An object of this invention is milk wherein the concentrations of palmitoleic acid and/or oleic acid are higher than in traditional milk. At the same time the amounts of trans fatty acids and C6-C12 saturated fatty acids are lower than in traditional milk. The invention also relates to food products which contain the milk according to the invention or part of it. The milk according to the invention has been produced by a process wherein to a lactating animal is given feed which contains inside and on the surface of feed raw material particles a fatty acid mixture wherein the content of satu- rated fatty acids is more than 90%.

Background

Consumption of liquid milk products decreased slowly in Finland during 1990's but during the last decade the decrease in consumption was broken. Moreover, the earlier trend towards low-fat and non-fat products has recently turned back to products containing more fat, the consumption of which products grows rapidly. Thus for example the consumption of butter has during the last 2 years almost doubled. As a whole, butter was eaten 10 million kilos more in 2011 than two years earlier. A similar trend prevails also elsewhere in Europe. At the same time milk production in our country has decreased and there is thus room for increase in milk production as well as in milk fat content. Furthermore, consumers prefer products wherein basic food products have been combined with health promoting components, such as plant sterols and their esters, n-3 fatty acids, nutritional fibers, vitamins, probiotics and minerals, such as cal- cium.

Thanks to rumen, fiber that is unsuitable for monogastric animals can be utilized in cow feeding. However, due to rumen function a problem is that approximately 10% of feed energy is lost as methane and thus the energy efficiency is declined. In addition, the environment is burdened. The rumen function is also linked to a problem concerning the nutritional value of milk fat. Milk fat is rich in saturated fatty acids and it contains a rather high amount of trans fatty acids. Trans fatty acids have been connected especially to an increase of the harmful LDL cholesterol and to a decrease of the bene- ficial HDL cholesterol in human blood. Saturated fats are not as harmful since they increase also the proportion of the good cholesterol, that is HDL.

Milk composition and fat quality can to a some extent be influenced by feeding of the cows. It is known that when oils are given to cows, milk fat becomes softer. However, oil feeding has negative impacts on both rumen function and milk quality. Protein content is lowered, the proportion of trans fatty acids is increased and the processabil- ity properties of milk fat are weakened. A high level of polyunsaturated fatty acids in milk also causes taste defects and preservation problems.

A typical fatty acid composition of milk fat contains more than 70% of saturated fatty acids. The total amount of trans fatty acids varies in the range of 3-10%. When vegetable oil is added into the feed, the proportion of trans fatty acids may rise even to more than 10%.

When a cow eats unprotected fat along with its feed, the fat is exposed to the action of rumen microbes. The lipase enzymes produced by the microbes hydrolyse the ester bonds of triglycerides, forming glycerol and free fatty acids. Hydrolysis is rapid, since already an hour after feeding most triglycerides have been hydrolysed and thus the content of free fatty acids in rumen is increased. Fatty acids have to be in free form before the microbes can utilize them. After polyunsaturated fatty acids have been released, they start to be hydrogenated in the rumen. Biohydrogenation proceeds step by step so that the end result is mainly stearic acid, but the biohydrogenation process is not complete and several different fatty acids, including trans fatty acids, are formed in the rumen as intermediate products of hydrogenation. For this reason, adding vegetable oil to feed results in accumulation of trans fatty acids in milk. The high amount of polyunsaturated fatty acids in feed causes taste defects and preservation problems in milk.

Biohydrogenation protects rumen microbes because polyunsaturated fatty acids are toxic especially to cellulolytic bacteria. Digestion of fiber may therefore decrease. The detrimental effect of fats can be diminished by preventing fat hydrolysis. Fat hydrolysis can be decreased for example by protecting fats with casein which has been treated with formaldehyde. Another alternative is to make insoluble fatty acid calcium salts whereby hydrogenation in rumen can be avoided. Also saturated fatty acids have been added into feed. They cannot be hydrogenated any more since they are already saturated. These fatty acids increase the amount of saturated fats in milk but do not increase milk production.

By infusing partly hydrogenated vegetabe oil past the rumen, milk fat content has decreased in experiments. Partly hydrogenated vegetable oil contains trans fatty acids which have been found to prevent fat synthesis in the mammary gland. A typical in- dustrially partly hydrogenated vegetable oil (soya oil) contains 30-35% trans fatty acids.

Until now, a disadvantage with all ways of feeding dairy cows in order to increase milk fat content has been that they lower milk production.

