Pumpable shortening comprising stably dispersed solid sheet- like flakes of fat

The present invention refers to a fluid, pumpable shortening that provides a flaky texture in bakery products.

BACKGROUND OF THE INVENTION

Shortenings, as well as margarines, are fat systems whose properties have been modified to provide specific characteristics useful to baking, confectionary and cooking applications. Different bakery products require different types of shortenings.

Most pie and short crust pastry producers today use solid margarine, containing about 20 % water and 80 % fat, or solid shortening, containing 100% solid fat, to achieve a flaky, crispy texture in bakery products. One of the main functions of the fat is to coat flour particles to prevent the formation of an extensive gluten network. Another function of the fat is to provide a flaky texture in the bakery product. This flakiness is attributed to a grainy crystal structure of the fat and an uneven distribution of fat. Traditionally lard was used due to its stable beta polymorphic forming properties of the fat crystals. In the past the solid fat was irreplaceable due to the need of large crystals to give the grainy texture of the fat and in turn the crispiness and flakiness of the short crust pastry. The handling of solid fat, packed in cartoon boxes, is, however, very unpractical. The fat will have to be stored at a certain temperature to achieve the right functionality when used, personnel is needed to unwrap the fat, the car- toon boxes have to be disposed of, and it takes time to distribute the solid fat in the pie dough. In addition solid fat is rich in saturated fatty acids, which are today considered to be less desirable for reasons of health.

Liquid fat at room temperature, that is oil, is easier to handle, but cannot be used in said applications, as the number of fat crystals is too low to provide the right flakiness.

Semi-fluid lipids, also called fluid or pumpable shortenings, are known to the bakery industry in Europe. This product, comprising a combination of a crystalline and a liquid fat, is used instead of just vegetable liquid oil in

bread formulations because the crystals in the fat help to stabilise the air bubbles during fermentation of the bread dough, which will improve the raise (volume) in the bread. In biscuits and cookies the fat crystals stabilize the foam during creaming (aeration) of the dough and give the dough its proper consis- tency, not to stick to the rolls or punchers when rolled or stamped. On the other hand one of the main reasons for why not just solid margarine (i.e. fat crystals) is used is that a solid margarine or solid shortening is much more labour intense to handle. In order to have a pumpable product it has traditionally not been possible to have a solid fat content, SFC, above approximately 6-8 % (measured by Nuclear magnetic resonance, IUPAC 2.150 (a)) at the pumping temperature, before the product becomes too viscous to be pumpable.

Flaked fat is today used in the food industry as an ingredient in dry soup or sauce mixes and as an additive to pizza dough to provide a better volume raise and a uneven "home baked" appearance of the pizza. The product is sold in large bags, approximately 25 kg, and should be added somewhere along the production line. PRIOR ART

US 4,889,740 discloses a process for preparing a stable pumpable shortening having solid fatty glyceride particles suspended in a liquid glyceride oil, which can be used for frying and pastry baking. The solid fatty glyceride particles should have a maximum particle size of 70 microns, with 80 % of the particles less than about 30 microns, and will form a β-crystal matrix.

US 4,891 ,233, discloses new pastry-making compositions comprising in combination premeasured amounts of pastry-making type flour and flakes of fat, and sufficient liquid fat to coat at least portions of the flakes to promote adherence of the composition and facilitate making a pastry dough. The solidified fat in the form of flakes are intended for use in making piecrust dough.

Prior art methods of adding shortening in bakery processes to obtain a flaky product, suffer from different disadvantages. The traditional way of adding solid shortening or margarine is time consuming and unpractical. If a pumpable shortening or a pumpable shortening comprising solid fat in the form of powder is used in a pie dough the crust will become harder and not

flaky compared to traditional pie crust. The use of solid flakes of fat together with oil would not create a stable suspension, which means that said mixture could not be used as a pumpable shortening, as the solid flakes of fat would sediment to the bottom in the oil.

