Patent Application
20090274798
The present invention relates to a frozen aerated product comprising a soy product, which comprises soy protein and less than 25 weight-% (wt-%), based on the total weight of the soy product, of soy fat and at least one destabilising emulsifier: as well as to a process for the production of such a frozen aerated product.
Cardiovascular disease is a leading cause of morbidity and mortality, particularly in the United States and in Western European countries and is emerging in developing countries. Several factors are mentioned relation to the development of cardiovascular disease including hereditary predisposition to the disease, gender, lifestyle factors such as smoking and diet, age, hypertension, and hyperlipidemia, including hypercholesteremia. Several of these factors, particularly hyperlipidemia and hypercholesteremia, contribute to the development of atherosclerosis, a primary cause of vascular and heart disease.
Elevated low-density lipoprotein cholesterol (hereafter “LDL-cholesterol”) is directly related to an increased risk of coronary heart disease.
The presence of soy protein in food consumed by humans is associated with a lower level of low-density lipoprotein cholesterol (LDL-cholesterol) and lower risk of coronary heart disease.
Food products comprising soy protein are well known. Examples of food products that may comprise soy protein are meat products, baked products, food analogs and dairy products. Types of soy proteins and food uses of soy proteins are described in Waggle, D. H. and Kolar, C. W., Soy protein and human nutrition, proceedings of a symposium held May 222-25, 1978 in Keystone Colourado, pages 19-51.
Soy protein materials are known to reduce total cholesterol and LDL-cholesterol levels in the blood of animals. An analysis of the effects of soy protein intake on serum lipids in humans has shown that dietary soy protein is significantly related to lowering serum concentrations of total cholesterol and LDL-cholesterol in humans (Anderson, Johnstone, and Cook-Newell, N. Engl. J. Med., Vol. 333, No. 5, pp. 276-82 (1995)).
Frozen aerated products such as ice cream contains usually 4-12 wt-% milk solids not fat (MSNF, which contains casein micelles, whey proteins and lactose). The aim is to replace the MSNF by proteins originated from soy beans.
In terms of product quality, this is related to the microstructural stability of the aerated frozen product and its melting behaviour in-mouth. Typically, a high quality ice cream product, for example, would be slow melting when consumed. This behaviour also provides the perception of warmer eating and a more creamy mouth feel, both of which are indicative of a favourable product.
In dairy ice cream, the product stability and melting behaviour are improved by formulation and process routes which lead to greater proportions of de-stabilised fat: this manifests itself in terms of fat particles adsorbed to air bubbles and fat particles partially coalesced in the continuous phase. Increasing levels of de-stabilised fat lead to a more stable air phase and slower product melting. However, high levels of de-stabilised fat may lead to air phase instabilities and the formation of large fat particles during the processing of ice cream (“buttering”). Therefore, this needs to be controlled.
For the case of ice cream comprising soy protein as opposed to dairy protein, the melting behaviour is more difficult to improve. This is because the amount of de-stabilised fat produced in products comprising soy protein tends to be relatively low (much less then 30%), and arises from what we believe to be an increased stability of the fat phase to shear and aeration when soy protein is used as the principal emulsion stabiliser. As a result, typical problems, which result when using soy proteins in a frozen aerated product are:
The textural changes and the poor melting behaviour will lead to a more undesirable product which melts too rapidly, is colder eating, and more icy in mouth. Additionally, such a frozen aerated product melts very quickly in the hand of a consumer, which is not appreciated either.
Therefore the goal of the present invention is to provide a frozen aerated product, with soy proteins (instead of milk protein) which has a good texture as a well as a good meltdown behaviour.
Surprisingly it has been found out that a frozen aerated product comprising a soy product which comprises (i) soy protein and (ii) less than 25 weight-% (wt-%), based on the total weight of the soy product, of soy fat and wherein the frozen aerated product comprises at least one destabilising emulsifier chosen from the group consisting of unsaturated monoglyceride, polyglycerol esters, sorbitan esters, stearoyl lactylate, lactic acid esters, citric acid esters, acetylated monoglyceride, diacetyl tartaric acid esters and propylene glycol ester has a good texture as well as a good meltdown behaviour.
