GB2081293A - Interesterified Oils and Margarines Containing such Oils - Google Patents

Abstract

Stick and pat margarines as well as blends and spreads, are formed from a blend of a vegetable oil, such as, sunflower oil, with varying proportions e.g. from 20 to 30 wt.% of a hardstock having an SFI solids content of at least 30% at 92 DEG F (33 DEG C) and formed by interesterification of saturated babassu nut oil and a second saturated vegetable oil, preferably palm oil, the oils having IV's of less than 2 and 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 II The present invention relates to edible fat products, particularly to edible fat products suitable for formation into stick margarines.

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-isomeric forms of the mono- and poly-unsaturates. Such trans-isomeric forms of fatty acid in the diet are 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 an 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 75:25 to about 40:60, the interesterified mixture resulting in a hardstock having an SFI solids content of at least about 30% 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 20% to about 30% 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 accordingly. The trans-isomercontent is determined by infra-red spectrophotometry according to the official method of the American Oil Chemists Association (AOCS) designated Cd-I 4-61.

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 75:25 to about 60:40. 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 30% at 92"F (330C) (as determined by the AOCS SFI method) and preferably a Wiley melting point of about 1 080F to 1 200F (42 to 490C).Preferably, the solids content at 920F (33do) will not be less than about 35%, and the Wiley melting point will be within the range of from 1080 to 1 130F (42 to 450C). Completion of the interesterification reaction usually is determined by a 1 ooh (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 a starting material of babassu nut oil, i.e., the oil from the babassu nutAttalea funifera or its equivalent fatty acid composition. Such equivalent fatty acid composition can be obtained by fractionation of other lauric oils. The use of babassu nut oil or equivalent 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 ihvention is the use as 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 600 C. 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 point of between about 550 and 600 C. 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 oii, 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 550 to 600 C, 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 values.

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. (70 C). 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 (70C). Lesser amount of margarine are sold in a form so soft that it is fluid, being at least capabie of being squeezed from a flexible container. The present invention is directed to the production of edible fat products suitable for printing into sticks or forming pats.It is also within the contemplation of the invention that the fat products of the invention can be employed in the preparation of calorie-reduced 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 product to be used in a stick margarine are a minimum solids content of 12% at 500F, (100C) a minimum solids content of 7% at 700F (21 OC) and a maximum solids content of 4%, preferably less than 3%, at 920F (330C). Most preferably, the maximum solids content at 920F (330C) will be about 2%. At this specification, the margarine may be formed and wrapped satisfactorily, maintains its stick form without substantial oil separation at room temperature and yet remains rapid melting on the tongue at about 960F (35.50C). Such a product may be formulated, in accordance with this invention, from an edible fat product which is a blend of liquid unsaturated vegetable oils and the hardstock containing about 20 to about 30 wt. % of the hardstock, preferably from about 21 to about 24 wt.%.

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 mixtare of fully hardened palm kernel oil and a fully hardened vegetable oil, such as palm oil, rapeseed oil * (Canola oil), cottonseedoil, or soyabean oil. The blends of the resulting hardstock 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 Elaeis 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-isomer-content fat, and in fact of the variouehardened vegetable oils which may be used to form the inter-esterification 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 ofthe slip-point range set forth in the Patent, contain detectable amounts of trans-isomers. In addition, the margarines preferably contain amaximum concentration of hardstock of 12 wt. % which produces an extremely soft margarine incapable of being into a stick or pat.There is no disclosure of a formulation suitable for use in a stick margarine.

The ability to formulate an edible fat product containing up to 80 wt. % of liquid vegetable oil enables high levels of polyunsaturates to be attained in stick and pat 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 edidble 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 i 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 formed into sticks and pats.

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 whipping units, before filling or forming the plastic emulsion into prints or pats.

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 lowtransisomer-content hardstock from babassu nut oil and palm oil for use in products according to the invention.

Babassu nut oil was hydrogenated at 3000F (1490C) using a suspension of 0.2% nickel catalyst (26% Ni) based on the oil to an iodine value of less than 2.0 to form a saturated product of melting point 11 30F (450 C). Palm oil was similarly hydrogenating 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 palm oil were mixed in the weight proportion of 70:30 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 a 100 F (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 800F (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 21 00F (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 36.0% at 920F (33"C) and a Wiley melting point of 109.00F (430C). 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 stick margarine from the blend.

The hardstock formed according to Example 1 was blended with sunflower oil to form a blend containing 23% by weight of the hardstock. The resulting blend had an unsaturates to saturates ratio of 1.8:1 (55% polyunsaturates to 30% saturates based on the total weight of the fat), and exhibited the following SF solids values: 13.9% at 500F (100C) 9.1% at 700F (210C) 2.4% at 920F (330C) The blend was combined with an aqueous phase and processed through conventional "Votator" A units and resting B unit to form a water-in-oil emulsion which is forwarded to a print former and a wrapping machine to provide a stick margarine. The resulting margarine spread readily, did not exhibit oil separation during processing or subsequently at room temperature, and had good mouth break. In addition, it compared favorably to conventional stick margarine both in shaping and wrapping characteristics. The margarine had a penetration of 95, 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 70% saturated babassu nut oil and 30% saturated tallow which is subsequently interesterified. The hardstock product produced was found to have an SFI solids value of 36.7% at 920F (33"C) and a Wiley melt point of 1 100F (43.50C).

In summary of this disclosure, the present invention provides an edible low-trans-isomercontent fat product which may be used in stick and pat margarine production. Modifications are possible within the scope of the invention.

Claims (20)

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 SF solids content of at least about 30% at 920F (33 OC).

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 20% to about 30% by weight of said hardstock.

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

4. Process as in any of Claims 1-3 wherein said hardstock has a Wiley melting point of about 1080 to about 1200F (42 to 490C).

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 content of at least 12% at 500F (100C), at least 7% at 700F (21 C) and a maximum of 3% at 920F (330C).

6. Process as in Claim 5 wherein said hardstock has an SFI solids content of at least about 35% at 920F (33"C).

7. Process as in any of Claims 1-6 wherein said blend contains from about 21 to 24% by weight of said hardstock.

8. Process as in any of Claims 1-7 wherein said saturated babassu nut oil and/or said second oil is prepared by hydrogenation.

9. Process as in any of Claims 1-8 wherein said second oil is a fat of animal or vegetable origin of an iodine value of less than about 60 and preferbaly.less than 50 prior to any hydrogenation.

10. Process as in any of Claims 1-9 wherein said second oil is palm oil, coconut oil, tallow or combinations thereof.

11. Process as in any of Claims 1-9 wherein said second oil is essentially palm oil.

12. Process as in any of Claims 2-11 1 wherein said liquid vegetable oil is safflower, sunflower, soyabean, corn, cottonseed, rapeseed, peanut, linseed, or wheat germ oil or mixture thereof.

13. Process as in any of Claims 1-12 including the further step of forming said blend into a stick margarine.

14. A hardstock for the preparation of a low trans-isomer-containing edible fat product having an SFI solids content of at least about 30% 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 vale 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 5. A low-trans-isomer-containing edible fat product comprising a blend of a hardstock as in Claim 14 and a liquid vegetable oil.

1 6. Product as in Claim 1 5 wherein said blend comprises from about 20% to about 30% of said hardstock.

1 7. A low-trans-isomer-containing margarine comprising a water-in-oil emulsion wherein the oil phase is the product of Claim 1 6.

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

19. A product as claimed in Claim 1 5 and substantially as hereinbefore described with reference to Example 2.

20. Margarine as claimed in Claim 17 and substantially as hereinbefore described with reference to Example 2.