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Title:
CALCIUM FORTIFIED EMULSIFIED FAT PRODUCT AND CALCIUM SALTS
Document Type and Number:
WIPO Patent Application WO/2001/017375
Kind Code:
A1
Abstract:
This invention provides an emulsified fat product which is fortified with calcium. This invention also provides novel calcium-containing salts and sources and methods for their preparation and their use in the above said emulsified fat product and other food products.

Inventors:
VULFSON EVGENY NAUM (GB)
Application Number:
PCT/GB2000/003339
Publication Date:
March 15, 2001
Filing Date:
September 01, 2000
Export Citation:
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Assignee:
NUTRALHEALTH LTD UK (GB)
VULFSON EVGENY NAUM (GB)
International Classes:
A23C9/13; A23C21/10; A23D7/005; A23D7/015; A23L1/304; C07C53/126; C07C55/10; C07C57/12; C07C59/08; C07C59/105; C07C59/265; (IPC1-7): A23L1/304; A23D7/00; C01F11/18
Domestic Patent References:
WO2000045650A12000-08-10
WO1991019692A21991-12-26
WO1999023896A11999-05-20
Foreign References:
US4446165A1984-05-01
US4018877A1977-04-19
US5215769A1993-06-01
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Claims:
CLAIMS
1. An emulsified fat product which is fortified with calcium where the calcium source is included in both the aqueous and oil phase of the product composition.
2. An emulsified fat product as claimed in claim 1, where the calcium source in at least one phase of the product composition is present in a largely insoluble form.
3. An emulsified fat product as claimed in claim 1, where two different calcium source are present in both the aqueous and the oil phase of the product composition in a largely insoluble form.
4. An emulsified fat product as claimed in claim 3, where the two largely insoluble calcium salts are incorporated in the aqueous and the oil phase of the product in a ratio from about 1: 2 to about 2: 1 on the basis of calcium.
5. An emulsified fat product as claimed in any of the claims 14, where the calcium salt present in the aqueous phase is a calcium salt of an organic acid and the calcium salt present in the oil phase is a calcium salt of an inorganic acid.
6. An emulsified fat product as claimed in any of the claims 14, where the calcium salt present in the aqueous phase is a calcium salt of an inorganic acid and the calcium salt present in the oil phase is a calcium salt of an organic acid.
7. An emulsified fat product as claimed in any of the claims 14, where the calcium salts present in both the aqueous and the oil phase are calcium salts of organic acids.
8. An emulsified fat product as claimed in any of the claims 14, where the calcium salts present in both the aqueous and the oil phase are calcium salts of inorganic acids.
9. An emulsified fat product as claimed in any of the claims 17, where the calcium salt of an organic acid is selected from the group comprising calcium citrate, calcium malate, calcium lactate, calcium citrate malate, calcium propionate, calcium glycerophosphate, calcium gluconate, calcium succinate, calcium ascorbate and mixtures thereof.
10. An emulsified fat product as claimed in any of the claims 16 and 8, where the calcium salt of an inorganic acid is selected from the group comprising calcium carbonate, calcium phosphate, calcium pyrophosphate, calcium sulphate, calcium chloride, and mixtures thereof.
11. An emulsified fat product as claimed in any of the claims 110, which contains at least one other physiologically active dietary supplement in addition to those required by legislation.
12. A calcium salt which contains a mixture of anions one of which is an anion of an inorganic acid and the other is selected from the group comprising alkyl and alkenyl carboxylic acids and alkyl and alkenyl carboxylates and mixtures thereof.
13. A calcium salt as claimed in claim 12, where the anion of an inorganic acid is selected from the group comprising carbonate, phosphate, pyrophosphate, sulphate and mixtures thereof.
14. A calcium salt which contains a mixture of anions one of which is an anion of an organic acid and the other is selected from the group comprising alkyl and alkenyl carboxylic acids and alkyl and alkenyl carboxylates and mixtures thereof.
15. A calcium salt as claimed in claim 14, where the anion of an organic acid is selected from the group comprising citrate, malate, glycerophosphate, succinate, ascorbate and mixtures thereof.
16. A calcium salt as claimed in any of the claims 1215, where the alkyl and alkenyl carboxylic acids and alkyl and alkenyl carboxylates are selected from the group comprising medium to long chain saturated and unsaturated fatty acid containing at least 6 carbon atoms and their salts and mixtures thereof.
17. A calcium salt as claimed in claim 16, where the fatty acid and its salt are oleic acid, oleate and mixtures thereof.
18. A calcium salt as claimed in any of the claims 1217, where the mole ratio of the alkyl and alkenyl carboxylic acids and alkyl and alkenyl carboxylates to calcium ions present is less than 1 to 100.
19. A method of preparation of the calcium salt as claimed in any of the claims 1218, where a calcium source and a source of anion are combined in water containing alkyl and alkenyl carboxylic acids and alkyl and alkenyl carboxylates and mixtures thereof, at temperatures of up to 100 °C.
20. A method as claimed in claim 19, where the initial pH of the aqueous solution is near neutral or alkaline.
21. A method of preparation of calcium citrate salt by combining a source of calcium and a source of citric acid in water, where (a) calcium and citric acid are present in nearly equimolar quantities, (b) are combined at temperatures of up to 100°C and (c) the resulting precipitate is allowed to mature over a period of time to give a smooth white paste.
22. A method of preparation of calcium salt by combining a source of calcium and a source of anion in a solution and in a suspension of milk derived solids at temperatures of up to 100°C and allowing the calcium source to precipitate.
23. A method as claimed in claim 22, where the milk derived solids are selected from the group comprising whey, whey protein, milk powder, casein, caseinates, butter milk and butter fat and products derived therefrom.
24. A method as claimed in any of the claims 22 and 23, where the anion is selected from the group comprising phosphate, carbonate, sulphate, pyrophosphate, glycerophosphate, succinate, citrate, malate, and mixtures thereof.
25. A food product which contains calcium salt as claimed in any of the claims 1218.
26. A food product which contains calcium salt and source prepared by the method as claimed in any of the claims 1924.
27. A food product as claimed in any of the claims 25 and 26, where the food product is an emulsified fat spread.
28. An emulsified fat product as claimed in any of the claims 111, which contains the calcium salts as claimed in any of the claims 1218.
29. An emulsified fat product as claimed in any of the claims 111, which contains the calcium salts and sources, prepared by the method as claimed in any of the claims 1924.
Description:
CALCIUM FORTIFIED EMULSIFIED FAT PRODUCT AND CALCIUM SALTS