Therefore the present invention relates to a frozen aerated product comprising a soy product, which comprises (i) soy protein and (ii) less than 25 weight-% (wt-%), based on the total weight of the soy product, of soy fat, characterized in that the frozen aerated product comprises at least one destabilizing emulsifier chosen from the group consisting of unsaturated monoglyceride, polyglycerol esters, sorbitan esters, stearoyl lactylate, lactic acid esters, citric acid esters, acetylated monoglyceride, diacetyl tartaric acid esters and propylene glycol ester.
The term “aerated” means that gas has been intentionally incorporated into the composition, for example by mechanical means. The gas can be any gas, but is preferably, particularly in the context of food products, a food-grade gas such as air, nitrogen, nitrous oxide, or carbon dioxide. The extent of aeration is defined in terms of “overrun”. In the context of the present invention, % overrun is defined in volume terms as:
((volume of aerated product−volume of mix)/volume of mix)×100
where the volumes are the volumes of a fixed mass of product/mix respectively.
Preferably, the frozen aerated product according to the present invention is essentially free from milk proteins.
The soy product can be any soy material as long as the soy fat content is less that 25 wt-% based on the total weight of the soy product. Preferably the fat content is less than 23 wt-%.
The soy product can be for example whole bean flour, soy protein concentrate or soy protein isolate. It is also possible to use mixtures of such soy products.
Destabilising emulsifier means any emulsifier which gives, at a level of 0.3%, a level of extracted fat of at least 25% in an ice cream premix containing 12% butter oil, 13% skim milk powder and 15% sucrose as described in relation to
A higher amount of extractable (or destabilized) fat indicates a less stable emulsion, and hence a more destabilising emulsifier, because more fat has coalesced. Examples of such destabilising emulsifiers are unsaturated monoglyceride, polyglycerol esters, sorbitan esters, stearoyl lactylate, lactic acid esters, citric acid esters, acetylated monoglyceride, diacetyl tartaric acid esters and propylene glycol esters.
In a very preferred embodiment of the present invention the destabilizing emulsifier is an unsaturated monoglyceride.
Therefore a very preferred embodiment of the present invention relates to a frozen aerated product comprising a
soy product, which comprises (i) soy protein and (ii) less than 25 weight-% (wt-%), based on the total weight of the soy product, of soy fat,
characterized in that the frozen aerated product comprises at least one destabilizing emulsifier chosen from the group consisting of unsaturated monoglyceride.
It is also possible to use a mixture of at least one destabilizing emulsifier and at least one non-destabilizing emulsifier. The term non-destabilising emulsifier covers all the emulsifiers, which do not fall under our definition of destabilizing emulsifier given above, for example saturated mono/di glycerides.
Soy can be sourced as whole bean, concentrate, protein isolate and soy milk powder and all are appropriate for use in ice cream, however the soy protein isolate is the preferred ingredient since it generally has lower viscosity and cleaner flavour (since carbohydrates are removed). The soy fat content must be lower that 25 wt-%, based on the total weight of the soy product. All ingredients are widely available with the following (table 1) typical breakdown of nutrients:
A frozen aerated product according to the present invention can comprise up to 25 wt-%, based on the total weight of the frozen aerated product, of a soy product as described above.
In a frozen aerated product the content of the soy protein can be up to 10 wt-%, based on the total weight of the frozen aerated product. Due to the fact that different sources of soy protein have a different amount of soy protein content, the amount of the soy product which has to be used to reach the same level of soy protein can vary. A preferred range of the soy protein content in a frozen aerated product is 0.5-10 wt-% based on the total weight of the frozen aerated product.
A frozen aerated product according to the present invention can comprise up to 1 wt-%, based on the total weight of the frozen aerated product, of at least one destabilizing emulsifier. A preferred range of the destabilizing emulsifier in a frozen aerated product is 0.05-1 wt-% based on the total weight of the frozen aerated product.
