WO1999021656A1

WO1999021656A1 - A process for conditioning grain

Info

Publication number: WO1999021656A1
Application number: PCT/DK1998/000460
Authority: WO
Inventors: Ramiro Martinez; María Eugenia Ruiz GARCIA; María Isabel Díaz LOPEZ-BECERRA; Juan Manuel Alvarez Frias
Original assignee: Novo Nordisk A/S
Priority date: 1997-10-29
Filing date: 1998-10-23
Publication date: 1999-05-06
Also published as: AU9622098A

Abstract

By the addition of enzyme(s) the efficiency of the conditioning process for the treatment of grain prior to milling can be substantially improved thereby providing for a substantial increase in the yield of flour, and/or reduction of the conditioning time, and/or improvement of the rheological properties of the flour/bran produced.

Description

Title: A Process for Conditioning Grain

FIELD OF THE INVENTION

The present invention relates to a process for conditioning grain in connection with the milling of flour. The invention furthermore relates to compositions for use in such a process.

BACKGROUND OF THE INVENTION

The milling of grain into flour etc. generally comprises a number of steps of which the first step is the conditioning of the grain to prepare it for the actual grinding and separation processes that ultimately provide for a number of final products, such as flour (s) , and bran(s) .

A number of conditioning processes have been developed for the industrial milling of wheat. The object of conditioning, the central feature of which is the addition of water to grain, is to modify the wheat kernel so that milling can be performed under optimal conditions. Water is added, usually to obtain a moisture content of =16%, and, after storage, which generally lasts several hours, additional water is often added before milling. The optimal amount of water as well as tempering time depends on the properties of the grain. When used, heat is also an important factor, with the mode of application varying as to the process. Conditioning influences not only milling quality but also the technological quality of the end flour product.

The primary aim of conditioning is to change the mechanical characteristics of the different tissues of the kernel and thereby improve the separability of the endosperm from the outer layers of the grain, notably the bran. The addition of water also triggers a number of biochemical reactions in the kernel, thereby modifying characteristics of its components. These modifications can be amplified by increasing the temperature and the moisture content.

However, improvements in the conditioning of grain in order to obtain an improved separation between the various components, and especially improvements in the yield of the flour in relation to the yield of the bran, are still in demand. SUMMARY OF THE INVENTION

It has now surprisingly been found that by adding enzym (s) the efficiency of the grain conditioning process can be substantially improved thereby providing for a substantial increase in the yield of flour, and/or reduction of the conditioning time, and/or improvement of the properties of the flour/bran produced.

DETAILED DESCRIPTION OF THE INVENTION According to the invention a process for the conditioning of grain is provided, wherein the grain is treated with an enzyme preparation.

It has been found that the process of the invention enhances the yield of flour obtained thereby increasing the value of product, as well as improving the rheological properties of the flour, thereby increasing the usefulness of the product so obtained.

Preferably, the process of the invention provides an enhanced yield of flour. Accordingly, an embodiment of the invention relates to a process for the conditioning of a grain of the invention, wherein an increased yield of flour is obtained as compared to the yield of flour obtained when performing the same process without the addition of the enzyme preparation. Examples of such increased flour yields, obtained by a process of the invention, are demonstrated in working example 1 and 3 herein (vide infra) .

A further advantage that may be a reduced conditioning time while the present flour yield is still obtained thereby increasing the throughput in the milling plant.

See working example 2 (vide infra) for an example of such a reduced conditioning time while the present flour yield is still obtained.

One example of an enzyme preparation according to the invention is an enzyme complex as described in US Patent No.

4,478,939 or equivalent enzyme complexes. Another example of an enzyme preparation according to the invention is at least one enzyme activity, or a mixture of the enzyme activities selected from the group comprising proteases, cellulases, pectinases, he i- cellulases, xylanases, glucanases, β-glucanases, glucose oxidases, laccases, and amylases.

Such enzyme complexes are available from Novo Nordisk A/S and are known under trade names such as Cereszyme™ or Viscozyme^®, or as SP249; or they can be produced, for example as described in US Patent No. 4,478,939, by fermentation of micro-organisms such as fungi, especially filamentous fungi, such as those belonging to the genus Aspergillus, especially A. aculeatus, and A. japonicus. The single enzyme activity or the preparations comprising mixtures of such activities can be produced according to known techniques.

Among the activities mentioned above it has been found that the most important ones are pectinase, hemicellulase, xylanase, cellulase, glucose oxidase, and laccase activities.

When performing the process of the invention it is preferred that the enzyme preparation is added in an amount of between 1 g or cm³ enzyme preparation per t of grain and 50000 g or cm³ enzyme preparation per t of grain, preferably between 10 g or cm³ enzyme preparation per t of grain and 2000 g or cm³ enzyme preparation per t of grain, and most preferably between 100 g or cm³ enzyme preparation per t of grain and 2000 g or cm³ enzyme preparation per t of grain.