FIELD OF THE INVENTION This invention relates to an emulsified fat product which is fortified with calcium. This invention also relates to novel calcium salts and sources, and methods for their preparation and their use in the above said emulsified fat product and other food products.

BACKGROUND OF THE INVENTION Calcium is an essential element in the human diet. It is necessary for the regulation of numerous metabolic functions in the body such as muscle contraction, blood clotting and neural transmission and also for normal growth and development of bones and teeth. In recent years calcium has received much attention due to its role in the prevention of bone mass reduction (osteoporosis). In the USA alone, osteoporosis affects about 25 min people and it is the major cause of bone fracture in elderly and post menopausal women. It is generally accepted that the occurrence of osteoporosis is dependent on the attainment of optimal bone mass in the early years of life and on the rate of its loss in later years. It is also generally accepted that an adequate dietary intake of calcium is an important preventive factor and consequently the fortification of food products with calcium has become a common practice in recent years. The recommended daily intake of calcium varies from country to country. For example, the recommended daily uptake of calcium for adolescents/young adults in Britain is 1 000mg for men and 800

mg for women and it is even higher (1200-1500 mg) for the same categories of people in the USA.

Many calcium sources are currently used for the fortification of food products. Some e. g. calcium carbonate, calcium phosphate and calcium citrate and other organic acid salts of calcium are poorly water soluble at neutral and slightly acidic pH which are most common in food formulations.

These salts, if precipitated in the aqueous phase of a food or drink or when used in food or drink in insoluble form, create an undesirable sensation of powderiness in the mouth, so-called"chalky"mouth feel. Other calcium sources e. g. calcium chloride, calcium acetate and a few organic acid salts of calcium are soluble in water in substantial quantities. However, at high concentrations they have poor organoleptic properties and also interact with other food components such as, for example, proteins leading to their precipitation and coagulation.

Among various calcium-fortified food formulations available to consumers, drinks remain the most numerous. This is due to the relative ease of formulating a drink composition of acceptable organoleptic quality which contains about 1% (w/w) of a water soluble calcium salt to provide a substantial part of the recommended daily uptake of calcium in several hundred cm3 of the liquid product. However, in many countries, notably in Europe, calcium fortified drinks are not consumed by a large proportion of the population on a regular basis. Thus, there is a need in the trade to develop and introduce new products to enable more people to benefit from calcium- supplemented foods. It is also desirable for these food products to be an integral part of people's diet so that they can draw the maximum benefit from

calcium fortification with minimum expense. Emulsified fat products such as fat spreads are particularly suitable vehicles for the incorporation of calcium as they are consumed by a large number of people on a daily basis.

Fat spreads can be prepared with different fat contents as legally specified, typically between 10% and 80% fat by weight, and the products can be labelle accordingly as, for example, low fat or very low fat spreads. The latter are especially appealing to many health conscious consumers.

