Patent Application
20190208797
The present invention relates to creams and methods of producing creams comprising protein aggregates which contribute to the improvement of creaminess, mouthfeel and texture.
Mouthfeel and creaminess, as well as reduction of fat, are key drivers of liking for milk based products such as cream and products derived from cream.
Today, there is a challenge to increase the mouthfeel/creaminess of present creams, in particular to achieve such increase in mouthfeel/creaminess using all-natural formulations or ideally by acting on the product matrix itself, instead of adding ingredients to the product. This is particularly true in low and no fat products.
It is known since 1980's that a slight pH adjustment of native fresh milk prior to heat treatment results in change of aggregation behavior between casein micelles and whey proteins. F. Guyomarc'h. 2006; Formation of heat-induced protein aggregates in milk as a means to recover the whey protein fraction in cheese manufacture, and potential of heat-treating milk at alkaline pH values in order to keep its rennet coagulation properties. A review, Lait, 86, 1-20, explored the effect of pH 6.3 on the formation of heat-induced aggregates in milk.
As described in US 2009/0041920, milk protein concentrate may be prepared by insolubilisation of milk proteins. Insolubilisation is achieved by aggregation of the whey protein and/or casein, by adjusting the milk protein concentrate to a pH of from 4.1 to 5.4, or from 4.3 to 5.3, preferably the isoelectric point of the milk protein concentrate. Thereafter, the pH-adjusted milk concentrate may be heat-treated and homogenised. This process results in a cream cheese product.
A recent article [T. Ozcan, Yogurt made from milk heated at different pH values, J. Dairy Sci. 98:1-10] investigated the effects of different pH values of milk at heating on the rheological properties of yogurt gels. Tested pH values were 6.2, 6.7 and 7.2. The study concluded that heating at the natural pH (6.7) resulted in yogurt with highest gel stiffness. The rheological measurements were carried out after incubation of the milk with the yogurt starter and at a pH of 4.6, so that those results are not as such applicable to infer the effect of pH at heating on the rheological properties of cream.
US 2015/0289538 relates to a method of producing a frozen confection product with improved freeze-thaw stability. In particular, the method comprises a post-pasteurisation acidification step.
WO 2015/197496 relates to liquid dairy blends suitable for being used in the preparation of dairy-based culinary sauces or prepared culinary dishes comprising milk proteins and fat. The Milk proteins are whey protein and casein, with a ratio of whey protein:casein ranging from 0.3 to 0.5 and a pH ranging from 5.8 to 6.2.
Taterka and Castillo (International Dairy Journal 2015, 48:53-59) discusses the effect of whey protein denaturation on light backscatter and particle size of the casein micelle as a function of pH and heat-treatment temperature. This article discloses several pH and heat treatments of reconstituted skim milk.
Thickeners (hydrocolloids, starches, etc.) have been added to milk products, such as cream, to increase their viscosity. However this solution had several drawbacks such as unexpected texture change and flavor loss, increased length of ingredient list and also increased formulation costs.
Thus it is an object of the present invention to improve mouthfeel, texture, thickness and/or creaminess of cream, particularly with lower or no fat. It is also an object of the present invention to keep mouthfeel, texture, thickness and/or creaminess of a cream constant while reducing fat content. Furthermore it is also an object of the present invention to keep mouthfeel, texture, thickness and/or creaminess of a cream constant while reducing thickening agents and/or stabilizers, e.g. hydrocolloids or starch.
It was surprisingly found that by adjusting pH of a cream in the range of 5.7 to 6.4, followed by a heat sterilization process carried out at a temperature above 100° C., the whey proteins form complexes with the casein micelles, which results in increased colloidal particle size and overall viscosity.
In a first aspect, the present invention relates to a cream comprising caseins and whey proteins in the ratio of 90:10 to 60:40, wherein the caseins/whey protein aggregates have a volume-based mean diameter d(4,3) of 5 to 30 μm as measured by laser diffraction.
In a second aspect, the present invention relates to a process for the preparation of a cream comprising the steps of:
In a third aspect, the present invention relates to a cream obtained or obtainable by the process of the invention.
In a fourth aspect, the present invention relates to a food or beverage product comprising a cream of the invention.
In a fifth aspect, the present invention relates to the use of a cream of the present invention to prepare a food or beverage product.