DESCRIPTION OF THE INVENTION

The invention refers to a pumpable shortening for food applications consisting of a semi-fluid lipid composition and solid particles of fat, which is characterised in that the solid particles of fat are sheet-like flakes of fat stably dispersed in the semi-fluid lipid composition. The pumpable shortening is especially designed for baking applications, and particularly for making pie and pastry doughs.

A pumpable product can be defined as having a viscosity not higher than 25 000 cP at the actual temperature, measured by a Brookfield vis- cosimeter according to the method described in the Examples below.

The solid sheet-like flakes of fat consist of solid fat with a high melting point, which can be produced by crystallisation on a cooled roller. The melted fat is sprayed on to a rotating drum mantled with a cooling medium, in a thin layer and then subsequently scraped of with a knife slanted against the drum. One process for manufacturing of said flakes is described in US

4,891 ,233. Other methods are also conceivable for the man skilled in the art. The produced fat flakes are of irregular shape and it is therefore difficult to provide a length and width dimension. Hence the dimension of the fat flakes is defined by means of the broadest width of the fat flakes. Thus the solidified fat forms thin solid sheet-like flakes of fat, at least 50 % of which have a broadest width of 1-25 mm, preferably 2-15 mm, and a thickness of 0.1-1.5 mm, preferably 0.2-0.6 mm.

Suitable components for the solid sheet-like fat particles are any high melting fat suitable for food applications, for example hydrogenated fat, like fully hydrogenated rapeseed oil, soybean oil, fractions of vegetable fat, such as fractions of palm oil or fractions of lauric fats, that is fat containing a high concentration of C12, interesterified fat component(s) or combinations thereof. The flakes preferably consist of one or more triglycerides of an edible

C4 to C 24 fatty acid, preferably of vegetable origin, and have a melting point preferably above 4O ⁰ C, most preferably above 45°C. The triglycerides have an iodine value of 80 or less.

Examples of commercially available flakes of fat are the different Akoflake products (Karlshamns AB, Sweden).

According to a preferred aspect of the invention the sheet-like flakes of fat constitute 2-35 % by weight of the total weight of the pumpable shortening, preferably 4-25 % by weight.

The semi-fluid lipid composition of the pumpable shortening of the invention comprises a liquid oil component enclosed by a crystalline matrix formed by a high-melting fat component. The liquid fat is entrapped within the matrix. The two components have to be pre-crystallised together in order to get a stable network in the system so that the fat crystals and oil do not phase separate. In order to produce the semi-fluid lipid composition of the invention the high-melting components are melted and blended with the liquid oil at a high temperature. Then the melted fat is cooled, for example in a vessel jacketed with cooling water during slow agitation, in a crystalliser (heat exchanger) or by other means known to the prior art. The semi-fluid lipid composition is then left to mature for several hours. After the maturing period the semi-fluid lipid composition is slowly stirred for some time before it is ready. The process described above should not be taken as limiting the scope of the present invention.

In the pumpable shortening of the invention the semi-fluid lipid composition comprises 80-98 % by weight, preferably 85-97 %, of the liquid oil component and 2-20 % by weight, preferably 3-15 %, of the high-melting fat component.

Suitable examples of the liquid oil component of the semi-fluid lipid composition are vegetable oils, such as soybean oil, rapeseed oil, fractions of oil such as palm oil, interesterified fat and oil components, hydrogenated oils or other lipids fluid at room temperature, or combinations thereof. The liquid oil can be chosen among any suitable oil for food applications. In the semi-fluid lipid composition the concentration of the liquid components should be 80-98 %, preferably 85-97 %.

