JPH0147977B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing W/O emulsion spreads with a low fat content, meaning a fat content of at most 60%.

Traditionally, W/O emulsions with fats ranging from about 40% to about 86% have been produced by adding an aqueous phase to an emulsifier-containing molten fat phase and producing emulsions in systems such as scraped surface heat exchangers and crystallizers. It is produced by cooling while working to obtain a homogeneous emulsion, which is then stabilized with solid fat crystals.

The phase volume ratio (fat/aqueous phase) is the limiting factor in producing fat continuous emulsions by conventional techniques.

When the volume of the aqueous phase increases from about 60% to 70% or more, the emulsion becomes susceptible to bacterial contamination in some cases, unless there are preservatives or water activity lowering agents that improve the storage stability of the product. The tendency for phase transformation to an undesirable O/W emulsion increases from this point.

A useful method for making W/O emulsions with very low fat content, e.g. less than 35%, is to gradually spray or inject the aqueous phase into the fat phase to achieve the desired fat level while applying high shear conditions. The aim is to increase the emulsion viscosity and obtain a very fine dispersion of the aqueous phase corresponding to an average droplet size of preferably less than 5 microns.

To obtain such fine dispersions, very high emulsifiers such as polyglycerol esters must be used or high shear conditions are required. Sufficient shear conditions can be obtained by pumping and recirculating the emulsion through the static mixer while controlling the degree of stress of the mixture in the static mixer.

The above operation has drawbacks. First of all, its disadvantage is the waste of energy, which requires more time, and finally, the required degree of dispersion of the aqueous phase is large, and although the stability of the emulsion is good, it does not dissolve in the mouth at the time of consumption. The organoleptic properties are poor due to insufficient release of water-soluble components under exposed shear and temperature conditions.

Other known methods for producing W/O emulsions include:
The reconstituted artificial cream or natural milk cream is churned in a rotating drum or so-called Fritz machine, where under shear conditions the interface between air and cream plays an important role in the destabilization and phase transformation of the emulsion. There is a particular thing. Not used in the dairy industry, but
In equipment such as scraped surface heat exchangers, crystallizer units (votators A and C units) and static mixers commonly used in the margarine industry, creams, especially those containing about 40% fat, are mixed with cream. It is very difficult to cast without an air interface. To facilitate phase transformation in the latter equipment, emulsifier systems have to be added to the cream, reducing the naturalness of the product and subjecting it to legal restrictions in some countries.

Process for producing stable spreads with acceptable organoleptic properties, low in fat level down to 15%, and production of low fat spreads by phase inversion from creams, especially dairy creams, substantially free of added emulsifiers There is a legal requirement.

The inventors have found a method which alleviates the drawbacks of this known method and which largely satisfies the above requirements.

The method of the invention comprises: (i) forming an oil and water containing emulsion from a fatty phase and an aqueous phase; and (ii) shearing and shearing the emulsion using an instrument internally coated with or made from a hydrophobic material. It is characterized by cooling and crystallizing the fat to obtain a W/O emulsion spread.

Devices coated with or made from hydrophobic materials can be prepared, for example, by preparing a pre-emulsion;
cooling and, for example, surface scraped heat exchangers or crystallizer units, (for example "Margarine" by Anderson and Williams, Pergamon Press,
Votator A or C unit described in 1965,
Furthermore, it consists of a tank that is operated by a static mixer, pump, etc.

Hydrophobic materials include polytetrafluoroethylene (PTFE), paraffin, which is plastic at room temperature.
It may also be composed of hydrophobic polymers such as perspex or fats. The instrument or device is preferably flushed with a plastic fat, preferably containing a component selected from monoglycerides, diglycerides, phospholipids or mixtures thereof, which adsorbs to the surface of the device (often made of stainless steel).

Ideally, the plastic fat consists of butter oil.

The use of devices coated with or made from hydrophobic materials greatly contributes to the formation and maintenance of fat-continuous emulsions, whereby it is no longer necessary to disperse the aqueous phase very finely, so that A more efficient use of the device (shorter holding times) is possible, as well as easier operation.