It has been found that the best economy in respect of performing the complete milling process including the grinding of the grain into flour and bran is obtained if the process of the invention is performed for a time period of from about 4 hours to about 32 hours, preferably from about 6 hours to about 24 hours.

Generally, the preferred conditioning time depends on the actual type of grain and in particular whether it is a soft, mid hard or hard grain.

In the present context a "soft grain" denotes a grain with the following average characteristics: W=80-150, P/L=0.2- 0.5 as measured on an Alveograph (W: strength; P: Tenacity; L: extensibility) ; a "mid hard grain" denotes a grain with the following average characteristics W=150-300, P/L= 0.5-0.8 as measured on an Alveograph (W: strength; P: Tenacity; L: extensibility) ; and a "hard grain" denotes a grain with the following average characteristics: W=300-400, P/L= 0.8-1 as measured on an Alveograph (W: strength; P: Tenacity; L: extensibility) .

For further details concerning the measurement of said grain characteristic with an Alveograph reference is made to the Materials and Methods section herein (vide infra) . Preferably, when the grain is a soft or mid hard grain the process of the invention is performed for a time period of from about 4 hours to about 18 hours, preferably from about 4 hours to about 12 hours; and when the grain is a hard grain the process of the invention is performed for a time period of from about 12 hours to about 32 hours, more preferably from about 12 hours to about 28 hours and most preferably from about 15 hours to about 24 hours.

The process of the invention has been found to provide fine results if the grain has a humidity of 10% to 50%. In this context humidity means % water present in the grain during the conditioning process.

Also, it has been found that the process of the invention works best if the treatment is performed at a temperature between 5°C and 60°C, preferably between 10°C and 40°C, and more preferably between 20°C and 30°C.

The process of the invention can be used for the conditioning of any cereal grain, such as barley, rye, corn, rice, or legume grain, such as alfalfa, soy beans.

Preferably the grain is wheat. Examples of industries which advantageously may use a process of the invention are industries such as the i) the milling industry for e . g. getting a higher yield of flour; ii) the brewing industry to e .g. get an improved malt from barley; and iii) the starch industry to e.g. get a higher yield of flour or to modify the flour composition such as an fibre enrichment of the flour. Accordingly, further embodiments of the invention relate to use of a process for the conditioning of grain, according to the invention, in the milling industry; the brewing industry and/or the starch industry.

MATERIALS AND METHODS

Grain: Wheat that has a humidity or moisture content below 16% as available on the market.

Enzyme preparations:

Cereszyme^® (Novo Nordisk A/S, Denmark) : A mixture of hemicellulase, cellulase and pectinase activities with other minor activities.

Viscozyme^® (Novo Nordisk A/S, Denmark) : An enzyme complex produced by a filamentous fungus of the genus Aspergillus, especially from the species A. aculeatuε .

Activities present in Viscozyme^® Pectinases:

Pectin lyase, pectin esterase, polygalacturonase I, polygalactu- ronase II, polygalacturonase III, rhamnogalacturonan acetyl esterase, rhamnogalacturonase I, rhamnogalacturonase II, pectin acetyl esterase, rhamnosidase(s) , galacturonosidase(s) , glucoronosida- se(s) .

Proteases:

Protease I, protease II, exo peptidases.

Esterases, Lipases: lipase(s) , phospholipase(s) , feroylic acid esterase.

Aylases: α-amylase(s) , β-amylase(s) , α-glucosidase(s) , β-glucosidase(s) .

Chitinases: endo chitinase, exo chitinase. Hemicellulases . Cellulases:

Arabinase, arabinofuranosidase I, arabinofuranosidase II, endoglucanase I, endoglucanase II, endoglucanase III, endoglucanase IV, galactanase, α-galactosidase, β-galactosidase, mannanase, xylan acetyl esterase, xylanase I, xylanase II, xylanase III, xylo galacturonase, mannosidase, manan acetyl esterase, cellobioase(s) .

Assessment of flour quality: Flour Yields:

A CHOPIN Laboratory Mill (model CD1) available from Chopin, France was used for the milling of the grain after conditioning. The mill separates the ground wheat into two fractions, flour and bran.

Rheological properties:

The rheological properties of the flour produced were examined using an Alveograph (available from CHOPIN, France) in accordance with the manufacturer's protocol.

These measurements provided the following properties: P: Tenacity L: Extensibility W: Strength expressed in mm.

EXAMPLES

EXAMPLE 1

Wheat treatment with Cereszyme^® during conditioning time:

Three tests were performed using the following amounts and conditions: 1: 600 g of wheat, wetted to 16% humidity _f resting 24 hours (standard) . 2: 600 g of wheat, wetted to 16% humidity, resting 24 hours +

400 cm³ Cereszyme® per ton grain 3: 600 g of wheat, wetted to 16% humidity, resting 6 hours +

400 cm³ Cereszyme® per ton grain

The results from the milling in the Chopin mill and the Alveograph measurements are indicated in Table I and Table II, respectively.