Examples of the high-melting fat component of the semi-fluid lipid composition are hydrogenated fats such as fully hydrogenated rapeseed oil or soybean oil or fractions of vegetable fat like fractions of palm oil, interesterified fat component(s), or combinations thereof. The solid fat is not restricted to the mentioned fats, but can be chosen among any suitable fat for food applications. The high-melting fat components should preferably have a melting point higher than 40°C, more preferably higher than 45°C and an IV value (iodine value measured according to IUPAC 2.205) of 80 or less. The concentration of the high melting fat components in the semi-fluid lipid composition should be 2-20 %, preferably 3 -15 %.

In order to be pumpable the semi-fluid lipid composition should have a solid fat content, SFC, of 0-8 %, preferably 2-7 % (measured by NMR, IUPAC 2.150 (a)) at the pumping temperature. For the pumpable shortening of the invention to be pumpable at 2O ⁰ C, the semi-fluid lipid composition should have a solid fat content, measured by NMR, IUPAC 2.150 (a), of up to 8 %.

The semi-fluid lipid composition can also comprise an emulsifier. Emulsifiers are for instance, but not limited to, distilled monoglycerides, mono- and diglycerides, lactylated monoglycerides, acetylated monoglycerides, propylene glycol mono- and diesters, sorbitan esters, polyglycerol esters, lecithin. As examples of semi-fluid lipid compositions can be mentioned

Akofluid (Karlshamns AB) and Vegao (Aarhus United AS).

After the maturing period and slow stirring of the semi-fluid lipid composition the solid sheet-like flakes of fat is added. The flakes can be added at a concentration of 2-35 % by weight, preferably 4-25 %. The resulting prod- uct is a pumpable shortening, preferably containing 100 % lipids, wherein the solid sheet-like particles flakes stay homogenously distributed and do not sediment.

The pumpable shortening of the invention can also comprise within the food industry acceptable additives, such as flavours, preservatives, en- zymes, and bread improvers.

Surprisingly we have managed to incorporate significantly more solid fat in a pumpable shortening, compared to traditional pumpable shortenings, and still have a stable, homogenous, pumpable product. This was

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achieved by adding solid fat in the form of flakes to a semi-fluid, pumpable, lipid composition. The flakes provide a very good flaky and crispy texture in bakery applications such as short crust pastry and pie crust, which was not possible to obtain from prior art pumpable fats or shortenings. Depending on the type of bakery application and preferred flaki- ness of said application the amount of flakes and the solid fat content of the semi-fluid lipid composition can be varied. The more flakes present in the composition, the flakier and crispier the texture of the baked product. In order to have the right melting properties of the fat in the bakery application the total composition and the concentration of the fat in form of flakes can be combined in such a way that the solid fat content, SFC, at 1 O ⁰ C will be 3-45 %, preferably 5-40 %, the SFC at 2O ⁰ C will be 3-35 %, preferably 4-35 %, and the SFC at 3O ⁰ C will be 2-25 %, preferably 3-25 %. A specific pumpable shortening of the invention for making a flaky short crust pastry should have a solid fat content within the range of 9-35 %, preferably 9-25 % at the pumping temperature.

Generally the pumping temperature of the shortening of the invention lies within the range of 5-45 ⁰ C, preferably at 10-35 ⁰ C.

In the pumpable shortening of the invention the solid flakes will provide the right uneven distribution of solid fat in the dough to give the wanted flaky structure in the final pastry. It is the particular thin, sheet-like structure of the solid flakes of fat that contributes to a flaky, crispy and palatable short crust pastry. This would not be the case if only a semi-fluid lipid composition, a pumpable shortening, or a blend of a pumpable shortening with a solid fat in the form of powder was used. Another function of fat in bakery applications such as short crust pastry and biscuits is to coat flour particles to prevent the formation of an extensive gluten network. The fluidity of the pumpable shortening of the invention also provides a coating of flour particles in a very efficient way, preventing gluten formation and the forming of a tough dough. The semi-fluid, pumpable shortening of the invention renders the handling much more efficient compared to the use of solid fat; no unwrapping, no disposal of the packaging, and no need of a tempering step, as the shortening is not temperature sensitive. Moreover the dosage of the fat into the dough

