GB2092878A

GB2092878A - Liquid mahewu production

Info

Publication number: GB2092878A
Application number: GB8203356A
Authority: GB
Original assignee: CHIBUKU BREWERIES Ltd
Current assignee: CHIBUKU BREWERIES Ltd
Priority date: 1981-02-06
Filing date: 1982-02-05
Publication date: 1982-08-25
Also published as: ZA82723B; ZW2981A1; ZM782A1

Abstract

A process for producing a beverage includes fermenting a liquid cereal extract to which has been added dairy whey. Also disclosed is a process for producing a beverage which includes fermenting a liquid cereal extract, at least part of which comprises spent grain extract and which may comprise a dairy product other than whey.

Description

SPECIFICATION Liquid mahewu production THIS INVENTION relates to a process for produc ing a non-alcoholic beverage, and to a beverage obtained from such a process.

According to one aspect of the invention, there is provided a process for producing a beverage, which includes fermenting a liquid cereal extract to which has been addes dairy whey.

At least part of the liquid cereal extract may comprise spent grain extract.

According to another aspect of the invention, there is provided a process for producing a beverage which includes fermenting a liquid cereal extract, at least part of which comprises spent grain extract.

Prior to said fermentation, a dairy product other than dairy whey may be added to the liquid cereal extract.

By 'spent grain' (which is also referred to in industry as 'masese') is meant the fresh, wet residue which is separated from traditional (also called 'African' or 'Bantu' or 'Sorghum') beer wort, or from traditional beer in the early stages of fermentation, for example, by means of straining or centrifugation.

'Spent grain' can also mean the fresh wet residue remaining after the lautering process in the prodction of clear beers, such as lager or ale type. 'Spent grain' can also mean the material obtained after the abovementioned residues have been dried, preferably when these are in a fresh condition prior to drying.

Prior to adding the dairy whey or other dairy product to the liquid cereal extract, an enzyme may be added to the whey or other dairy product (when it is in liquid form) to break down at least some of the lactose therein to simpler sugars. The removal of lactose from the dairy whey or other dairy product is beneficial when the beverage is to be consumed by lactose-intolerant people.

The dairy product may be milk, such as whole cows' milk or skimmed milk, either in liquid or pow deform.

The spent grain extract may be prepared by suspending spent grain in water, boiling the suspension at atmospheric pressure, and, if necessary, removing any excess suspended material from the suspension, the suspension so produced forming the spent grain extract. In another version the suspension may be boiled at elevated pressure. Any excess suspended material may be removed from the suspension by straining, for example, through a fine wire mesh screen or by centrifugation, which may be effected at a temperature high enough to preclude natural fermentation starting up. The product suspension is a watery liquid containing the desired quantity and size of suspended solids, soft fibres, dissolved solids, and some nutrients, and is of the desired colour.It will often, but not always, be necessary to remove some excess suspended material after boiling to obtain the desired product suspension.

Afterthe boiling ofthe spent grain suspension, but before any excess suspended material is removed therefrom, an enzyme may be added to the suspen sion for at least partial conversion of gelatinized starch therein, thereby to improve the quality of the extract. The enzyme may be commercially available heat sensitive alpha amylase enzyme, or any other enzyme which can convert starch to the same or similar products. The enzyme should be added to the spent grain suspension after it has been cooled to the optimum temperature for enzyme action, which may be about 800C.

The liquid cereal extract may be prepared by admixing cereal, and water and, optionally, other starch sources. The cereal may in one version be malted. In another version the cereal may be unmalted. The mixture may be gelatinised, for example by boiling. The cereal may be milled sorghum grain, wheat or the like. The other starch sources may be low oil starch sources such as maize grits, brewers' grits, or other milled starch sources.

Normally this aspect of the process would not include removal of suspended material, but would be carried out by using the raw materials in such quantities so as to produce a product with the desired suspended solids content. This is to eliminate waste of raw materials.

The low oil starch sources may be added to the liquid cereal extract so as to impart the desired viscosity, colour and total suspended solids content thereto. After the grits have been added to the liquid cereal extract, the extract may be boiled at atmospheric pressure and then cooled prior to inoculation as described hereunder.

Priorto said fermentation, the liquid cereal extract may be inoculated with a seed culture of lactobacillus species, thereby to initiate a lactic acid fermentation. A sweetener may be added to the liquid cereal extract prior to fermentation. The sweetener may be sucrose, for example cane sugar, which provides the sugar required for fermentation as well as imparting sweetness to the final product, and/or an artificial sweetener, such as saccharin. The liquid cereal extract may be cooled prior to said inoculation.

When the process includes dairy whey and/or milk, this can be added to the hot spent grain extract.

Preferably the dairy whey and/or milk should be cold.

Prior to said inoculation, nutrient salts, such as sodium, magnesium and potassium salts, and taste providing salts of sodium magnesium and potassium may be added to the liquid cereal extract to aid fermentation thereof, and to provide an acceptable flavour thereto.

