Improvements in edible fats

Abstract: The processability of a margarine or other edible spread fat blends and the properties of the resulting products are to a large extent determined by the crystallisation behaviour of the fat blend. Problems of delayed crystallisation are known in the art of margarine or other spread manufacture, in particular, it is common knowledge in margarine blend formulation that interesterification of fats quite often results in slower crystallising fat blends and often fat blends which are impractically or inconveniently slow to crystallise. We have now determined that the crystallisation of margarine fats from a supercooled melt can be accelerated by the use of a triglyceride having a trans fatty acid at the 2-position, preferably a 1,3-saturated-2- trans -unsaturated (FTF) tempering accelerator. These include, in particular the HTH TAGs where H is stearic or palmitic, and especially PEP.

Description: The present invention relates to improvements in edible fats, and in particular to improvements in fat blends suitable for the manufacture of margarines and other spreads. The invention further relates to a process for the manufacture of edible fat spreads and to a tempering additive for use in such a process. GB 1564363 (to Dynamit Nobel AG: 1975) describes how molten chocolate fats are often difficult to solidify from a supercooled melt and while solidification can be accelerated by the application of steep temperature gradients, this can result in the fat crystallising in one or more alternative crystalline forms (polymorphs). While some of these forms may have properties appropriate for the envisaged use of the fat in confectionery, other crystalline forms do not have the desired properties and crystallisation in these forms should be avoided. As a solution to this problem GB 1564363 proposes the use of a crystalline powder-form composition which is dispersed in the supercooled cocoa butter melt to promote the desired crystal habit, and suggests that this should be selected from 'mono-acid triglycerides' and/or 'symmetrical triglycerides' which comprise saturated fatty acids of carbon chain length of at least 10 carbon atoms, 16 and 18 carbon chains being preferable. For the purposes of the present specification, triacylglycerides (TAGs) capable of accelerating the rate of crystallisation of fats from a supercooled melt will be referred to as 'tempering accelerators'. Remaining on the subject of notation, oils and fats may be conveniently described by reference to the fatty acid composition of their constituent tri-acyl glycerides (TAGs), both as regards the length of the carbon-chain in the constituent fatty acids and the positional isomerism on the glycerol backbone. For the type of fatty acids it is convenient to use the notation given below in table 1, as used throughout this specification; S= stearic acid, (18-carbon) P= palmitic acid, (16-carbon) M= lauric fats, (12-14 carbon) H= stearic + palmitic (16-18 carbon) O= oleic acid, (18 carbon mono-unsat.) L= linoleic acid, (18 carbon di-unsat.) T= mono-trans fat, and (12-18 carbon mono-unsat) E= Elaidic acid (18 carbon mono-trans) U= oleic + linoleic. (18 carbon unsaturated) F= saturated fat (12-18 carbon saturate) In order to complete the notation the letter 'X' is used to indicate a fatty acid which is either saturated or cis or trans unsaturated and of chain length 8-20 carbons. Using this notation, it is convenient to write tripalmitoyl glycerol as PPP, and to indicate the two positional isomers of say an oleic acid substituted PPP as PPO and POP. XXX is of course the general definition of the types of fats used in foodstuffs: as there can be no positional ambiguity this may be written X3. The TAG tempering accelerators of NOBEL are characterised as being, for example, SPS (1,3-distearoyl-2-palmitoyl glycerol) and PSP (1,3-dipalmitoyl-2-stearoyl glycerol). In generic terms NOBEL discloses the use of FFF TAGs in which at least one F represents a different saturate from at least one other F. The effectiveness of another chocolate tempering accelerator is disclosed in a paper of N. Matsui in: Crystallization and polymorphism of fats and fatty acids; edited by N. Garti and K. Sato; New York (1988), pages 410-2, wherein it is stated that PEP in binary mixture with POP increases the rate of transformation from the unstable polymorphs of POP to more stable polymorphs, and that PEP accelerates the crystallisation of cocoa butter. A third chocolate tempering accelerator is disclosed in EP-A-0 294 974 (Fuji Oil Company, Limited), which states that a powdery tempering accelerator for use in chocolate can comprise a 1,3-saturated-2-unsaturated (FUF) TAG comprising a total carbon content in the