It is interesting that commonly applied metal surfaces tend to acquire hydrophilic properties, for example by absorption of proteins.

Using the method of the invention, even when the dispersed phase consists of aqueous droplets with diameters close to the upper limit of the range from 2 to 20 microns, there is no tendency for phase transformation from W/O emulsions to O/W emulsions. It has been found that less spread can be produced.

Preferably, emulsions are prepared in which the dispersed phase consists primarily of aqueous droplets with a diameter of 8 to 20 microns.

In particular, within the range of 8 to 20 microns, the release of flavors, especially water-soluble flavors and proteins upon consumption is better.

Although emulsions with an aqueous phase of 15-85% by weight could be produced by the method of the present invention, the production of ultra-low fat continuous spreads (15-35% fat content) that are very susceptible to phase transformation when processed using conventional methods. It is particularly useful to apply the method to.

The process of the invention is particularly suitable for the production of spreads containing less than about 35% fat, especially spreads containing 15-35% fat. When it is contemplated to produce such a W/O emulsion, step (i) of the process according to the invention involves gradually injecting or spraying a small amount of the aqueous phase into the preferably liquid fatty phase to form the W/O emulsion. obtain.

The aqueous phase of such emulsions is preferably present in the form of dispersed droplets with a diameter preferably in the range of 8 to 20 microns and may contain conventional ingredients such as salts, acids, hydrocolloids and proteins. , and the fatty phase may contain coloring substances, oil-soluble flavors and optionally emulsifiers, especially emulsifiers having an HLB of less than 10, such as monoglycerides.

Starting from reconstituted or natural cream, it is also possible to produce spreads with a low fat content, ie with a fat content of less than 60%, by phase inversion in the absence of a cream/air interface.

The starting material used is preferably natural milk cream. Dairy creams with a fat content of about 40% are easily converted by churning without the presence of special emulsifiers. In this case, the processing is carried out in the absence of a cream/air interface, in equipment commonly used in the margarine industry for cooling and texturing the emulsion (e.g. the Votator unit mentioned above), but using the hydrophobic materials mentioned above. .

According to an embodiment of the invention, the reconstituted cream (O/W emulsion) is initially plastic at room temperature and is pre-internally coated with a fat containing preferably phospholipids, monoglycerides or diglycerides. 1) working the emulsion through (scraped, cryogenic rotating vessel) and cooling the fatty or hydrophobic material, preferably also containing one or more of the above-mentioned additives; Pass through a crystallizer unit 2 coated with polytetrafluoroethylene. The final spread of W/O type exits the crystallizer unit.

The emulsions produced according to the present invention are useful on their own or as ingredients for admixture with other edible emulsions.

The present invention will be specifically explained by the following examples.

Example 1 A W/O emulsion spread was prepared from the following ingredients.

Aqueous Phase weight % Water 77.650 Salt 1.750 Adjusted to PH 4.5 with lactic acid 0.100 Fat Phase weight % Fat blend with the following dilation values: 20 640 at 10 °C 130 at 25 °C 425 at 15 °C 48 at 30 °C 248 at 35°C 25 Monoglycerides (Hymono Sf44) 0.550 Vitamins and Colorants 0.0425 Flavors 0.0075 The process was carried out as follows.

(1) The aqueous phase was sprayed onto the fat phase at 38° C. in a PTFE-coated container. The size of the spray droplets is approx.
It was 150 to 220 μm.

(2) attached to the container during the addition of the sprayed aqueous phase;
The emulsion was then recirculated into an external loop equipped with a static mixer (both coated with PTFE). Upon completion of the addition of the aqueous phase, a maximum viscosity of 18000 cP at a shear rate of 13.0 sec ^-1 and a maximum viscosity of 2700 cP at a shear rate of 134 sec ^-1 measured at 38°C was reached.

(3) The emulsion obtained was then cooled to 13° C. in a heat exchanger, further coated with PTFE, crystallized in a stirred crystallizer unit without cooling, and then filled at 21° C. The average droplet size of the dispersed aqueous phase is 5μ in the spread.
and this spread remains a stable fat continuous spread upon storage.