The term “caseins/whey protein aggregates having a volume based mean diameter value d(4,3)” of a particular value refers to protein network comprising casein micelles and whey proteins either present in aggregates or covalently associated and having such volume mean diameter d(4,3), as measured using laser diffraction. For example the volume mean diameter d(4,3) can be measured using a Malvern Mastersizer 2000 granulometer (Malvern Instruments Ltd, UK). In a preferred embodiment, dispersion the cream is achieved in distilled or deionised water and measurements of the particle size distribution by laser diffraction using a Malvern Mastersizer 2000 granulometer (Malvern Instruments Ltd, UK). Even more preferably, measurement settings used are a refractive index of 1.46 for fat droplets and 1.33 for water at absorption of 0.01 and samples are measured at an obscuration rate of 2.0-2.5%. The measurement results are preferably calculated in the Malvern software based on the Mie theory.
The term “cream” for the purpose of the present invention has its usual meaning in the art. All types of creams are encompassed, such as low fat, medium fat and full fat creams. The term “cream” refers herein to cream as such or with added thickeners and/or stabilizers. For the purpose of the present invention a cream typically has a fat content of 10 to 50 wt %, preferably 14-40 wt % and most preferably 16-30 wt %, based on the total weight of the cream. Typical protein content is of 1 to 4 wt %, based on the total weight of the cream.
For the purpose of the present invention the terms “flowtime” refer to the time required for 100 ml of a cream to flow through a glass efflux viscosimeter as depicted in
The present invention relates to a cream comprising caseins and whey proteins in the ratio of 90:10 to 60:40, wherein the caseins/whey protein aggregates have a volume-based mean diameter value d(4,3) of 5 to 30 μm as measured by laser diffraction.
The casein and whey ratio of 90:10 to 60:40 encompasses cream with a slight modification of the casein whey content, as well as natural cream. The casein and whey ratio can be modified by adding whey or casein to natural cream. In a preferred embodiment, the cream has the natural casein and whey ratio of cream from bovine origin, which is of 80:20.
The cream of the present invention preferably comprises casein-whey protein aggregates having a specific volume-based mean diameter d(4,3) that provides improved viscosity and mouthfeel to the cream, while avoiding phase separation in the cream. It is preferred that the casein-whey protein aggregates have a volume-based mean diameter d(4,3) of at least 6, 7, 8, 10, 11, 12, 13, 14 or 15 μm. In another embodiment, the volume-based mean diameter d(4,3) of the casein-whey protein aggregates is of at most 25, 20, 15 or 10 μm. In another embodiment the volume-based mean diameter d(4,3) of the casein-whey protein aggregates ranges from 6 to 30 μm, from 6 to 20 μm, from 6 to 15 μm or from 6 to 10 μm. Protein aggregates having a size comprised in the above mentioned ranges have the advantage of providing improved texture/mouthfeel to the cream while being stable, i.e. they do not sediment in the cream. In particular, the fat-like perception of the cream is improved by the presence of particles in the above-mentioned ranges. Controlled aggregation with particles in the above mentioned ranges is also advantageous in that it is at the fine balance between thicker texture/mouthfeel and avoidance of excessive sandiness.
The viscosity of the cream of the present invention varies depending mainly on the fat content and the presence or absence of thickeners. In particular the viscosity of a full fat cream of the invention is higher than the viscosity of a low or medium fat cream of the invention. However, irrespective of the type of cream, the cream of the present invention has a higher viscosity than a cream of same composition that has not been subjected to the process of the present invention and thus not having casein-whey protein aggregates with a volume-based mean diameter d(4,3) in the above-described ranges. For example, in the case of a low fat cream without thickener, the viscosity of the cream of the present invention is typically of 10 to 25 mPas, preferably 10 to 20 mPas, at a shear rate of 100 s−1, whereas a cream of same fat and thickener content not subjected to the process of the invention would have a viscosity around 9 mPas at a shear rate of 100 s−1.
In an embodiment of the invention, the cream has a viscosity of at least 10 mPas at a shear rate of 100 s−1, for example 10 to 1000 mPas, 10 to 500 mPas, 10 to 400 mPas, 10 to 300 mPas or 10 to 250 mPas. The viscosity can be measured using any kind of rheometer, for example using a plate-plate system (such as for example a Haake ReheoStress 6000, optionally coupled with a temperature controller (such as for example an UMTC-TM-PE-P).
The texture of a cream can be advantageously characterized by the time that the cream requires to flow through a calibrated viscometer as depicted in
The flowtime is preferably measured as follows. It is first assessed that the product is perfectly liquid. If the product contains solid insoluble particles, the sample is sifted. The sample is then placed in a bath set a 20° C. and brought to this temperature. The viscometer is fixed in a vertical position. The lower end of the viscometer is sealed, for example by applying a finger on the lower end, the viscometer is filled with the sample at 20° C. up to above the 100 ml guide mark. The lower end is then un-sealed. The chronometer is started when the upper surface of the sample passes the 100 ml mark and stopped when this surface passes the 0 ml mark. The flowtime is measured in a viscometer as represented in
The invention relates to a process for preparing a cream comprising the steps of:
The cream obtained by the process of the invention is advantageously characterized by the presence of larger protein particles and an increased viscosity, the whey protein forming covalent aggregates with the casein micelles.
