FI58857C - FOERFARANDE FOER ISOLERING AV EN KAFFEAROMFRAKTION - Google Patents

Description

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JfltA ^ (11) UTLÄGGNINGSSKRIFT 588 5 7 C Patent granted, 11 05 1501 • AÄS? (^ 5) Patent issued

Vs ^ v ^ (51) Kv.lk?/IntXI.3 A 23 P 5/48 ENGLISH —FINLAND (11) P «iit« lhilwmu —PKwuweknlni 7531 ^ 2 (22) Htkamltpllvi - Anaeknlngsd ·! 10.11.75 (23) AlkuptM — Giltlghattdaf 10.11.75 (41) Published * * krl - Bllvlt offuntllf 12.05.76

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Patent * och registerstyrelsen 'Amöktn utlifd och uti.skrtfun pubitc * r »d 30.01.8l (32) (33) (31) PyH # tty« uoikaui — B «flrd prlorltet ll.ll.7l * Switzerland-Switzerland (CH) 150 ^ 2/7 ^ (71) Societe des Produits Nestle SA, Vevey, Switzerland-Switzerland (CH) (72) Paul Cazenave, Chavomay, Switzerland-Switzerland (CH) (7 * 0 Leitzinger Oy (5 ^) Method for coffee aroma fraction The present invention relates to a process for isolating coffee aroma components, in which the coffee aroma components are extracted from an aqueous medium as a water-insoluble organic solvent and the aroma fraction is recovered from the solvent.

After extraction from a natural medium, coffee aromas are sensitive compounds that are difficult to store for long periods in the presence of water. Therefore, in most methods of isolating aromatic coffee fractions, where these fractions are converted to aqueous solutions or come into contact with high amounts of moisture, the fractions are immediately extracted with a suitable liquid such as organic solvent, oil, etc. However, it has been found carefully, the fractions deteriorate rapidly, even at low temperatures and also regardless of the concentration of these fractions in the liquid. Thus, the coffee aroma in methylene chloride as a 20% solution does not last longer than a few days, even at a temperature of 20 ° C and in a light-free state. Attempts have been made to eliminate this instability of volatile coffee fractions by combining extracts obtained with solvents of different polarity or by using solvent mixtures in the extraction. However, the stability of the volatile fractions does not appear to have improved much.

However, with the present invention, volatile coffee fractions with excellent stability can be obtained. The process of the present invention is characterized in that the organic solvent used is an azeotropic mixture having a boiling point below or below 50 ° C at or below normal pressure and consisting of: a) at least one non-aromatic hydrocarbon having 4 to 7 carbon atoms, and b) at least one of methylene chloride, ethylene chloride, isopropyl chloride, chloroform, dichlorodifluoromethane, trichlorofluoromethane and trichlorotrifluoromethane, and / or c) diethyl ether, ethyl isopropyl ether, diisopropyl ether or furan.

An azeotropic mixture or azeotrope is known to be a mixture which, at a given pressure, behaves in the same way as a pure substance, and in particular which has a fixed boiling point Pg. According to the invention, the azeotropic mixture has a boiling point below about 50 ° C. In cases where the process is carried out at atmospheric pressure, the components of this azeotropic mixture are thus compounds with a relatively low molecular weight. In addition, the azeotrope may be a more complex mixture than a binary mixture. Some suitable azeotropic mixtures are exemplified below: 3,5857

Components Volume ratios Pg (760 mm Hg)

Pentane / methylene chloride 68; 32 30 ° C

Pentane / isopropyl chloride 58:42 30.5 ° C

Pentane / freon 113 (trichloro-

ritrifluoroethane) 94: 6 36 ° C

Pentane / diethyl ether 20.80 36 ° C

Pentane / methylene chloride /

diethyl ether 34.5: 3.5, 62 33 ° C

It is obvious that the process according to the invention can also be carried out with azeotropic mixtures having a boiling point below 50 ° C at a pressure other than atmospheric pressure, in which case the components of this azeotropic mixture must be selected accordingly. For example, if the method is performed under reduced pressure, the components of the azeotrope may be selected from compounds having a relatively higher molecular weight. If, on the other hand, the process is carried out under pressure, the components of the azeotrope must be selected from compounds having a very low molecular weight, for example compounds which are gaseous under normal conditions.