Description of the invention

According to the invention, milk has been developed, the fatty acid composition of which comprises at least 1.8% palmitoleic acid and/or at least 20% oleic acid, and at most 2.9 % total trans fatty acids. The fatty acid composition of the milk according to the invention preferably comprises at most 2.5% of trans fatty acids, more preferably at most 2.2%, 2.1%, 2.0%, 1.9%, 1.8%, 1.7%, 1.6%, 1.5%, 1.4%, 1.3%, 1.2%, 1.1%, 1.0%, 0.90%, 0.80%, 0.70%, 0.60%, 0.50%, 0.40%, 0.30%, 0.20% or 0.10%, and most preferably the milk fatty acid composition does not comprise trans fatty ac- ids.

The fatty acid composition of the milk according to the invention contains at least 5%, preferably at least 10% more palmitoleic acid than the fatty acid composition of traditional milk. Further, the milk fatty acid composition contains at least 5% more oleic acid than the fatty acid composition of traditional milk. Moreover, the milk fatty acid composition comprises less C6-C12 saturated fatty acids than the fatty acid composition of traditional milk, preferably at least 5% less, more preferably at least 10% less. Preferably the milk fatty acid composition comprises at least 2.0% palmitoleic acid, more preferably at least 2.3%, even more preferably at least 2.5% and most preferably at least 2.7%. Further, the milk fatty acid composition contains oleic acid preferably at least 22%, more preferably at least 25%, even more preferably at least 28% and most preferably at least 32%.

Furthermore, the fatty acid composition of the milk according to the invention preferably comprises C6-C12 saturated fatty acids at most 10%, preferably at most 9.8%, more preferably at most 9.5%, even more preferably at most 9.3%, still even more preferably at most 9.0%» and most preferably at most 8.5%.

The milk according to the invention has been produced by a process wherein to a lac- tating animal is given feed, which contains conventional feed ingredients and conventional additives and other auxiliary agents and, in addition, inside and on the surface of feed raw material particles a fatty acid mixture wherein the content of saturated fatty acids is more than 90%.

Conventional feed ingredients include e.g. protein-, carbohydrate- and fat-containing raw materials such as grains, peas, beans, molasses and vegetable oil meals. Also minerals can be classified as conventional ingredients. In addition to conventional ingredients the feed may contain other components, such as additives and auxiliary agents. The additives include e.g. micronutrients and vitamins. As an example of auxiliary agents, pelletizing agents can be mentioned. The milk according to the invention is particularly preferably produced by a process, in which to a lactating animal is given a feed containing inside and on the surface of the conventional protein-, carbohydrate- and fat-containing raw material particles a fatty acid mixture in which the proportion of saturated fatty acids is more than 90%. Preferably the mixture does not substantially contain trans fatty acids.

Conventional protein-, carbohydrate- and fat-containing feed raw materials include e.g. grains, peas, beans, molasses and vegetable oil meals. In addition to protein-, carbohydrate- and fat-containing raw materials the feed may contain other raw materials, such as minerals, additives and/or other auxiliary agents. The additives include e.g. micronutrients and vitamins. As an example of auxiliary agents, pelletizing agents can be mentioned. The inventions relates also to a food product which has been prepared from the milk according to the invention or from a composition isolated or prepared therefrom. Such food products include conventional food products prepared from milk, such as for example various basic milks, special milks, creams, fermented milk products, such as sour milks, curdled milk, curdled cream, yoghurt, quark, sour cream, cottage cheese, French sour cream, as well as puddings, ice creams, milk powders, infant formulas, cheese, butter, butter-vegetable oil mixtures, etc.

Furthermore, the food product according to the invention may contain at least one health promoting component selected from the group consisting of plant sterols and their esters, n-3 fatty acids, vitamins, such as A, D, E and K vitamins, dietary fibers, probiotics and minerals, such as calcium.

The invention is also related to a process for preparing milk, wherein to a lactating animal is given feed which contains conventional feed ingredients and conventional additives and other auxiliary agents and, in addition, the feed contains inside and on the surface of feed raw material particles a fatty acid mixture wherein the content of saturated fatty acids is more than 90%, and then the milk is recovered.

The invention is also preferably related to a process for preparing milk in which pro- cess to a lactating animal is given a feed which contains inside and on the surface of conventional protein-, carbohydrate- and fat-containing raw material particles a fatty acid mixture in which the fatty acid content is more than 90%. Preferably the mixture does not substantially contain trans fatty acids. The milk according to the invention has many beneficial health effects. A high amount of trans fatty acids has been connected to an increase of the detrimental LDL cholesterol and to a decrease of the good HDL cholesterol, and therefore lowering of their amount in milk is highly desirable. For palmitoleic acid (CI 6:1), several health- promoting effects have been proposed. Oleic acid (C18:l), which is found plenty of for example in olive oil, lowers blood cholesterol level.