In step a), the temperature is advantageously set to a temperature below 25° C. so as to avoid the occurrence of acid induced casein precipitation/coagulation before the heat sterilization step c). Thus the controlled protein aggregation happens under the specific conditions of the heat sterilization treatment step c). For the same reason, a heating step is also preferably avoided between the pH adjustment and the heat sterilization step. Thus, in a preferred embodiment the cream is not subjected to a heat treatment step between the pH adjustment step b) and the sterilization step c).
In step b), the pH is preferably adjusted to a pH in the range of 5.9 to 6.4, more preferably 6 to 6.4, even more preferably 6.2 to 6.4, most preferably 6.2 to 6.3. Setting the pH to a value above 6, preferably above 6.2 is advantageous in that the desired particle size is obtained while keeping a “créme fraiche” flavor note. An acidic flavor note appears when decreasing the pH, which may not be desirable in some applications.
The pH can be adjusted using any kind of edible acid known to the person skilled in the art. Example of such acids are for example citric acid, lactic acid or phosphoric acid. The amount of acid needed to achieve the desired pH adjustment as described above can also be determined by a skilled person on the basis of his general knowledge.
The aggregation of the whey and casein proteins is achieved through a heat sterilization treatment. The temperatures of at least 100° C. used in a heat sterilization treatment, which are need to achieve proper spores inactivation, proved adequate to achieve controlled aggregation in creams without forming too large aggregates that would phase separate, while providing desired textural change. Such high temperatures advantageously achieve at the same time the safety of the cream through sterilization and the agglomeration of the whey and casein proteins, thus increasing the viscosity of the cream and improving its texture and/or mouthfeel.
The heat sterilization treatment carried out in step c) can be any type of heat sterilization treatment known in the art. The person skilled in the art knows how to use such standard sterilization methods. Preferably the heat sterilization treatment is a UHT sterilization process or a retorting sterilization process, most preferably it is a UHT sterilization process. UHT sterilization process is preferred because, due to the relatively high viscosity of the product, agitation of the product improves the heat transfer in the product, whereas retorting is an in-container sterilization method, in which there is no agitation. UHT sterilization process has been identified as providing better sterilization efficiency, as well as efficient protein aggregation and viscosity/mouthfeel improvement.
Preferred UHT sterilization process is carried out at a temperature of 135 to 150° C., for example of 140 to 155° C., 143 to 155° C., 143 to 150° C. or 143 to 148° C. Preferably, the UHT sterilization process time is comprised between 2 and 30 s, longer times being typically used for lower temperatures and shorter times for higher temperatures. For example, the UHT sterilization process can be carried out at 143° C. for 8 seconds or at 148° C. for 8 seconds. Selection of a temperature in the specific ranges described above is advantageous in that controlled aggregation is achieved, leading to the desired size of the protein aggregates as described above, thus leading to improved texture/mouthfeel of the cream. In addition, selection of a particular temperature for the UHT sterilization process may also impact the flavor of the cream. For example the use of high temperatures may lead to more cooked flavor notes, whereas lower temperatures may lead to more “créme-fraiche” flavor. Within the above ranges, the selection of the temperature may thus also be fine-tuned based on the desired flavor, depending on the intended use of the cream.
In a particular embodiment of the invention, the pH in step b) is adjusted to a pH in the range of 6 to 6.4 and in step c) a UHT sterilization process at 143° C. for 8 seconds is carried out. In another particular embodiment of the invention, the pH in step b) is adjusted to a pH in the range of 6.2 to 6.4 and in step c) a UHT sterilization process at 143° C. for 8 seconds is carried out. In another particular embodiment of the invention, the pH in step b) is adjusted to a pH in the range of 6 to 6.4 and in step c) a UHT sterilization process at 148° C. for 8 seconds is carried out. In another particular embedment of the invention, the pH in step b) is adjusted to a pH in the range of 6.2 to 6.4 and in step c) a UHT treatment at 148° C. for 8 seconds is carried out. In another particular embodiment of the invention, the pH in step b) is adjusted to a pH in the range of 6 to 6.4 and in step c) a UHT treatment at 153° C. for 8 seconds is carried out. In another particular embedment of the invention, the pH in step b) is adjusted to a pH in the range of 6.2 to 6.4 and in step c) a UHT treatment at 153° C. for 8 seconds is carried out.
