JPH02104242A - Method for preventing deterioration of coffee flavor - Google Patents

Abstract

PURPOSE:To prevent the deterioration of a coffee flavor to stably retain the excellent coffee flavor for a long period by utilizing a specific fraction obtained by treating an aqueous solvent extract of a roasted coffee with an ultrafiltration membrane. CONSTITUTION:Coffee beans are roasted, ground and subsequently extracted with hot water or a water-containing water-miscible organic solvent (e.g., water- containing methanol). The obtained aqueous solvent extract of the roasted coffee is treated with an ultrafiltration membrane having a fractionation mol.wt. of approximately 6000 and a non-passed fraction having fractionation mol.wts. of >=6000 is collected. The obtained fraction having a flavor deterioration- preventing effect is added to a coffee extract prepared from a roasted coffee, mixed coffee flavors, coffee-flavored beverages compounded with the flavors, etc., to prevent the deterioration of the coffee flavors.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is directed to the use of a coffee extract, a recovered volatile aroma component of coffee, etc., which has a favorable aroma characteristic to roasted coffee.
For more information on a method for preventing coffee flavor deterioration that can stably maintain flavor and effectively prevent flavor changes over time due to oxygen, heat, light, etc.
This invention relates to a method for preventing deterioration of coffee flavor, which comprises blending as an active ingredient an aqueous solvent extract of roasted coffee that has a molecular weight cut off of about 6,000 or more and is obtained by treating an aqueous solvent extract of roasted coffee with an ultrafiltration membrane.

(Prior art and its problems) Volatile aroma components, which are the main components of the seven levers of roasted coffee, are extremely unstable substances, and it is necessary to extract them without changing them or to prevent them from changing during storage. is extremely difficult.

Conventionally, to prevent flavor deterioration, for example, tocopherols, flavone derivatives, phylloglutins, kojic acid, cryolic acid derivatives, catechin and its esters, nordihydroguaiaretic acid, gossypol, sesamol, guaiacol, Guaiac oil, spices and their extracts, herbal medicines and their extracts, fermented soybean products, etc. have been used, but these antioxidants have no antioxidant effect on oils and fats as far as preventing flavor deterioration. There was no significant anti-deterioration effect and the results were not satisfactory.

Coffee volatile aroma present in roasted coffee 4'IC
The components are extremely unstable and deteriorate in a very short time, especially in aqueous liquids, and no effective preventive measures have yet been established.

(Another Means to Solve the Problem) The present inventors have proposed a method of condensing in advance the volatile coffee flavor component-containing gas phase that has been previously released into the roasted coffee grounds through water vapor and/or inert gas. However, we proposed a method for producing coffee flavor that involves introducing and trapping sugar amino reaction products and/or caramel in a solution in the acidic range of pH 5 or less (Japanese Patent Application Laid-open No. 109133/1982), but research continued. As a result, we discovered that a specific fraction with a relatively large molecular weight in the aqueous extract of roasted and ground coffee surprisingly prevents flavor deterioration in coffee, and completed the present invention.

It is well known that green coffee beans contain antioxidant substances such as caffeic acid, chlorogenic acid, 7-erulic acid, and p-coumaric acid. Specification No. 3663581, British Patent No. 1275129 and JP-A-62-269
It is disclosed in the specification of No. 642, etc. There are also proposals to use caffeic acid, chlorogenic acid, ferulic acid, etc. to prevent fading of paprika pigments and anthocyanic pigments (Japanese Patent Laid-Open No. 117566/1983; Japanese Patent Laid-Open No. 58-6
5761).

The present inventors fractionated the extract of roasted and ground coffee using an ultrafiltration membrane and examined each fraction in detail. Surprisingly, it was discovered that both fractions with a molecular weight cutoff of about 6,000 or more have an extremely strong flavor deterioration preventing effect, rather than the low molecular weight fraction.

It is known to use ultrafiltration membranes or reverse osmosis membranes to concentrate coffee extracts or to remove precipitates and foaming substances from coffee extracts. However, it is not known to ultrafiltrate coffee extract and utilize both of its specific molecular weight components to prevent deterioration of coffee flavor.

In the present invention, coffee flavor refers to, for example, (a) volatile coffee aroma components and their concentrates released from roasted and ground coffee through steam and/or inert gas; (b) roasted and ground coffee; It also includes water and/or organic solvent extracts; (c) blended coffee flavor combinations; mixtures of (a) to (c), and foods and drinks containing these coffee flavors.

