GB2078245A - Interesterfied Oils and Margarines Containing Such Oils - Google Patents

Abstract

Soft margarines of both the tub and fluid type, as well as blends and spreads, are formed from a unique blend of liquid vegetable oil, such as sunflower oil, with varying proportions e.g. from 5 to 20 wt. % of a hardstock having an SFI solids content of at least 45% at 92 DEG F (33 DEG C) and formed by interesterification of saturated babassu nut oil and a second saturated vegetable oil, e.g. palm oil, the oils having IV's of less than 2 and being in a weight ratio of 75:25 to 40:60. The blend of vegetable oil and hardstock is high in polyunsaturates and has a low-trans-isomer fatty acid content.

Description

SPECIFICATION Edible Fat Product I The present invention relates to edible fat products, particularly to edible fat products suitable for formation into soft magarines.

Table margarines generally have been produced by emulsification of blends of liquid unsaturated vegetable oils with hydrogenated hardstock in varying proportions depending on the consistency of product desired. A margarine product is required to have certain flow characteristics while resisting free oil separation and yet should be rapidly melting on the tongue.

The hydrogenation required to form a hardstock which can provide such characteristics also leads to residual unsaturation which is in trans-iosmeric forms of the mono- and poly-unsaturates. Such trans-isomeric forms of fatty acids in the diet are currently the center of much scientific controversy and the subject of on-going research to determine what role, if any, they play in dietary health.

In accordance with the present invention, a specific hardstock has been found which alleviates this concern, while at the same time is suitable for the formulation of edible fat products for use in the production of margarines which are substantially free of trans-isomers. The invention, in its broad aspects, provides a process for forming a hardstock useful for the preparation of a low-trans-isomer-containing fat product, which comprises: preparing a randomly interesterified mixture of saturated babassu nut oil having an iodine value of less than 2.0, and a second saturated edible oil having iodine value of less than 2.0, the mixture comprising said saturated babassu nut oil and said saturated second oil in the weight proportions of 60:40 to about 40:60, the interesterified mixture resulting in a hardstock having an SFI solids content of at least about 45 at 920F (330C) (as determined by the AOCS SFI Method). The resulting hardstock is blended with a liquid vegetable oil preferably in proportions such that the resulting blend contains from about 5% to about 20% by weight of said hardstock to produce a low-trans-isomer-containing fat product.

While it is impractical commercially to prepare a product having absolutely no determinable trans-isomer content, the present invention contemplates those products where the transisomer content is substantially eliminated.

Preferred products are made under suitable controls to assure a trans-isomer content of less than 1%. The term "low-trans-isomer-content" is thus defined accordinly. The trans-isomer content is determined by infra-red spectrophotometry according to the official method of the American Oil Chemists Association (AOCS) designated Cd 14-61.

The term "fat" as used herein is intended to include all edible, fatty acid triglycerides regardless of origin or whether they are solid or liquid at room temperature. Thus, the term "fat" includes normally liquid and normally solid vegetable and animal fats and oils. Where the term "oil" is employed herein, it is intended to refer to those fats which are normally liquid in their unmodified state.

The hardstock which is utilized in the present invention is a randomly interesterified mixture of saturated babassu nut oil and a saturated second oil in proportions by weight of about 75:25 to about 40:60, preferably from about 60:40 to about 40:60. These oils must be saturated, having iodine values of less than 2.0. Suitable saturated fats may be obtained by hydrogenating, either in admixture or separately, or by fractionating a suitable fat.The interesterification is effected at an elevated temperature and under vacuum in the presence of a suitable catalyst to form a product having a solids content of not less than about 45% at 920F (330C) (as determined by the AOCS SFI method) and preferably a Wiley melting point of about 1120 to 12?OF. (44.5 to 490C) Preferably, the solids content at 920F (33 C) will not be less than about 50% and the Wiley melting point will be within the range of from 1150 to 1190F (46 to 480C). Completion of the interesterification reaction usually is determined by a 100F (5.50C) lowering of the melt point of the product as compared to the mixture prior to interesterification.

It is also possible to form the hardstock by first interesterifying the specified oils and then hydrogenating to the required degree of saturation. The latter procedure, however, is less preferred since completion of the interesterification is less susceptible to precise determination than in the case when the interesterification is effected after saturation of materials.

