IES62576B2 - "A method for preparing an edible water-in-oil emulsion" - Google Patents

Abstract

A spread is prepared from a water-in-oil emulsion, which is prepared using a margarine process, in which the fat phase of the emulsion comprises fish oil containing an antioxidant blend of ascorbyl palmitate. The aqueous phase of the emulsion is prepared without ingredients or additives which may react with or act as a catalyst for a reaction with ascorbyl palmitate to at least retard the development of a metallic type off-flavour or fishy taste. The aqueous phase is prepared without one or more of the following ingredients or additives: whey, whey powder, skimmed milk, skimmed milk powder, butter milk, butter milk powder, whole milk, whole milk powder, and sodium caseinate.

Description

A method for preparing an edible water-in-oil emulsion The present invention relates to a method for preparing an edible water-in-oil emulsion containing fish oil and the invention also relates to a water-in-oil emulsion containing fish oil.

Fish oil has very significant and desirable nutritional properties. It is also relatively high in omega-3 polyunsaturated fatty acids, which have been found to play a significant role in the prevention, or at least reduction in the incidence of heart disease. However, fish oil suffers from a serious disadvantage in that it deteriorates at a relatively rapid rate. To arrest the relatively rapid deterioration of fish oil, fish oil is subjected to various processes, such as, for example, refining, deodorising, and other stabilising processes, for example, treating the fish oil with antioxidants and the like. Such processes, while they overcome to a large extent the problem of deterioration of the fish oil, unfortunately, significantly affect the nutritional properties, and in particular, the omega-3 polyunsaturated fatty acids content of the fish oil. In general, such processes tend to destroy the omega-3 polyunsaturated fatty acids. Thus, the beneficial effects of fish oil are effectively eliminated.

Processes for treating fish oil to prevent or to at least retard deterioration of the fish oil, while at the same time minimising the adverse effects on the nutritional properties, and in particular, on the omega-3 polyunsaturated fatty acids content of the fish oil require the addition to the fish oil of an antioxidant or an antioxidant blend. Such an antioxidant or antioxidant blend may comprise ascorbyl palmitate. It has, however, been found that fish oil containing such an antioxidant blend of ascorbyl palmitate when included in the fat phase of an edible water-in-oil emulsion, such as, for example, a spread, causes the spread to develop a metallic type off-flavour which is often described as a fishy taste.

There is therefore a need for a method for preparing an edible water-in-oil emulsion containing fish oil and an antioxidant containing ascorbyl palmitate in which the development of such an off-flavour or fishy taste is avoided, or at least retarded.

There is also a need for such an edible water-in-oil emulsion.

The present invention is directed towards providing such a method and an edible water-in-oil emulsion containing fish oil.

According to the invention there is provided a method for preparing an edible water-in-oil emulsion comprising fish oil, the water-in-oil emulsion comprising a fat phase and an aqueous phase, the fat phase comprising fish oil containing an antioxidant including ascorbyl palmitate, wherein the aqueous phase is prepared without ingredients or additives which may react with or act as a catalyst for a reaction with, ascorbyl palmitate to at least retard the development of a metallic type off-flavour or fishy taste. Preferably, the aqueous phase is prepared without any one or more of the following ingredients or additives: whey, whey powder, skimmed milk, skimmed milk powder, butter milk, butter milk powder, whole milk, whole milk powder, and sodium caseinate.

In one embodiment of the invention the aqueous phase is prepared with de-ionised water. In another embodiment of the invention, a sequestrant is added to the aqueous phase for binding metal ions in the aqueous phase. Preferably, the sequestrant is selected from any one or more of the following sequestrants: citric acid and/or its salts, phosphate salts, and ethylene diamine tetra-acetic acid and/or its salts.

In another embodiment of the invention the aqueous phase is prepared with water having a relatively low calcium content, and preferably, the water comprises a very low level of calcium. Preferably, the calcium content of the aqueous phase is less than 20 parts per million of the aqueous phase. Advantageously, the calcium content of the aqueous phase is less than 10 parts per million of the aqueous phase, and ideally, the calcium content of the aqueous phase is less than 5 parts per million of the aqueous phase. It is believed that the presence of calcium in the aqueous phase reduces the effectiveness of the sequestrant, and accordingly, by minimising the calcium content of the aqueous phase, the binding property of the sequestrant for binding metal ions is enhanced.

