbits. Journal of Applied Rabbit Research, 15, 938-946. [0186] Boisen, S. & Fernandez, J. A. (1991 a). In vitro digestibility of energy and amino acids in pig feeds. In Digestive Physiology in Pigs, pp, 231-236 [M. W. A. Verstegen, J. Huisman and L. A. den Hartzog, editors]. Wageningen: Puduc. [0187] Boisen S. & Eggum B. O (1991). Critical evaluation of in vitro methods for estimating digestibility in simple stomach animals. Nutrition Research Reviews (1991), 4, 141-162. National Institute of Animal Science, Foulum, DK-8830 Tjele, Denmark [0188] Graham H, Aman P (2014) Carbohydrate chemistry, analysis and nutrition. In Proceedings of poultry feed quality conference. (Ed. T R Walker) Kuala Lumpur, Malaysia, 21-22 Aug. 2014. (Asian Agribusiness: Singapore) [0189] Englyst H (1989) Classification and measurement of plant polysaccharides. Animal Feed Science and Technology 23, 27-42 [0190] American Society of Agricultural and Biological Engineers. 2008 R2012. Method of Determining and Expressing Fineness of Feed Materials by Sieving. In A. S. Engineers, American Society of Agricultural and Biological Engineers: St. Joseph, Mich. [0191] Pfost, H. B. 1976. Grinding and Rolling. Feed Manufacturing Technology II. pp. 71-85. American Feed Manufacturers Association: Arlington, Va. [0192] Stark, C. R. and Chewning, C. G. 2012. The effect of sieve agitators and dispersing agent on the Fahrenholz, A. and C. R. Stark. 2014. Mixing feeds and mixer test procedures for batch mixers. Feed Additive Compendium. Pages 105-108. Ed. T. Lundeen, Minnetonka, M N: Miller Publishing Co. [0193] Herrman, T. and K. Behnke. 1994. Testing mixer performance. MF1172. Kansas State University Agricultural Experiment Station and Cooperative Extension Service Bulletin, Manhattan, Kans.: Kansas State University [0194] Traylor, S. L., J. D. Hancock, K. C. Behnke, C. R. Stark and R. H. Hines. 1994. Mix time affects diet uniformity and growth performance of nursery and finishing pigs. KSU Swine Day Report, Pages 171-175. Kansas State University Agricultural Experiment Station and Cooperative Extension Service, Manhattan, Kans.: Kansas State University [0195] Wicker, D. L. and D. R. Poole. 1991. How is your mixer performing? Feed Management (42):40. [0196] Wilcox, R. and D. Unruh. 1986. Feed manufacturing problems-feed mixing times and feed mixers. MF-829, Kansas State University Agricultural Experiment Station and Cooperative Extension Service, Manhattan, Kans.: Kansas State University