CH615088A5 - Process for producing a stabilised icecream - Google Patents

Description

The invention relates to a method for producing stabilized ice cream and the stabilizing agent.

The way an ice cream behaves when exposed to normal room temperature is important to the consumer. If a product behaves too atypically, for example if it melts too quickly or if it melts into a fat phase and a clear, aqueous phase, then the product is not acceptable. Methods have been developed in the ice cream industry to measure such properties as melt-down and stand-up. These methods are described below.

It is known that such properties can be influenced by the use of stabilizers, which are often also referred to as thickeners. One problem that arises is that the stabilizers adversely affect the taste or the feeling of the ice cream in the mouth. A loamy, rubbery, or even slimy feeling may appear. This problem is particularly acute with ice creams that require more than usual stabilization. What is desired is a stabilization system that is good or at least sufficient in terms of all stability requirements. This is difficult to achieve for normal ice creams and especially for ice creams that require more than the usual stabilization.

Unexpectedly, a stabilization method has now been found that is surprisingly effective in stabilizing ice cream without causing an uncomfortable feeling in the mouth.

The inventive method for producing a stabilized ice cream is defined in claim 1.

The amount of microcrystalline cellulose to be added is preferably at least 0.01%, especially at least 0.1%. For cost reasons, preferably not more than 0.8% is used, in particular not more than 0.4%. A preferred range is 0.15 to 0.4%, especially up to 0.25%. The total amount of carboxymethyl cellulose (calculated as sodium carboxymethyl cellulose) and galactomannan gums present is preferably not more than 1%, in particular not more than 0.5%. The amount is preferably in the range of 0.15 to 0.35%. The lower limit for carboxymethyl cellulose is preferably 0.01%. The lower limit for calactomannan gums, especially for carob flour, is preferably 0.05%. Of course, in any stabilization system, there should be no more than one component at or near the lower limit.

The weight ratio of microcrystalline cellulose to total carboxymethyl cellulose (calculated as sodium carboxymethyl cellulose) and galactomannan gums is preferably in the range from 4: 1 to 1: 4, the range from 2: 1 to 1: 3 being particularly preferred. The total amount of stabilizing agent is preferably in the range from 0.15 to 1.0%, in particular from 0.30 to 0.5%. The weight ratio of microcrystalline cellulose to carboxymethyl cellulose is preferably not more than 3: 1 and in particular not less than 1: 2.

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As already emphasized above, the stabilization system is particularly useful in ice creams that require more stabilization than usual.

A problem with conventional ice creams is that they operate at freezing temperatures, e.g. B. -20 ° C, can not be served or eaten as easily as at normal eating temperature, e.g. B. -10 ° C. The consumer cannot treat them nearly as normally when they are removed from the freezer. In some cases, conventional ice creams cannot be spooned in the same way with a spoon at -20 ° C. H. they cannot be spooned. The reformulation to ensure that such properties as. B. spoonability, at freezing temperatures are approximately as expected at normal eating temperatures, is relatively simple. Methods will be described later. The difficulty is that such reformulation leads to products that do not have acceptable properties, particularly stability, at normal eating temperatures. It seemed impossible to obtain an ice cream which, both at freezing temperatures and at normal eating temperatures, only approximated the serving and eating properties normally expected at normal eating temperatures and which is sufficiently stable. The present invention provides a stabilization system with which this can be achieved.

It will be appreciated that the product characteristics required for a conventional ice cream depend on the personal taste of the consumer, and ice creams are formulated to satisfy as many flavors as possible. The formulation of any conventional ice cream will depend on the taste of the consumer under consideration. In this context, a conventional ice cream is one made by a process in which the cream is frozen and cured at temperatures on the order of -20 to -40 ° C. An important property of ice cream, especially in connection with the spoonability, is the log C of the ice cream, which is defined below. For example, in the United Kingdom, an ice cream can normally only be called a conventional ice cream if its log C at -20 ° C after hardening is in the range of 2.9 to 3.7. Typically, in the United Kingdom, the log C of a non-milk ice cream at -20 ° C after curing is in the range of 3.3 to 3.7 and for milk ice cream is in the range of 2.9 to 3.3. In other countries, the log-C values will be comparable, but they can be different, often higher, and even within a country, different conventional ice creams can have different log-C values.

