AU2006233185A1

AU2006233185A1 - Dietary Fibre from Plant Material

Info

Publication number: AU2006233185A1
Application number: AU2006233185A
Authority: AU
Original assignee: BESTLAN BANANAS Pty Ltd
Current assignee: BESTLAN BANANAS Pty Ltd
Priority date: 2006-10-25
Filing date: 2006-10-25
Publication date: 2008-05-15
Also published as: AU2008249175A1

Description

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DIETARY FIBRE FROM PLANT MATERIAL

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c FIELD OF THE INVENTION 00 5 The present invention is directed generally to the isolation of dietary fibre from plant material and particularly from plant material of the banana plant. The 0 invention includes a method of processing the plant material to give the dietary fibre, as well as the fibre produced by the method of processing.

BACKGROUND ART It has been known for quite some time that people having a diet high in dietary fibre have lower risk of several diseases. Scientific studies continue to produce new evidence to support the need to increase dietary fibre in the diet.

Dietary fibre is the undigested remains of plant materials, particularly indigestible plant carbohydrates the non-starch polysaccharides). Fibre is found only in foods derived from plants, and all plant food provides some fibre, but the amount of fibre depends on the processing conditions. For instance, unpeeled fruit and vegetables and wholemeal or whole-grain cereal foods (which still contain the outer layers of the grain) will provide the most fibre. Brown rice can contain seven times more fibre than white rice. The exact balance of the various components of dietary fibre (cellulose, hemicelluloses, pectin and lignin) varies between foods.

Dietary fibre can be soluble or insoluble. Soluble fibre includes [-glucans, pectins, gums, mucilages and some hemicelluloses. It dissolves in the gut, to form a viscous gel that slows down the release of some nutrients, particularly the sugar glucose, into the bloodstream; it is therefore good for diabetics. It can also reduce the risk of heart O 2 disease, by reducing blood cholesterol levels. Soluble fibre is present in fruit, vegetables, Spulses kidney beans, baked beans, lentils) and foods containing oats, barley or rye.

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Insoluble fibre includes celluloses, some hemicelluloses and lignin. It has 5~ a sponge-like effect in the gut, soaking up water and swelling in size. This effect 00 produces a feeling of fullness and adds bulk to the gut contents, making waste matter Cc heavier and speeding it through the large intestine, thereby reducing the risk of INO constipation, and possibly even cancers of the digestive system. In the colon, dietary fibre tends to increase faecal bulking due to increased water retention and the insoluble dietary fibre reduces transit time. This is particularly important since the conversion of sterols to carcinogenic polycyclic aromatic hydrocarbons is known to occur with time.

Epidemiological evidence suggests that low faecal weights are associated with an increased risk of cancer of the colon, dietary fibre may also bind toxins, bile acids and carcinogens. Cereal and grain products bread, flour, breakfast cereals, rice, pasta), especially wholemeal varieties, and fibrous vegetables carrots and celery) are primary sources of insoluble fibre.

The overall nutritional balance of diets could be improved by consuming a greater amount of high-fibre foods. However, fibre in an isolated form such as bran (the outer layers of cereal grain, which are removed when grain is milled such as in the preparation of white rice or white flour) is not the answer because bran can actually reduce the absorption of minerals. Fibre is thought to be far more beneficial if it is consumed as an integral part of food, rather than as bran supplements or fibre-containing drinks.

The Food and Drug Administration (FDA) of the United States of America, allows health claims relating to dietary fibre on food labels. Several health claims have been authorised referring to the effects of a high fibre, low fat diet in helping to lower the risk of coronary heart disease and cancer. The FDA has recently approved health claims relating to wholegrain foods and prevention of heart disease and cancers.

O 3 The prior art describes processing of plant material to a dietary fibre

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o product in various forms. WO 2004/069143 describes the processing of plantains or Sbananas to give a fibre product for use in the treatment of inflammatory bowel disease.

The bananas are mashed and boiled in water, and to this mixture is added amylase to hydrolyse starch in the raw material. The fibre product is optionally precipitated with 00 ethanol.

IDUS 6,838,099 describes the processing of corn hull to give a fibre product.

SThe starch and protein in the raw material are removed with an alkali treatment; enzymes are added to the material, and the fibre product is filtered.

US 6,753,019 describes the processing of two or more fruit and/or vegetable extracts to give a fibre product. The juice of the raw material is extracted, and the resulting solid material, when milled and dried, comprises the fibre product.

US 5,622,738 describes a soluble dietary fibre comprising mainly partially hydrolysed hemicellulose, as extracted from vegetable material with alkali, and subsequent enzymolysis.

