GB2190394A - Edible fats by rearrangement of sunflower oil - Google Patents

Abstract

Edible fats particularly for confectionery are prepared by rearrangement, in the presence of saturated fatty acids or their esters and lipase enzyme catalyst, of sunflower oil.

Description

1 GB2190394A 1 SPECIFICATION catalyst with lipase enzyme and in the pres

ence of saturated fatty acids or esters thereof High oleate sunflower oil enzyme feedstock wherein the sunflower oil exhibits a high oleate content. The present invention also This invention relates to edible fats and their 70 provides novel fats comprising symmetrical di preparation for use in particular in confection- saturated triglycerides, in which the saturated ery including chocolate, shortenings, margarine fatty acid residues are in random distribution and other plastic emulsion food spreads. and the unsaturated fatty acid residues com The modification of edible oils and fats by prise at least 90% oleic acid residues, prefera- rearrangement of the fatty acid residues on 75 bly at least 95% and more particularly at least the glycerides of which they are composed, 99% of such residues.

has been practised in the food industry for a Commercially useful high oleic sunflower va considerable time. rieties may be obtained by conventional plant Proposals have also been made to synthe- breeding techniques, for example by crossing sise the glycerides from glycerol and appropri- 80 the naturally occurring high oleic varieties such ate fatty acids. More recently, catalysts both as that reported by Horowitz and Winter (Na for rearrangement and synthesis processes ture 179:582 (1975). High oleic mutants pro have been proposed comprising lipase en- duced by artificial means, such as the muta zymes. A particularly interesting proposal is gen treatment of seed, can also be used and the use of selectively active enzymes which 85 the Pervenets variety (reported by Kharachenk are effective in the 1- and 3-positions of gly- in Fisiologiya Rastenfl 26:1226 (1979)) is an cerides, while leaving the 2-position unafexample. Progenies derived from such mutants fected. By the use of this development, un- are known, eg. those reported by Fick. Prefer saturated vegetable oils for example sunflower ably sunflower seed is used from plant varie- oil, may be converted in the presence of satu- 90 ties giving oils with 10% or less eg. 1 % of rated fatty acids themselves or alkyl esters linoleic acid, particularly those having AOM thereof, to symmetrical disaturated triglycer- values (Active Oxygen Method) of at least ides, particularly of palmitic and stearic acids, 100 hours measured by the AOCs method the presence of which in cocoa butter and Cd 12-57.

other vegetable butters accounts for the 95 sharp-melting and other physical attributes for CLAIMS which these expensive and often scarce pro1. Process for the rearrangement of su ducts are so highly prized. The most beneficial nflower oil under the influence as rearrange of these glycerides are the 2-oleoyl homolo- ment catalyst of lipase enzyme in the pres- gues. The corresponding 2-linoleoyl disatu- 100 ence of saturated fatty acids or esters thereof rated triglycerides exhibit somewhat less satis- wherein the sunflower oil exhibits a high factory characteristics; being more highly un- oleate content.

saturated they are significantly softer and ma- 2. Process according to claim 1 wherein terially more susceptible to deterioration by the sunflower oil contains at most 10 per cent oxidation. Their conversion to mono-olefinically 105 combined linoleic acid.

unsaturation by selective hydrogenation is not 3. Process according to claim 2 wherein a satisfactory solution, owing to the high inci- the AOM value of the oil is at least 100 dence of conversion by isomerisation to hours.

elaidic acid i.e. the trans-form of oleic acid, 4. Process according to any of the preed thereby introducing a higher melting glyceride 110 ing claims wherein the said lipase enzyme ex to the glyceride composition than the corre- hibits selective catalyst activity.

sponding 2-oleoyl isomer, which is the natu- Printed in the United Kingdom for rally occurring form. These higher-melting disa- Her Majesty's Stationery Office, Dd 8991685, 1987, 4235.

turated triglycerides additionally confer a de- Published at The Patent Office, 25 Southampton Buildings, gree of incompatibility with the triglycerides London, WC2A lAY, from which copies may be obtained.

already present and this is reflected in anamolous and undesirable melting behaviour. Moreover, the by-products of all rearrangement processes of highly unsaturated glyceride oils which are separated from more saturated products, are themselves highly unsaturated and similarly unstable, being susceptible to atmospheric oxidation. While they may be hydrogenated to saturated fatty acids or their deri- vatives, for recycle to the rearrangement process, they consume considerable quantities of hydrogen in the process.

The present invention provides a process for the rearrangement of sunflower oil to more saturated fats by contact as rearrangement