is easier and the distribution of the fat into the dough faster, that is the mixing time is shorter. The described pumpable fat can be stored in a tank or container at ambient temperature. The efficient handling will increase the capacity, decrease the need of manual work and lower the costs. The content of saturated fat is considerably lower in the pumpable shortening of the invention, less than 40 % by weight, preferably less than 25 %, compared to traditional pastry margarines and shortenings having more than 50 % by weight of saturated fat. Saturated fatty acids have been shown to contribute to obesity and cardiovascular diseases. Furthermore, because of the efficient mixing of the dough based on semi-fluid lipid composition and the particular concentration of fat in the form of solid flakes of fat, it was also possible to reduce the total amount of fat up to 20 % compared to the traditional use of solid margarine.

The pumpable shortening of the invention can preferably be used for preparing all types of pastry such as short crust pastry, pie doughs, laminated doughs, puff pastry (15-40 %), for example Danish and croissants, as well as biscuits and cookies, such as rich short pastry (up to 30 %). The shortening can also be used in fermented doughs, like for example bread, rusks and pizza doughs (up to 15 %). For a pumpable shortening to be used in fermented doughs, which require a lower content of fat compared to flaky pastries, a preferred solid fat content at 2O ⁰ C is 3-8 %.

EXAMPLES The following examples refer to different fat compositions and especially to the preparation of pumpable shortenings of the invention. In the examples parts refer to parts per weight.

The pumpability of the fat compositions was defined by viscosity measurements using a Brookfield DV fl + Pro viscometer, at 12 rpm and at a constant temperature of 20°C. The viscosity value after 2 minutes was registered. 500 g of the fat was poured into a 500 ml beaker and was left to rest for 24 hours before the measurement was performed

The solid fat content, SFC, of the lipid compositions was measured by NMR, IUPAC 2.150 (a) and stated in % by weight of the total composition.

The melting point of the lipid fractions was measured as the slip melting point according to AOCS Cc 3-25. The Iodine value, IV, reflecting the degree of saturation, was measured in accordance with IUPAC 2.205.

Example 1

1a) Flakes of fat A fully hydrogenated hard palm fraction, melting point 58°C, was melted and at a temperature of above 60°C sprayed onto a flaking drum device, rotating at a tangential velocity of 0.25 m/s and at a uniform temperature of 5°C. The crystallised fat was then scraped of the surface of the drum using a hardened knife in contact with the drum at an internal angle of 20 degrees. 1b) Semi-fluid lipid composition

Low erucic rapeseed oil, 96 parts, emulsifier (Dimodan, monoglyc- erides from Danisco), 1 part, and fully hydrogenated rapeseed oil, 3 parts, were thoroughly mixed at 60°C. Thereafter the fat was poured into a vessel mantled with cooling water (10°C) and crystallised during slow agitation. After the crys- tallization the semi-fluid lipid composition was matured over night at room temperature and then agitated for 10 minutes.

The semi-fluid lipid composition had a SFC value of 4 at 10°C, 3 % at 20°C and 3 % at 30°C. The viscosity was measured to 1790 cP. Pumpable shortening Finally the flakes of fat described above, 11 parts, were mixed with the semi-fluid lipid composition, 100 parts, and agitated for 10 minutes. The resulting pumpable shortening had a SFC value of 11 % at 10°C, 9 % at 20°C, and 7 % at 30°C. The viscosity of the shortening was 2010 cP.

Example 2

Flakes were prepared from hydrogenated palm oil, melting point 46°C, as described in Example 1.

The semi-fluid lipid composition was prepared from low erucic rapeseed oil, 94 parts, and fully hydrogenated rapeseed oil, 6 parts, which were thoroughly mixed at 60°C. Thereafter the mixture was crystallised in a tube chiller with an outlet temperature of about 10 ⁰ C. After the crystallization the semi-liquid fat was pumped to maturing tanks where the product was left to mature over night at room temperature and then agitated for 4 hours. The semi- lipid composition had a SFC value of 6 % at 10-20 ⁰ C, and 5 % at 30°C.