The lactobacillus seed cultures may in general be grown in a liquid medium. For example, the seed culture can be fermented in seed culture vessels, the volume of which is approximately 5% of the volume of the liquid cereal extract. This can be done up to 24 hours before the liquid cereal extract is to be inoculated. The seed culture growth medium can contain milled maize grits, dairy whey and/or milk (whole or skimmed) sodium, magnesium and potassium salts, cane sugar, other cereal grains and should preferably approximate the composition of the material used in the fermentation of the liquid cereal extract.

The materials used in the seed culture should be mixed with water, boiled, cooled and held at the optimum temperature for fermentation.

In ano: sr version, the seed culture can be that obtained from commercial sources and made by a process as described above, but which is used in freeze dried powder form. In this case it will not be necessary to prepare a seed culture prior to the fermentation of each batch of liquid cereal extract.

However, an equivalent number of lactobacillus cells should be used in the powder form to effect the same rate of fermentation as is obtained with freshly prepared cultures.

The seed culture may be inoculated into the liquid cereal extract when both the culture and the extract are at the fermentation temperature which may be maintained during said fermentation. The fermentation temperature may be the optimum temperature for the devopment of lactic acid. The extract may be stirred during the fermentation. The fermentation temperature may be between about 40 and 55"C, depending on the species of lactobacillus used. The extract may be fermented for between 3 to 6 hours, depending on the seed culture used.

The fermentation may be terminated by heating the fermentation product tc about 80-90"C, once the required degree of acidity has been reached. The temperature at which the fermentation is terminated will depend upon the desired product shelf life and the type of packaging to be used. Thus, when the product is to be aseptically packed, the fermentation will be terminated by heating the product to about 80"C. The prodict is then treated by means of an ultra-high temperature procedure (i.e. heating itto a temperature of approximately 1500 for about 3 seconds and cooling it rapidly), whereafter it is packed aseptically, without addition of chemical stabilising agents.Alternatively, when the product is to be packed non-aseptically, the fermentation is terminated by heating it to 80-90"C, adding chemical stabilizing agents, and packaging the product. The product may include hot filling the packages. The product may be cooled prior to packaging thereof, in another version.

The invention extends also to a product when produced by the process(es) as described above.

The invention will now be described in more detail, with reference to the following Examples: EXAMPLE 1-Beverage produced from spent grains and whey. Afresh spent grain extract is prepared by mixing fresh spent grain containing 65% (by weight) moisture with water, the concentration of spent grain in the water being 15% wet weight solids per volume of mixture (i.e. grams solids per 100 millilitres of mixture). The volume of the spent grains/water mixture, before straining, is about 75% of the final product volume.

-The mixture is boiled by means of indirect heating for about one hour to effect some gelatinisation of the spent grain, and to extract as much material into the soluble phase as possible. Thereafter, the suspension is strained or centrifuged to remove excess suspended material.

The spent grain extract obtained in this way contains up to 30% (by weight) of the original solids of the spent grain, depending on the efficiency of starch and other material solubilisation and the particle size accepted into the extract.

The extract volume at the end of straining is about 65-70% of the final product volume.

Fresh, chilled, lactose-free whey is added to the spent grain extract to form a liquid cereal extract, the volume of the whey being 20% of the final product volume. Partially refined cane sugar is also added to the liquid cereal extract to provide the required degree of sweetness of the final product. The amount of cane sugar added is usually between 8% and 10% weight per final brew volume.

Thereafter, milled maize grits is added to the liquid cereal extract, the amount of milled maize grits being in the range of 3,3 to 4,4% weight per final brew volume, depending on the desired viscosity of the final product. Trace amounts of sodium, magnesium and potassium salts are also added to the liquid cereal extract.

The mixture is boiled for one hour at atmospheric pressure and cooled to 47"C. A freeze dried culture of 3 lactobacillus species, (L. Bulgaricus, L. Helviticus, and L. Delbruckii) previously prepared, is inoculated directly into the liquid cereal extract, and fermentation allowed to procees until the total acidity reaches an acceptable level, for example, 0.25% weight per volume.

Fermentation is terminated by pasteurizing the product (ie the beverage) at 900Cso that it is microbiologically stabilised, cooling it to 60"C, and packing it into suitable containers.

The beverage obtained has the following specification: total acid 0,25% w/v pH 4,0 total solids 12,5% w/v (i.e. weight per volume) lactic acid 0,24% w/v volatile acid 0,004% w/v alcohol 0,01% w/v Protein (N x 6,25) 1,3% calorificvalue 430 Kcal/litre.

The applicants have found that the beverage obtained is nourishing, non-alcoholic, pleasanttasting, shelf stable and refreshing.

The use of low cost whey and spent grain containing a significant amount of carbohydrates, and which are by-products of the cheese-making and brewing industries respectively, results in a low cost product (since the raw materials are of low cost), which also provides good nutrition in the form of protein and energy. Hirtherto, these raw materials have usually been used as animal feeds.

It is to be appreciated that a different, or a mixture of different, lactobacillus species may be used, depending on the beverage which it is desired to obtain.