The heat sterilization treatment, preferably the UHT sterilization process may be carried out using direct steam injection (DSI) or using indirect heating. Preferably it is carried by direct stream injection.
When a retorting sterilization process is used, the cream is preferably heated in a container in a commercial cooker/retort to temperatures of 110-130° C. for 10-30 minutes. When the sterilization process is a retorting process, it is preferred that the pH is adjusted in the range of 6.3 to 6.4, preferably to about 6.4 in step b), as the texture of the obtained cream has superior properties.
In step d), the cream is cooled to a temperature below 70° C. to stop the agglomeration process. Preferably, the cream is cooled down to a temperature below 60° C. The temperature can be reduced to even lower values in order to allow for filling, such as aseptic filling of the liquid cream. Thus the cream can advantageously be cooled down to below 50° C., below 40° C., below 30° C., or even 20° C. or below.
In a further step, the cream may thus be filled in a container, preferably aseptically filled in an appropriate packaging, such as, for example in bricks (such as those from Tetrapack), cans or in plastic bottles.
Optionally, the cream may also be further processed. For example it may be diluted, concentrated or dried.
In a preferred embodiment the process described above is a process for preparing a cream comprising caseins and whey proteins in the ratio of 90:10 to 60:40, wherein the caseins/whey protein aggregates have a volume-based mean diameter d(4,3) of 5 to 30 μm as measured by laser diffraction. More preferably the process is a process for preparing a cream as defined in any of the embodiments described in the section entitled “cream”.
It has surprisingly been found that texture and mouthfeel of creams are enhanced as a result of the optimized process of the invention, in which the sterilization process ensures the safety of the cream and, combined with specific acidic conditions, causes controlled protein aggregation and consequently improved texture and mouthfeel of the cream.
These protein aggregates form a network that is suspected of binding water and entrapping fat globules (in case of presence of fat) and increases mix viscosity to create a uniquely smooth, creamy texture.
In one embodiment of the present invention, the cream does not include any thickeners and/or stabilisers. Examples of such thickeners include hydrocolloids, e.g. gums, carrageenans or pectins as well as food grade starches or maltodextrins.
The process of the invention, as described above, leads to a cream having caseins/whey protein aggregates of unique structure providing enhanced viscosity, texture and/or mouthfeel compared to a cream of similar composition, which has not been subjected to the process of the present invention. Thus, a cream obtained or obtainable by the process according to any of the above-described embodiments is also an object of the present invention.
The invention also relates to a food or beverage product comprising the cream of the present invention. Such food or beverage product may be selected from a ready-to-drink beverage, a dairy culinary product, a soup or soup base, a dessert, a whipping cream, a tea or coffee creamer or enhancer, a dairy component in coffee mixes and dairy component for use in a beverage system such as a beverage vending system.
Ready-to-drink beverages can for example be selected from ready-to-drink creams, cocoa and/or malt beverages and ready-to-drink coffee, tea or chocolate beverages comprising a dairy component. A dairy culinary product may be selected from dairy culinary savoury sauce, a baking aid and a savoury or sweet cooking aid. For its incorporation in the food or beverage product, the cream may be simply admixed with further solid or liquid ingredients or further transformed such as for example be diluted, concentrated, dried or in any other way processed.
In other words, the invention relates to the use of a cream of the present invention for producing a food or beverage product, preferably as described in any of the above embodiments.
Low fat cream (protein (Nx2.8%) 3.4%, fat 18%, total solids 25%) was produced by admixing skim milk, anhydrous milk fat and lactose for 30 minutes. The cream was then homogenized at 150 bar and then cooled by a plate heat exchanger to 5° C. and pH of homogenized liquid cream was measured to be 6.7. The composition was then subjected to a UHT sterilization process by direct steam injection (DSI) at 143° C. for 8 seconds. After the heat treatment, the cream was subjected to flash cooling at 78° C. and then the product was cooled down to 20° C. with a plate exchanger. Finally the product was aseptically filled in plastic bottles.
Low fat cream (protein (Nx2.8%) 3.4%, fat 18%, total solids 25%) was produced by admixing skim milk, anhydrous milk fat and lactose for 30 minutes. The cream was then pasteurized (70° C. for 30 s), then homogenized at 150 bar and then cooled by a plate heat exchanger to 5° C. and pH of homogenized liquid cream was measured to be 6.7. The composition was then subjected to a UHT sterilization process by direct steam injection (DSI) at 143° C. for 8 seconds. After the heat treatment, the cream was subjected to flash cooling at 78° C. and then the product was cooled down to 20° C. with a plate exchanger. Finally the product was aseptically filled in plastic bottles.