constituent fatty acid residues of 50-56 carbon atoms. In these compositions the preferred accelerator comprises SOS. Chemical Abstracts, 74 , 100828x, (1971) discloses synthesized POP and PEP and mixtures thereof. These mixtures were found to have different melting ranges depending on tempering procedures and the composition, but even quickly solidified mixtures tempered without melting to the highest melting range as they were slowly heated during 2 hours. Consequently there was no slow recrystallization observed and there was no problem of impractically or inconveniently slow crystallization observed. World Patents Index Latest Section Ch, week 9036, Derwent publications Ltd., London, GB, Class D, AN 90-270721 on JP-A-02 189 395 (Tsukishia Shokuhin) discloses the preparation of a powdered fat having a melting point of 30-42°C, and a trans fatty acid content of at least 40%, preferably at least 45%, obtained by hardening oil and subsequent fractionation and/or interestrification followed by spray-cooling. The powdered fat is stated to be useful for the food industry in general without further specification. Journal of Food Science, vol 47, no 1, 1982, Chicago, Ill.,USA, pp. 36-39, A. Strocchi: Fatty acid composition and triglyceride structure of corn oil, and corn oil margarine p. 38 discloses corn oil margarine, more in particular, the effect of hydrogenation on the content of trans unsaturated fatty acid glycerides and it was shown that this amount increased considerably, also the trans-18:1 isomers were preferentially in the β-position. The biological and nutritional aspects of processing are discussed. Furthermore US-A-4 045 588 (Lever Bros Co) discloses a margarine fat containing a liquid oil and a hard fat component and the latter contains a considerable amount of trans fatty acids due to a hydrogenation treatment with a poisoned nickel catalyst. The advantage of such margarines is that they require only a small amount of hard fat and consequently a large amount of liquid oil. There is no mention of an effect as a crystallisation accelerator. The processability of a margarine or other edible spread fat blends and the properties of resulting products are to a large extent determined by the crystallization behaviour of the fat blend. The latter in turn is mainly controlled by the TAG composition of the fat blend. The TAG compositions of margarine and other fat blends is very different from the composition of fat blends employed in chocolate manufacture and it is not to be expected that a tempering accelerator from one art will be applicable in the other. However, problems of delayed crystallization are known in the art of margarine and other spread manufacture, in particular, it is common knowledge in margarine blend formulation that interesterification of TAGs quite often results in slower crystallizing fat blends and often fat blends which are impractically or inconveniently slow to crystallize. We have now determined that the crystallization of margarine fats from a supercooled melt can be accelerated by the use of a TAG having a trans fatty acid at the 2-position, preferably a 1,3-saturated-2- trans -unsaturated (FTF) TAG as a tempering accelerator. Using the above mentioned notation these include the XTX TAGs and in particular the HTH TAGs where H is a stearic or a palmitic acid residue. Consequently the invention relates to the use of 2-trans-unsaturated triacyl-glycerol as a tempering accelerator in a process for the manufacture of an emulsion spread and to a process for the preparation of an edible emulsion spread blend which comprises the addition of a 2-trans-unsaturated triacyl-glycerol as a tempering accelerator. Preferably this accelerator is added in powder form. The invention also relates to a supercooled melt of generally liquid fat for edible emulsion spreads comprising as the bulk of the solid fat components an oil liquid at 10°C and 1-10% of 2-trans-unsaturated triacyl-glycerol. Generally, the trans fatty acid chain is an elaidic acid residue: i.e. in the above-mentioned notation the accelerator comprises HEH TAGs. Many margarine fat blends containing trans fatty acids as plasticity improvers, although the use of high levels of trans fatty acids is becoming unpopular for nutritional reasons. In trans containing fat blends TAGs with elaidic acid (E) on the 2-position of the glycerol accelerate crystallisation: other trans containing TAGs, without this feature have little or no beneficial effect on crystallization rate. Therefore the 2-trans-unsaturated fatty acid group in the triacyl-glycerol is preferably an elaidoyl group. Typically, the 1,3 position residues are H fats: as HTH, preferably palmitic acid residues: as PTH or as PTP. The