WO2000002457A1

WO2000002457A1 - Fermented, pasteurised preferment

Info

Publication number: WO2000002457A1
Application number: PCT/EP1999/004733
Authority: WO
Inventors: Laurence Bellissen; Marco Luigi Giuseppin; Jan Ouwehand; Eelko Ter Schure
Original assignee: Unilever N.V.; Unilever Plc
Priority date: 1998-07-09
Filing date: 1999-07-05
Publication date: 2000-01-20
Also published as: ATE283633T1; EP1094715A1; DE69922374D1; EP1094715B1; DE69922374T2; AU5032399A; PT1094715E; ES2230868T3

Abstract

Fermented, pasteurised preferments, comprising fermentation products of a mixture of gluten and bran, hydrolyzed with glycosidase and/or glycanase and fermented with LAB and yeast and displaying FFA-contents < 5 wt.% and ratios acetic acid: lactic acid > 0.25 can be used in dough composition at lower addition-levels than prior art products.

Description

FERMENTED, PASTEURISED PREFERMENT

Baking improver compositions are well known in the bakery area. These are often used for improving the baking performance of doughs, resulting in improved baked products, but regularly they are also used to improve the properties of a dough sothat the handling of the dough is easier. Eg the compositions disclosed in WO 95/13706 are said to solve the problems of the presence of high amounts of gluten in doughs (ie dough toughness and inflexibility) . According to this WO compositions are made by a process wherein cereal germs are fermented in the presence of a starter culture comprising lactic acid and/or propionic acid forming bacteria. The starter culture can also contain yeast and other enzymes like lipase, or glycosidase (in particular amylase) . Although the compositions disclosed solve above problems in an acceptable way these compositions also have a number of drawbacks. Ie the compositions are insufficiently intense in flavour ingredients, sothat relatively large amounts must be used in order to achieve a desired flavour intensity by the addition of these compositions. This is due to a number of factors as we found out. First of all the compositions are relatively rich in long and medium chain free fatty acids (more than 5 wt%) and these free fatty acids have a negative impact on total flavour profile. The acids present are mainly acetic acid and lactic acid however in a ratio of acetic acid to lactic acid that does not give the optimum flavour impression when applied in bread dough. Further the compositions are relatively low in dry matter content. All this results in the fact that to achieve an acceptable flavour impression by addition of these compositions relatively large amounts have to be added, whereas the taste even then is not optimal. Similar products and processes are disclosed in EP 684306; EP 684307 and EP 684308. So it will not be a surprise that the products disclosed herein have similar drawbacks as the products from WO '706.

We have studied whether we could find new products and new processes to obtain products that would not have the drawbacks of the prior art discussed above. This study resulted in the finding of new products and novel processes to make these products. Therefore our invention concerns in the first instance a fermented, pasteurised preferment comprising: the fermentation product of a mixture of gluten and/or bran resulting from the hydrolysis thereof with protease and/or lipase and/or a glycosidase and/or glycanase, preferably a glucanase, followed by a fermentation with an acid forming bacterium, preferably lactic acid forming bacteria and a yeast, preferably in the presence of enzymes capable of liberating flavour ingredients or flavour precursors from proteins and/or carbohydrates, preferably selected from proteases and another glycosidase and/or glycanase, in particular amylases, which fermented, pasteurised preferment displays a free fatty acid content of less than 5 wt% on dry matter, preferably less than 3 wt% and/or displays a weight ratio between acetic acid and lactic acid of more than 0.25, preferably 0.3-0.75.

Glycosidases are enzymes that can split off one end standing sugar-moiety from a carbohydrate, whereas glycanases are enzymes that can split off larger (non- monomeric) moieties from carbohydrates. Examples of glycosidases and glycanases are: glucanase; amylases; cellulase, hemi-cellulases, glucosidase, galactosidase etc.

Even better products are obtained if sugars and/or amino acids are externally added to the fermentation culture prior to, during or after the fermentation. This then results in fermented, pasteurised preferment according to claim 1, wherein the preferment also comprises the fermentation products of externally added amounts of sugars and/or amino acids resulting from a fermentation with the micro-organisms and/or enzymes mentioned in claim 1. In addition to above also other enzymes could be applied in the fermentation culture in addition to the ingredients mentioned above. In that case fermented, pasteurised preferments are obtained that also comprise the fermentation products of carbohydrates and other glycosidase e.g. glycanase-enzymes selected from hemi- cellulase and cellulase.

Although sources for gluten and bran could be any known source we found that very good results were obtained when we used gluten and bran derived from wheat .

The novel products that we found have higher dry matter contents than the products from the prior art. So our prefermented, pasteurised preferments have a dry matter content of more than 32 wt%, preferably more than 35 wt%, in particular 35-50 wt%.