The feed mixture which is given to a lactating animal in a process according to the invention, contains a fatty acid mixture having a high melting point. When this fatty acid mixture is added to a feed which is heated to at least above the melting point of the fatty acid mixture, the fat gradually melts into the raw material particles of the feed. The heat treatment is carried out before pelletizing the feed or in connection with it. When the feed cools down, part of the protein and starch of the feed mixture is protected from microbial degradation. Also the fat is protected from microbial action and, on the other hand, microbes are protected from fat and thus digestion of coarse feed remains good. The amount of saturated fatty acids in the fatty acid mixture used in the feed is high, and in addition the mixture is essentially free of trans fatty acids.. "Essentially free" or "does not essentially contain" mean within this context that the fatty acid mixture contains at most 5%, preferably at most 4%, more preferably at most 3%, even more preferably at most 2%, still even more preferably at most 1%, again even more preferably at most 0.5% and most preferably no trans fatty acids at all. In the milk preparation process according to the invention the fatty acid mixture is used in an amount of approximately 1-10 % by weight, based on the total weight of the feed. In case of a complete feed, the fatty acid mixture is used in an amount of approximately 1-6 % by weight, preferably 2-5 % by weight. In a concentrate feed, the amount of fatty acid mixture is 2-10 % by weight, preferably 3-8 % by weight, based on the total weight of the feed. Both milk production and milk fat content can be increased. Moreover, milk protein content is not lowered but rather is increased. Also the proportion of milk trans fatty acids diminishes. The proportion of saturated fatty acids remains approximately the same but the proportion of oleic acid and/or palmitoleic acid is increased.

However, the feed mixture used in the milk preparation process according to the invention does not disturb rumen function. Digestion of fiber remains at the same level, milk protein content is slightly increased and fat content is remarkably increased. Also milk production rises. Since part of the easily digestable nutrients can pass directly by the rumen, methane formation can be decreased which improves utilization of nutrients. The fatty acid mixture used in the feed contains usually at least 90%, preferably more than 95%, more preferably more than 98%, of saturated fatty acids, based on the total amount of the fatty acid mixture. The fatty acid mixture may also wholly consist of saturated fatty acids. One preferred feed for the purposes of the invention contains a fatty acid mixture comprising at least 60%, more preferably at least 90%, of palmitic acid (C16:0) and at most 30%, more preferably at most 10%, of stearic acid (C18:0), based on the total amount of the fatty acid mixture. Even more preferably the fatty acid mixture contains at least 95% palmitic acid and not more than 5% stearic acid, and 0-1% of other fatty acids. The above mentioned saturated fatty acids are already as such protected from microbes as their melting point is high. When the feed is prepared as describe above, also other components of the feed are protected, and thus both fatty acids and starch and amino acids are more evenly absorbed from the small intestine. Thus a high amount of fat does not get alone as such into the small intestine, in which case the absorbtion capacity could limit its good effects on milk production.

The A9-desaturase enzyme in cow's mammary gland converts part of stearic acid into oleic acid (CI 8: 1), which softens milk fat. Because stearic acid in large amounts may weaken milk production capacity in the mammary gland, in the process according to the invention a feed is used in the preparation of which a fatty acid mixture containing no more than 30% of stearic acid is used.

The fatty acid mixture may also contain small amounts of unsaturated fatty acids. The proportion of unsaturated fatty acids of the total amount of the fatty acid mixture is 0- 10%, more preferably 0-5%, even more preferably 0-2%. The most preferred unsaturated fatty acid for the purposes of the invention is oleic acid (CI 8: 1). Another useful fatty acid is palmitoleic acid (CI 6:1). According to one preferred embodiment the fatty acid mixture to be added in the feed may contain the following fatty acids (percentages of the fatty acid mixture):

C16:0 60-100, preferably 80-100

C18:0 0-30, preferably 0-20

C18:l 0-10, preferably 0-3

others 0-10, preferably 0-3

trans fatty acids 0-2, preferably 0-1 The melting point of a fatty acid mixture rich in saturated fatty acids is high, typically more than 60°C, for example 60-80°C, preferably 63-65°C. Preferably the iodine value of a fatty acid mixture usable in the invention is 0-5, more preferably 0-3, and most preferably 0-1. Fatty acids in the fatty acid mixture which the feed to be given to a lactating animal contains are preferably almost hundred-percent free fatty acids. It is also possible that part of the fatty acids are in triglyceride form but when given as free fatty acids, their utilization in the small intestine is improved as lipase enzymes do not need first to degrade triglycerides into glycerol and free fatty acids. The fatty acid mixture thus preferably comprises 50-100% of free fatty acids, more preferably 75-100% of free fatty acids and most preferably 95-100% of free fatty acids.