Generally, depending on the fat content and other ingredients used, a fat spread is a water-in-oil or oil-in-water mulsion (or a combination of the two) which has a butter like consistency and taste and which is spreadable. The daily intake of butter and fat spreads varies from country to country but a typical adult consumes about 25-30 gram of butter or butter like product a day. Thus, to provide a substantial part of the recommended daily intake of calcium, a fat spread should contain several grams of calcium source per 100 gram of product, depending on the calcium content of the source. Given that the water content of a typical spread is only about 30% and of a typical low fat spread is about 60%, a highly concentrated solution or suspension of the calcium source in water or in oil must be used to provide the consumer with the health benefits sought.

Recently Cante et al (EP 0 549 290) disclosed a calcium citrate- vegetable oil composition which is spreadable. According to the invention of Cante et al a new crystalline calcium citrate in the form of distinct platelets of about 1 by 1.5 micron, can be obtained by combining a source of calcium ions and citric acid in a mole ratio from 2.5: 2 to 2.95: 2 under carefully controlled conditions of pH and temperature. It is claimed (EP 0 549 290) that the thus

obtained crystalline calcium citrate, when admixed into vegetable oils, results in a significant increase in the viscosity of the oil and this admixture gives a semi-solid fat product which is spreadable. However, the invention of Cante et al can only be practised with the disclosed calcium citrate platelets of defined size, shape and composition. Also, according to the invention of Cante et al the product does not contain a mixture of vegetable oil and hardened fat which is necessary to provide the butter-like sensation in the mouth on melting. Also, according to the invention of Cante et al the product is not an emulsified spread and it is manufactured by a process which is different from those employed for the production of conventional fat spreads. The present invention provides a novel fat spread which is an emulsified product and has a butter like taste and can be prepared with a variety of calcium sources, including some new ones disclosed herein, and where the above said calcium sources are not platelets of defined composition, size and shape and where the calcium source is incorporated into both the aqueous and the oil phase of emulsified fat products.

SUMMARY OF THE INVENTION This invention relates to the discovery that by using two sources of calcium ions, one in the aqueous and one in the oil phase of an emulsified fat spread, a product with good organoleptic properties and no undesirable chalky sensation in the mouth is produced. According to this invention at least one largely insoluble calcium source can be incorporated into either the aqueous or the oil phase of the fat spread prior to emulsification. This invention also provides several new calcium salts and sources, methods for the preparation thereof and their use in calcium-fortified emulsified fat spreads with good organoleptic properties and other food products.

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the discovery that by using two sources of calcium ions, one in the aqueous and one in the oil phase of an emulsified fat product such as, for example, a fat spread, a product with good organoleptic properties and no undesirable chalky sensation in the mouth is produced.

This is a surprising finding because it is well known in the art that the organoleptic properties of emulsified fat spreads are very sensitive to the composition of the phases. Furthermore, in a search for the most suitable sources of calcium to practice the present invention it was discovered that certain new calcium salts and sources have superior organoleptic properties than those conventionally used in the art, even when these new salts and sources are used in a single phase of the emulsified fat product, either on their own, or in combination, or in combination with conventional calcium salts. The composition of these new calcium salts and sources and methods of their preparation are also the subject of the present invention.

Thus, when fat spreads are prepared with commercially available calcium salts such as, for example, calcium citrate, calcium phosphate or calcium carbonate, at a loading of about 1 gram of calcium per 100 gram of spread, the resulting products typically have poor organoleptic properties, regardless of whether the above mentioned calcium salts are used on their own or in combination and added to the aqueous or the oil phase of the fat spread. However, when a source of calcium ions and a source of anion such as, for example, citrate, phosphate or carbonate, are combined in an aqueous solution or suspension containing a certain additional substance or substances, and precipitated from this solution, the resulting calcium salt or

source can be used to produce food products such as, for example, emulsified fat spreads, with good organoleptic properties at the same loading of calcium.

Thus, it was found that a fat spread with good organoleptic properties and no undesirable sensation of chalkiness in the mouth can be produced when, for example CaCI2 and NaHCO3 or NaH2PO4, are combined in an aqueous solution of whey powder (preferably of high protein content) or other milk-derived solids, preferably at a temperature above 50°C with stirring, and the resulting calcium source is precipitated from this solution, and incorporated into emulsified fat spread, preferably in the aqueous phase of the above said spread. It was further found that when the same CaCI2 and Na2CO3 or Ca (OH) 2 and citric acid, are combined in an aqueous solution or suspension of an alkyl or alkenyl carboxylic acid or acids, or alkyl or alkenyl carboxylate or carboxylates, or mixtures thereof, preferably at a temperature of up to 100°C, and the resulting calcium salt is precipitated from this solution and, preferably dried, and incorporated in emulsified fat spread, preferably in the oil phase of the above said spread, a product with good organoleptic properties and no undesirable sensation of chalkiness in the mouth is obtained. Surprisingly, even less than 1 mole % of the above said alkyl or alkenyl carboxylic acids and carboxylates as calculated on the basis of the amount calcium ions present was found to be sufficient for the preparation of calcium salts which, according to the present invention, give emulsified fat products such as spreads with good organoleptic properties when incorporated into the oil phase of the product. In order to distinguish between the different calcium salts and sources described herein, some of these

preparations are referred to as calcium citrate/oleate or calcium carbonate/oleate. However, as the calcium oleate is a very minor constituent of the calcium carbonate/oleate, with calcium oleate content being only about 0.6 mole % as compared to 99.4 mole % of calcium carbonate, this calcium source is in practical terms an inorganic calcium salt.