In another embodiment of the invention the fat phase constitutes up to 82% bv weight of the water-in-oil emulsion.

Advantageously, the fat phase constitutes up to 60% by weight of the water-in-oil emulsion, and ideally, the fat phase constitutes approximately 40% by weight of the water-in-oil emulsion.

In one embodiment of the invention the fish oil containing the antioxidant constitutes up to 50% by weight of the water-in-oil emulsion, and preferably, the fish oil containing the antioxidant constitutes up to 40% by weight of the water-in-oil emulsion. Advantageously, the fish oil containing the antioxidant constitutes up to 30% by weight of the water-in-oil emulsion, and in a preferred embodiment of the invention, the fish oil containing the antioxidant constitutes between 3% and 20% by weight of the water-in-oil emulsion. Ideally, the fish oil containing the antioxidant constitutes approximately 4% by weight of the water-in-oil emulsion.

Preferably, the fish oil is an unhardened fish oil, and in a preferred embodiment of the invention the fish oil is a fish oil sold by Roche Products Limited of Great Britain under the Trade Mark ROPUFA 30.

In another embodiment of the invention the fat phase comprises a vegetable oil, and preferably, a vegetable oil liquid at room temperature.

Preferably, the vegetable oil is selected from any one or more of the following oils: rape seed oil, soya bean oil, sun flower oil, and olive oil.

Advantageously, the fat phase comprises a hard stock oil solid at room temperature. In one embodiment of the invention the hard stock oil is a vegetable oil.

Advantageously, the hard stock oil is selected from any one or more of the following oils: hydrogenated or partly hydrogenated soya bean oil, hydrogenated or partly hydrogenated rape seed oil, hydrogenated or partly hydrogenated palm oil, hydrogenated or partly hydrogenated coconut oil, hydrogenated or partly hydrogenated palm kernel oil, a vegetable oil naturally hard at room temperature, for example, coconut oil, palm kernel oil, palm oil and fractions thereof, animal fats, for example, milk fat, tallow or lard or P fractions thereof.

In a further embodiment of the invention the fat phase may also contain an emulsifier, for example, a mono and di glycerides; the fat phase may also contain colouring; flavouring and/or vitamins.

In another embodiment of the invention the aqueous phase may contain lactic acid, proteins and/or flavouring additives.

In one embodiment of the invention the water-in-oil emulsion is prepared using a margarine process.

Additionally, the invention provides an edible water-in-oil emulsion containing fish oil, the water-in-oil emulsion comprising a fat phase and an aqueous phase, the fat phase comprising fish oil containing an antioxidant including ascorbyl palmitate wherein the aqueous phase is prepared without additives which may react with, or act as a catalyst for a reaction with ascorbyl palmitate to at least retard the development of a metallic type off-flavour or fishy taste. Preferably, the aqueous phase is prepared without any one or more of the following ingredients: whey, whey powder, skimmed milk, skimmed milk powder, butter milk, butter milk powder, whole milk, whole milk powder, and sodium caseinate.

Preferably, the aqueous phase is prepared from de-ionised water, advantageously, the aqueous phase contains a sequestrant for binding metal ions in the aqueous phase, preferably, the sequestrant is selected from any one or more of the following: citric acid, and/or its salts, phosphate salts, and ethylene diamine tetra-acetic acid, and/or its salts.

In one embodiment of the invention the aqueous phase is prepared with water with a relatively low level of calcium and preferably, a very low level of calcium.

In another embodiment of the invention the fat phase constitutes up to 82% by weight of the water-in-oil emulsion, and preferably, the fat phase constitutes up to 60% by weight of the water-in-oil emulsion. Advantageously, the fat phase constitutes approximately 40% by weight of the water-in-oil emulsion.

