GB1597068A - Cultured butter or fully ripened cream butter - Google Patents

Description

(54) CULTURED BUTTER OR FULLY RIPENED CREAM BUTTER (71) We, MILK MARKETING BOARD, a British Body Corporate, of Thames Ditton, Surrey KT7 OEL, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to an improved method for preparing cultured butter, alternatively termed full ripened cream butter.

Cultured butter has traditionally been prepared from cultured cream by inoculating culture into sweet cream, the cream then being ripened at a temperature suitable for bacterial development. The culture, termed a "starter", usually comprises a lactic acid producing bacterium e.g. Streptococcus lactis, alone or in combination with a citric acid fermenting bacterium e.g. Leuconostoc citrovorum. After incubation for say 24 to 48 hours, ripened cream is produced which contains fat, lactic acid, aroma compounds and bacteria. This product is then subjected to continuous or batch churning to produce on the one hand, fully ripened cream butter containing fat, lactic acid, aroma compounds (diacetyl) and viable organisms, and on the other hand, sour (or cultured) butter milk.

This traditional method, does, however, have certain disadvantages, for example: the churning process must be carried out under temperature conditions which are suitable initially for the microbiological control required and for the subsequent churning; the buttermilk produced is cultured buttermilk ior which there is only a small market (sweet buttermilk has better properties for use in producing other dairy products); churning of cultured rather than sweet cream leads to more copper migrating into the butter so that the butter is more easily oxidised and also more free fatty acids migrate into the butter leading to a higher rancid fatty flavour (this latter effect occurs because of the lower pH of cultured cream).

In an attempt to overcome some of these disadvantages. a method has been used in West Germany and elsewhere for several years by which sweet cream is churned to obtain butter granules which are separated from the buttermilk before adding starter culture to the butter and working it in. The serum of the butter produced by this method usually has a higher pH than the serum of cultured butter made from ripened cream, and also it has little aroma and is therefore more like sweet than cultured butter. Further this butter can suffer from variable taste properties due to insufficiently good moisture dispersion.

It is also known that the mere addition of diacetyl (the aroma compound) to butter is not particularly satisfactory since the flavour is not the same as that developed by diacetyl produced in situ and in any event the flavour is usually lost during storage.

A further method, termed the "Dutch process", by which some of the abovementioned disadvantages can be overcome has been proposed in Milchwissenschaft 31 (11) 648 to 662 (1976). According to this method, sweet cream is churned to produce sweet butter and sweet buttermilk, and to the sweet butter so produced are added starter cultures which produce aroma compounds and a socalled "culture concentrate" containing lactic acid. This process therefore has the advantage that the cream is churned sweet and therefore there is less copper and free fatty acid in the butter, also sweet buttermilk is produced and the temperature range for the churning can be wider leading to a better control of its consistency because no bacteria are present during the churning step. However, sweet butter has the disadvantage that it has a higher pH than cultured butter so that it is more usually deteriorated by bacteria. Accordingly, the Dutch proposed this process which comprises adding to the sweet butter starter cultures, one of which produces diacetyl (aroma compound). These starters are cultivated in skim milk to produce a product which contains viable bacteria, aroma compounds and some lactic acid which is then added to the sweet butter.

Examples of starters used are a mixture of 4/25 containing Streptococcus diacetylactis as aroma bacterium to produce diacetyl, and Fr 19 which contains, as aroma bacterium, only Leuconostoc cremoris which procedures less diacetyl than 4/25; the use of 4/24 alone is not recommended because it makes acetaldehyde which can adversely affect the flavour, whereas Fr 19 can transform acetaldehyde. This Dutch process also involves the separate addition of lactic acid which is added in the form of the "culture concentrate" produced by souring quark whey or whey with a reduced lactose content by adding to it Lactobacillus helveticus; the addition of the culture concentrate to the sweet butter has the effect of lowering the pH to 5.3 or below to meet Dutch Official Regulations.