The starting material is an aqueous medium containing the aromatic ingredients of coffee. The aqueous medium may contain only the aromatic constituents of coffee, regardless of the way in which these constituents are dissolved, although it may also contain other substances, in particular solids such as solids found in coffee, flavor enhancers, substances intended to correct possible imbalances, etc. for example, the ingredients may be derived from the condensation of flavors released during roasting of green coffee or during the grinding of roasted coffee, or even from the condensation of flavors obtained by stripping gases or steam of either roasted coffee, dry or aqueous suspension, or an aqueous extract of roasted coffee.

As will become apparent later, the aromatic fraction obtained by the process according to the invention is characterized by its significant stability.

It has been found that this stability is not determined by the type of coffee treated ("arabica", "race", "excels * ^" santoa ", etc.), or its geographical origin (America, Africa or Asia) or its degree of roasting or the concentration of the aqueous medium used as a starting material. , which can vary within wide limits. One suitable way to measure the concentration of condensate obtained by stripping dry roasted coffee with steam is, for example, the stripping level, i. the weight ratio of concentrate to water for the dry coffee used as starting material. This level is usually between 1-300%.

The method according to the invention can be carried out in various ways. In the first embodiment, the aqueous medium is extracted in batches. In another embodiment, the aqueous medium is continuously extracted. In general, extraction techniques are well known. Some of them are mentioned below for the sake of clarity. For example, the extraction can be performed in a tank equipped with a stirrer. Due to the azeotropic properties of the solvent, the extraction can be performed in a Soxhlet or similar apparatus at the maximum temperature allowed by the solvent. Many modifications are possible, including recycling of the azeotropic mixture or cascade extraction in a tank series.

The aromatic constituents can also be extracted continuously, for example by circulating two liquids countercurrently.

In cases where the extraction is carried out in a tank, relatively stable emulsions may form, especially if the aqueous medium containing the aromatic coffee ingredients also contains solids. In this case, simply cooling the emulsion and then returning it to the initial temperature is usually sufficient to break the emulsion.

In addition, it has been found that the amount of azeotropic mixture used, as measured by the ratio of the mixture to the aqueous medium, is not a determining factor.

Thus, it is desirable to use as small amounts as possible, but at the same time ensure proper extraction of the aromatic ingredients of the coffee. These amounts (by volume) are of the order of 0.3 to 3 times the volume of aqueous medium to be treated in each extraction.

As for the concentration of the aromatic fractions, it can be carried out by any known method which does not denature them, in particular by distilling off the solvent, since the solvent is an azeotropic mixture with a low boiling point. In addition, since the distillation is carried out at a constant temperature and the solvent composition is constant, the degree of concentration of the aromatic fraction is no longer a critical factor. In practice, it has been found that the aromatic fraction can be concentrated without damaging it to a residual solvent content of about 5%.

In a preferred embodiment of the process of the invention, the azeotropic mixture is extracted with an aqueous medium obtained by stripping 1-300% ground roasted Colombian "arabica" coffee or a mixture of Colombian, Cameroonian and Mexican "arabica" coffee and even nikar a blend of Angolan "robusta" coffee. For this purpose, the extraction is carried out batchwise in tanks and in three or four stages using an azeotropic mixture in a total volume corresponding to about 1.5 times the volume of the aqueous medium. The extraction is carried out at atmospheric pressure and at a temperature of about 20 ° C. The aromatic fraction contained in the azeotropic mixture is then concentrated by distilling the azeotropic mixture at atmospheric pressure so that the initial volume is reduced by about 40-50 times. The recovered concentrated aromatic fraction then contains about 10% of the remaining azeotropic mixture.

It has already been mentioned above that, in addition to its coffee aroma, the aromatic fraction obtained by the process has exceptional stability. For example, a methylene chloride extract of a stripped coffee aroma, concentrated to leave only about 20% solvent, remains only a few days at -20 ° C and only a few days longer at -80 ° C, an otherwise comparable extract obtained from pentane and with an azeotropic mixture of methylene chloride, is stable for at least one year at -20 ° C. This stability can be accurately demonstrated by chromatographic analyzes of the gas phase.