In one embodiment of the invention the fish oil containing the antioxidant constitutes up to 50% by weight of the water-in-oil emulsion. Advantageously, the fish oil containing the antioxidant constitutes up to 40% by weight of the water-in-oil emulsion. Advantageously, the fish oil containing the antioxidant constitutes up to 30% by weight of the water-in-oil emulsion, and in a preferred embodiment of the invention, the fish oil containing the antioxidant constitutes between 3% and 20% by weight of the water-in-oil emulsion. Ideally, the fish oil containing the antioxidant constitutes approximately 4% by weight of the water-in-oil emulsion.

Additionally, the invention provides a spread prepared from the edible water-in-oil emulsion according to the invention.

Further, the invention provides a spread in which the water-inoil emulsion is prepared by a method according to the invention.

The invention will be more clearly understood from the following description of the following non-limiting examples.

Example 1 A spread is prepared from an edible water-in-oil emulsion, which is prepared from the following ingredients in the proportions by weight set out below: Fat phase refined deodorised rape seed oil 22.6% Hydrogenated soya bean oil 12.9% Dimodan 0T (glycerol mono stearate) 0.5% β Carotene 0.003% Fish oil containing an antioxidant blend 4.0% Aqueous phase De-ionised water 58.66% Sobalg FD 120 (sodium alginate) 1.20% Potassium sorbate 0.10% Citric acid 0.04% The fish oil is an unhardened fish oil containing an antioxidant blend, which antioxidant blend includes ascorbyl palmitate. In this particular embodiment of the invention the fish oil is a fish oil sold by Roche Products Limited of Great Britain under the Trade Mark ROPUFA 30. The refined deodorised rape seed oil is liquid at room temperature, and the hydrogenated soya bean oil is solid at room temperature. The de-ionised water is very low in calcium so that the calcium content of the aqueous phase is less than five parts per million of the aqueous phase.

The spread is prepared using a margarine process. The ingredients of the fat phase including the fish oil are raised to a temperature of approximately 40°C to 45°C in a mixing tank until all the fats have melted and are thoroughly mixed. The ingredients of the aqueous phase are mixed and added to the fat phase in the mixing tank and stirred to form a water-in-oil emulsion. The emulsion is then processed in a scraped surface heat exchanger and ancillary/ equipment to achieve pasteurisation, and is subsequently cooled and then subjected to texturising or plasticising. The spread is then packed as desired in foil, tubs or other suitable packaging.

Example 2 A spread is prepared from the following ingredients in the proportions by weight set out below using a similar method to that of Example 1: Fat phase refined deodorised rape seed oil 22.6% Hydrogenated soya bean oil 12.9% Dimodan 0T (glycerol mono stearate) 0.5% β Carotene 0.003% Fish oil containing an antioxidant blend 4.0% Aaueous phase De-ionised water 57.16% Sobalg FD 120 (sodium alginate) 1.2% Potassium sorbate 0.1% Sodium chloride 1.5% Citric acid 0.04% Example 3 A spread is prepared from the following ingredients in the proportions by weight set out below using a similar method that of Example 1: Fat phase refined deodorised rape seed oil 33.59% Hydrogenated soya bean oil 19.8% Dimodan 0T (glycerol mono stearate) 0.5% β Carotene 0.003% Oil soluble flavour 0.01% Fish oil containing an antioxidant blend 6.0% Aqueous phase De-ionised water Water soluble flavour Sodium chloride Citric acid 37.75% 0.005% 1.2% 0.04% Example 4 A spread is prepared from the following ingredients in the proportions by weight set out below using a similar method to that of Example 1: Fat phase refined deodorised rape seed oil 15.5% butterfat (anhydrous) 40.0% Dimodan 0T (glycerol mono stearate) 0.5% Fish oil containing an antioxidant blend 4.0% Aqueous phase De-ionised water 38.46% Sodium chloride 1.5% Citric acid 0.04% Example.5 A spread is prepared from the following ingredients in the proportions by weight set out below using a similar method to that of Example 1: Fat phase refined deodorised rape seed oil 3.6% Hydrogenated soya bean oil 26.0% Dimodan 0T (glycerol mono stearate) 0.4% Carotene 0.003% Fish oil containing an antioxidant blend 50.0% Aqueous phase De-ionised water 19.96% Citric acid 0.04% In Examples 2 to 5, the fish oil is identical to the fish oil used in Example 1. The spreads of Examples 2 to 5 are prepared using the margarine process similar to that described with reference to Example 1, and after texturising and plasticising the spread is packed. In each of Examples 2 to 5, the refined deodorised rape seed oil is liquid at room temperature. The deionised water is very low in calcium so that the calcium content of the aqueous phase is less than five parts per million of aqueous phase. In each of the Examples 2, 3 and 5, the hydrogenated soya bean oil is solid at room temperature. In Example 4, the butterfat is also solid at room temperature. In each of the Examples 2 to 4, a small quantity of sodium chloride is included in the aqueous phase without adverse results.