US 5,112,964 describes processing of rice bran, wheat and grain to give a fibre product. The raw material is treated with amylase to hydrolyse the starch therein.

The hydrolysed starch forms a gel, which is removed. Further processing give the fibre product.

It should be appreciated that the mere reference of a publication is not to be seen as an acknowledgement that the publication forms part of the common general knowledge in Australia and overseas.

N 4 There would be an advantage in having a simple method of processing fruit and vegetables, the method optionally excluding chemical reaction of starch, which would give a high yield of good quality dietary fibre for human or animal consumption.

5 SUMMARY OF THE INVENTION 00 oO \It is an object of the invention to provide a dietary fibre from fruit and/or 0 vegetable material, and a method of processing fruit and/or vegetable material to give the Sdietary fibre, which may overcome at least some of the disadvantages of existing technology or provide a useful or commercial choice.

In one form, the invention resides in a method of preparing a dietary fibre composition from plant material, the method comprising: a.dicing the plant material; b.subjecting the diced material to acid or alkali treatment at room temperature or elevated temperature; c.adding xylanase and/or at least one other enzyme to the treated material to give a crude composition; drying and milling the crude composition to give the dietary fibre composition.

In a second form, the invention resides in a dietary fibre composition when prepared by the method of the first form of the invention.

In another form, the invention resides in a method of preparing a dietary fibre composition from plant material, the method comprising: a. dicing the plant material; b. subjecting the diced material to acid or alkali treatment at room temperature or elevated temperature; and O c. drying and milling the crude composition to give the dietary

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o fibre composition. O 00 5 The plant material will typically be fruit and vegetable plant material. The Cc fruit or vegetable plant material may comprise the fruit, stalks, stems and roots of the plant. A suitable plant is a banana plant. In particular, green (unripe) banana fruit provide a preferred material. Also preferred are the stalks of the banana plant. Both preferred Sforms contain a low level of starch, which is a less desirable component of the fibre composition. In addition, the use of the stalks, which is a waste material from processing bananas, is particularly valuable with respect to adding value to waste.

The plant material can be diced in any manner with any dicing apparatus, for example a simple dicing machine or food-processing-like device can be used. It is preferred that the raw material is diced to from 2 to 20mm in size, more preferably from 4 to 10mm. While not wishing to be bound by theory, it appears that this size is optimal for retaining the structure of the plant cell walls and their components, which are the main constituents of the fibre product.

In an aspect of the invention, the raw material is subjected to a wash which may comprise hydrogen peroxide, cellobiase and xylanase. Any concentrations of these chemicals can be used. However, it is preferred that they are added at from 100 to 500ppm, more preferably at 200ppm. The chemicals can be added at ambient temperature, or the temperature of the mixture of raw material and chemicals can be heated. The mixture of raw material and chemicals is preferably heated for a period of time to assist in the cleaning action of the peroxide, and commencement of the digestive process by the enzymes. More preferably, the mixture of raw material and chemicals is heated to about 70 0 C for about 10 minutes. The mixture can then be cooled to ambient temperature, and filtered.

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O The diced material may be subjected to acid or alkali treatment. The acid In or alkali can be any appropriate acid, for example citric acid, phosphoric acid, nitric acid; or any alkali, for example sodium or potassium hydroxide. Preferably, the alkali is sodium hydroxide, added as a solution in water. The acid is also preferably added as a 00 0solution in water. The solutions can be any useful concentration, but the solutions are ¢€3 Cc preferably from 0.1 to 3.2% solutions.

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SThe acid or alkali treatment can be at ambient temperature, or can be at elevated temperature. Preferably, the mixture comprising the diced material and the acid or alkali solution is heated for a period of time. More preferably, the mixture is heated to about 90C for from 2 minutes to 2 hours, then cooled to ambient temperature, and filtered.

In addition to xylanase, at least one other enzyme is added to this cooled and filtered mixture. The additional enzymes are preferably papain, cellobiase and cellulase. Xylanase is an enzyme which hydrolyses xylans (polysaccharides in plant cell walls); cellulase hydrolyses cellulose in plant fibres and is not found in humans; papain is a protein-cleaving enzyme derived from plants. Papain has a mild soothing effect on the stomach and aids in protein digestion. Cellobiase is a cellulase which is specific to cellobiose, a disaccharide from cellulose hydrolysis.

The enzymes can be added in any amount, but are preferably added from 0.1 to 5% of the dry weight of the mixture.