In a modification of the above-mentioned Dutch process, it has been proposed to increase th- solids in the milk used for culturing the starter organisms such that they then require longer culture times to produce an enriched starter. This enriched stayer is then mixed with the culture concentrate before being added to the sweet butter rather than adding the two separately; the mixture has a low pH which causes the bacteria to die and this low pH also causes a higher diacetyl concentration to be produced. This modification was proposed because it was found that the storage temperature. if lower than about 6"C. affects the diacetyl production in the stored butter and hence it was desired to produce a higher initial diacetyl concentration.

The disadvantage of the above described Dutch process is that the starter cultivated in skim milk must be used fresh as it deteriorates on storing and hence the production of this fraction must almost certainly be carried out on the creamery site. Conversely, the process provided by the present invention does not require the additives which are inoculated into the sweet butter to be used fresh in fact, the fractions produced are suitable for long-term storage and hence can be produced elsewhere than on the creamery site.

The present invention accordingly provides a process of producing cultured butter which process comprises: inoculating sweet butter with: (i) diacetyl and at least one other aroma compound, (ii) lactic acid, and, separately from components (i) and (ii), with (iii) a viable culture of at least one acid-producing micro-organism which can ferment lactose to produce lactic acid and at least one flavour producing micro-organism which can produce diacetyl components (i) and (ii) being substantially free from any viable microorganisms.

The acid-producing micro-organism used in the process of this invention is suitably one conventionally used in the processes described above for manufacturing cultured butter e.g. Streptococcus cremoris and Streptococcus lactis.

The flavour producing micro-organism is also suitably one conventionally used in the process described above e.g. Streptococcus diacetylactis and Leucono@toc chrovorum.

It is belived that these acid producing and/or flavour producing micro-organisms may contribute to flavour retention.

By "sweet butter" is to be understood the butter obtained by chu@ning sweet cream to produce sweet butter and set butter milk and separating off the sweet buttermilk.

Apart from the fact that the lactic acid and aroma compounds, in being free from viable micro-organisms, are suitable for long-term storage, they can also rendlly be standardised for quality and strength.

The product produced by the process of this invention is cultured butter which is substantially indistinguishable to the consumer from that produced by the traditional or the Dutch process. It has all the advantages mentioned above for the Dutch process, ie. sweet buttermilk is produced and less copper and free fatty ac@@ migrates into the butter, and in addition, it has the advantages that the production of the lactic acid and flavouring can be carried out at any time and these components can be stored for use as required and that no incubation is required after production for full flavour development.

The aroma compounds component (i), used in the present invention, are suitably added as a "flavour distillate" such as that prepared by the manufacturers of cultures (e.g. Chr. Hansen's Laboratory Ltd or Miles Laboratories Ltd, Marschall Division). Hansen's 15X Starter Distillate is said by the manufacturers to be a mixture of flavour compounds steam distilled from specially cultured reconstituted skim milk. It contains flavour compounds which are volatile with water at 100 C. Such flavour distillates have generally been used as a butter flavour in flour and sugar confectionary in cases where no artificial flavours are desired. Their main flavour ingredient is diacetyl, but there are other trace materials present in this steam distillate, and it is belived that these trace materials may contribute to the flavour retention. The injection of this flavour distillate gives a flavour entirely comparable with that of conventionally cultured butter.

The lactic acid, component (ii), can be produced by any known method but is preferably produced by fermentation of a dairy substrate. It can, if desired, be extracted from the cultured skim milk used to prepare the flavour distillate. In this case, the biomass is separated off and discarded: hence the flavour and lactic acid components contain substantially ne organisms which would render them unsuitable for long-term storage. Dutch Patent Application 7513464 de scribes the production of a lactic acid fraction which may be used in the process of this invention.

In the process of the present invention, the viable organisms in the final cultured butter are provided by adding them directly to the sweet butter and separately from components (i) and (ii). It is not considered essential to control the concentration of organisms in the final product as this has been shown to vary greatly in conventionally cultured butter. However, the concentration is usually about 5,000 organisms per gram.

By the process of the present invention it has proved possible to manufacture cultured butter indistinguishable to the consumer from conventionally cultured butter but prepared in such a way that closer control of the components used is possible.