The calcium content of the resulting emulsified fat products can be further increased by using conventional calcium salts, preferably soluble salts which are well known in the prior art. It is preferable to use such soluble calcium salt (s) in the aqueous phase of the fat spread if one of the new calcium salts of the present invention is used in the oil phase or visa versa i. e. to use a conventional calcium salt in the oil phase of the spread when one of the new calcium sources or salts of the present invention is used in the aqueous phase. It was also found that the organoleptic properties of emulsified fat spreads, can be further improved if the calcium source prepared with milk derived solids as disclosed in the present invention is combined with the calcium salt prepared in the solution containing an alkyt or alkenyl carboxylic acid or acids, or alkyl or alkenyl carboxylate or carboxylates, or mixtures thereof, as disclosed in the present invention and these new calcium sources and salts are incorporated in the aqueous and the oil phase of an emulsified spread respectively. When practising the present invention it is preferable to have at least one calcium salt or source to be largely insoluble in either the aqueous or the oil phase of the emulsified fat product or spread, regardless of whether the above said calcium salt or source is used on its own or in combination with conventional calcium salts (soluble or insoluble) or in combination with other new calcium salts and

sources as disclosed in the present invention. In the context of this invention, the term"largely insoluble"is understood to mean a calcium salt or source which, at the concentration used, remains substantially undissolved in either water or oil phase of the product such as, for example, emulsified fat spreads at temperatures used for the storage and consumption of the product, typically between about 4°C and about 30°C.

It was further found after extensive study and research that the initial source of anion is not crucial to successfully practice the present invention.

Thus, organic anions such as, for example, citrate, malate or a mixture thereof in any molar ratio, or inorganic anions such as, for example, carbonate and phosphate, can all be successfully employed either with milk solids or with alkyl or alkenyl carboxylic acids or carboxylates to obtain novel calcium slats and sources and emulsified fat products of the present invention. It was also found that a wide range of alkyl or alkenyl carboxylic acid or acids, or alkyl or alkenyl carboxylate or carboxylates, or mixtures thereof, can be used, with those poorly soluble in water such as medium and long chain fatty acids containing more than six carbon atoms, for example, C6-C22 saturated and unsaturated fatty acids and their salts, with oleic acid and oleate being preferred. Also, various milk derived solids such as whey, whey proteins, milk powders, casein and caseinates, and the like can all be successfully employed. It was further surprisingly found that in one particular case the use of milk-derived solids was not essential and a suitable largely insoluble calcium citrate salt can be obtained by combining approximately equimolar quantities of calcium ion and citrate in water. This calcium salt was found to undergo a transition from a particulate, powdery material which is

unsuitable for the preparation of calcium fortified spreads according to the present invention to a suitable smooth paste which can be used satisfactorily.

This transition typically takes between about 5 to 24 hours at room temperature and about 1-4 hours at elevated temperatures of between 50°C to 95°C and is accompanied by a significant change in appearance, organoleptic properties and FT-IR spectrum of the calcium citrate as exemplified in the present invention. A suitable paste can also be obtained when using a moderate excess of calcium ions over citrate ions or citrate ions over calcium ions, typically about 50%.

It was further found that the contact time between the source of calcium and the source of anions, when preparing new calcium salts and sources according to the present invention is not crucial as it can be as short as 15-45 minutes or substantially longer, if desired. It was also found that the initial source of calcium ions is not crucial for practising the present invention.

Thus, new calcium salts and sources which give fat spreads and other food products with good organoleptic properties as disclosed herein can be obtained when using either CaC12 or CaCO3 or CaO as a source of calcium ions.

It was further found that different calcium salts and sources can be used in the aqueous and oil phase of the emulsified fat products of the present invention in any combination i. e. inorganic or organic salts of calcium can be used in either the aqueous or the oil phase to give a product with good organoleptic properties. For example, good products are obtained by using calcium citrate in the aqueous phase and calcium citrate/oleate in the oil phase or calcium phosphate in the aqueous and calcium carbonate/oleate in

the oil phase or any combination of the above with or without other soluble salts. Furthermore, conventional water soluble calcium salts such as, for example, calcium chloride or metastable calcium citrate malate (US 4 722 375) or oil soluble calcium salts as, for example, calcium oleate or stearate can be used together with the largely insoluble calcium salts and sources of the present invention, preferably in different phases of the emulsified fat product, to give the fat spreads as disclosed herein.