Finally the flaked fat, 15 parts, was added to the semi-liquid fat and the mixture was agitated for 1 hour. The resulting pumpable shortening had a SFC value of 15 % at 10 ⁰ C, 14 % at 20°C, and 11 % at 30°C.

Example 3

Flakes of a hard palm fraction, with a melting point of 60°C, were prepared as described in Example 1a. A semi-fluid lipid composition was prepared from rapeseed oil, 93 parts, and hard palm fraction having a melting point of 6O ⁰ C, 7 parts, as described. The SFC at 20°C and 30°C was measured to 5 % and 4 %, respectively.

Finally the flakes, 11 parts, were added to the semi-fluid lipid com- position, 100 parts. The resulting pumpable shortening had a SFC value of 17 % at 1O ⁰ C, 14 % at 20 ⁰ C, and 11 % at 3O ⁰ C. IV was measured to be 99.

Example 4

Flakes of fat and a semi-fluid lipid composition were prepared as described in Example 1a.

The flakes, 34 parts, were mixed with the semi-fluid lipid composition, 100 parts, as described. The resulting pumpable shortening had a SFC value of 34 % at 1O ⁰ C, 24 % at 20 ⁰ C and 13 % at 30 ⁰ C. The viscosity was measured to 2510 cP.

Example 5

Flakes of a hard palm fraction, melting point 60 ⁰ C, were prepared as described in Example 1a.

A semi-fluid lipid composition was prepared from soybean oil, 85 parts, and hard palm fraction having a melting point of 54 ⁰ C, 15 parts, as described. The semi-lipid composition had a value of 11 % SFC at 10 ⁰ C, 7 % at 20°C, and 4 % at 30 ⁰ C. Finally the flakes, 3 parts, were added to the semi-fluid lipid composition, 100 parts. The resulting pumpable shortening had a SFC value of 12 % at 10 ⁰ C, 10 % at 2O ⁰ C, and 7 % at 30 ⁰ C.

Example 6 Flakes were prepared from hydrogenated palm oil as described in

Example 1 a. The melting point of the flaks was measured to be 46 ⁰ C.

A semi-fluid composition was prepared from soybean oil, 85 parts, and hard palm fraction, 15 parts, as described in Example 5.

Finally the flaked fat, 53 parts, was added to the semi-liquid com- position, 100 parts, and the mixture was agitated. The resulting pumpable shortening had a SFC value of 39 % at 1O ⁰ C, of 34 % at 2O ⁰ C, and of 24 % at 3O ⁰ C.

Example 7 Flakes were prepared from hydrogenated palm oil as described in

Example 1 a. The melting point of the flakes was measured to be 46 ⁰ C.

A semi-fluid composition was prepared as described in Example 1 b.

Finally the flaked fat, 3 parts, was added to the semi-liquid fat, 100 parts, and the mixture was agitated. The resulting pumpable shortening had a SFC value of 5 % at 1O ⁰ C, of 4 % at 2O ⁰ C, and of 3 % at 3O ⁰ C.

Comparative Example 8

Flakes of fat, as described in Example 1a, 10 parts, were mixed with low erucic rapeseed oil, melting point below 1O ⁰ C ₅ that is a SFC of 0 %, 90 parts. The stability of the fat composition was tested.

Comparative Example 9

A semi-fluid lipid composition, the commercial trans free product Akofluid (produced by AarhusKarlshamn AB, Sweden) based on palm and low erucic rapeseed oil, has a SFC value of 9 % at 20°C and 5 % at 30°C. The viscosity was measured to 36 400 cP, which means that this composition can- not be pumped.

TESTS

Viscosity From the results of the viscosity measurements it was shown that there was a large difference in viscosity between the lipid composition from Example 9 and the compositions from Examples 1 , 4 and 1 b, as can be seen from Table 1 below.