accelerating effect of the TAGs with E on the 2 position is more pronounced if the melting point of the TAG is higher hence PEP is preferred to PEE, as PEP has the higher melting point. Moreover, many margarine fat blends contain so called H2U TAGs (HUH and HHU). In fat blends with high H2U content and low HUH/HHU ratio an acceptable accelerating effect is found for TAGs with trans on the 2-position and at least one palmitic acid residue on the 1-3 positions, i.e PTH and PTT. So the tempering accelerator of this invention is preferably a 1,3-disaturated triacyl-glycerol. In exceedingly preferred embodiments at least one of the terminal acyl groups is a palmitic or a stearic acid group, in particular the former. Preferably the tempering accelerator comprises PEP. It is observed that PEP is not only functional in the presence of trans fats (due to the E on the 2-position), but also gives acceptable results with margarine fat blends containing H2U TAGs. In an embodiment of the invention the 1,3-saturated-2- trans -unsaturated (FTF) TAG tempering accelerator is added at a level such that it comprises at least 2% by weight of total blend, more preferably at least 5%wt. In general levels of the tempering accelerator should not be greater than 10%. With PEP, transition times from liquid to solid phase can be decreased by a factor 4 at a 5% inclusion level. The effects of trans containing TAGs on the N-line (solids index at given temperature) are : SES increases N10,N20, N30 and N35. The effects on N35 and N30 are larger in blends rich in stearic acid. PEP increases N10, N20 and to a smaller extent N30, and hardly affect N35. EXAMPLES: In order the illustrate the present invention, moderately pure synthetic TAG-concentrates were used to compose synthetic fat blends of specified composition. The compositions (Table 3) were chosen such, that they contained all 2% H3 ,about 25% of the main TAG (SOS,SSO,POP,PPO or EEE) and further only liquid oils (see Table 2 for analysis). Mono and diglyceride content were kept constant. (mono: 0.1%, di:1-2 %) as this could otherwise have affected the properties of the fat blend. As a consequence of these somewhat peculiar formulation requirements, the fat blends are rather complex as compared with conventional edible spread fat blends. However, the N-lines (solids index at given temperature) of these basic blends and of the basic blends with their additions are all in the range of possible margarine and other edible spread blends: typically N10: 20-40, and N35: 0-4. N-lines, TAG-composition and blend composition for the blends 'SOS', 'SSO', 'POP', 'PPO' and 'EEE' are given in Table 2 (N-lines and TAG composition) and Table 3 (composition of fat blend) below. N-lines and TAG-analysis of the basic blends: N-line TAG-analysis N10 N20 N30 N35 H3 HOH HH0 EEE SSLi SLiS REST SOS 35.5 21.5 4.4 2.2 2.4 29.4 3.8 .0 4.5 11.1 48.8 SSO 35.5 20.1 3.8 1.7 2.0 10.3 15.0 .0 3.8 12.3 56.6 POP 24.7 5.7 .5 .0 2.1 28.3 3.2 .0 6.1 9.4 50.9 PPO 31.2 11.4 1.1 .0 2.4 12.3 11.4 .0 4.2 11.6 58.1 EEE 28.3 20.3 9.1 3.1 2.2 .5 .1 7.0 3.2 4.5 62.5 The above terms SSLi and SLiS refer to triacyl-glycerol having linoleic acid in the 1-(or 3-) and 2-position respectively. Composition of fat blends: SOS: 0.8% Sunflower hydrogenated to m.p 69°C 28.6% Dry fractionated shea stearin 5.0% Wet mid-frac. of (in(40 SF69/60 OV)) 18.6% Wet foot-frac. of (in(40 SF69/60 OV)) 47.0% Sunflower oil. The abbreviation (in [40SF69/60 OV]) means an interesterified mixture of 40% sunflower oil hardened to a melting point of 69°C and 60% olive oil and (in [40 wfPOs/60 OV]) an interesterified mixture of 40% wet fractionated palm oil stearin and 60% olive oil. SSO: 0.9% Sunflower hydrogenated to m.p. 69°C 3.0% Dry fractionated shea stearin 34.5% Wet mid-frac of (in(40 SF69/60 OV)) 5.0% Wet foot-frac. of (in(40 SF69/60 OV)) 56.6% Sunflower oil. POP: 1.1% Wet frac palm stearin hardened to m.p. 58°C 28.6% Wet mid-frac. palm oil 19.0% Wet foot-frac palm oil 51.4% Sunflower oil. PPO: 1.3% Wet frac palm stearin hardened to m.p 58°C 3.0% Wet mid-frac. palm oil. 34.4% Wet foot-frac. of (in(40 wfPOs/60 OV)) 2.0% Wet foot-frac. palm oil 59.3% Sunflower oil EEE: 2.0% Sunflower hydrogenated to m.p. 69°C, 27.0% EEE (synthetic triglyceride) 71.0% Sunflower oil. The only synthetic TAG used in the above-described general formulations was the EEE TAG. However, SES, SSE, PEP, PPE, ESE, SEE, PEE and EPE TAGs were obtained by synthesis for use in the examples described below. The analyses of the synthetic TAGs showed that all had a purity of at least 90%, the impurities being very small amounts of other trans containing TAGs. Isothermal crystallisation was examined using the following experimental procedure. The molten fatblend