The emulsified fat spreads according to this invention can be made with a different fat content. For a low fat spread such as those containing about 40% of fat or less it is preferable to use a largely insoluble calcium source prepared in the presence of milk derived solids or the calcium citrate paste according to the present invention with or without further addition of oil soluble or largely oil insoluble calcium salts. For full fat emulsified spreads containing about 70% of fat or more it is preferred to use the calcium salts precipitated from solution containing alkyl or alkenyl carboxylic acids or carboxylates such as, for example, calcium citrate/oleate or calcium carbonate/oleate, with or without further addition of conventional water soluble calcium salts or water insoluble calcium salts and sources, including those disclosed in the present invention. For fat spreads with intermediate fat content of between about 40% and 70% it is preferred to use a combination of largely insoluble calcium salts and sources such as those disclosed in the present invention, incorporated in both the aqueous and the oil phase of the product and, optionally, fortified further with conventional soluble calcium salts. The largely insoluble calcium salts and sources can be used in approximately equal amounts (on the basis of calcium content) in the

aqueous and the oil phase of the product or in different proportions of, for example 1: 2 or 2: 1 (on the basis of calcium content), depending on the fat content of the product and as desired.

Conventional vegetable oils such as, for example, sunflower oil, soybean oil, rapeseed oil and the like can all be used as obtained or after hardening or any other chemical or physical treatment, as known and acceptable in the art. Animal fats, preferably butter fat, may also be used.

Other ingredients can be optionally added to the oil phase. Examples of the above said ingredients include flavouring and colouring agents and vitamins, preferably those which are conventionally used in the manufacture of fat spreads.

When producing low and very low fat spreads according to the present invention it is preferred to use stabilisers. The stabilisers which can be used to practice the present invention include gelatine, maltodextrins, starch and modified starch, cellulose and its derivatives and pectins and their derivatives and other polysaccharides of plant or seaweed origin. However, this is not an exhaustive list and those skilled in the art will instantly recognise that other stabilisers as well as various mixtures thereof can also be successfully employed.

Conventional emulsifiers, preferably mono/di-glycerides (E471), lecithin (E322) and polyglycerol esters (E476), can be used to produce the fat spreads according to the present invention. The above said emulsifiers can be used on their own or as a mixture or any combination thereof or in conjunction with other suitable emulsifiers which are known in the art. The

emulsifier can be added to the oil phase or to a part of the oil phase or to the aqueous phase.

The spreads according to the present invention can be prepared to contain vitamins, such as vitamins A and D, which are conventionally incorporated into fat spreads or are required to be added by legislation. In addition the spreads according to this invention can be further fortified with any other physiologically active additives known to be beneficial to human health. For example, plant sterols or their esters or can be included in the oil phase, if desired, to provide the addition benefit of lowering cholesterol (US 5 502 045). Also according to the present invention water soluble additives such as, for example, other minerals and vitamins can be incorporated into the aqueous phase.

The present invention is further illustrated by specific examples which are provided herein exclusively for the purpose of illustration and are not intended to be limiting. Any person sufficiently skilled in the art will recognise that numerous alterations to the conditions and protocols presented herein can be introduced within the spirit and scope of the present invention.

The Invention will now be described in more detail with respect to the following Examples and Figures wherein Figure 1 shows calcium citrate crystals after 45 minutes (top) and the resulting paste after overnight incubation (bottom). See Example 4 for further details.

Figure 2 shows calcium carbonate + whey (control; left) and calcium carbonate/whey composition (right). See Example 5 for further details. Figure 3 shows calcium phosphate (control; top), calcium phosphate/whey composition (middle) and calcium phosphate + whey protein (control; bottom). See Example 6 for further details.

Figure 4 shows the FT-IR spectra of calcium citrate crystals after 45 minutes of stirring (A) and after standing at room temperature overnight (B). See Example 3 for more details.

EXAMPLES Example 1.

Preparation of calcium citrate/oleate for the oil phase of fat spreads: A solution of citric acid (485.2 g) in water was prepared to give about 2200 ml and the pH of the resulting solution was adjusted to 7.1 with NaOH. Oleic acid (4.2 g) was added and the mixture was heated up to 90°C with stirring.

Calcium hydroxide (195 g; approximately 1 to 1 mole ratio of Ca2+ to citric acid) was added slowly with stirring and the final volume was adjusted to 2500 ml with water. When all the Ca (OH) 2 was added, the suspension was stirred for another 45 min and cooled down to room temperature with continuous stirring. The resulting calcium/citrate/oleate was washed with water to remove the excess of sodium citrate and pH of the suspension was adjusted to 7.0 by adding solid citric acid. This preparation was then spray- dried.

Example 2.