Table I: Flour Yields

Table II: Rheological properties

From Tables I and II it is seen that the conditioning process of the invention provides for a substantial improvement in respect of both yield and rheological properties of the flour produced. It can also be seen that even when reducing the conditioning time substantially (24 hours => 6 hours) a substantial improvement was obtained in the yield.

EXAMPLE 2

Wheat treatment with Viscozyme^® during conditioning time: Two types of wheat grain ( (A) German wheat check and (B) French wheat check) were tested by conditioning samples thereof without enzyme for 14 hours and with an enzyme product

(Viscozyme^®) for different periods.

Both types of wheat are considered mid hard wheat with average characteristics W=150-300, P/L= 0.5-0.8, measured on an Alveograph as described above.

The tests were performed by using 500 cm³ enzyme per ton grain

Tables III and IV show the results.

Table III Flour yields

The results confirm once more that a considerably shorter conditioning time can be used by the process of the invention and still obtain the same yields as obtained by the traditional conditioning time. Viscozyme is a multi-enzyme complex comprising a wide range of carbohydrases, including arabinase, cellulase, β-glucanase, hemicellulase and xylanase. A more detailed listing of the activities present are given above.

EXAMPLE 3

Evaluation of the influence on yields of flour a hard wheat pre- treated with Viscozyme during conditioning time.

Wheat: GAZUL, hard wheat, average characteristics: W=300-400, P/L= 0.8-1.

Enzyme Dose: 400cm3 of Viscozyme pr lton of wheat.

Conditioning time: 24 hours

Assessments: Alveograph parameters: W: Baking Strength, P: Tenacity, L: Extensibility, P/L: ratio, (see above)

Table V: Yields of flour produced from wheat processed.

Technical Conclusions:

The process of the invention significantly increases the flour yield obtained from the hard wheat.

Claims

PATENT CLAIMS

1. A process for the conditioning of a grain characterised in that the grain is treated with an enzyme preparation.

2. The process of claim 1, wherein said treatment is performed for a period of time from about 4 hours to about 32 hours, preferably from about 6 hours to about 24 hours.

3. The process of claim 1 or 2 , wherein said grain is a soft grain or a mid hard grain and wherein said treatment is performed for a period of time from about 4 hours to about 18 hours, preferably from about 4 hours to about 12 hours.

4. The process of claim 1 or 2 , wherein said grain is a hard grain and wherein said treatment is performed for a period of time from about from about 12 hours to about 32 hours, more preferably from about 12 hours to about 28 hours and most preferably from about 15 hours to about 24 hours.

5. The process of any of claims 1 to 4, wherein said enzyme preparation comprises at least one enzyme activity selected from the group comprising proteases, cellulases, pectinases, hemicellu- lases, xylanases, glucanases, ╬▓-glucanases, glucose oxidase, laccase and amylases.

6. The process of claim 5, wherein said at least one enzyme activity is chosen from the group comprising pectinase, hemicellulase, xylanase, cellulase, glucose oxidase, and laccase activities.

7. The process of claims 5 or 6, wherein said enzyme preparation is an enzyme complex known as SP 249 or by the trade names Cereszyme┬« or Viscozyme┬«.

8. The process of claims 5 or 6, wherein said enzyme preparation is an enzyme complex that can be produced as described in US Patent No. 4,478,939 by fermentation of microorganisms such as fungi, especially filamentous fungi, such as those belonging to the genus Aspergillus, especially A. aculeatus , and A. japonicus .

5 9. The process of any of claims 1 to 8, wherein said grain is selected from the group comprising cereal grain, barley, rye, corn, rice, and legume grains, such as alfalfa, soy bean, and preferably wheat.

10 10. The process of any of claims 1 to 9, wherein said grain has a humidity content of 5% to 50%, preferably from 10% to 40% or from 12% to 30%.

11. The process of any of claims 1 to 10, wherein said 15 treatment is performed at a temperature between 5┬░C and 60┬░C, preferably between 10┬░C and 40┬░C, and more preferably between 20┬░C and 30┬░C.

12. The process of any of claims 1 to 11, wherein said 20 treatment is performed by the addition of said enzyme preparation in an amount of between 1 g or cm³ enzyme preparation per t of grain and 50000 g or cm³ enzyme preparation per t of grain, preferably in an amount of between 10 g or cm³ enzyme preparation per t of grain and 2000 g or cm³ enzyme preparation per t of

25 grain, and most preferably in an amount of between 100 g or cm³ enzyme preparation per t of grain and 2000 g or cm³ enzyme preparation per t of grain.

13. The process of any of the preceding claims, wherein an 30 increased yield of flour is obtained as compared to the yield of flour obtained when performing the same process without the addition of the enzyme preparation.