Low fat cream (protein (Nx2.8%) 3.4%, fat 18%, total solids 25%) was produced by admixing skim milk, anhydrous milk fat and lactose for 30 minutes. The cream was then homogenized at 150 bar and then cooled by a plate heat exchanger to 5° C. The pH was adjusted to specific values as recited in Table 1 below. The pH adjustment was carried out in batch with phosphoric acid and controlled by a Mettler Toledo Seven Compact pH meter. The composition was then subjected to a UHT sterilization process by direct steam injection (DSI) at 143° C. for 8 seconds. After the heat treatment, the cream was subjected to flash cooling at 78° C. and then the product was cooled down to 20° C. with a plate exchanger. Finally the product was aseptically filled in plastic bottles.
Low fat cream (protein (Nx2.8%) 3.4%, fat 18%, total solids 25%) was produced by admixing skim milk, anhydrous milk fat and lactose for 30 minutes. The cream was then pasteurized (70° C. for 30 s), then homogenized at 150 bar and then cooled by a plate heat exchanger to 5° C. The pH was adjusted to specific values as recited in Table 1 below. The pH adjustment was carried out in batch with phosphoric acid and controlled by a Mettler Toledo Seven Compact pH meter. The composition was then subjected to a UHT sterilization process by direct steam injection (DSI) at 143° C. for 8 seconds. After the heat treatment, the cream was subjected to flash cooling at 78° C. and then the product was cooled down to 20° C. with a plate exchanger. Finally the product was aseptically filled in plastic bottles.
The creams of Samples 1 to 17 were compared to References 1 and 2 and were characterized by laser diffraction in order to determine particle size distribution (PSD=Particle Size Distribution)
The particle size of the protein aggregates, expressed in micrometers (μm) was measured using Malvern Mastersizer 2000 granulometer (laser diffraction unit, Malvern Instruments, Ltd., UK). Ultra pure and gas free water was prepared using Honeywell water pressure reducer (maximum deionised water pressure: 1 bar) and ERMA water degasser (to reduce the dissolved air in the deionised water).
Dispersion of the cream was achieved in distilled or deionised water and measurements of the particle size distribution by laser diffraction.
Measurement settings used are a refractive index of 1.46 for fat droplets and 1.33 for water at absorption of 0.01. All samples were measured at an obscuration rate of 2.0-2.5%.
The measurement results are calculated in the Malvern software based on the Mie theory. The results are presented in Table 1.
The PSD profiles of Samples 1 to 9 and of Reference 1 are provided in
The PSD Profiles of Samples 10 to 17 and of Reference 2 are provided in
The microstructure of the systems was investigated directly in liquid creams using light microscopy.
For investigation of liquid samples, a Leica DMR light microscope coupled with a Leica DFC 495 camera was used. The systems were observed using the differential interference contrast (DIC) mode. An aliquot of 500 microliters of the sample (Sample 2 and Reference 1) was deposited on a glass slide and covered with a clover slide before observation under the microscope. A picture was taken, which is provided in
The same procedure was followed to assess the cream structure using microscopy in PC mode. Pictures were taken, which are provided in
In both modes, large protein aggregates are visible on pictures or Sample 2, whereas they are absent from Reference 1. Such aggregates appear as the structural signature of the cream of the present invention. They are responsible for a change of perception of the product texture by the consumer, and namely for a significant mouthfeel improvement.
Flow behavior of Samples 1 to 6 and of Reference 1
Samples according to the invention and a reference were characterized for their flow using a Haake RheoStress 6000 rheometer coupled with temperature controller UMTC-TM-PE-P regulating to 20+/−0.1° C. The measuring geometry was a plate-plate system with a 60 mm diameter and a measuring gap of 1 mm.
The flow curve was obtained by applying a controlled shear stress to a 3 mL sample in order to cover a shear rate range between 0 and 300 l/s (controlled rate linear increase) in 180 seconds.
The graphs are provided in
The shear viscosity of the samples and of the reference at 25° C. and at a shear rate of 100 s−1 is provided in Table 2 below. As can be seen from those results, the viscosity is significantly improved in the Samples 1 to 6 of the invention than in the cream of the reference.
This data shows that the viscosity is increased for the cream of the present invention (Samples 10 to 13, 15 and 16) compared to the standard cream of the Reference 2.
The physical properties of the samples of the present invention are associated with a significant change in texture and with an improved mouthfeel.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16176757.9 | Jun 2016 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/065999 | 6/28/2017 | WO | 00 |