In all the examples, as can be seen, neither the aqueous phase or the fat phase contain any of the following ingredients or additives: whey, whey powder, skimmed milk, skimmed milk powder, butter milk, butter milk powder, whole milk, whole milk powder, and sodium caseinate.

In all the examples, trace metals in the aqueous phase are kept to a minimum.

It has been found that the spreads produced according to the above examples do not develop a metallic type off-flavour nor do they develop a fishy taste. In fact, it has been found that the spreads prepared according to the examples are relatively stable. Precisely why this is so is not fully understood, however, it is believed that by minimising the metal content of the aqueous phase considerably contributes to the stability of the spreads.

It is believed that metals present in the aqueous phase either react with ascorbvl palmitate and cause the metallic type offflavour, or alternatively, it may be that the metals present in the aqueous phase act as a catalyst for a reaction of the ascorbyl palmitate with other constituents in either the fat or aqueous phases which leads to the metallic type off-flavour. Accordingly, the use of de-ionised water significantly minimises the metal content of the water. The addition of citric acid to the aqueous phase which acts as a sequestrant for binding any residual metal ions in the aqueous phase further reduces the effect of any remaining metals in the water. It is believed that by keeping the level of calcium in the aqueous phase to a minimum the effectiveness of the sequestrant is increased. It is also believed that by preparing the aqueous phase without whey powder, skimmed milk powder, sodium caseinate and with relatively low levels only of sodium chloride, also minimises the possibility of a reaction with the ascorbyl palmitate which may lead to the metallic type off-flavour or fishy taste.

While the water-in-oil emulsion has been described in the examples as being a spread, it will be apparent to those skilled in the art that the edible water-in-oil emulsion may be other than a spread, for example, mayonnaise, and the like.

The invention is not limited to the examples hereinbefore described, and it will be readily apparent to those skilled in the art that other edible water-in-oil emulsions may be prepared according to the invention with other ingredients and other proportions of ingredients.

Claims (5)

1. A method for preparing an edible water-in-oil emulsion comprising fish oil, the water-in-oil emulsion comprising a fat phase and an aqueous phase, the fat phase comprising fish oil containing an antioxidant including ascorbvl palmitate, wherein the aqueous phase is prepared without ingredients or additives which may react with or act as a catalyst for a reaction with, ascorbyl palmitate to at least retard the development of a metallic type off-flavour or fishy taste.

2. A method as claimed in Claim 1 in which the aqueous phase is prepared without any one or more of the following ingredients or additives: whey, whey powder, skimmed milk, skimmed milk powder, butter milk, butter milk powder, whole milk, whole milk powder, and sodium caseinate.

3. A method as claimed in Claim 1 or 2 in which the aqueous phase is prepared with de-ionised water, and a sequestrant is added to the aqueous phase for binding metal ions in the aqueous phase.

4. An edible water-in-oil emulsion containing fish oil, the water-in-oil emulsion comprising a fat phase and an aqueous phase, the fat phase comprising fish oil containing an antioxidant including ascorbyl palmitate wherein the aqueous phase is prepared without additives which may react with, or act as a catalyst for a reaction with ascorbyl palmitate to at least retard the development of a metallic type off-flavour or fishy taste.

5. An edible water-in-oil emulsion as claimed in Claim 4 in which the aqueous phase is prepared without any one or more of the following ingredients: