It is known to isolate flavours from fat.

Thus, EP 463 660 describes the preparation of a flavouring mixture by gentle oxidation of fatty acids and/or of fatty acid derivatives in the presence of antioxidants. Preferably, the animal or vegetable fat used is hydrolysed beforehand, so as to obtain an oxidized mixture containing a sufficient quantity of flavouring compounds.

To isolate flavours from fat, it is also known to use CO2 under supercritical conditions. However, to obtain a good yield in such a process for isolating flavouring compounds, other compounds in the fat are isolated, in particular peroxides, long-chain free fatty acids and cholesterol. Now, the presence of long-chain fatty acids, either in the form of glycerides or in free form contributes to the rapid deterioration of the flavouring compounds during a prolonged storage.

Moreover, the consumption of cholesterol present in animal fat is responsible for health problems.

Thus, K. W. Um et al (J. Agric. Food Chem.-40 p. 1641-1646-1992) describes a flavour concentrate obtained by extraction with CO2 under supercritical conditions from beef fat with a very low yield.

The use of COZ involves relatively high costs. Furthermore, if the extraction conditions are such that the long-chain free fatty acids are absent from the flavour concentrate extracted, the extraction is carried out at a very low yield.

Moreover, it is known to use fluorocarbons as extraction solvent for extracting certain compounds.

Thus EP 616,821 describes the use of 1,1,1,2-tetrafluoroethane for the extraction of flavours from flower perfumes, or compounds from roots, seeds or algae.

The known processes for isolating flavours from fat do not allow the isolation, from oxidized fat, of stable flavours having good organoleptic qualities. Indeed, these processes involve the isolation of flavours in combination in particular with oxidizable lipids and peroxides in high concentration. Moreover, unsaturated fatty acids, in particular in free form, are the main precursors of the peroxides which are responsible for the instability of the fats. Furthermore, in the known processes, a large portion of the volatile flavours are not isolated.

The aim of the present invention is to provide a volatile flavour concentrate extracted from fat which remains stable and the process for the extraction of such a concentrate.

To this effect, the subject of the present invention is a volatile flavour concentrate extracted from fatty material which contains, relative to the quantity contained in the original fatty material, at most 5% of free fatty acids having a carbon chain greater than or equal to 14 carbons and at most 1% of oxygen in peroxide form.

It has been observed, surprisingly, that the volatile flavour concentrate according to the invention is stable because it contains, in a small quantity, peroxides and free fatty acids having a carbon chain greater than or equal to 14 carbons. It is known that long-carbon-chain fatty acids are easily oxidized, especially when they are in free form, and therefore cause instability during storage. Accordingly, it is highly advantageous to obtain a volatile flavour concentrate only containing long-carbon-chain free fatty acids in a small proportion. Moreover, the volatile flavour concentrate according to the invention, extracted from animal fat, is low in cholesterol, which confers on it very good nutritive qualities. Finally, the volatile flavour concentrate according to the invention has very good flavour properties.

The fatty material from which the flavour concentrate is extracted may be of animal or plant origin and may be in fat or oil form. It may also be prepared by heat treatment of a fat, an oil and/or free fatty acids at 150°C to 475°C so as to obtain a"thermolysate"as fatty material source.

When the volatile flavour concentrate is extracted from fatty material of animal origin, it has less than about 5% of chlolesterol relative to the

quantity of cholesterol in the original fatty material. This confers on the volatile flavour concentrate very good nutritional qualities.

The volatile flavour concentrate according to the invention is extracted from the fatty material with the aid of a fluorocarbon and, preferably, 2-tetrafluoroethane.

Preferably, 2-tetrafluoroethane is used in liquid form, so as not to dissolve the lipids such as the free fatty acids, the triglycerides and the phospholipids.

The present invention also relates to a process for the manufacture of a volatile flavour concentrate, in which an extraction is carried out on the fatty material under pressure at a temperature of 10-30°C, with the aid of an extraction solvent, 1,1,1,2-tetrafluoroethane, so as to isolate a volatile flavour concentrate.

In order to lower the value of the melting point of the original fatty material, it is possible to add during the extraction fats or oils having a melting point whose value is lower than that of the original fatty material. To this effect, there may be added, in particular, MCTs, medium-chain triglycerides.

It is possible to carry out 2-5 cycles of extraction on the orginal fatty material, so as to obtain an enriched volatile flavour concentrate.

It is possible to carry out the extraction in a countercurrent extraction column. There are introduced, through the top of the column, the extraction solvent and, through the bottom of the column, the original fatty material in liquid form. It is thus possible to collect at the end of the extraction, through the bottom of the column, the volatile flavour concentrate extracted and, through the top of the column, the spent fatty material containing the extraction solvent. The extraction solvent may be recovered by distillation and used for a new extraction.