Preparation of calcium carbonate/oleate for the oil phase of fat spreads: A solution of Na2CO3 (266.3 g) in water was prepared to give about 2200 ml.

Oleic acid (4.2g) was added and the mixture was heated up to 57°C with stirring. CaCl2x6H20 (558.9 g; approximately 1 to 1 mole ratio of Ca2+ to Cl32- ) was added slowly with stirring and the final volume was adjusted to 2500 ml with water. When all the calcium chloride was added, the suspension was stirred for another 45 min and cooled down to room temperature with continuous stirring. The resulting calcium/carbonate/oleate was washed with

water to remove the excess of sodium chloride and the pH of the suspension was adjusted to 7.0 by adding solid citric acid. This preparation was then spray-dried.

Example 3.

Preparation of calcium citrate paste for the aqueous phase of fat spreads: Citric acid (485.2 g) was dissolved in water to give about 2200 ml of solution.

To this solution calcium hydroxide (195 g; approximately 1 to 1 mole ratio of Ca2+ to citric acid) was added slowly with stirring and the final volume was adjusted to 2500 ml with water. When all the Ca (OH) 2 was added, the suspension was stirred for another 45 min and, after adjusting the pH to 5.8, it was left to stand overnight. The resulting suspension spontaneously transformed into a thick paste during this time.

The FT-IR spectra of calcium citrate crystals after 45 minutes of stirring (A) and after standing at room temperature overnight (B) are shown

Example 4.

Preparation of calcium citrate paste for the aqueous phase of fat spreads: Citric acid (485.2 g) was dissolved in water to give about 2200 ml of solution and the solution was heated to 90°C with stirring. Calcium hydroxide (195 g; approximately 1 to 1 mole ratio of Ca2+ to citric acid) was added slowly with stirring and the final volume was adjusted to 2500 ml with water. When all the Ca (OH) 2 was added, the suspension was stirred for another 2-3 hours until a thick paste occurred. The paste was cooled down to room temperature and the pH was adjusted to 5.8 by adding sodium hydroxide. The FT-IR spectra obtained for the crystals after 45 minutes and for the paste after 3 hours were the same as A and B in Example 3 respectively. SEM microphotographs of the calcium citrate crystals and the calcium citrate paste are shown in Figure 1.

Example 5.

Preparation of calcium carbonate/whey composition for the aqueous phase of fat spreads: A solution of NaHCO3 (422.2 g) in water was prepared to give a final volume of 2500 mi. This was heated gently to about 40°C to aid the dissolution of the salt. To this solution protein-rich whey powder (140 g) was added and the mixture was heated up to 57°C with stirring. CaCI2x6H20 (558.9 g) was then added slowly and the stirring continued for further 45 min.

The suspension was cooled down to room temperature with stirring. The resulting calcium carbonate/whey composition was washed with water to remove the excess of sodium chloride and the pH was adjusted to 7.0 by adding solid citric acid. SEM microphotographs of the calcium carbonate/whey composition and calcium carbonate crystals with whey added after the crystallisation was completed (calcium carbonate + whey control) are shown in Figure 2.

Example 6.

Preparation of calcium phosphate/whey composition for the aqueous phase of fat spreads: A solution of NaH2PO4 (265.3 g) was dissolved in water (2000 mL) and to this solution whey protein (140 g) was added. The mixture was heated up to 57°C with stirring, CaCI2x6H20 (558.9 g) was added slowly and the volume was made up to 2500 mL with water. The stirring was continued for a further 45 min, after which time the suspension was cooled down to room temperature with stirring. The resulting calcium phosphate/protein composite was washed with water to remove the excess of salt and the pH was adjusted to 5.8 with sodium hydroxide. SEM microphotographs of the calcium phosphate/whey composition, calcium phosphate and calcium phosphate crystals with added after the crystallisation was completed (controls) are shown in Figure 3.

Example 7.

A 70% fat spread was prepared to contain 63 g of calcium citrate/oleate (prepared as described in Example 1) per kg of spread. Calcium citrate/oleate (6.3 parts), was added to a mixture (70 parts) consisting of sunflower oil (78.5%) and hydrogenated vegetable oil (21 %), emulsifiers E471 and E322 (0.5%), fat soluble butter flavours (0.035%), colouring (0.04%) and vitamins.

The mixture was stirred until a fine homogenous suspension of calcium citrate/oleate in the oil phase was obtained. The thus prepared oil, containing calcium citrate/oleate (76.3 parts) was emulsified with aqueous phase (23.7 parts) containing salts (7% w/w), whey powder (2% w/w) and water soluble flavours. Using a conventional scrape surface heat exchanger, the final product containing about 1% (w/w) of calcium was obtained.

Example 8.

A 70% fat spread was prepared as described in Example 7 but water-soluble calcium citrate malate was added to the aqueous phase at a concentration of 6 g/L. The spread contained one soluble (calcium citrate malate) and one largely insoluble (calcium citrate/oleate) organic calcium salt in the aqueous and the oil phase of the product composition respectively with the overall amount of calcium being in excess of 1% (w/w).