A frozen aerated product can be for example an ice cream, a sherbet, a sorbet or a frozen yoghurt. Preferably the frozen aerated product is an ice cream.
The aerated products such as ice cream, sherbet, sorbet or frozen yoghurt, can further comprise any ingredient which is necessary or desired to obtain such a product.
Such ingredients are fats/oils; sugars, such as sucrose, fructose, dextrose, lactose, corn syrups, sugar alcohols; salts; colours and flavours; fruit or vegetable purees, extracts, pieces or juice; stabilisers or thickeners, such as polysaccharides, e.g. locust bean gum, guar gum, carrageenan, microcrystalline cellulose; and inclusions such as chocolate, caramel, fudge, biscuit or nuts.
Coconut oil, palm oil, palm oil fraction, sunflower oil, soybean oil, and butter fat are the most common oils/fats used in the ice cream production.
Therefore the present invention relates to an ice cream, a sherbet, a sorbet or a frozen yoghurt comprising
Therefore the present invention relates to an ice cream, a sherbet, a sorbet or a frozen yoghurt comprising
A further embodiment of the present invention relates to an ice cream, a sherbet, a sorbet or a frozen yoghurt comprising
The amount of overrun present in the product will vary depending on the desired product characteristics. The overrun is at least 10%, preferably at least 25 or 50%. Preferably the amount of overrun is less than 400%, more preferably less than 300 or 200%. For frozen aerated products, the overrun is most preferably from 70 to 150%.
Any commonly used process of production for the frozen aerated products according to the present invention can be used.
As a source of soy protein in such a process whole soy bean flour, soy protein concentrate soy protein isolate and/or soy milk powder can be used.
Therefore a further embodiment of the present invention relates to a process of production of a frozen aerated products comprising at least one destabilizing emulsifier, characterized in that a soy product comprising
The present invention will now be described further with reference to the following non-limiting examples. If not otherwise stated the percentages are based on weight.
The ice creams in the following examples were formulated and produced as follows:
Mixing—all ingredients were combined in an agitated heated mix tank. Once all the ingredients had been blended together, the mixture was subjected to high shear mixing at a temperature of at least 65° C. for 2 minutes in order to hydrate the stabilisers.
Homogenisation—the mix was then subjected to a homogenisation stage to reduce the bulk of the fat droplets to less than 1 μm. This was accomplished by homogenising the mixture using an APV Crepaco 3DDL homogeniser operating at a pressure up to 300 bar at a typical temperature of 70° C.
Pasteurisation—The mix was heated to a temperature of 83° C. and held for 20 seconds to achieve satisfactory treatment. The pasteurised mix was then rapidly cooled to 4° C.
Ageing—The mix was held at 4° C. for a minimum of 2 hours.
Freezing—the mix was aerated and frozen using a WCB MF75 Freezer with a closed dasher. Sufficient air was incorporated to deliver the desired overrun of 100%. The products were extruded at temperatures between −5° C. and −7° C.
For the following experiments the ingredients from Table 2 were used:
The products obtained in the examples were analysed using the following methods.
a. Fat Droplet Size in Ice Cream Mixes
The mix samples were prepared in a solution of Sodium dodecyl sulphate (SDS) (Sigma UK) and urea (Sigma UK) (0.04 w/v % 6.6M urea, 0.1% SDS) and then analysed using a Malvern Mastersizer 2000. The SDS/urea solution ensures that any weakly bound or flocculated fat droplets are separated into individual fat droplets; it can not break up fully coalesced or aggregated fat droplets. 2 ml of chilled mix were added to 20 ml solution of SDS/urea, mixed and left for 10 minutes. The samples were added drop-wise into the Mastersizer 2000 for analysis. The samples were characterised by the surface weighted diameter, D(3,2), which is a measure of the mean fat droplet size.
b. Determination of Destabilised Fat in Ice Cream Products
Samples of the melted ice cream were prepared using the same method described above. The level of destabilised fat was then calculated as the proportion of fat in the ice cream with a particle size greater than the d(0,9) value from the original mix samples.