Although our product could be made by different novel process routes we found that far the best products are obtained by a process, wherein: 1) a mixture of gluten and bran is fermented with a glycosidase and/or glycanase, preferably a glucanase in the presence of water at a temperature of less than 80 °C 2) the fermented product resulting from step 1) is cooled to a temperature below 45 °C 3) the cooled product of step 2) is subjected to a fermentation with acid forming bacteria and yeast at a temperature below 45 °C

4) at least one of the products obtained as or used in either the final product obtained after step 3) and/or an intermediate product obtained after step 1) and/or the starting material used in step 1) is (are) pasteurised.

In this process it is very beneficial to perform step 3) after a treatment of the product of step 2) with amylase and/or protease, or in the presence of enzymes that are capable of forming flavour ingredients and/or flavour precursors from proteins and/or carbohydrates . Typical examples of these enzymes are amylases and proteases .

The fermentation needs to be performed in the presence of water. We found that very good results are obtained if the amount of water in step 1) of our novel process is adjusted to 40-80 wt % on total of gluten, bran and water. Very good results were obtained by using 50-60 wt % of water in step 1) .

Gluten and bran can be applied in a wide range of ratio's however we found that the best results are obtained if gluten and bran are used in a weight ratio of 5:1 to 1:1.

Yeast has to be added to the fermentation mix, suitable amounts are amounts of 10² to 10⁶ cells per ml of mix of water, gluten and bran. Very good results were obtained by using Saccharomyces cerevisiae as yeast.

The acid forming bacteria can be added in a wide range of amounts, suitable amounts being 10⁵ to 10¹⁰ cells per ml of mix of water, gluten and bran. Very good results were obtained by using Lactobacillus brevius as acid forming bacterium.

The glucanases, as example of glycanase, are used in amounts of 0.1 % (w/w) - 3 % (w/w) preferably at 0.1-0.2% on mix of water, gluten and bran. These enzymes can have an activity of 500 betaglucanase units/ml, measured according to the amount of glucose moieties released per minute using betaglucane as substrate.

Proteases can be added in amounts of 0.04 % (w/w) to 1% (w/w) preferably at 0.05 %-0.08% on mix of water, gluten and bran. These proteases can have an activity of 80000 HUT units/ml, measured according to the amount of tyrosine released per minute using hemoglobine as substrate.

Glycosidase are applied in amounts of 0.03 % (w/w) - 3% (w/w) preferably at 0.05 % - 1 % on mix of water, gluten and bran. These enzymes can have an activity of 1100 amyloglucosidase GOPAP units/ml, measured according to glucoseoxidase peroxidase amino phenezoni (GOPAP) assay in which one unit is defined as moeities per minute. A very convenient process, resulting in excellent products is obtained by performing the fermentation with acid forming bacteria in the presence of externally added culture medium in the form of hydrolysed carbohydrate, preferably being glucose, while the pH of the fermenting liquid is controlled within the range of 4-9 and preferably oxygen, in particular in the form of air is introduced in the fermentation liquid, in such an amounts that enough acetate is produced in order to obtain an acetate lactate ratio of 0.25 (preferably with a rate of at least 1 liter air per min per 100 liter fermentation liquid) . 5

EXAMPLES AND COMPARATIVE EXAMPLES

Example 1. 10 Production of a gluten based fermented pasteurised preferment .

Experiments were carried out in glass walled fermentors having a metal bottem plate and a metal head plate . The

15 fermentor was supplied with a metal heating jacket, temperature probe, pH probe, and rushton type of stirrors. The volume of the fermentor vessel was 15 litre. The fermentor was filled with 3228 g of water, 2040 g of wheat gluten and 732 g of wheat bran. After the dry matter was

20 dissolved 10.2 g of promalt 295 (Quest biocon Activity 500 betaglucanase units/ml) is added. The mixture was incubated at 58 °C for 30 min and subsequently pasteurised at 85 °C for 30 min. Hereafter the ferment was cooled down to 30 °C .

When during the cooling stage the temperature reached 50 °C 25 2 g bioprotease FL (Quest Biocon Activity 80000 HUT units/ml) , dissolved in 6 ml sterile water was added. As soon as the temperature reached 30 °C 3.6 g of amylo 300 (Quest Biocon Activity 1100 amyloglucosidase GOPAP units/ml) and 1 g bioprotease FL (Quest Biocon Activity 30 80000 HUT units/ml) , suspended in 3 ml water, were added. Hereafter a washed preculture of both L . brevis and S . cerevisiae were added This was followed by a fermentation phase of 72 h at 30 °C at pH 5 by continuous addition of 8 M NaOH. After 24 h of fermentation 300 g of glucose were added via a hole in the headplate of the fermentor and air was supplied at a rate of 0.08 V/V/Min. Hereafter the ferment was pasteurised at 80 °C for 30 min.

The dry matter and fatty acid content and the concentrations of lactate, acetate and ethanol of the fermented, pasteurised preferment are presented in Table 1.