Essential to the present invention is the use as starting material of babassu nut oil i.e., the oil from the babassu nutAttalea funifera. The use of this material results in a hardstock which enables margarines of varying consistencies and yet acceptable properties to be provided while at the same time permits the use of conventional processing, packaging. and equipment.

Also essential to the present invention is the use of a starting material of a second edible oil saturated to an iodine value of less than 2.0 which preferably has a melting point of from about 550 to about 600C. This second oil is interesterified with the saturated babassu nut oil, resulting in a hardstock which contains no residual trans-unsaturation. It is within the scope of the invention to utilize suitable animal and vegetable fats which are saturated to have iodine values of less than 2.0 with preferable melting points of between about 550 and 600C. These materials will provide a desirable range of physical properties and be free of transunsaturation.Among the suitable fats are those of animal and vegetable origin which are capable of providing these properties when saturated, but in their natural state, prior to any hydrogenation, exhibit iodine values of less than about 60, preferably less than about 50.

Blends or fractions of vegetable fats including palm oil, and coconut oil; and animal fats such as tallow, can be employed where they meet the above criteria. The preferred vegetable fat according to the invention comprises palm oil, and the preferred animal fat comprises tallow.

The requisite low-trans-fat of the present invention is not achieved when the second edible oil comprises an unsaturated oil such as rapeseed oil (Canola oil), cottonseed oil, soyabean oil or a highly unsaturated fraction of these or other fats.

When such fats are employed and the hydrogenation is continued to the point necessary to yield the melting point range of 55 to 60 , trans-isomer contents detectable in amounts significantly greater than 1% remain. And, where hydrogenation is effected to result in saturation with a correspondingly higher melting point, the interesterification product is incapable of providing an edible fat product having the preferred SFI value.

In the market place, margarines are generally sold as one of two principal types, namely, print, hard or stick margarine and soft or tub margarine.

Hard or stick margarine would have a firmness consistent with a penetration range of 65 to 120 being in units of 0.1 mm using an ASTM grease cone at 450F. (7O0C) Soft or tub margarine would have a firmness consistent with a penetration range of 130 to 210 being in units of 0.1 mm using an ASTM grease cone at 450F. (7 cm) Lesser amounts of margarine are sold in a form so soft that it is fluid, being at least capable of being squeezed from a flexible container. The present invention is directed to the production of edible fat products suitable for use in the tub and fluid forms.It is also within the contemplation of the invention that the fat products of the invention can be employed in the preparation of caloriereduced margarine (diet margarine), industrial shortenings, blends with dairy products and spreads containing less than 80% fat.

The SFI solids values required for an edible fat to be used in formulations of a tub margarine are minimum solids content of 9% at 5O0F, (1 O0C) a minimum solids content of 5% at 7O0F (21 CC) and a maximum solids content of 4% at 920F.

(330C) Preferably, the maximum solids content at 5O0F (10 C) will be less than 12%, at 7O0F (21 OC) will be less than 7%, and will be less than 3% at 920F (330C) Most preferably, the maximum solids content at 92CF (330C) will be about 2%. A margarine formed from an edible fat product of this specification is easily spread at room temperature without substantial oil separation, and yet good mouth break at about 960F (35.50C) results.Such a product may be formuiated, in accordance with this invention, from an edible fat product which is blend of liquid unsaturated vegetably oils and the hardstock containing about 5 to about 20 wt. % of the hardstock, preferably from 14 to 20 wt. %, most preferably above 15, typically from about 1 6 to about 19 wt. %.

For sqeezable fluid spreads having a minimum hardstock content of 5 wt. %, the SFI solids values should be near the lower ends of the above ranges and are preferably just below them having, for example, a minumum solids content of 2% at 50 F (1 00C) a minimum solids content of 1% at 70cm, (21 OC) and a maximum solids content of 1% at 920F (330C). Preferably, the maximum solids content at 5O0F (1 00C) will be 5% and at 7O0F (21 OC) will be 3%.

It has previously been suggested in United States Patent No. 3,617,308 to use, in the formulation of margarines, a randomly interesterified product of a mixture of fully hardened palm kernel oil and a fully hardened vegetable oil, such as palm oil, rapeseed oil (Canola oil), cottonseed oil or a soyabean oil. The blends of resulting hardstock with liquid vegetable oil contain 8 to 1 5 wt %, preferably 8 to 12 wt. % of the hardstock. One key starting material in that patent is palm kernel oil, i.e., the oil from the kernel of the palm fruit Elaesis guineensis, a quite different starting material from that used in this invention, where babassu nut oil is used.This patent is not concerned with the production of a low-trans-isom er-content-fat, and in fact of the various hardened vegetable oils which may be used to form the interesterification product, only palm oil is suitable for forming a product having no trans-unsaturation. The soyabean oil, rapeseed oil (Canola oil) and cottonseed oil when hardened to only 550C, the low end of the slip point range set forth in the Patent, contain detectable amounts of transisomers.