was drawn from a 100 g premix vessel, through a microvotator A-unit (RTM) operating at a throughput of about 10 kg/hr (2.78 g/s). The well known purpose of the A-unit is to cool fat blends and emulsions in spreads manufacture. Subsequent to passage through the A-unit, the fatblend was remelted in a small tube heat exchanger and recycled into the premix vessel. This cycling system provided a continuous supply of supercooled fat from the A-unit. For measurement a sample was drawn off after the A-unit, into an NMR-tube and placed into a thermostated pulse NMR. Solids measurements were taken at 5-15 second intervals under the supervision of a computer program (in BASIC on Hewlett Packard 200-300 series computer). Tests showed that during crystallisation the sample temperature in the NMR tube was constant within 0.5 °C. Only very fast crystallising blends showed a minor increase in temperature (<2°C) during 15-20 secs. The time/solids curve was used to calculate the so-called 'transition time' for the fat blend. 'Transition time', as used herein, is defined as the time difference after which the rate of crystallisation of the supercooled fat reaches a maximum. This is typically close to the time after which half of the induced crystallisation has occurred. COMPARATIVE and ILLUSTRATIVE EXAMPLES: Isothermal crystallisation behaviour was investigated for the formulations given in examples 1-5. During the trials the composition was always adapted such, that the H3-content of the blend remained at about 2%, irrespective of the additions. Transition times were measured after supercooling to 10-12°C. EXAMPLE 1: In this example the 'parent blend' was 'SOS' as mentioned in Table 2 and Table 3 above. Without additions the SOS blend contains 2% of the HHH TAG, and the measured transition time was 578s (all times are given in seconds). Successive modifications of the fat blend were made with additions of essentially pure synthetic TAGs, to give the transition times listed to the right of the additions. With additions the following results were obtained: From these figures it can be seen that a marked reduction in transition time is obtained with additions of PEP and SES, whereas no effective improvement in transition time is obtained with additions of SSE and PPE. EXAMPLE 2: Example 1 was repeated with the SSO blend. The following results were obtained: From these figures it can be seen that PEP gives a very marked improvement in transition time whereas PPE gives a much lesser improvement. EXAMPLE 3: Example 1 was repeated with the POP blend. The following results were obtained: From these figures it can be seen that SES, PEP and PEE all show a marked improvement, with PEP being by far the most marked. EXAMPLE 4: Example 1 was repeated with the PPO fat blend. The following results were obtained: From these results it can be seen that PEP has the most marked effect, and PEE is better than EPE. EXAMPLE 5: Example 1 was repeated with the EEE fat blend. The following results were obtained: From these results it can again be seen that PEP is the most effective tempering accelerator.

Claims: Use of 2-trans-unsaturated triacyl-glycerol as a tempering accelerator in a process for the manufacture of an edible emulsion spread. Process for the preparation of an edible emulsion spread blend which comprises the addition of a 2-trans-unsaturated triacyl-glycerol as a tempering accelerator. Process according to claim 2 in which a 2-trans-triacyl-glycerol is added in powder form. Process according to claim 2 or 3 in which the 2-trans-unsaturated fatty acid group in the triacyl-glycerol is an elaidoyl group. Process according to claim 2, 3 or 4 in which the 2-trans-unsaturated triacyl-glycerol is a 1,3-disaturated triacyl-glycerol. Process according to any of the claims 2-5 in which at least one of the terminal acyl groups is a palmitic or a stearic acid group. Process according to any of the claims 2-6 in which at least one of the terminal acyl groups is a palmitic acid group. Process according to any of the claims 2-7, in which the accelerator is added at a level such that it comprises at least 2% by weight of total blend. Process according to any of the claims 2-8, in which the accelerator comprises 1,3-dipalmitoyl 2-elaidoyl glycerol. A supercooled melt of generally liquid fat for edible emulsion spreads comprising as the bulk of the solid fat components an oil liquid at 10°C and 1-10% of 2-trans-unsaturated triacyl-glycerol.

Inventors: VAN MEETEREN JOHANNA ANTONIA U, WESDORP LEENDERT HENDRIK, VAN MEETEREN, JOHANNA ANTONIA, UNILEVER RESEARCH, WESDORP, LEENDERT HENDRIK
Applicants: UNILEVER NV, UNILEVER PLC, UNILEVER N.V.
Application year: 1992
Main classification: A23D7
IPC codes: A23D9, A23D7