The mixture containing the enzymes can be held at ambient temperature, or can be at elevated temperature. Preferably, the mixture is heated for a period of time.

More preferably, the mixture is heated to 60 0 C for form 1 minute to 2 hours, then cooled to ambient temperature.

7 The final mixture is milled to a fine powder to give the dietary fibre composition of the invention.

In order that the invention may be more readily understood and put into practice, one or more preferred embodiments thereof will now be described.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a stem and bananas as used in an aspect of the invention.

Figure 2 shows partially diced raw material (banana plant).

Figure 3 shows finished fibre composition.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Having broadly described the invention above, a non-limiting example of the dietary fibre, its synthesis, and its efficacy, will now be given.

Example 1: Preparation of the Dietary Fibre Stalks of the banana plant are washed with hydrogen peroxide, cellobiase and xylanase (200ppm). The mixture is heated to 70 0 C for 10 minutes. The mixture is then cooled to ambient temperature and filtered.

The filtrand is diced into pieces of 4-10mm. The diced material is mixed with citric acid aqueous solution) at 90'C for between 2 minutes and 2 hours, then cooled to ambient. temperature. The material is filtered.

Xylanase, papain, cellobiase and cellulase of the dry weight) are added to the filtrand. The mixture containing the enzymes is heated to 60 0 C for between 1 minute and 2 hours, then cooled to ambient temperature, and filtered.

The filtrand is milled to a fine powder to give the dietary fibre composition of the invention.

Example 2: Comparative Bread Preparation The following results indicate the efficacy and attractiveness of the fibre composition of the invention.

METHOD

The following ingredients were used to bake two loaves of bread. Loaf A was prepared incorporating the dietary fibre of Example 1. Loaf B was prepared using conventional ingredients. Both loaves were baked under identical conventional conditions.

Ingredient White All Purpose Flour Yeast Water Salt Sugar Milk Shortening Dietary fibre Total Amount (LOAF A) 784 25 665 21 50 20 40 106 1711 Amount (LOAF B) 1000 656 21 1812 NO 9 -q- O

RESULTS

The resultant loaves of bread had the same mass, although Loaf A had 00 5 100g less ingredients. This is beneficial because bread is usually sold on mass.

ND Loaf A had a more golden colour than Loaf B. The visual appeal of products such as bread is very important for sales.

Loaf A had less air pockets than Loaf B. This is also an important feature for sales.

It is clear from the foregoing that the invention provides a simple and efficient method of producing dietary fibre from fruit or vegetable material. In addition, use of the dietary fibre in edible products gives a superior product with known health benefits.

The foregoing embodiments are illustrative only of the principles of the invention, and various modifications and changes will readily occur to those skilled in the art. The invention is capable of being practiced and carried out in various ways and in other embodiments. It is also to be understood that the terminology employed herein is for the purpose of description and should not be regarded as limiting.

The term "comprise" and variants of the term such as "comprises" or "comprising" are used herein to denote the inclusion of a stated integer or stated integers but not to exclude any other integer or any other integers, unless in the context or usage an exclusive interpretation of the term is required.

010 0 Any reference to publications cited in this specification is not an admission 0 that the disclosures constitute common general knowledge in Australia.

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Claims

2. The method of claim 1, wherein the plant material comprises fruit or vegetable material and particularly banana plant material.
3. The method of claim 1, wherein the plant material is waste from fruit or vegetable processing.
4. The method of claim 3, wherein the waste is banana plant stalks.
5. The method of any one of claims 1-4, further comprising, prior to dicing the plant material: washing the plant material with a solution of hydrogen peroxide, cellobiase, and xylanase of from 100 to 500ppm; heating the washed material to from 50 to 100 0 C for from 2 to 20 minutes; and cooling the material to ambient temperature.
6. The method of claim 5, further comprising, after enzyme addition at step IO 0 O I- In oo O O (-N 12 heating the crude composition to from 40 to 80 0 C for from 1 minute to 2 cooling the crude composition to ambient temperature; and washing the crude composition with water. hours;
7. The method of claim 6, wherein the plant material is diced to from 2 to
8. The method of claim 7, wherein the alkali is a sodium hydroxide solution of from 0.1 to and the acid is citric, phosphoric or nitric acid solution of from 0.1 to
9. The method of any one of claims 1-8, wherein the at least one other enzyme is papain, cellobiase, cellulase or a combination thereof. claims 1-9.
11. A dietary fibre composition when prepared by the method of any one of A dietary fibre composition prepared from banana plant stalks. DATED this 25 October 2006 Bestlan Bananas Pty Ltd By their Patent Attorneys CULLEN CO.