The ability to formulate an edible fat product containing up to 95% wt. % of liquid vegetable oil enables high levels of polyunsaturates to be attained both in tub and fluid formulations in this invention. In general, higher polyunsaturate levels in the margarine may be attained than in conventionally-formulated margarines, and, at the same time, trans-unsaturated isomers are absent from the product.

A wide variety of edible liquid vegetable oils may be used in formulating the edible fat product from the interesterified hardstock, including safflower oil, sunflower oil, soyabean oil, corn oil, cottonseed oil, rapeseed oil (Canola oil), peanut oil, linseed oil, wheat germ oil. The liquid vegetable oils most suitable have a ratio of polyunsaturates to saturates (P/S) of greater than 2:1.

The fat blends provided in accordance with this invention may be emulsified to form margarines in conventional manner, as well as to form blends and spreads. Typically, the edible fat product is emulsified with an aqueous phase at an elevated temperature at which the fat product is liquid and then subjected to rapid chilling. This procedure may be effected using apparatus of conventional kind comprising one or more scraped surface tubular heat exchangers, for instance, "Votator" apparatus, wherein the emulsion is worked up to form a water-in-oil emulsion of suitable consistency for spreading. The super-cooled emulsion is filled into suitable containers.

If desired, the initial liquid fat mixture may be subjected to a crystallizing step, either before or after emulsification or, before the final chilling step, and further crystallization may be effected, for example, in resting or working units such as Votator B-units or whippingunits, before fiiling or forming the plastic emulsion into containers.

Additionally, the plastic emulsion may be worked mechanically between the resting or working units and the filling or forming device.

The invention is illustrated further by the following examples: Example 1 This example illustrates the formation of lowtrans-isomer-content hardstock from babassu nut oil and palm oil for use in products according to the invention.

Babussu nut oil was hydrogenated at 3000F (1490C) using a suspension of 0.2% nickel catalyst (25% Ni) based on the oil to an iodine value of less than 2.0 to form a saturated product of melting point 1 1 3 OF (45 C). Palm oil was similarly hydrogenated using nickel catalyst to an iodine value of less than 2.0 to form a saturated product of melting point 1 400F (600C). The hydrogenated materials were filtered to remove the nickel.

The resulting saturated babassu nut oil and saturated pam oil were mixed in the weight proportion of 50:50 and steam stripped to decrease the free fatty acid content below about 0.03 wt. %. Under a high vacuum of 2 to 3 mm Hg, the mixture was heated at 2500F (121 0C) in the presence of 0.05% sodium methoxide catalyst under agitation for 1 5 minutes. A sample of product was analyzed to confirm that the interesterification was complete, as determined by 100F (5.50C) lowering of the melt point of the product as compared to the mixture prior to interesterification.

The temperature was then decreased to 1 80 F (82"C) and 0.4 wt. % of a 30% aqueous solution of magnesium sulphate in hot water was added to destroy residual catalyst. The temperature was then raised to 2100F (990C) and 1% bleaching earth was added to bleach the product.

Thereafter, the interesterified material is cooled and filtered.

The hardstock product produced was found to have an SFI solids value of 54.4% at 920F (330C) and a Wiley Melting point of 11 7.50F (47.50C). In addition, the hardstock product was found to contain no trans-isomeric forms, as determined by infra-red spectrophotometry.

Example 2 This example shows the blending of the hardstock of Example 1 with a liquid vegetable oil and the formation of low-trans-isomer-content tub margarine from the blend.

The hardstock formed according to Example 1 was blended with sunflower oil to form a blend containing 16% by weight of the hardstock. The resulting blend had an unsaturates to saturates ratio of 2.2:1 (57% polyunsaturates to 24% saturates based on the total weight of the fat), and exhibited the following SFI solids values: 9.4% at 500F (100C) 6.2% at 700F (21 OC) 2.0% at 920F (330C) The blend was combined with about 20% of its weight of an aqueous phase and processed through conventional "Votator" A units and working B unit to form a water-in-oil emulsion which is forwarded to conventional packaging equipment to provide a tub margarine. The resulting margarine spread readily, did not exhibit oil separation during processing or subsequently at room temperature, and had good mouth break. The margarine has a penetration of 160, being in units of 0.1 mm using an ASTM grease cone at 450F. (70C).

