GB2170506A

GB2170506A - Hard butters

Info

Publication number: GB2170506A
Application number: GB08431789A
Authority: GB
Inventors: Alasdair Robin Macrae
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1984-12-17
Filing date: 1984-12-17
Publication date: 1986-08-06
Also published as: GB8431789D0; DE3582030D1; EP0185524A2; EP0185524B1; ZA859618B; SE8505956L; EP0185524A3; AU5127585A; GB2170506B; SE8505956D0; JPS61179299A; AU568035B2; ATE61390T1

Abstract

Hard butters for use in confectionary are recovered by fractionating a vegetable fat containing substantial amounts of symmetrical disaturated triglycerides of C16/C18 fatty acids and separating a mid-fraction containing the triglycerides from stearine and oleine fractions recombining the stearine and olein fractions and rearranging the glycerides in the resulting mixture in the presence of catalyst, preferably a lipase enzyme, which is selectively active in the 1,3 positions only of glycerides, to provide increased amounts of symmetrical disaturated triglycerides.

Description

1 GB 2 170 506 A 1 SPECIFICATION asymmetric disaturated mono-unsatu rated

glycer ides and symmetric di-unsaturated glycerides, i.e.

Edible fats 1,3-d i u nsatu rated, 2-saturated glycerides.

The interesterified glycerides may be split as in This invention relates to hard butters and their 70 conventional fractionation processes, to recover a preparation from edible fats. fraction consisting essentially of symmetrical disatu- The eating quality of chocolate fat and other hard rated glycerides. The more highly unsaturated butter compositions containing cocoabutter is attri- glycerides in the interesterification mixture, includ butable to the presence in this fat of a high ing in particular the symmetrical 1,3-diunsaturated proportion of symmetrical disaturated triglycerides, 75 glycerides, form a lower-melting oleine fraction. Any principally the 2-oleyl glycerides of palmitic and reacted trisaturated glycerides may be separated if stearic acid. Various substitute fats which have been necessary in a top fraction. Any asymmetric disatu proposed as an alternative to this expensive fat rated glycerides remaining following interesterifica similarly contain more or less substantial quantities tion may be subjected to further interesterification of these triglycerides. Processes forthe production 80 by recycling, whether it appears in a stearine or of cocoabutter substitutes and extender fats from oleine fraction separated from the symmetrical these alternative sources generally include fractionadisaturated fraction.

tion steps in which these more valuable glycerides The mixture of interesterified glycerides may be are separated from others with less desirable melt- separately fractionated or recombined with feed- ing attributes, notably trisaturated glycerides and 85 stock in the fractionation step of the process. In a mono-saturated and tri-unsaturated triglycerides, continuous operation in which feedstock is intro but also asymmetric disaturated glycerides, where duced to, and a symmetrical disaturated glyceride these can be separated. The separation is usually fraction removed from, circulation through frac effected by fractional crystal I isation, particularly tionation and interesterification units, the feedstock from a solvent such as acetoneor hexane, the more 90 may be introduced into either unit and may thus be highly saturated glycerides being removed in a fractionated first, in admixture with the entire in higher-melting or stearing fraction, and the more teresterification output, or interesterified first highly unsaturated glycerides being removed in a together with the recycled interesterified fractions lower-melting or oleine fraction. These less desir- from which the symmetrical disaturated glycerides able fractions may constitute as much as half the 95 have been removed. In continuous operations in original fat and command a much lower premium which feedstock is introduced and a symmetrical than the hard butter fraction. disaturated fraction removed, a purge may also be The present invention proposes a process for the necessary of the symmetrical di-unsaturated glycer recovery of hard butters from vegetable fats, in ides to avoid build-up of this intractable material in which a vegetable fat containing substantial 100 the recycled composition. Rearrangement catalyst amounts of symmetrical disaturated triglycerides of may also be used to convert this material and return C16 and C18 fatty acids is fractionated to recover a it in a more tractable form, for example, a non mid-fraction comprising the said glycerides by selective catalyst, a 2- selective catalyst, or one which separating a more highly saturated stearine fraction is selectively active to saturated but not unsaturated and a more highly unsaturated oleine fraction, 105 fatty acid residues. A particuar advantage of con wherein these separated fractions are recombined tinuous operation is that the interesterification need and the mixture interesterifies in the presence of an be of relatively short duration since the interesterifi enzyme catalyst which is preferably selectively ac- cation can be incomplete for each pass through the tive in the outer positions only of glycerides, i.e. the unit. Enzyme interesterification is generally substan 1- and 1,3 - positions or alpha-positions of the 110 tially slowerthan interesterification underthe influ glycerides, to yield further quantities of symmetrical ence of inorganic catalysts which are also used at disaturated glycerides. much higher temperatures. But continuous recycling Since the greatest proportion of the oleine fraction however, the residence time in the interesterification consists of glycerides having an unsaturated fatty step need be sufficient only to provide a significant acid residue in the 2-position, all these are theoretic- 115 improvement in the yield of the desired glycerides, ally capable of conversion by interesterification without necessarily reaching equilibrium.