In the milk according to the invention it was surprisingly succeeded to lower milk trans fatty acid content so that the produced milk contained less than 2.5%, more pref- erably less than 2.0% trans fatty acids, of the milk fatty acids. In Finland, the fatty acid composition of a typical winter milk contains about 3% trans fatty acids. If the diet contains oil, the amount is increased.

In the milk preparation process according to the invention a feed is used, the prepara- tion of which comprises adding with simultaneous mixing to conventional feed ingredients and conventional feed additives and auxiliary agents a fatty acid mixture in which the proportion of saturated fatty acids is more than 90%, heating the feed mixture so that the fatty acid mixture melts and spreads on the surface and inside of the feed raw material particles, and then the mixture is pelletized and cooled. This means that one can protect the whole feed mixture from microbial degradation.

In the milk preparation process according to the invention is preferably used a feed, in the preparation of which from conventional protein-, carbohydrate- and fat-containing raw materials and from a fatty acid mixture in which the content of saturated fatty acids is more than 90%, a feed mixture is made, the feed mixture is heated in order to melt and spread the fatty acid mixture inside and on the surface of the feed raw material particles, whereafter the mixture is pelletized and cooled. In the feed preparation the whole feed mixture is protected from microbial degradation, whereby in the milk preparation process starch is fermented slower and part of the nutrients passes by the rumen. The aim of the feed preparation process is to treat the whole feed mixture.

By preparing feed as described above, more digestible nutrients are transported to the cow's small intestine. This enables positive changes in milk production as well as in milk composition and in utilization of the feed.

Melting of the fatty acid mixture inside and on the surface of feed raw material particles can be done by heating the feed mixture in a long term conditioner, for example at a temperature of at least 75 °C for at least 20 minutes. When higher temperature is used, heating time may correspondingly be shorter. However, the temperature may preferably not exceed 85 °C. On the other hand, also lower temperature, for example 70 °C for at least 25 minutes, may be used. After the heat treatment the feed mixture is pelletized and cooled.

Alternatively, a feed mixture wherein the fatty acid mixture has been blended can be treated with an expander whereby the pressure and heat in the expander cause the fatty acid mixture to melt and to be absorbed inside and on the surface of the feed raw material particles. The pressure in an expander treatment is typically 10-40 bar and tem- perature more than 100°C, whereby the retention time may be 3-6 seconds. After the expander treatment the feed mixture is pelletized and cooled. An emulsifier which promotes the absorption of fatty acid mixture into the feed raw material particles can be added to the feed mixture before heating. An emulsifier is added in an amount of 0.01-1.0 %, preferably 0.02-0.05% by weight, based on the total weight of the feed mixture. The emulsifier can be chosen among conventional substances used as emulsifiers. Examples of emulsifiers usable in the process according to the invention are castor oil based emulsifiers which are sold for example under the trade name Bredol ^® .

The milk according to the invention is produced by a process wherein to a lactating animal is given a milk composition changing amount of the feed disclosed above. A milk composition changing amount means an amount of complete feed or concentrate feed which conforms to the normal feeding recommendations of the lactating animal. The changes in milk composition are detected as an increase in the amount of pal- mitoleic acid and/or oleic acid. Preferably the changes are detected also as a decrease in the amount of trans fats and C6-C12 saturated fatty acids. The changes are partly shown already a week after the change in feeding but the change in the microbial function takes 3—4 weeks and thus the whole change is detectable only after 3 weeks.

A special feature of the feed to be given to the lactating animal is that the fatty acid mixture added into it has during the preparation process of the feed mixture protected digestible nutrients of the feed, because by means of the process according to the invention the fatty acid mixture is evenly applied inside and on the surface of the feed raw material particles whereby utilization of the nutrients becomes more effective and also methane production is decreased. In particular, the feed raw material particles are protected also inside the feed pellets. Also the fat itself is protected from microbial degradation and, on the other hand, the fat does not disturb microbial function and thus digestion of coarse feed. A fatty acid having a melting point more than 60 °C is as such already protected against microbial action. The feed thus prepared rises the content of palmitoleic acid and/or oleic acid in milk.