It is possible to carry out the extraction on the fatty material in a fat/extraction solvent weight ratio of 0.2 to 5.

The volatile flavour concentrate according to the invention may be advantageously used for the manufacture of food products. Indeed, it is possible to use this concentrate to give a fatty flavour note to a food product

without increasing its lipid content. It is thus possible to obtain a food product having a very good stability and excellent nutritive properties.

It is possible to flavour fat substitutes, mayonnaise, margarine, ice creams, bakery products, sauces, soups and/or snacks, for example.

The volatile flavour concentrate according to the invention, the process for the manufacture of this concentrate as well as its use are described in greater detail with the aid of the nonlimiting examples below. The percentages are given be weight, unless otherwise stated.

Example 1 The extraction of a volatile flavour concentrate is carried out using olive oil.

To do this, an extraction is carried out in the presence of 3 kg of extraction solvent, 1,1,1,2-tetrafluoroethane, per 1 kg of olive oil at a temperature of 30°C and a pressure of 7.7 bar. 3 kg of 1,1,1,2-tetrafluoroethane are therefore added to 1 kg of olive oil, with stirring, and then the mixture is allowed to stand, so as to obtain a separation of the phase consisting of the olive oil and that containing the extraction solvent and the volatile flavour concentrate.

Then, the phase containing the extraction solvent and the volatile flavour concentrate are transferred to an evaporation tank containing 100 g of extraction support, MCT, marketed by IMPAG chimi import AG, Feldeggstrasse 26, CH-8034 Zurich.

The volatile flavour concentrate is thus recovered on the extraction support and the extraction solvent, 1,1,1,2-tetrafluoroethane is then distilled off at a temperature of less than 15°C and liquefied with the aid of a compressor so as to be able to recycle the extraction solvent for a new extraction. The extraction of the volatile flavour concentrate is repeated twice on the 3 kg of olive oil as described above.

The concentration of peroxide contained in the olive oil, before and after the extraction process, in the extraction support and in the volatile flavour concentrate is measured. All the values are mentioned in Table I below. The quantity of peroxide in Table I is given in mmol 02/kg of material. This is

the concentration of oxygen bound in peroxide form per kilogram of material.

Table I peroxide concentration (mmol 02/kg of material) olive oil before extraction 14.5 olive oil after extraction 14.5 MCT <0.4 volatile flavour concentrate on MCT <0.4 The measurements mentioned in Table 1 demonstrate the fact that the volatile flavour concentrate thus isolated from olive oil contains a smaller quantity of peroxides relative to the quantity contained in the original oil, the olive oil. There are therefore obtained 14.5 mmol of oxygen bound in peroxide form in the original olive oil and 0.04 mmol of oxygen bound in peroxide form in the volatile flavour concentrate. Thus, the peroxide extraction yield during the extraction is less than 0.3%.

A volatile flavour concentrate having the desired organoleptic qualities and having a fat flavour typical of olive oil is thus obtained.

Example 2 The extraction of the volatile flavour concentrate is carried out using chicken fat.

To do this, an extraction is carried out in the presence of 3 kg of extraction solvent, 1,1,1,2-tetrafluoroethane per 600 g of unrefined chicken fat, marketed by Saria Industries, 77 rue Charles Michels, BP 230, F-93523 SAINT DENIS. This extraction is carried out at a temperature of 30°C and a pressure of 7.7 bar. 3 kg of 1,1,1,2-tetrafluoroethane are therefore added to the 600 g of unrefined chicken fat, with stirring, and then the mixture is allowed to stand so as to obtain a separation of the phase consisting of the chicken fat and that containing the extraction solvent and the volatile flavour concentrate.

Then, the phase containing the extraction solvent and the concentrated volatile flavours is transferred to an evaporation tank containing 60 g of

extraction support, sunflower oil, marketed by Elchem Continental S. A., Avenue du Clairevaux 15, BE-Louvain La Neuve.

The volatile flavour concentrate is thus recovered on the extraction support and the extraction solvent, 1,1,1,2-tetrafluoroethane is then distilled off at a temperature of less than 15°C and liquefied so as to be able to recycle the extraction solvent for a new extraction. The extraction of the volatile flavour concentrate is repeated twice on the 600 g of chicken fat as described above.

The percentage of long-carbon-chain free fatty acids (C, 6-C, 8) contained in the chicken fat, before and after the extraction process, in the extraction support and in the volatile flavour concentrate is measured. All the values are mentioned in Table II below.

Table II long-carbon-chain free fatty acids (Cl6-Cl8) (%) chicken fat before extraction 4 chicken fat after extraction 4.4 extraction support <0.2 volatile flavour concentrate 1.9 The results mentioned in Table II demonstrate the fact that the volatile flavour concentrate thus extracted contains long-carbon-chain free fatty acids in a small quantity. There are therefore 24 g of long-carbon-chain free fatty acids in the original chicken fat and 1.14 g in the volatile flavour concentrate. Thus, during the extraction process, the long-carbon-chain free fatty acids are extracted at a low extraction yield of 4.75%.