Butter may be either saltless or may contain some salt in the amount up to, for example, 3% by weight. The British palate generally demands a high salt level in butter (up to about 2%). The salt is usually added in conventional butter manufacture after it has been separated from the butter milk and washed with water. However, in the traditional process for producing cultured butter, salt may, for example, optionally be added to the churn in the form of a 50/50 slurry of salt and water before the cultured buttermilk is removed. In the Dutch process, it is customary to inoculate the sweet butter, from which the sweet buttermilk has been separated, with a mixture of culture concentrate (lactic acid) and, at the same time, with the flavour and biomass. However, it has been found that it is not possible to achieve the high salt level required by the British palate during manufacture using the Dutch process. In the Dutch process. most of the flavour is developed in the butter after churning and before packing by allowing the culture to "grow".

This is possible because Dutch cultured butter is unsalted. According to the 1966 Butter Regulations (S I No. 1074) the moisture content of ripened (cultured) butter must not exceed 16% w/w. The minimum obtainable moisture content of finished sweet butter amounts to about 13 to 13.5% usually so that an amount of not more than 2.5 to 3% extra moisture may be used for working starter and culture concentrates into sweet butter in the Dutch process. For a salt level of 2% in the final butter which is restricted to this maximum 16% moisture content, the salt level in the aqueous phase. in which most, if not all of the salt is, approaches 10% by weight and this is too high to allow growth of the vulture micro-organisms and hence adequate flavour development. In the process of the present invention, on the other hand, there is no requirement for the microorganisms to grow to develop the aroma compounds, since the aroma compounds and lactic acid are added to the butter initially in the required amounts. Accordingly by the process of the present invention, it is possible to produce cultured butter of high salt level at the time of manufacture.

The present invention will be further described with reference to the following Example.

EXAMPLE Sweet cream is subjected to a continuous churning process in a churn of the type conventionally used for introducing salt into butter and having two injection points. Sweet buttermilk is produced and removed from the churn.

A mixture of: 22 ib 7 oz of salt, 20 lb 13 oz of water, 784 ml of lactic acid (85% by weight solution, manufactured by Croda Food Ingredients Ltd) and 261 ml of steam distilled flavour (15X Starter Distillate of Hansen's) per ton of butter is injected into the sweet butter at one of the injection points in the churn. The ratio of lactic acid and flavour to the other components was such as to result in a final butter having a flavour and acidity identical with conventionally cultured butter.

The salt concentration was in the region of 1% by weight.

At the same time as the above injection was carried out, a viable culture of Streptococcus cremoris, Streptococcus lactis, Strew to coccus diacetylactis and Leuconostoc citrovorum was injected at the second injection point in the churn. These micro-organisms were of the same type as would be used to culture cream in conventional cultured butter manufacture and the injection was such as to give a total amount of approximately 5,000 organisms per gram of cultured butter product; this figure compares with the level of micro-organisms determined in conventionally cultured butter.

The level of moisture was measured and controlled during the manufacture by adjustment of the churn settings in conventional manner. It is essential that this moisture level does not exceed 16% w/w in the final cultured butter product. The amount of salt used was determined (in conventional manner by weighing), as was the ratio of salt to acid to flavour at the time of the preparation of the salt slurry to be injected at the first injection point. By ensuring the correct salt level and the appropriate ratio of salt to acid and to flavour, the flavour and acidity of the final product were correct and these components were adequately distributed throughout the butter.

The flavour characteristics of the final product are acceptable from the moment of manufacture and throughout its normal shelf life.

Claims (6)

WHAT WE CLAIM IS:

1. A process for producing cultured butter which process comprises: inoculating sweet butter with: (i) diacetyl and at least one other aroma compound, (ii) lactic acid, and, separately from components (i) and (ii), with (iii) a viable culture of at least one acid producing micro-organism which can ferment lactose to produce lactic acid and at least one flavour producing micro-organism which can produce diacetyl, components (i) and (ii) being substantially free from viable micro-organisms.

2. A process according to claim I wherein components (i) and/or (ii) are inoculated as a mixture with salt.

3. A process according to claim 2 wherein the salt is introduced in an amount such that the cultured butter contains up to 2% by weight of salt.

4. A process according to any one of the preceding claims in which component (i) is produced by steam distillation of cultured skim milk.

5. A process according to claim I substantially as described in the Example.

6. Cultured butter when prepared by a process as claimed in any one of the preceding claims.