(A method for measuring C, the penetrometer value and log C from it is described below).

Whatever has been used for conventional ice cream, its properties at freezing temperatures can be approximated to those expected at normal eating temperatures by adding freezing point depressants, e.g. monosaccharides and low molecular weight alcohols, preferably polyalcohols, especially glycerol and sorbitol. It has been found that normally sufficient amounts of such freezing point depressants should be added to the formulation of a conventional ice cream, for example at the expense of water, by about 0.25 to 1, preferably 0.4 to 0, log C at -20 ° C. To humiliate 75. The imaginary replacement, e.g. B. of freezing point depressants for sugar / water, should be such that the product has the desired sweetness (by the consumer) as well as the desired log C or the spoonability at -20 ° C.

As mentioned above, one problem that ice cream manufacturers face is that ice creams have unacceptably poor properties, such as: B. Stand-up and melt-down, at normal eating temperatures if the ice creams are formulated to have conventional eating temperature properties at -20 ° C, especially spoonability at -20 ° C. It has been found that the log C of ice cream should preferably be less than 2.8, particularly preferably less than 2.5, if the ice cream is to be spoonable at -20 ° C. A connection between spoonability and log C was found. A particularly important aspect of the present invention is the improvement of an ice cream whose log C (where C is its penetrometer value) has been reduced by 0.25 to 1 at -20 ° C by using freezing point depressants, the improvement in use of the stabilization system according to the invention.

Microcrystalline cellulose is a well-known commercial product. Their use in relatively large amounts in low-calorie products, including in low-calorie ice creams, is described in GB-PS 961 398. Processes for their preparation are known and are described, for example, in US Pat. No. 3,157,518, to which express reference is made here. A problem with microcrystalline cellulose is its dispersibility. Methods of overcoming this problem are known. A special method involves the use of carboxymethyl cellulose. Microcrystalline cellulose, sold by FMC Corporation under the trade name "Avicel", and an easily dispersible form containing sodium carboxymethyl cellulose is sold under the name "Avicel RC-591". It is said to be a colloidal form of microcrystalline cellulose that has been mixed with sodium carboxymethyl cellulose and then dried. The amount of sodium carboxymethyl cellulose is 11 ± 1% by weight, based on microcrystalline cellulose. Microcrystalline cellulose is described in detail, for example, in GB-PS 961 398 and US-PS 3 157 518; in short it can be said that microcrystalline cellulose consists of cellulose crystallite aggregates with a level-off DP.

Level-off-DP is the average level-off degree of polymerization measured using the method developed by O.A. Battista in "Hydrolysis and Crystallization of Cellulose" in Industriai and Engineering Chemistry, Volume 42 (1950), pp. 502 to 507. As indicated in GB-PS 961 398, a suitable microcrystalline cellulose has medium level-off DP's in the range from 125 to 375, in particular from 200 to 300. The particle size of the aggregates of the microcrystalline cellulose is usually in the range from 1 to 300 μm .

Galactomannans are well known materials, for example described by M. Glickman in "Rubber Technology in the Food Industry", Academic Press, 1969. Preferred galactomannan gums for use in the process according to the invention are locust bean gum and locust bean gum and taro gum. Carboxymethyl celluloses are standard industrial products.

In the present description and in the claims, all percentages are by weight, in particular they relate to the amount by weight of ice cream, unless the context requires otherwise.

In contrast to the use of a sufficient amount of freezing point depressants, no particular acuity is required to formulate or produce ice creams by the process according to the invention in accordance with the preferred embodiment of the invention and when using a thickening agent which contains special components. Details of conventional

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Formulations and processing conditions for ice cream can be found in the usual commercial publications and manuals. In this regard, Arbuckle, "Ice Cream," 1972 (2nd edition) AVI Publishing Corporation, Westpoint, Conn., Is particularly useful.