A volatile flavour concentrate having very good organoleptic qualities and having a characteristic chicken fat flavour is thus obtained.

Example 3 The extraction of a volatile flavour concentrate is carried out using duck fat. To do this, an extraction is carried out in the presence of 3 kg of extraction solvent, 2-tetrafluoroethane, per 400 g of duck fat, marketed by SPI Diana, France. 3 kg of 1,1,1,2-tetrafluoroethane are therefore added to the 400 g of duck fat, with stirring, and then the mixture is allowed to stand so

as to obtain a separation of the phase consisting of the duck fat and that containing the extraction solvent and the volatile flavour concentrate.

Then, the phase containing the extraction solvent and the volatile flavour concentrate are transferred to an evaporation tank containing 40 g of extraction support, MCT, marketed by IMPAG, Feldeggstrasse 26, CH- 8008 ZURICH. The volatile flavour concentrate is thus recovered on the extraction support and the extraction solvent, 1,1,1,2-tetrafluoroethane is then distilled off at a temperature of less than 15°C and liquefied with the aid of a compressor so as to be able to recycle the extraction solvent for a new extraction. The extraction of the volatile flavour concentrate is repeated twice on the 400 g of duck fat as described above.

The quantity of cholesterol contained in the duck fat, before and after the extraction process, in the extraction support and in the volatile flavour concentrate is measured. All the values are mentioned in Table III below.

Table III cholesterol concentration (%) duck fat before extraction 0.19 duck fat after extraction 0.19 extraction support <0.01 I volatile flavour concentrate 0.07 1 The results mentioned in Table III demonstrate the fact that the cholesterol is only extracted in a low yield. Indeed, the original duck fat contains 0.76 g of cholesterol and the volatile flavour concentrate thus extracted contains 0.028 g of cholesterol. A cholesterol extraction yield of 3.7% is thus obtained.

Example 4 The extraction of a volatile flavour concentrate is carried out using oxidized sunflower oil.

To oxidize the sunflower oil, a mixture of 10 kg of sunflower oil, 2.5 kg of water and 0.4 kg of salt is stirred in a reactor at 105°C for 16 hours. After oxidation, a separation is obtained between the aqueous phase and the lipid

phase consisting of the sunflower oil. The oxidized sunflower oil is then used for the extraction.

The extraction is carried out in the presence of 3 kg of extraction solvent, 1,1,1,2-tetrafluoroethane, per 1 kg of oxidized sunflower oil at a temperature of 20°C and a pressure of 5.7 bar. 3 kg of 1,1,1,2-tetrafluoroethane are therefore added to 1 kg of oxidized sunflower oil, with stirring, and then the mixture is allowed to stand so as to obtain a separation of the phase consisting of the oxidized sunflower oil and that containing the extraction solvent and the volatile flavour concentrate.

Next, the phase containing the extraction solvent and the volatile flavour concentrate is transferred to an evaporation tank containing 100 g of extraction support, MCT, marketed by IMPAG, Switzerland.

The volatile flavour concentrate is thus recovered on the extraction support.

The extraction solvent is distilled off at a temperature of less than 15°C and it is liquefied with the aid of a compressor so as to be able to recycle it for a new extraction. The extraction of volatile flavour concentrate is repeated twice on the 3 kg of sunflower oil as described above.

The concentration of peroxide contained in the sunflower oil is measured before and after the oxidation process and before and after the extraction process, in the extraction support and in the volatile flavour concentrate. All the values are mentioned in Table IV below. The quantity of peroxide in Table IV is given in mmol 02/kg of material. It is the concentration of oxygen bound in peroxide form per kilogram of material.

Table IV peroxide concentration (mmol 02/kg) sunflower oil before extraction 1.0 oxidized sunflower oil before 8.5 extraction oxidized sunflower oil after 9.6 extraction MCT <0.4 1 volatile flavour concentrate 0.7

The measurements mentioned in Table IV demonstrate the fact that the volatile flavour concentrate thus isolated from oxidized sunflower oil contains a small quantity of peroxides relative to the quantity contained in the original sunflower oil. There are therefore obtained 8.5 mmol of oxygen bound in peroxide form in the original olive oil and 0.07 mmol of oxygen bound in peroxide form in the volatile flavour concentrate. Thus, the peroxide extraction yield during the extraction is less than 0.8%.

0.1% of Herbor 025 antioxidant, marketed by Food Ingredients Specialities, CH-Chatel Saint Denis, is added to a sample of volatile flavour concentrate on MCT. Next, a test of storage stability is carried out.