under the influence of the enzyme catalystto Fractionation steps carried out in accordance with symmetrical disaturated triglycerides, provided only the invention may be conventional, either by solvent that sufficient glycerides are present in the upper- fractionation using acceptable solvent, for example melting or stearine fraction with which it is com120 acetone, hexane or nitroparaff ins or ambient gases bined, containing saturated fatty acid residues in the in liquid condition under pressure. Fractionation alpha or 1,3-positions that are vulnerable to the may also at least in part be dry without solvents and catalyst for effecting interesterification with the may then be aided as in the so-called Lanza process, more highly unsaturated glycerides. For example, by the use of the surfactant aqueous dispersions for trisaturated glycerides may undergo interesterifica- 125 facilitating separation of liquid and solid phases tion with tri-unsaturated glycerides to provide 1- during fractionation. Preferably the fractionation is saturated di-unsaturated glycerides and these in turn carried out however in acetone attemperatures from to 1,3-disaturated glycerides, under the influence of 15 to -50C or in hexane attemperatures from 10'C to the selective action of the catalyst. The trisaturated -20'C.

glycerides themselves convert correspondingly to 130 Suitable enzymes which are active to catalyse 2 GB 2 170 506 A 2 interesterification only in the outer positions of catalyst which is preferably a lipase enzyme and glyceride molcules include, for example, Aspergillus which is selectively active in the 1- and 3-positions niger etcetera. These enzyme catalysts ensure that only of glycerides to yield further qualities of the un saturated fatty acid residue in the 2-position of symmetrical disaturated triglycerides.

Claims

the glycerides of the lower-melting fraction remain. 70
2. Continuous

process according to Claim 1 unaffected by the interesterification, to provide a comprising fractionation and interesterification foundation forthe production in that reaction of the stages between which reaction burden is circulated, desired symmetrical disaturated glycerides forthe into which feedstock comprising the said vegetable mid-fraction. Enzyme catalysts are particularly pre- is introduced and from which a symmetrical disatu- ferred forthis process, but other catalysts may of 75 rated glyceride fraction is removed.

course be adopted provided they show selective
3. Continuous process according to Claim 2 interesterification atthe alpha-positions only. The wherein an additional fraction is removed compris interesterification reaction may be carried out in ing 2-saturated mono- and di-unsaturated triglycer solvents which leave the catalyst unaffected, particu- ides.

larly hexane for enzyme -catalysts, and the reaction 80
4. Process according to any of the preceding may be batchwise or continuous, the catalyst in the claims at last part of which is carried out in solution [a er event being preferably fixed in a reaction in an organic solvent.

vessel through which the reaction burden compris ing the mixed upper and lower-melting fractions are passed. Enzyme catalysts may be pre-activated by contact with water and they may be suported on a Printed inthe UKforHMSO, D8818935,6186,7102.

Published byThe Patent ofrice,25 Southampton Buildings, London, suitable carrier, as described in our patent Case WC2A 1AY, from which copies may be obtained.

A.171 (1313 1577933). The water content may be obtained during the reaction, to predetermined limits in accordance with our patent Case A.194 (1313 abandoned but EP 64855) by the use of hurnectants and/or other means for removing water from the reaction phase. The water content is preferably not more than 2% of the reaction mass, including solvent, and particularly not more than 1 %. In particular, the water activity Aw, is preferably less than 50% during reaction. Enzyme catalysts may also however be used in polyhydric alcohol solution to maintain a very low water content. The water content is preferably low enough to minimise the extent of hydrolysis taking place with the production of partial glycerides. These may however be removed by selective adsorption means using silicatype absorbents.

Suitable fats include in particular palm oil but also Shea, Sal, pentadesma oil and of course cocclabutter itself, may all be processed in accordance with the present invention. Vegetable oils and fats are preferred since these contain an abundance of unsaturated fatty acid residues in the 2-position of their glycerides. Mixtures of oils and fats may be used and a fat which is deficient in trisaturated glycerides may be mixed with another containing them, or hydrogenated to provide sufficient for the interesterification reaction. Preferably the oils are refined before use as feedstock in the present invention and both neutralised and un-neutralised oils and fats may be used.

CLAIMS 1. Process for the recovery of hard butter from vegetable fats wherein a vegetable fat containing substantial amounts of symmetrical disaturated triglycerides of CIB and Cjs fatty acids is fractionated to recover a mid-fraction comprising the said glycerides by separating a more highly saturated stearine fraction and a more highly saturated stearing fraction and a more highly unsaturated oleine fraction, wherein these separated fractions are recombined and the mixture interesterified in the presence of