c. Meltdown Behaviour of Ice Cream Products
Tests were performed on a stainless steel wire mesh grid having a size of 25×25 cm, with 3 mm diameter squares, 1 mm thick wire. Underneath the grid was a collecting vessel (of large enough volume to collect the entire sample tested of the product volume) and balances for weighing the material collected in the vessel. The balances were connected to a data logging system to record the mass collected. The grids were placed in a meltdown cabinet set at a constant temperature environment of 22° C. capable of holding up to 12 of these grids simultaneously. For each example, melting tests were performed in triplicate. Before placement in the cabinet the ice cream samples were equilibrated in a freezer at −25° C., and then weighed on a zeroed balance. They were then placed on the mesh grid and were arranged randomly over the available positions in the meltdown cabinet. Once all samples were in place, the data logging system measured the amount of collected material every minute over a 240 minute time period.
d. Scanning Electron Microscopy (SEM) of Ice Cream Products
The samples were cooled to −80° C. on dry ice and a sample section cut. This section, approximately 5 mm×5 mm×10 mm in size, was mounted on a sample holder using a Tissue Tek: OCT™ compound (PVA 11%, Carbowax 5% and 85% non-reactive components). The sample including the holder was plunged into liquid nitrogen slush and transferred to a low temperature preparation chamber Oxford Instrument CT1500HF. The chamber was under vacuum, approximately 10−4 bar, and the sample was warmed up to −90° C. Ice was slowly etched to reveal surface details not caused by the ice itself, at this temperature under constant vacuum for 60 to 90 seconds. Once etched, the sample was cooled to −110° C. ending the sublimation, and coated with gold using argon plasma. This process also took place under vacuum with an applied pressure of 10−1 millibars and current of 4 milliamps for 45 seconds. The sample was then transferred to a conventional Scanning Electron Microscope (JSM 5600), fitted with an Oxford Instruments cold stage at a temperature of −160° C. The sample was examined and areas of interest captured via digital image acquisition software.
Ice creams were made using formulations A-E given in Table 3. A is a comparative example with no emulsifier. B is a comparative example containing a saturated mono-diglyceride (HP60) which is typically used to make ice cream. C and D are according to the invention and contain PS222, which consists of unsaturated monoglycerides. E is a comparative dairy equivalent example.
In
As can be seen from table 4, surprisingly A-D do not show any significant level of destabilised fat compared to E.
From
In summary, adding an unsaturated mono/di-glyceride emulsifier leads to an improved meltdown behaviour compared to ice creams containing a standard saturated mono-diglyceride as the only emulsifier.
Zero-fat soy ice creams were made using formulations F, G and H given in table 5 below. F is a comparative example with no emulsifier. G is a comparative example containing saturated mono-diglyceride emulsifier. H is an example according to the invention.
It can be seen in
Ice creams were made according to formulations I-L shown in table 6 (the same base formulation as A-D) using various different types of emulsifier in order to investigate the effect of the emulsifier type: I=lactic acid ester, K=unsaturated mono/di-glyceride, L=acetic acid ester of monoglycerides+saturated mono/di-glyceride. J=a comparative example using Tween 80, a very powerful emulsifier.
The meltdown behaviour for each of the ice creams is shown in
The mix droplet size and destabilised fat produced in each soy ice cream are shown in Table 7. These data show that relatively little destabilised fat is formed during the ice cream shear-freeze process, with the exception of the comparative example containing Tween 80. This has a much higher amount of destabilized fat, even though the emulsifier is only present at a level of 0.1%, due to the fact that Tween 80 is a very powerful emulsifier.
SEM images were taken of example L (Acetem 70). They showed air bubbles with a smaller size distribution than in example A.
In summary, soy ice creams containing emulsifiers according to the invention in leads to improved meltdown behaviour compared to a standard saturated mono-diglyceride emulsifier alone. Although comparative example J containing Tween 80 also gave good meltdown, it had much higher levels of destabilised fat, which could result in buttering, especially if the amount of Tween were to be increased, or a freezing process with more shear were to be used.
| Number | Date | Country | Kind |
|---|---|---|---|
| EP07250787 | Feb 2007 | EP | regional |