Preferred embodiments of the invention are explained in more detail below with the aid of examples.

The properties of the stabilization system are extremely surprising when compared to the properties of the individual separate components. This is illustrated in the examples, but it should be emphasized that the stabilization system is also useful for products other than ice cream.

example 1

An ice cream of the following composition was produced by conventional processing methods:

Components weight%

Artificial skimmed milk

(32.5% solids) 27

Sucrose 13

Glucose Syrup 2

Liquid oil mixture 9.5

Monoglyceride emulsifier 0.45

Colorings and flavors 0.03

Carob flour 0.15

"Avicel RC 591" ** 0.2

Sodium carboxymethyl cellulose * 0.15

Salt 0.05

Glycerin 3.0 water ad 100.0

* Available from ICI as "Powder B600"

** supplied by FMC; probably contains 11% by weight sodium carboxymethyl cellulose

The presence of thickeners can be verified analytically in such a product. The product itself is an excellent ice cream, the eating properties of which are reminiscent of conventional VK ice cream (United Kingdom), but can be spooned at -20 ° C.

Example 2

An ice cream mix was made from the following ingredients (parts by weight):

Components

% By weight

Palm oil

5.5

Stearic acid monoglyceride

0.15

Spray dried milk powder

10.0

Sucrose

14.0

Microcrystalline cellulose (11% sodium carboxy

containing methyl cellulose)

0.4

Sodium carboxymethyl cellulose *

0.2

Carob flour

0.22

Trisodium citrate

0.3

water

64.0

* Supplied by ICI as SCMC powder B600

The stearic acid monoglyceride was dispersed in the palm oil to a fat phase. The milk powder was dispersed in water, and the remaining ingredients were added to the obtained dispersion to obtain an aqueous phase. The fat phase and the aqueous phase were mixed at 65 ° C, homogenized at a pressure of 141 kg / cm2 (2000 psi) and the emulsion formed was pasteurized at 70 ° C for 20 minutes and then cooled to 5 ° C; at this temperature the pH was 6.5. After aging for 2 hours at 5 ° C., 6 parts of orange juice concentrate, 0.04 part of dye and 3 parts of a 33% strength by weight aqueous solution of citric acid were mixed with the emulsion. The resulting pH 3.5 emulsion was converted to ice cream by cooling and whipping at -4 ° C, and the ice cream was blast frozen to -20 ° C and stored.

This example demonstrates the use of the stabilization system to stabilize an acid ice cream, a type of ice cream that requires more stabilization than a conventional ice cream.

The stabilization system is with an acidic ice cream, e.g. B. in an ice cream with a pH in the range of 3.0 to 5.2, particularly valuable. The pH, as it should be within this range, should preferably be well below the isoelectric point of any acid-precipitable protein that is present in substantial amounts so that the protein present remains substantially uncoagulated. Optionally, whey protein can be used, preferably purified by reverse osmosis; Whey protein is not acid-precipitable. Such ice creams are described in GB-PA 57493/72 (corresponding to DE 2 361 658 and US-PA 422 617, filed on December 7, 1973).

Examples 3 to 14 and comparisons A to F ice cream mixtures were prepared in the usual way according to the following formulations. Further details are given immediately before the claims in Table 1, which also shows the results obtained with ice cream made in a conventional manner from the mixtures. A standard UK non-milk ice cream differs from this formulation in that it contains no glycerin but 1.4% by weight more sugar. 3% glycerin corresponds to about 1.5% sugar in the sweet.

Components

% By weight

Spray dried milk powder

9.5

sugar

13.5

Maltodextrin 40 DE * (glucose syrup)

1.7

Palm oil

9.5

Monoglyceride from palm oil

0.5

Glycerin

3.0

salt

0.05

Flavors and colors

0.1

Stabilizers

Table 1

Water ad 100.0

* DE = dextrose equivalent The SCMS used was the “powder B 600” available from ICI Limited.