To do this, a sample of nonoxidized sunflower oil, a sample of oxidized sunflower oil, a sample of oxidized sunflower oil after extraction, a sample of volatile flavour concentrate on MCT and a sample of volatile flavour concentrate on MCT with 0.1% Herbor 025 antioxidant are stored at 20°C.

The same types of sample are also stored at 37°C.

The concentration of peroxide contained in these different samples are then measured before storage, after 4 weeks and then after 8 weeks. All the values are mentioned in Table V below.

Table V peroxide concentration (mmol 02/kg) before 20°C 20°C 37°C 37°C storage 4 wk. 8 wk. 4 wk. 8 wk. nonoxidized sunflower oil 1.0 0.9 18.6 15.4 26.9 oxidized sunflower oil 8.5 19.7 35.3 13.5 21.5 volatile flavour concentrate 0. 7 1.7 6.3 6.4 6.8 volatile flavour concentrate + 0.1% of 0.7 0.4 3.2 1.4 2.1 antioxidant

The results mentioned in Table V demonstrate the fact that the volatile flavour concentrate on MCT and the volatile flavour concentrate with the addition of 0.1% of antioxidant are much more stable than the original sunflower oil and the oxidized sunflower oil. If the peroxide concentration is less than or equal to 6 mmol 02/kg, it is considered that the oxidative qualities are good during storage. On the other hand, if the peroxide concentration is greater than 10 mmol 02/kg, it is considered that a product exhibits poor oxidative qualities.

Example 5 A poultry stock is prepared containing volatile flavour extract on MCT as produced in Example 3.

To do this, a mixture is prepared containing 378 g of maltodextrin, 190 g of salt, 100 g of yeast extract, 91 g of dextrose, 80 g of starch, 13 g of volatile flavour extract on MCT, 36 g of sugar, 0.5 g of caramel colour, 2.5 g of turmeric, 2 g of citric acid, 1 g of pepper, 0.5 g of garlic, 0.5 g of rosemary, 0.5 g of ginger.

The stock is then prepared from 1 1 of hot water into which 19 g of the mixture and 1.2 g of salt are mixed. The stock produced with the volatile flavour extract has a very pronounced poultry flavour.

Example 6 The extraction of a volatile flavour concentrate is carried out using a flavour composition according to patent US 5,104,672 in which the fatty acids are heated to 150-475°C in the presence of oxygen. The flavour composition is called hereinafter"thermolysate".

To do this, an extraction is carried out in the presence of 3 kg of extraction solvent, 1,1,1,2-tetrafluoroethane per 500 g of thermolysate, provided by FIS, New Milord, CT, USA. This extraction is carried out in the apparatus described in Example I at a temperature of 25°C and a pressure of 6.6 bar. 3 kg of 1,1,1,2-tetrafluoroethane are therefore added to the 500 g of thermolysate, with stirring, and then the mixture is allowed to stand so as to obtain a separation of the phase consisting of the thermolysate and the phase containing the extraction solvent and the volatile flavour concentrate.

Next, the phase containing the extraction solvent and the concentrated volatile flavours are transferred to a separate evaporation tank. The volatile flavour concentrate separated from its original fat is thus recovered and the extraction solvent, 1,1,1,2-tetrafluoroethane, is then distilled off at a temperature of less than 15°C and liquefied so as to be able to recycle the extraction solvent for a new extraction.

The extraction of volatile flavour concentrate is repeated four times on the 500 g of thermolysate as described above. 59 g of volatile flavour concentrate were obtained from 500 g of thermolysate (mass yield = 11.8%).

The percentage of C8-C24 carbon chain free fatty acids contained in the thermolysate and in the volatile flavour concentrate is measured. All the values are mentioned in Table VI below.

Table VI Free fatty acid concentration in concentration in the yielda the thermolysate volatile flavour (%) concentrate (%) C-8 1. 73 4. 20 28.6% C-10 0. 45 0. 97 25.4% C-12 1. 46 1. 54 12.4% C-14 0. 56 0. 40 8. 4% C-16 4. 70 2. 47 6.2% C-18 1. 36 0. 48 4.2% C-18=1 55. 10 20. 30 4.3% C-18=2 3. 40 1. 55 5.4% C-18=3 0. 45 n. d.- C-20 0. 23 0. 04 2. 1% C-22 0. 04 n. d.- C-24 0. 05 n. d.- Total C-14 to 4.5% 24 1 1 1 1 concentration in the concentrate x mass yield<BR> ª yield (free fatty acid) =<BR> concentration in the thermolysate

The results mentioned in the table demonstrate the fact that the long-chain free fatty acids (C14 and more) have a low extraction yield.

A volatile flavour concentrate is thus obtained having very good organoleptic qualities and having a roast/barbecue flavour after dilution in water.