The degree of concentration of the aromatic fraction does not appear to have any effect on its stability. For this reason, most of the azeotropic mixture is usually removed by distillation.

The organoleptic quality of the aromatic fractions obtained by the process of the invention is significant, although it is affected by the concentration of the aqueous medium extracted with the azeotropic mixture. In the case of a medium consisting of condensate obtained by steam stripping of ground and roasted coffee, the quality has been found to be at its best at 58857 with stripping levels of 100-150%, i.e. in cases where ground coffee has been treated with 1-1.5 times the amount of steam by weight.

The aromatic fraction thus prepared, concentrated or otherwise prepared can be used as a flavoring agent either to impart a coffee flavor to a substance without such a flavor or to reinforce an existing coffee flavor.

In the first application, called ab initio aromatization, the amounts of aromatic fraction added to the substance to be flavored depend on the nature of that substance. If this substance is aromatically neutral, the addition rates may be 0.5-12 ° / 0o (per thousand) based on the weight of the aromatic fraction (without residual solvent) based on the dry weight of the substance to be treated. Thus, it is possible to flavor, for example, milk, low-aroma coffee powders, creams, ice cream, chewing gums, etc. If this substance has an existing flavor, the addition amounts must be determined on a case-by-case basis. In general, relatively larger amounts must be used to supplement an existing flavor, although in some cases relatively smaller amounts may be sufficient due to the synergistic effect.

In another application, i.e. when it comes to strengthening an existing coffee aroma, the aromatic fraction is added in much smaller amounts, usually between 1/5 and 1/20 of the amounts required for ab initio aromatization. For example, in order to enhance or emphasize the aroma of medium quality instant coffee, it is sufficient to add an aromatic fraction of 0.1-0.6 ° / oo.

In a variation of these two applications, the aromatic fraction is attached to an "aroma carrier", for example a salt or a polysaccharide-based substance, by any known method. This attached aromatic fraction is used for aromatics.

Finally, in order to aromatize solid coffees or to strengthen their coffee aromas, it is possible, for example, to add an aromatic fraction either directly to the coffee brew extract, to instant coffee powder or to reconstituted instant coffee, or indirectly, i.e. after attaching the aromatic fraction to the coffee oil.

58857

It is recommended to use a concentrated aromatic fraction with very little residual solvent, in which case no special means are required to remove the remaining solvent from the final product. In this context, it should be noted that the flavored substance does not have any solvent taste even at higher levels of flavoring than defined above.

In a preferred embodiment, the aromatic fraction prepared by the process of the invention is added directly after concentration to a residual solvent content of about 10%, to solid coffees 0.35-1 ° / oo (as a reinforcing agent) and 3.5-10 ° / oo in the case of sparse -aromatic solid coffees.

The following examples illustrate the process of the invention and the use of the aromatic fraction prepared by this process. In these examples, percentages and ratios are by weight.

Example 1

A series of aromatic brews are made from Colombian "arabica" coffee by separately suspending 100 g of samples of this coffee ground and roasted at about 165 ° C with a weight loss of the order of 18%. These suspensions are then stripped at different times. The amounts of condensation recovered are measured; the amounts are expressed as stripping levels by comparing these amounts with the amounts of coffee used as starting material. Each condensate is then treated as follows: Extract using an azeotropic mixture of 4 x 25 ml of pentane (68%) and methylene chloride (32%), combine the four organic phases, dry over anhydrous sodium sulphate and concentrate the azeotrope by distillation at 30 ° C. , that the concentration of the remaining solution is of the order of 10% as assessed by gas phase chromatography. The preparation parameter and the properties of the concentrated aromatic fractions thus obtained are shown in the following table, in which the vertical rows mean: 1. Stripping times in minutes 2. Amount of condensates recovered in grams = stripping level in percent 3. Volumes of concentrated aromatic fractions in milliliters 4. Minimum stability 8 587 8 587 5 6 months 11,100 1.9 1 year 14,150 2.3 1 year 17,200 2.5 6 months 20,250 2.8 6 months

The stability of the corresponding non-concentrated aromatic fractions is similar and, after concentration, they give concentrated fractions having the same properties.