The log-C values at -20 ° C of Examples 3 to 14 and Comparative Experiments A to F ranged from 2.5 to 2.9 and averaged 2.7. The log C of the standard ice cream mentioned above ranged from 3.2 to 3.3.

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Test Methods Meltdown Test and Shape Retention A 13.6 cm long, 4.0 cm high, and 8.8 cm wide rectangular block of ice cream that had been stored at -20 ° C was placed on a Wire gauze (10 wires per 2.54 cm) was placed and stored in an atmosphere kept at 15 ° C. A device was provided to collect the liquid dripping from the gauze. The time to collect the first 10 ml of the liquid was noted. The volume of liquid collected for periods of 10 minutes each was measured and the slope of the curve obtained by plotting the volume collected against time was measured as the meltdown (ml / hour). After 4 hours of thawing, a photograph of the residue of the cube was taken and the degree of shape retention was reported as poor, poor, moderate, good or very good.

Stability in cyclic temperature changes This test was carried out with an approximately cubic ice block of 1.891 (V2 gallon) in a plastic container. After being stored in a freezer, the block was kept at room temperature (20 ° C) for 1/2 hour and then placed in a refrigerator at -10 ° C. The next day, the block was subjected to another cyclic thermal shock treatment by removing it from the refrigerator and leaving it at room temperature for V2 hours. This (V2 hour at room temperature every day) was repeated up to a total of six times, and then the block was returned to the freezer to be measured the next day. The overall test lasted no more than 10 days with one weekend break. The product stability was stated as follows:

Poor: complete breakdown Poor: more than 20% of the product converted into aqueous residue Moderate: 5 to 20% of the product converted into aqueous residue

Good: less than 5% of the product was converted into aqueous residue (converted to serum)

C and log C

The following method was used to determine C and log C:

principle

Ice cream hardness is measured by allowing a standard cone to soak into a sample for 15 seconds using a cone penetrometer. The C-value can be calculated from the penetration depth.

Apparatus hard rubber cone With an opening angle of 40 ° ± 10 ° and a point blunted by a few lines on fine sandpaper, so that a flat surface of 0.3 ± 0.03 mm diameter is created. Total weight of the cone with sliding penetrometer shaft 80 ± 0.3 g; additional weight of 80 ± 0.3 g.

Penetrometer

Equipped with a scale calibrated in 0.1 mm and with a magnifying glass. The penetrometer manufactured by Sommer and Runge in Berlin is recommended, especially for static use. The Hutchinson instrument can also be used; it does not require electrical connection, but must be modified for satisfactory use. The accuracy of the adjustment mechanism must be checked regularly. The use of a triple magnifying magnifier with a diameter of about 6 to 8 cm to match the penetrometer makes it easier to place the tip of the cone on the surface of the sample, and not focused light, limited to the value of a 1-watt lamp at a distance of about 5 cm (to avoid this heating of the sample surface) is also advantageous.

Temperature probe

Reading accurate to 0.1 ° C. The temperature probe should have a tube about 1 mm in diameter and about 4 cm in length. Their accuracy should be checked regularly in baths of known temperature.

Temperature control devices

(a) space maintained at the desired temperature with an accuracy of ± 1 ° C;

(b) Thermostatic cabinets, accuracy ± 0.2 ° C

The air-cooled thermostat cabinets from Zero N.V., Rotterdam, are satisfactory.

Sampling procedure

The samples should be of conventional size and preferably smooth surfaces to increase accuracy.

Heat treatment

Two days at the required temperature, e.g. B. -20 ° C. The temperature is measured immediately before penetration.

Measurement

Where possible, penetrations are carried out in the room at constant temperature; they should be removed from the thermostat cabinet within 2 minutes of taking the sample.