Example 9.

A 70% fat spread was prepared as described in Example 7 but water-soluble calcium chloride was added to the aqueous phase at a concentration of 8 g/L.

The spread contained one soluble inorganic calcium salt (CaCl 2) and one largely insoluble organic calcium salt (calcium citrate/oleate) in the aqueous and the oil phase of the product composition respectively, with the overall amount of calcium being in excess of 1% (w/w).

Example 10.

A 70% fat spread was produced as described in Example 7 but adding 2.5 parts of calcium carbonate/oleate (prepared as described in Example 2) instead of calcium citrate/oleate to the oil and increasing the amount of water by 3.8 parts. The final product contained about 1% (w/w) of calcium.

Example 11.

A 70% fat spread was prepared as described in Example 10 but water-soluble calcium citrate malate was added to the aqueous phase at a concentration of 6 g/L. The spread contained one soluble organic calcium salt (calcium citrate malate) and one largely insoluble inorganic calcium salt (calcium carbonate/oleate) in the aqueous and the oil phase of the product composition respectively, with the overall amount of calcium being in excess of 1% (w/w).

Example 12.

A 70% fat spread was prepared as described in Example 10 but water-soluble calcium chloride was added to the aqueous phase at a concentration of 8 g/L.

The spread contained one soluble (calcium chloride) and one largely insoluble (calcium carbonate/oleate) inorganic calcium salts in the aqueous and the oil phase of the product composition respectively, with the overall amount of calcium being in excess of 1% (w/w).

Example 13.

A 40% fat spread with calcium citrate in the aqueous phase was prepared as follows: The aqueous phase was prepared by mixing 30 parts of the calcium citrate paste prepared as described in Example 3 with 25 parts of water. The mixture was heated to 60°C and gelatine (2 parts), whey powder (2 parts) and salts (1 part) were added. After dissolution of gelatine, the mixture was homogenised, water soluble flavours were added and the pH of the aqueous phase was adjusted to 5.8. The resulting aqueous suspension (60 parts) was emulsified with the oil phase (40 parts) which was prepared using sunflower oil, hydrogenated vegetable oil, emulsifiers, fat soluble butter flavours, colouring and vitamins as described in Example 7. The final product contained about 1% (w/w) of calcium.

Example 14.

A 40% fat spread was prepared as described in Example 13 but using the calcium citrate paste which was prepared as described in Example 4 and

adding 0.5% (w/v) of calcium stearate to the oil phase. The final product contained calcium in excess of 1% (w/w).

Example 15.

A 40% fat spread was produced as described in Example 13 but using 30 parts of calcium carbonate/whey composition (which was prepared as described in Example 5) in the aqueous phase of the spread instead of the calcium citrate paste. The final product contained about 1% (w/w) of calcium.

Example 16.

A 40% fat spread was produced as described in Example 13 but using 30 parts of calcium phosphate/protein composition (which was prepared as described in Example 6) in the aqueous phase of the spread instead of the calcium citrate paste. The final product contained about 1% (w/w) of calcium.

Example 17.

A 60% fat spread was produced by emulsifying 60 parts of oil of the same composition as in Example 7, to which 3.15 parts of calcium citrate/oleate (prepared as described in Example 1) was added and the aqueous phase (36.85 parts) containing 15 parts of the calcium citrate paste (prepared as described in Example 4), gelatine (1 part), salts (1 part) and whey powder (0.5 parts) with the rest being water. The final product contained two largely insoluble organic calcium salts (at an overall level of about 1% (w/w) of calcium) which were incorporated in approximately equal proportions in the oil and water phases of the emulsified spread.

Example 18.

A 60% fat spread was produced as described in Example 17 but calcium citrate paste in the aqueous phase was replace with 15 parts of calcium carbonate/whey composition prepared as described in Example 5. The final product contained two largely insoluble organic and inorganic calcium salts (at an overall level of 1% (w/w) of calcium) which were incorporated in approximately equal proportions in the oil and the water phase of the emulsified spread.

Example 19.

A 60% fat spread was produced as described in Example 17 but calcium citrate paste in the aqueous phase was replace with 15 parts of calcium phosphate/whey composition prepared as described in Example 6. The final product contained two largely insoluble organic and inorganic calcium salts (at an overall level of 1 % (w/w) of calcium) which were incorporated in approximately equal proportions in the oil and the water phase of the emulsified spread.

Example 20.

A 60% fat spread was produced as described in Example 17 but calcium carbonate/oleate (1.25 parts; prepared as described in Example 2) was added to the oil instead of calcium citrate/oleate. The amount of water in the aqueous phase was increased by 1.9 parts. The final product contained two largely insoluble inorganic and organic calcium salts (at an overall level of 1%

(w/w) of calcium) which were incorporated in approximately equal proportions in the oil and the water phase of the emulsified spread.