Comparable results are further obtained from a blend containing 40% Colombian "aräbica®", 30% Kamamnila "arabica" and 30% Mexican "arabica" coffee, or from a blend containing 60% Nicaraguan "arabica" and 40% % English "r <ab» eta "coffee.

In addition, similar results are obtained for these types of coffee or coffee blends with different degrees of roasting.

Examples 2-5

The tests described in Example 1 are repeated using Colombian "arabica" coffee and other azeotropic blends.

The results obtained are shown in the following table, in which the numbers in columns 2 and 3 have the same meaning as in Example 1.

Example Azeotropic mixture and its Ρβ 2 3 2 Pentane 58% 100 1.9

Isopropyl chloride 42%, 30.5 ° C 150 2.3 3 Pentane 94% titer 100 1.6 Freon 113 6% J 150 2.0 4 Pentane 20% 32 ° 100 100 1.2

Diethyl ether 80% 150 1.6 5 Pentane 34.5% 100 2.0

Methylene chloride 3.5% 33 ° C 150 2.4 ether 62% 95857

In all cases, shelf life is greater than 6 months.

Example 6

Aromatic fractions of Colombian "arabica" coffee are prepared from soup extracts obtained by separately treating 100 g samples of this coffee with one liter of boiling water. After separating the precipitate, these soup extracts are treated in the same way as in Example 1 (steam stripping, 68% pentane extraction). ) and methylene chloride (32%) with an azeotropic mixture, etc.) The volumes of the concentrated aromatic fractions thus prepared are 1.6 ml (stripping level 100%) and 1.9 ml (stripping level 150%) with a minimum storage life οή 1 year.

Example 7

The procedures described in Example 6 are repeated using an azeotropic mixture of pentane (20%) and diethyl ether (80%) as the solvent. The volumes of aromatic fractions prepared are 1.2 ml (stripping level 100%) and 1.6 ml (stripping level 150%). They last for at least 6 months.

Example 8 60 kg of Colombian "arabicaC" coffee, ground and previously roasted at 165 ° C with a weight loss of the order of 18%, is treated for 18 minutes with 300 kg of steam superheated at 185 ° C.

After 100 kg of condensate have been removed, 196 kg of extract with a dry matter content of the order of 11% are obtained. This extract is then steam stripped for about 10 minutes until 9 kg of condensate is recovered, corresponding to a stripping level of 15%. The procedure is then continued in the same manner as in Example 1, using an azeotropic mixture of pentane (68%) and methylene chloride (32%) as solvent.

The aromatic fraction (90 ml) obtained after concentration to a residual solvent content of about 10% is very stable and remains intact for at least 6 months.

The results are similar when the aromatic fraction is prepared using pentane (58%) / isopropyl chloride (42%) as the azeotrope. Example 9 60 kg of Colombian "arabica" coffee, ground and previously roasted at 165 ° C to a weight loss of the order of 18%, is moistened with steam superheated to 185 ° C, after which this moistened coffee is steam-stripped to a stripping level of about 4 %. The vapors are condensed by passing them through two successive condensers, the first of which is cooled with lukewarm water (30 ° C) and the second with cold water (10 ° C). This gives 1.2 liters of "cold" condensate. The process is then continued in the same manner as in Example 1 using an azeotropic mixture of pentane (68%) and methylene chloride (32%) as solvent.

The aromatic fraction obtained by concentrating the residual solvent to a concentration of 10% is very stable. It will remain unchanged for at least 6 months.

Example 10

The neutral base powder is prepared as follows:

A mixture of three "arabica, Lkahafa species (Colombian 40%, Cameroonian 30% and Mexican 30%) and ground and previously roasted at 165 ° C to a weight loss of the order of 18% is extracted in the same manner as in Example 8.

The extract thus obtained is then stripped with steam to remove its aroma. Finally, the de-aromatized extract is spray-dried to the desired neutral base powder.