1. Place the temperature probe as horizontally as possible a few millimeters below the sample surface, and after 30 seconds the sample temperature is measured and noted (samples that deviate more than 0.5 ° C from the nominal test temperature are discarded).

2. The samples are placed on the horizontally set petrometer table.

3. The cone tip is placed exactly on the sample surface using a magnifying glass and - if necessary - indirect light.

4. The locking device is released and the cone is left to act for 15 seconds.

5. The depth of penetration is read and noted.

6. If the penetration depth (penetration depth) is less than 72 x 0.1 mm (a C value of more than 500 g / cm2 equivalent), the measurement should be repeated with a cone weight increased by 80 g.

Additional 80 g weights can be added if necessary to ensure adequate penetration of the sample, the reading of the C-value scale should be corrected accordingly.

7. Penetration measurements should not be made within 2 cm of the edge of the sample or within 2.5 cm of each other. Determinations in which air bubbles, cracks etc. disturb the measurement should be discarded.

Calculation of the C values

The C-value can be calculated from the depth of penetration using the following formula:

r _ KxF

"P"

wherein

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= Compliance value or C value (g / cm2) = total weight of the cone and the adjustable

Stems (g) *

= Depth of penetration (0.1 mm)

= factor dependent on the cone angle:

Cone angle in degrees

K value

30 40 60 90

9670 5840 2815 1040

5 Depending on the likely softness of the product, the cone weight should be selected as follows, e.g. B.

at -10 ° C 80 g at -15 ° C 160 g at -20 ° C 240 g d. H. the weight depends on the measuring temperature.

C values are usually measured after the ice cream has been hardened in the customary manner, for example as described above or in the relevant manuals.

It should be noted that an ice cream produced according to the invention preferably has a melting down (determined as above) of less than 25 ml / hour and in particular between 25 ml / hour.

It should also be noted that the log C at −20 ° C. of an ice cream obtainable according to the invention should preferably be not less than 2.3.

Further details of suitable microcrystalline cellulose can be found in the brochures of FMC Corporation, Avicel Department, Marcus Hook, Pennsylvania 19060, 15 for example in bulletin RC-16 and brochures RC-30 and RC-34. RC-30 describes the use of microcrystalline cellulose in frozen desserts and provides u. a. found that it is compatible with all stabilization systems except those containing guar, carob and sodium alginate 20.

Table 1

Stabilizers wt.% Melt down at 15 ° C

example

Avicel

LBG

Guar flour

Water bread

SCMC

Mixed

Excess

1. 10 ml

Speed

Formbeibe

Stability at

Overall acceptability or

R 591 *

root

viscosity

(overrun)

(Min.)

Attitude

temperature

comparison

rubber

(cps)

(ml / hour)

change

A

0.2

13

45

40

134

bad bad completely unacceptable

B

0.175

44

95

80

26

poor poor completely unacceptable

C.

0.15

27th

143

135

20th

poorly moderately completely unacceptable

D

0.175

0.15

128

147

> 240

<3

moderately moderately unacceptable **

E

0.175

0.15

115

163

> 240

<3

poorly moderately unacceptable **

F

0.175

0.15

134

140

> 240

<3

moderately moderately unacceptable **

3rd

0.2

0.175

45

132

110

14

well moderately acceptable

4th

0.2

0.15

46

130

145

12

poorly just acceptable

5

0.2

0.175

0.15

94

147

> 240.