The remarkable decrease in the amount of milk trans fats was particularly surprising. It was not expected, since the trans fatty acid amount of normal milk fatty acids is at least 3% even without fat addition, when feeding comprises silage and conventional compound feed based on grain and rapeseed. This confirms that the raw material particles of the feed prepared according to the process of the invention have been protected from rumen degradation. Thus for example the triglyceride hydrolysis of the feed raw materials and the hydrogenation of the unsaturated fatty acids released therefrom has evidently at least partly been hindered which has decreased formation of trans fatty acids.

The following examples illustrate the invention. The fatty acid percentages presented in this application are percentages which disclose relative chromatogram peak areas, as is evident to a person skilled in the art.

Example 1. Complete feed usable in the invention

The following raw materials were selected for the preparation of complete feed (in percentages by weight).

Feed grain (wheat, barley, oats) 0-70

Sugar beet pulp 0-20

Wheat bran 0-30

Molasses 4-8

Wheat middlings 0-20

Minerals 0-5

Premixes (vitamins and micronutrients) 0-2

Fatty acid mixture usable in the invention 2-5

Emulsifier 0.02-0.05

Example 2. Concentrate feed usable in the invention

The following raw materials were selected for the preparation of concentrate feed (percentages by weight):

Vegetable oil meal (soya, rapeseed) 70-97

Pea, broad bean 0-20 Distiller's grains 0-20

Fatty acid mixture usable in the invention 3-10

Sugar beet pulp, bran 0-20

Grain 0-10

Molasses 0-5

Premixes (vitamins and micronutrients) 0-3

Minerals 0-5

Emulsifier 0.02-0.05

Example 3. Fatty acid composition of a fatty acid mixture usable in the invention

Fattv acid %

C16:0 >90

CI 8:0 <10

others <3

trans fatty acids 0

free fatty acids ca. 100

melting point >60 °C

iodine value <1

Example 4. Preparation of a test feed usable in the invention

The raw materials of example 1 were selected as starting materials as follows (percentages by weight):

Rapeseed meal 30

Barley 30

Wheat 20

Sugar beet pulp 10.3

Mixed molasses 4.0

Mineral mixture 2.3

Micronutrient mixture 0.2

Vitamin mixture 0.2 The fatty acid mixture according to example 3 (3.0 % by weight) was mixed into the starting materials to obtain 100% by weight of feed raw material. The feed mixture was mixed in a horizontal mixer for 3 minutes, an emulsifier (0.03%) was added and the fatty acid mixture was melted with it into the feed mass in a long term conditioner for 20 minutes at a temperature of 77 °C, in order to slowly melt and spread the fatty acid mixture evenly inside and on the surface of feed raw material particles with the help of the emulsifier. Then the feed mass was pelletized and cooled. Example 5. Preparation of milk according to the invention

In this feeding experiment cows were given 6-16 kg a day of a reference feed or the test feed according to example 4. As a reference feed was used a complete feed mixture which had been prepared by mixing the starting materials of example 4 with rape- seed oil (1.5 % by weight) and calcium salt of palm oil fraction (1.5 % by weight). Both test periods lasted for 4 weeks and the following results were obtained:

Reference feed Test feed Milk (kg/d) 30.0 33.5

Milk fat content (% by weight) 4.16 4.53

Milk protein content (% by weight) 3.16 3.27

The effect of test feeding on milk fatty acids:

Reference Test feeding trans fatty acids 4.3 % 1.9 %

palmitoleic acid 2.7 %

C6-C 12 unsaturated 9.0 % Example 6. Another preparation of milk according to the invention

In this feeding experiment cows were given 8-12 kg a day of a reference feed or the test feed according to example 4. A commercially obtained complete feed mixture was used as a reference feed. Both test periods lasted for 4 weeks and the following results were obtained:

Reference feed Test feed

Milk (kg/d) 28.5 30.5

Milk fat content (% by weight) 4.45 4.90

Milk protein content (% by weight) 3.55 3.67

The effect of test feeding on milk fatty acids:

Reference Test feeding

trans fatty acids 4.9 % 1.8 %

palmitoleic acid 2.8 %

C6-C 12 unsaturated 9.4%

The results from test feedings show that in the milk according to the invention the amount of trans fatty acids is significantly lower.

Example 7. Cocoa drink from the test milk of Example 5

Two cocoa drinks with the following recipes (% by weight) were prepared:

1 2

milk 92.4 89.9

sugar 5.0 5.0

cocoa 2.5 2.5

emulsifier 0.1 0.1

plant sterol ester - 2.5

Example 8. Yoghurt drink from the test milk of Example 5

A yoghurt drink was prepared with the following recipe (% by weight): milk 85.8

sugar 6.0

fruit/berry concentrate 6.0 stabilizer plant stanol ester

linseed oil

fermented with lactic bacteria