3 15 g samples of this powder are then removed and 50 μΐ (i.e. about 3,5 ° / oo), 100 [mu] (7 ° / oo) and 150 [mu] (10 ° / oo) of aromatic fraction with a stripping level of is 100%, obtained according to Example 1 (pentane / methylene chloride) Three types of instant coffee are then made by dissolving each of these flavored powders in one liter of hot water, and a panel of 8 experienced tasters is asked which coffee they prefer. a sample flavored at 7 ° / oo is considered to be equilibrated, followed by a sample flavored at 10 ° / oo and then a sample flavored at 11 58857 flavored at 3.5 ° / oo. described as having a very representative aroma and no solvent aftertaste.

Additional instant coffee types are then prepared using a neutral base powder flavored with 7 ° / oo of the aromatic fractions of Example 1 with different levels of stripping (50, 150, 200 and 250%). The tasters' review was as follows: 50% aroma fresh, slightly pyrazine 150% and 100%, balanced 200% aroma "burnt", too heavy 250% same as 200%, "burnt", too heavy

The results are similar when lyophilized powder is used as the neutral base powder.

Examples 11-13

The procedure described in Example 10 is repeated using the aromatic fractions of Examples 6-8. The results obtained are shown in the following table:

Flavoring Pre-

Examples Aromatic fraction used, ° / o rents 11 6 3,5 3 (pentane / methylene chloride) 7 1 10 2 12 7 3,5 3 (pentane / diethyl ether) 7 2 10 1 13 8 3,5 2 (pentane / methylene chloride) 7 L and pantane / isopropyl chloride

Example 14

From a mixture of 40% Brazilian "Santos" coffee, 30% Colombian "arabica" coffee and 30% Salvadoran "arabica" coffee, 12 5 88 5 7 is prepared into a soup extract with a concentration of about 50 g / l. the extract is fortified by the addition of 0.7 ° / oo (based on dry matter) of the aromatic fraction of Example 1 with a stripping level of 100%, and the tasting extract thus obtained has better organoleptic properties than the untreated coffee extract used as starting material and has a very strong aroma.

Example 15 300 ul (i.e. 2.5 ° / oo) of the aromatic fraction according to Example 1 with a stripping level of 100% is added to one liter of normal commercial pasteurized milk with a dry matter content of the order of 12%. The beverage thus obtained has a sour taste, but nevertheless the taste is very similar to that of a coffee containing milk without being similar in appearance.

Example 16

Cream is made using 3.5% flour, 13% fine sugar, 2.5% caramel, 0.02% vanillin and about 80% pasteurized milk. After cooking, 0.1% of the aromatic fraction according to Example 1 (stripping level 100%) is added. This cream is a very pleasant coffee-tasting cream.

Example 17

Ice cream is made using 12% fresh cream containing 35% fat, 7% egg yolk, 12% sucrose, 3.5% 80% glucose syrup, 3.5% invert sugar (glucose and fructose), 14% caramel and 48% whole milk. Prior to freezing, 0.1 ° / oo of the aromatic fraction according to Example 1 (stripping level 100%) is added. Tasters appreciated this coffee-flavored ice cream very highly.

Claims (3)

5 8 8 5 7 A process for isolating a coffee aroma fraction, wherein the coffee aroma components are extracted from an aqueous medium as a water-insoluble organic solvent and the aroma fraction is recovered from the solvent, characterized in that the organic solvent is an azeotropic mixture having a boiling point below or below 50 ° C at or below normal pressure. one non-aromatic hydrocarbon having from U to 7 carbon atoms, and h) at least one of methylene chloride, ethylene chloride, isopropyl chloride, chloroform, dichlorodifluoromethane, trichlorofluoromethane and trichlorotrifluoroethane, and / or c) diethyl ether, ethyl diethyl ether, isopropyl ether or furan. Process according to Claim 1, characterized in that the azeotropic mixture is one of the following azeotropic mixtures: pentane / methylene chloride 66: 32% pentane / isopropyl chloride 58: k2% pentane / freon 113 (trichlorotrifluoroethane) 9: 6% pentane / diethyl ether 20: 80% pentane / methylene chloride / diethyl ether 3 ^, 5: 3.5: 62% Process according to Claim 1 or 2, characterized in that the extraction is carried out at a temperature of 20 to 30 ° C. Process according to Claim 1 or 2, characterized in that the extraction is carried out at the boiling point of the azeotropic mixture used.