Example 2 A W/O emulsion spread was prepared from the following ingredients.

Fat phase wt% soybean oil 11.0 Hydrogenated soybean oil 5.0 Hydrogenated palm oil/palm kernel oil 3.5 Distilled monoglycerides (IV44) 0.45 Colorant 0.015 Flavor 0.0079 Aqueous phase wt % salt 0.25 Potassium sorbate 0.16 Carrageenan gum 0.80 Locust bean gum 0.60 Potassium chloride 0.20 Sodium caseinate 1.20 Cultured milk protein 25.00 Sodium hydroxide 1.83 Water Adjust to 100.00 Emulsion was prepared as follows.

The aqueous phase was sprayed onto the fat phase at 38°C in a PTFE-coated vessel. The size of the droplets in the spray phase is approximately 200μ
It was m. During the addition of the sprayed aqueous phase, a static mixer (both
The emulsion was recirculated into an external loop with a PTFE coating.

The viscosity was approximately 150 poise at a shear rate of 6.4 sec ^-1 .

The average droplet size was 15 microns.

By controlling the amount of shear, the desired viscosity was obtained.

The resulting emulsion was then cooled to 13°C in a heat exchanger, further coated with PTFE, crystallized in an uncooled stirred crystallizer unit and then filled at 21°C.

No phase transformation occurred during processing. Upon consumption, the water-soluble flavors were found to be easily released and the product had good organoleptic properties.

Example 3 Starting from reconstituted cream containing whole butter in the absence of non-dairy emulsifiers, low calorie W/
Production of O-Type Emulsion Spread % Total Butter (Ingrid Country Life) 50.00 Liquid Skimmed Milk 48.42 Potassium Sorbate 0.08 Gelatin 1.50 PH 5.5 by Addition of Lactic Acid An O/W emulsion was first prepared as follows. .

Skimmed milk was heated to 60°C and then potassium sorbate was added with stirring. Melt all the butter;
It was then added to skim milk using a Silverson emulsifier. Gelatin was then added to the resulting O/W emulsion and the PH was adjusted to the desired value.

The emulsion was then sterilized at 80°C,
It was cooled to 60°C and then passed through a Votator A unit that had been previously flushed with fat (preferably butterfat). In this unit the emulsion was rapidly cooled and stirred. The emulsion left the A unit at a temperature of 12-15°C. This emulsion was then placed in a crystallizer unit flushed with fat (preferably also butterfat) at 18-20°C and then subjected to very high shear.

This resulted in a complete phase transformation and a W/O emulsion was obtained with the following properties: C value at 50° C.=2740 g/cm ² C value at 15° C.=1060 g/cm ² .

The conductivity at 15°C was 0.00017μScm ^-1 .

Claims (1)

[Claims] 1. An emulsion containing oil and water is sheared and cooled using a device internally coated with a layer of a hydrophobic substance consisting of polytetrafluoroethylene or butter oil to
A method for producing a W/O emulsion spread with a fat content of 60%. 2. The method according to claim 1, which uses butter oil containing monoglycerides, diglycerides, phospholipids or mixtures thereof. 3 The diameter of the dispersed droplets of the aqueous phase of the emulsion spread obtained by shearing and cooling the emulsion is 2 to 20.
2. A method according to claim 1, characterized in that it is micron. 4. The method according to claim 3, characterized in that the diameter of the dispersed droplets is 8 to 20 microns. 5 Using an O/W emulsion prepared from milk cream containing substantially no emulsifier as an emulsion containing oil and water, shearing and cooling in the absence of a cream/air interface to perform phase transformation;
2. Process according to claim 1, characterized in that a W/O emulsion spread is obtained which has the same fat level as the starting O/W emulsion. 6 W/ prepared by gradually injecting or spraying the aqueous phase into the liquid fatty phase as an emulsion containing oil and water.
6. A method according to any one of claims 1 to 5, characterized in that an O-type emulsion is used. 7. The method according to claim 6, characterized in that the W/O emulsion prepared has a fat content of 15 to 35 wt%.