Further, the specific fraction of coffee extract that can be used for preventing flavor deterioration according to the present invention can be obtained from an extract obtained by extracting roasted and ground coffee beans, which are usually used for drinking, with an aqueous solvent. .

As such coffee beans, any type of coffee beans such as Arabica and Robusta can be used.

These coffee beans are roasted to about 200 to about 250 by a conventional method.
Although roasting is performed at °C, the degree of roasting is not particularly limited. Further, roasted coffee beans can be used by pulverizing them as they are, but they can also be used as a residue from which volatile aroma components have been recovered in advance by steam distillation or inert gas, and this residue can also be used in the present invention. Included in roasted and ground coffee.

In the extraction process, roasted and ground coffee is generally extracted using hot water, but if desired, a water-containing water-miscible organic solvent such as methanol, ethanol, 2-
Water-containing water-miscible organic solvents such as globanol, acetone, methyl ethyl ketone, etc. can also be used. These hot water or water-containing water-miscible organic solvents are usually used in an amount of about 2 to about 50 parts by weight per 1 part by weight of roasted and ground coffee, and extraction is carried out at a temperature of about 20 to about 95°C.

The extraction operation can be carried out either batchwise or continuously using a column.

The flavor of the present invention is produced by treating the obtained roasted coffee water or water-miscible water-containing organic solvent extract with an ultrafiltration membrane with a molecular fraction of about 6,000, and fractionating and collecting the remaining portion. A fraction with anti-deterioration effect can be obtained.

Fractions with a molecular weight cut off of about 6,000 or less have almost no effect of preventing flavor deterioration according to the present invention, and have no practical value.

Examples of the ultrafiltration membrane that can be used in the present invention include synthetic polymer porous membranes such as cellulose acetate, polyvinylidene fluoride, polyacrylonitrile polymer, polysulfone, polycarbonate, and polyolefin. As long as the membrane has a molecular weight of about 6000, any type of ultrafiltration membrane module can be used, such as a flat membrane, hollow fiber, plate, tube, or spiral wound. The ultrafiltration process may be either a pressure filtration method or a negative pressure filtration method, and any one of a one-pass type, a multi-stage filtration type, and a circulation type can be adopted.

The filtrate obtained by filtration through an ultrafiltration membrane with a molecular weight cut off of 6000 can be used as it is as a clear coffee extract or as a raw material for collecting coffee bitter components, if desired.

The fraction with a molecular weight cut-off of about 6,000 or more obtained by the ultrafiltration membrane treatment as described above can be used as is for the purpose of preventing flavor deterioration in the present invention, but generally, diatomaceous earth, cellulose, etc. The obtained filtrate is further concentrated to a refractive sugar content of about 60 to about 75 degrees by a conventional concentration method such as vacuum concentration.
;something is used.

The amount of the coffee flavor deterioration inhibitor of the present invention can be arbitrarily selected depending on the concentration or type of aroma components in the coffee flavor, but is generally about 5 to 50%.
Examples include about 50% by weight, preferably about 20 to about 30% by weight.

Aspects of the present invention will be explained in more detail below using production examples, comparative examples, and examples.

(Example) Production Example 1 The steam distillation residue of roasted and ground coffee was extracted with hot water at 90'C by a continuous column extraction method to obtain coffee extract [Bx(
refractive sugar content) 11.3°] was prepared.

An ultrafiltration module with a molecular weight cutoff of 6000 (SP-
1010: manufactured by Asahi Kasei Co., Ltd.) at a pressure of approximately 2 kg/cm"
1,472 g of a pass-through liquid (Bx 7.5°) and 3.2 bg of a non-passage liquid (Bx 16°) were obtained. Next, the obtained unfiltered liquid was suction filtered using KC Flock (manufactured by Sanyo Kokusaku Pulp Co., Ltd.) as a filter aid to obtain a filtrate of 3.0J29. This filtrate was concentrated under reduced pressure to obtain 650 g of a flavor deterioration preventing fraction having Bx 73° (concentrate A).

Comparative Example 1 The ultrafiltration membrane-passing liquid (Bx 7.5°) with a molecular weight cutoff of 6000 obtained in Production Example 1 was concentrated under reduced pressure to prepare a concentrated liquid with Bx 73° (Concentrate B).

Comparative Example 2 The coffee extract obtained in Production Example 1 was directly concentrated under reduced pressure without membrane treatment to prepare a concentrated liquid with Bx73° (Concentrate C).