3rd

good good very acceptable

6

0.1

0.175

0.05

64

112

65

7

moderately acceptable

7

0.2

0.175

34

152

210

10th

moderately moderately just acceptable

8th

0.2

0.175

49

129

160

18th

well moderately acceptable

9

0.2

0.175

0.15

92

160

> 240

<3

good good very acceptable

10th

0.2

0.175

0.15

104

144

> 240

<3

very good good very acceptable

11

0.1

0.175

0.15

110

110

> 240

<3

moderately acceptable

12

0.05

0.175

0.15

102

125

> 240

<3

moderate 1

moderate 1

acceptable1

13

0.2

0.1

0.15

-

120

> 240

<3

well well acceptable

14

0.2

0.05

0.15

57

130

> 240

<3

good2

moderately acceptable 2

* Contains 11% by weight SCMC

** The main reason was the poor organoleptic properties. The products were too rubbery. The presence of microcrystalline cellulose surprisingly reduces this effect; this is of general validity. It was also found that an excessively high mixed viscosity was an indication that the product would have poor organoleptic properties, particularly in the absence of microcrystalline cellulose.

1 worse than 11

2 worse than 13

Claims (15)

615 088 2nd PATENT CLAIMS 1. A process for the preparation of a stabilized ice cream, characterized in that microcrystalline cellulose and at least one carboxymethyl cellulose and / or galactoman-nane are added to the ice cream in the manufacture as a stabilizing agent, the weight ratio of min-crocrystalline cellulose to carboxymethyl cellulose in the absence of galactomannans is not more than 3: 1. 2. The method according to claim 1, characterized in that the amount of microcrystalline cellulose is at least 0.01% by weight, preferably at least 0.1% by weight, but not more than 0.8% by weight, preferably not more than 0, 4% by weight, in particular 0.15 to 0.4% by weight, particularly preferably 0.15 to 0.25% by weight, based on the weight of the ice cream. 3. The method according to claim 1, characterized in that the total amount of carboxymethyl cellulose - calculated as sodium carboxymethyl cellulose - plus galactomannane not more than 1% by weight, preferably not more than 0.5% by weight, in particular 0.15 to 0, 35% by weight that makes up ice cream. 4. The method according to claim 1, characterized in that the amount of galactomannans is not less than 0.01% and preferably not more than 0.05%. 5. The method according to claim 1, characterized in that the weight ratio of microcrystalline cellulose to the total amount of carboxymethyl cellulose - calculated as sodium carboxymethyl cellulose - plus galactomannans in the range from 4: 1 to 1: 4, preferably in the range from 2: 1 to 1: 3, lies. 6. The method according to claim 1, characterized in that the amount of stabilizing agent is in the range from 0.15 to 1.0% by weight, preferably in the range from 0.3 to 0.5% by weight. 7. The method according to claim 1, characterized in that the weight ratio of microcrystalline cellulose to carboxymethyl cellulose is in the range from 3: 1 to 1: 2. 8. The method according to claim 1, characterized in that the ice cream has a log-C value at -20 ° C of less than 2.8, preferably less than 2.5, in particular not less than 2.3. 9. The method according to claim 1, characterized in that an ice cream is produced, the melting down of less than 25 ml / hour. at 15 ° C, preferably in the range between 5 and 20 ml / hour. at 15 ° C. 10. The method according to claim 1, characterized in that the stabilization system contains galactomannans, preferably from locust bean gum or from taro root and / or carboxymethyl cellulose. 11. The method according to claim 1, characterized in that an ice cream is produced which has a pH in the range from 3.0 to 5.2, which is sufficiently below the isoelectric point of any acidic, precipitable protein which is present in substantial amounts is so that the protein remains substantially uncoagulated, the protein preferably being whey protein, preferably one that is purified by reverse osmosis. 12. Ice cream produced by the process according to claim 1. 13. Stabilizing agent for carrying out the method according to claim 1, characterized in that it contains microcrystalline cellulose and at least one carboxymethyl cellulose and / or galactomannans, the weight ratio of microcrystalline cellulose to the total amount of carboxymethyl cellulose plus galactomannan gum in the range from 4: 1 to 1 : 4 is. 14. Stabilizing agent according to claim 13, characterized by a weight ratio of microcrystalline cellulose to the total amount of carboxymethyl cellulose plus galactomannan gum in the range from 2: 1 to 1: 3. 15. Stabilizing agent according to claim 13, characterized in that the galactomannans come from locust bean gum or from taro root.