Example 21.

A 60% fat spread was produced as described in Example 20 but calcium citrate paste in the aqueous phase was replace with 15 parts of calcium carbonate/whey composition prepared as described in Example 5. The final product contained two largely insoluble inorganic calcium salts (at an overall level of about 1% (w/w) of calcium) which were incorporated in approximately equal proportions in the oil and the water phase of the emulsified spread.

Example 22.

A 60% fat spread was produced as described in Example 20 but calcium citrate paste in the aqueous phase was replace with 15 parts of calcium phosphate/whey composition prepared as described in Example 6. The final product contained two largely insoluble inorganic calcium salts (at an overall level of about 1% (w/w) of calcium) which were incorporated in approximately equal proportions in the oil and the water phase of the emulsified spread.

Example 23.

A 60% fat spread was produced as described in Example 17 but the amount of calcium citrate/oleate was increased twofold to 6.3 parts and the amount of water in the aqueous phase was reduced by 3.15 parts. The final product contained about 1.5 % (w/w) of calcium which was incorporated in the oil and the water phase of the emulsified spread in the ratio of about 2 to 1.

Example 24.

A 60% fat spread was produced as described in Example 20 but the amount of calcium carbonate/oleate (prepared as described in Example 2) was increased twofold to 2.5 parts and the amount of water in the aqueous phase was reduced by 1.25 parts. The final product contained about 1.5 % (w/w) of calcium which was incorporated in the oil and the water phase of the emulsified spread in the ratio of about 2 to 1.

Example 25.

A 60% fat spread was produced as described in Example 19 but twice the amount of calcium phosphate/whey composition, prepared as described in Example 6, was used in the aqueous phase. Accordingly, the amount of water used in the aqueous phase was decreased by 15 parts. The final product contained about 1.5 % (w/w) of calcium which was incorporated in the oil and the water phase of the emulsified spread in the ratio of about 1 to 2.

Example 26 A 60% fat spread was produced as described in Example 22 but twice the amount of calcium phosphate/protein composition, prepared as described in Example 6, was used in the aqueous phase. Accordingly, the amount of water used in the aqueous phase was decreased by 15 parts. The final product contained about 1.5 % (w/w) of calcium which was incorporated in the oil and the water phase of the emulsified spread in the ratio of about 1 to 2.

Example 27.

A 60% fat spread was produced as described in Example 20 but the amount of calcium carbonate/oleate (prepared as described in Example 2) added to the oil was increased 1.5 fold to 1.9 parts and 22.5 parts of calcium citrate paste (prepared as described in Example 3) rather than 15 parts in the aqueous phase was used. Accordingly, the amount of water in the aqueous phase was reduced by 8.15 parts. The final product contained about 1.5 % (w/w) of calcium which was incorporated in approximately equal proportions in the oil and the water phase of the emulsified spread.

Example 28.

A 60% fat spread was produced as described in Example 19 but twice the amount of calcium citrate/oleate (prepared as described in Example 1) in the oil phase and twice the amount of calcium phosphate/whey composition (prepared as described in Example 6) in the aqueous phase were used.

Accordingly, the amount of water in the aqueous phase was reduced by 18.15 parts. The final product contained about 2% (w/w) of calcium which was incorporated in approximately equal proportions in the oil and the water phase of the emulsified spread.

Example 29.

A 60% fat spread was produced as described in Example 22 but twice the amount of calcium carbonate/oleate (prepared as described in Example 2) in the oil phase and twice the amount of calcium phosphate/whey composition (prepared as described in Example 6) in the aqueous phase were used.

Accordingly, the amount of water in the aqueous phase was reduced by 16.25 parts. The final product contained about 2% (w/w) of calcium which was incorporated in approximately equal proportions in the oil and the water phase of the emulsified spread.

Example 30.

A 60% fat spread was produced as described in Example 17 but 52 parts of oil and 8 parts of stanol esters prepared as described in US 5 502 045 was used.

Example 31.

A standard yoghurt base was prepared by adding 1.5% by weight of high protein whey powder to pasteurised skimmed milk. 1.5 gram of the calcium citrate prepared as described in Example 4 was added per 100 gram of milk and the mixture was homogenised, heated to 80°C and held at this temperature for 30 minutes. The mixture was then cooled to 45°C and the yoghurt mix was inoculated with starter culture containing 1: 1 Lactobacillus bulgaricus and Streptococcus thermophilis. (0.5-0.8% w/v), distributed into containers and incubated at 43°C until pH 4.5 was reached. Typically, the fermentation took about 5 hours. The resulting yoghurt was virtually indistinguishable organoleptically and on examination with the naked eye from the yoghurt prepared without the calcium citrate present.