EXAMPLE2 - Beverage produced from spent grains and whole cows milk.

The procedure followed is similar to that of Example 1, up to the stage where the hot spent grain extract has been prepared (i.e. before addition to the dairy whey).

Fresh whole milk is added to the spent grain extract, the volume of the milk being approximately 1% of the final product volume, together with between 8% to 10% weight perfinal brew volume of partially refined cane sugar to provide the desired degree of sweetness to the final product.

It may be desirable to increase the quantity of whole milk, and it has been found that an acceptable product can be produced with the milk component being up to 3% weight per final brew volume.

The procedure, after addition of the milk, is similar to that described in Example 1, except that the final product is made up to the desired volume with water, after the spent grain extract has been boiled with the milled maize grits.

EXAMPLE3 - Beverage produced from milled sorghum grain and dairy whey.

The liquid cereal extract is produced by mixing finely milled sorghum grain with water, the volume of the suspension being 50-60% of the final product volume. The amount of sorghum grain used is about 3% weight per final product volume.

Fresh, chilled, lactose-free whey is added to the suspension, the volume of whey being about 20% of the final product volume. Between 8% to 10% weight per final product volume of partially refined cane sugar is added to the liquid cereal extract to provide the required degree of sweetness to the final product.

After addition of the sugar, the procedure followed is similar to that described in Example 1.

Claims

1. A process for producing a beverage, which includes fermenting a liquid cereal extract to which has been added dairy whey.

2. A process according to Claim 1, wherein, prior to adding the dairy whey to the liquid cereal extract, an enzyme is added to the whey to break down at least some of the lactose therein.

3. A process according to Claim 1 or Claim 2, wherein at least part of the liquid cereal extract comprises spent grain extract.

4. A process according to Claim 3, wherein the spent grain extract is prepared by suspending spent grain in water, boiling the suspension, and removing part of the suspended material from the suspension, the residual suspension forming the spent grain extract.

5. A process according to Claim 4 wherein, after said boiling, an enzyme is added to the suspension to break down at least some of the starch in the spent grain.

6. A process according to any one of the preceding claims wherein, prior to said fermentation, the liquid cereal extract is inoculated with a seed culture of lactobacillus species.

7. A process according to any one of the preceding claims wherein, prior to said fermentation, a sweetener is added to the liquid cereal extract.

8. A process according to any one of the preceding claims wherein, prior to said fermentation, a low oil starch source is added to the liquid cereal extract.

9. A process according to any one of the preced ing claims wherein, prior to said fermentation, nut rientsalts are added to the liquid cereal extractto aid fermentation thereof.

10. A process according to any one of the preceding claims, wherein the fermentation is effected at between 40 and 55 C.

11. A process according to any one of the preceding claims, wherein the duration of the fermentation is between 3 and 6 hours.

12. A process according to any one of the preceding claims, wherein the fermentation is terminated by heating the fermentation product to about 80 to 90"C.

13. A beverage whenever produced by the process as claimed in any one of Claims 1 to 12.

14. A process for producing a beverage, which includes fermenting a liquid cereal extract, at least part of which comprises spent grain extract.

15. A process according to Claim 14 wherein, prior to said fermentation, a dairy product other than dairy whey is added to the liquid cereal extract.

16. A process according to Claim 15 wherein, prior to adding the dairy product to the liquid cereal extract, an enzyme is added to the dairy product to break down at least some of the lactose therein.

17. A process according to Claim 15 or Claim 16, wherein the dairy product is milk.

18. A process according to any one of Claims 14 to 17 inclusive wherein, prior to said fermentation, the liquid cereal extract is inoculated with a seed culture of lactobacillus species.

19. A process according to any one of Claims 14 to 18 inclusive, wherein the spent grain extract is prepared by suspending spent grain in water, boiling the suspension, and removing part of the suspended material from the suspension, the residual suspension forming the spent grain extract.

20. A process according to Claim 19 wherein, after said boiling, an enzyme is added to the suspension to break down at least some of the starch in the spent grain.

21. A process according to any one of Claims 14 to 20 inclusive wherein, prior to said fermentation, a sweetener is added to the liquid cereal extract.

22. A process according to any one of Claims 14 to 21 inclusive wherein, prior to said fermentation, a low oil starch source is added to the liquid cereal extract.

23. A process according to any one of Claims 14 to 22 inclusive wherein, prior to said fermentation, nutrient salts are added to the liquid cereal extract to aid fermentation thereof.

24. A process according to any one of Claims 14 to 23 inclusive, wherein the fermentation is effected at between 40 and 55"C.

25. A process according to any one of Claims 14 to 24 inclusive, wherein the duration of the ferrnenta- tion is between 3 and 6 hours.

26. A process according to any one of Claims 14 to 25 inclusive, wherein the fermentation is terminated by heating the fermentation product to about 80 to 90"C.

27. A beverage whenever produced by the process as claimed in any one of Claims 14 to 26.

28. A process for producing a beverage, substantially as described and exemplified herein.