Table 1. Pumpability test at 20°C

The results show that the lipid compositions of Examples 1 , 4 and 1 b were pumpable since they had a lower viscosity value than 25 000 cP at the actual temperature. The composition of Example 9 had a viscosity of 36 400 cP and was not pumpable at the same temperature. It was surprising to find that the compositions of the Examples 1 and 4, having SFC values above 8 %, were pumpable, defined by viscosity measurements, unlike the lipid composition of Example 9.

The lipid compositions in Example 1 , 4 and 1 b remained pumpable during the full storage period.

Pourability

As a demonstration of the pourability, 150 g of the lipid compositions of Examples 1 , 4, 1b and 9 were put in four identical 400 ml glass beakers and were left to rest at 20°C for 8 hours. Thereafter the beakers were quickly (1

second) turned upside down on a table and the time measured for the content of the beaker to reach the table was measured. For the lipid compositions of Example 1 , 4 and 1 b the time for the content of the beaker to reach the table was less than 3 seconds but for the lipid composition of Example 9 nothing from the content in the beaker had reached the table after 24 hours.

Stability

The stability of the lipid compositions of Examples 1 , 1a and 8 after different periods of time was studied by visual examination and it was decided if the fat was homogenous or not. The fat was no longer homogenous if the flakes of fat had settled to the bottom or if there was an oil separation. The results are shown in Table 2.

Table 2. Stability test

The results of the stability tests showed that the lipid composition of Example 1 appeared to remain stable and that solid sheet-like particles stayed homoge- nously distributed and did not sediment during a storage period of ten weeks. The test also showed that the fat composition of Example 8 was not stable at all. The flakes of fat could not remain dispersed in the oil in the absence of a crystalline network. A semi-fluid lipid composition seems to be necessary for obtaining a stable dispersion of flakes.

Test of sensory properties of a baked product

Short crust pastry/pie shells are baked from a pumpable shortening of the invention, and compared to a baked product based on a traditional margarine, as well as based on a semi-fluid lipid composition. A typical recipe is given in Table 3 below. Recipe 1 is with margarine, a commercial pastry margarine, Marba Wiener SP 2 (IV 42; Karlshamns AB), and Recipe 2 with the

pumpable shortening described in Example 3 above, (Recipe 2a); and also with the semi-fluid lipid composition described in Example 1a above, (Recipe 2b).

Table 3. Recipe of short crust pastry/pie shell

All ingredients were put in a Hobart mixer and mixed until they became a dough. A piece of the dough (approximately 120 g) was then rolled to a thickness of 5 mm, stamped to circles and draped into pie moulds. Optional filling was put in the pie shell and the pie was baked at 200°C. The doughs made according to Recipe 1 had to be mixed for a longer time for the margarine to be distributed into the dough, compared to the dough based on Recipe 2 (6 minutes compared to 2-3 minutes). The dough made with margarine (Recipe 1 ) was also harder to roll out.

Taste, hardness and flakiness of the baked short crust pastries were evaluated by a sensory panel of 5 persons (A-E) were the hardness, fla- kyness and taste of the three short crust pastries were evaluated and ranked as follows:

+++: very flaky, very hard or very neutral taste ++: medium flaky, medium hard or medium neutral taste +: just a little flaky, a little hard or a little neutral taste

- no sensed flakiness, no sensed hardness or no neutral taste The results are shown in Table 4 below.

Table 4. Results of the sensory evaluation of short crust pastries

The results show that the short crust pastry of Recipe 2a was recognized to have at least the same flaky texture as compared to short crust baked with margarine, the short crust pastry of Recipe 1. Also the hardness was similar to short crust pastry of Recipe 1. The hardness of short crust pastry baked with the semi-fluid fat (short crust pastry of Recipe 2b) was perceived as harder compared to short crust pastries of the Recipes 1 and 2a.