Example 3 This example shows the formation of a lowtrans-isomer-content hardstock formed in similar manner to example 1 but in the weight proportion of 55% saturated babassu nut oil 45% saturated tallow, which blend was subsequently interesterified. The hardstock product produced was found to have an SFI solids value of 45.7% at 920F (330C) and a Wiley melt point of 11 60F.

(46.50C).

In summary of this disclosure, the present invention provides an edible low-trans-isomer content fat product which may be used in both tub and fluid margarine production. Modifications are possible within the scope of the invention.

Claims (22)

Claims

1. A process of forming a hardstock useful for the preparation of a low-trans-isomer-containing edible fat product which comprises preparing a randomly interesterified mixture of saturated babassu nut oil having an iodine value of less than 2.0 and a second saturated edible oil having an iodine value of less than 2.0, the mixture comprising said babassu nut oil and said second oil in the weight proportions of about 75:25 to about 40:60, the interesterified mixture resulting in a hardstock having an SFI solids content of at least about 45% at 920F. (330C).

2. Process as in Claim 1 wherein said hardstock is blended with a liquid vegetable oil in proportions such that the resulting blend contains about 5% to about 20% by weight of said hardstock.

3. Process as in Claim 1 or 2 wherein said second saturated edible oil has a melt point of from 550C. to 600C.

4. Process as in any of Claims 1-3 wherein said hardstock has a Wiley melting point of from about 1 1 2 to about 120 F. (44.5 to 49 C).

5. Process as in any of Claims 1-4 wherein said hardstock and said liquid vegetable oil are blended in such proportions that the resulting blend exhibits SFI solids contents of at least 9% at 500F.,(100C) at least 5% at 700F (21 OC) and a maximum of 3% at 920F. (330C).

6. Process as in Claim 5 wherein said blend contains about 14 to 200 by weight of said hardstock.

7. Process as in Claim 5 wherein said blend contains from about 16 to about 19% by weight of said hardstock.

8. Process as in any of Claims 4-7 wherein said resulting blend exhibits SFI content maximum of 12% at 500F. (100C) and 7% at 700F (21 0C).

9. Process as in any of Claims 1-8 wherein said saturated babassu nut oil and/or said second oil is prepared by hydrogenation.

10. Process as in any of Claims 1-9 wherein said second oil is a fat of animal or vegetable origin of an iodine value of less than about 60 and preferably less than 50 prior to any hydrogenation.

11. Process as in any of Claims 1-10 wherein said second oil is palm oil, coconut oil, tallow or combinations thereof.

12. Process as in any of Claims 1-10 wherein said second oil is essentially palm oil.

13. Process as in any of Claims 2-12 wherein said liquid vegetable oil is safflower, sunflower, soyabean, corn, cottonseed, rapeseed, peanut, linseed, or wheat germ oil or mixtures thereof.

14. Process as in any of Claims 1-13 wherein the hardstock has an SFI solids content of at least about 50% at 920F.

1 5. Process as in any of Claims 1-14 including the further step of forming said blend into a tub margarine.

1 6. A hardstock for the preparation of a low trans-isomer-containing edible fat product having an SFI solids content of at least about 45% at 920F., (330C) said hardstock being a randomly interesterified mixture of saturated babassu nut oil having an iodine value of less than 2.0 and a second saturated edible oil having an iodine value of less than 2.0, the mixture comprising said babassu nut oil and said second oil in weight proportions of about 75:25 to about 40:60.

1 7. A low-trans-isomer-containing edible fat product comprising a blend of a hardstock as in Claim 1 6 and a liquid vegetable oil

1 8. Product as in Claim 17 wherein said blend comprises from about 5% to about 20% of said hardstock.

1 9. A low-trans-isomer-containing margarine comprising a water-in-oil emulsion wherein the oil phase is the product of Claim 18.

20. A process as claimed in Claim 1 and substantially as hereinbefore described with reference to Example 1 or 3.

21. A product as claimed in Claim 17 and substantially as hereinbefore described with reference to Example 2.

22. Margarine as claimed in Coaim 19 and substantially as hereinbefore described with reference to Example 2.