Table 1. Dry matter content, fat content, lactate and acetate in a gluten based fermented pasteurised preferment. concentration dry matter content 40 wt%

FFA content 1.3 wt% lactate 45 g/1 acetate 15 g/1

The final product was subsequently dried using the technique of spray drying. The optimal inlet temperature of the drying tower was determined to be 180 °C and the outlet temperature was about 60 to 80 °C .

The product has been tested and evaluated in QDA panel test and it appeared that it improved the flavour of the bread.

Example 2

Production of a fermented wheat product.

A fermented wheat germ product has been produced according to the process described in WO 95/13706. The characteristics of this bread improver are presented in table 2. Experiments in our own laboratory revealed that the maximal dry matter content was 32 wt% (w/w) .

Table 2. Characteristics of a fermented wheat germ liquid product produced by us according to the process described in WO 95/13706

Maximal dry Matter content 32 wt%

FFA content 6 wt% lactate 23 g/1 acetate 3 g/1

Claims

1. Fermented, pasteurised preferment comprising: the fermentation product of a mixture of gluten and/or bran resulting from the hydrolysis thereof with a protease and/or lipase and/or glycosidase and/or glycanase, preferably a glucanase, followed by a fermentation with an acid forming bacterium, preferably lactic acid forming bacteria and a yeast, preferably in the presence of enzymes capable of liberating flavour ingredients or flavour precursors from proteins and/or carbohydrates, preferably selected from proteases and another glycosidase and/or glycanase, in particular amylases, which fermented, pasteurised preferment displays a free fatty acid content of less than 5 wt% on dry matter, preferably less than 3 wt% and/or displays a weight ratio between acetic acid and lactic acid of more than 0.25, preferably 0.3-0.75.

2. Fermented pasteurised preferment according to claim 1, wherein the preferment also comprises the fermentation products of externally added amounts of sugars and/or amino acids resulting from a fermentation with the microorganisms and/or enzymes mentioned in claim 1 or externally added amounts of sugars and amino acids as such.

3. Fermented, pasteurised preferment according to claims 1 or 2, wherein the preferment also comprises fermentation products of carbohydrates and other enzymes selected from hemi-cellulase and cellulase.

4. Fermented, pasteurised preferment according to claims 1-

3, wherein the gluten and the bran are both from wheat.

5. Fermented, pasteurised preferment according to claims 1-

4, wherein the preferment has a dry matter content of more than 32 wt%, preferably more than 35 wt%, in particular 35- 50 wt%

6. Process for the production of a pasteurised preferment with the composition according to claims 1-5, wherein:

1) a mixture of gluten and bran is fermented with a glycosidase and/or glycanase, preferably a glucanase in the presence of water at a temperature of less than 80 ┬░C

2) the fermented product resulting from step 1) is cooled to a temperature below 45 ┬░C

3) the cooled product of step 2) is subjected to a fermentation with acid forming bacteria and yeast at a temperature below 45 ┬░C

7. Process according to claim 6, wherein the fermentation in step 3) is performed after a treatment of the product of step 2) with amylase and/or protease, or in the presence of enzymes capable of forming flavour ingredients and/or flavour precursors from proteins and/or carbohydrates.

8. Process according to claim 7, wherein the enzymes capable of forming flavour ingredients and/or flavour precursors are selected from amylases and proteases.

9. Process according to claims 6-8, wherein the amount of water used in step 1 of claim 6 is between 40 and 80 wt% on total of gluten, bran and water applied.

10. Process according to claims 6-9, wherein the gluten and bran are both derived from wheat and are applied in a weight ratio of 5:1 to 1:1

11. Process according to claims 6-10, wherein the yeast, preferably Saccharomyces cerevisae, is added in an amount of 10² to 10⁶ cells per ml of mix of water, gluten and bran.

12. Process according to claims 6-11, wherein the acid forming bacterium is a LAB, preferably a Lactobacillus brevis and is added in an amount of 10⁵ to 10¹⁰ cells per ml of mix of water, gluten and bran.

13. Process according to claims 6-12, wherein the glucanase is applied in an amount of 0.1% (w/w) - 3% (w/w) preferably at 0.1-0.2% on mix of water, gluten and bran.

14. Process according to claims 6-13, wherein the protease is applied in amounts of 0.04% (w/w) to 1% (w/w) preferably at 0.05 %-0.08% on mix of water, gluten and bran.

15. Process according to claims 6-14, wherein the glycosidase is applied in amounts of 0.03% (w/w) to 3% (w/w) preferably at 0.05% - 1% on mix of water, gluten and bran.

16. Process according to claims 6-15, wherein the fermentation with acid forming bacteria is performed in the presence of externally added culture medium in the form of hydrolysed carbohydrate, preferably being glucose, while the pH of the fermenting liquid is controlled within the range of 4-9 and preferably oxygen, in particular in the form of air is introduced in the fermentation liquid,