Example 1 Roasted and ground coffee (Colombia Excelso) 1000g
was steam-distilled using a conventional method, and 180 g of distillate was collected. The obtained distillate was immediately mixed with the concentrates A-C obtained in Production Example 11 Comparative Example 1 and Comparative Example 2, commercially available caramel (Bx75°), and water as a control in the following proportions, and the mixture was mixed with water as a control. This was used as a test sample.

■Mixing ratio (wt%) - 1 week, 2 weeks, 3 weeks, and 1 month at 30℃, 5℃, and 25℃. The degree of deterioration was sensory evaluated by a two-point comparison method using the prepared distillate as a standard.

As a result, rankings were made in descending order of flavor deterioration under each storage condition, and the results were as follows after 1 week to 12 weeks, 3 weeks, and 1 month.

-30°O: #l>#4>#2>#3>#55°C
: #1>#4>12>#3>#525°O: #
1>#4>#2>#3>#5 As is clear from the above results, sample #1 (product of the present invention) to which concentrate A was added showed an excellent deterioration prevention effect under any storage conditions, It was significantly superior to #4 in which caramel, which is one of the effective ingredients for preventing flavor deterioration, was added as described in JP-A-59-109133.

A slight effect was also observed in Sample #2 to which Concentrate C, which is simply concentrated coffee extract, was added, but there was no practical effect. Control sample #5, in which only water was added, showed significant aroma deterioration under all storage conditions and lost its commercial value.

Production Example 2 Strongly roasted and ground Robusta coffee is extracted by column extraction method to obtain 90%
Hot water extraction at °C, Bx, 11.3° extract 2'5k
g'G: Obtained. This coffee extract has a molecular weight cutoff of 20,
000 ultrafiltration module NTU3520: (membrane surface seed port 76-rrf; Nitto Denko) at a pressure of 5 kl? /C
- to obtain 26.8 kg (Bx, 7.0°) of the passthrough and 6.5 kg (Bx, 12.0°) of the retentate.

Then, the obtained unfiltered liquid was concentrated under reduced pressure to obtain 1 kg of a flavor deterioration prevention fraction with a Br of 1 x 70 degrees (a Silk D).

Comparative Example 3 Fractionated molecules obtained in Production Example 2! A part of the 20,000 ultrafiltration membrane-passing liquid (B x, 7.0°) was concentrated under reduced pressure, and
x.

A 70° concentrate was prepared (a Silk E).

Comparative Example 4 Coffee extract (Bx) obtained in Production Example 2 before ultrafiltration
, 11.3°) was concentrated under reduced pressure to prepare a concentrate of Bx, 70° (Concentrate F).

Example 2 Continuous extraction column with jacket (glass: u4cm x 20
0+1) were connected in series, and 100 g of strongly roasted and ground Robusta coffee was charged into each.

A condenser and a trap (absorption tower) are installed at the exit of the extraction tower at the fourth grain, and in the trap, 40% of the flavor deterioration prevention fraction concentrate (!Silk D) obtained in Production Example 2 is installed.
filled g.

Next, the column jacket was maintained with heated steam, nitrogen gas was passed through the lower part of the first column at a flow rate of 500 min/min for 1 hour, and the column was cooled to below 10°C through a cooler at the lower outlet of the fourth column. The volatile aroma component-containing nitrogen gas and the condensate are introduced to the bottom of the trap and bubbled, and the volatile aroma components are absorbed and collected by the condensate trap to obtain coffee flavor (A).

Comparative Example 5 In Example 2, concentrate E4 of Comparative Example 3 was placed in the trap.
0g was processed under the same conditions except for @f: and coffee flavor (B) t: obtained.

Comparative Example 6 In Example 2, the concentrate F4 of Comparative Example 4 was placed in the trap.
All treatments were performed under the same conditions except that 0g was met.
Coffee flavor (C) was obtained.

Comparative Example 7 Coffee flavor (D) was obtained by carrying out the same process as in Example 2 except that 40 g of commercially available caramel (Caramel C-13ONT: Ikeda Toka) was filled in the trap.

[Storage Test 1 The coffee flavors (A) to (D) obtained in Example 2 and Comparative Examples 5 to 7 were stored at 25°C, 5°C and -25°C.
I stored it for a while.

[Storage test results] A well-trained panel of 20 people tested freshly prepared I
; 1 by two-point comparison method using each condensate as standard.
The degree of flavor deterioration after storage for several months was sensory evaluated.

As a result, the following rankings were made in descending order of flavor deterioration under each storage condition:

(Left below) -30°O: A > D > C > 85°C:
A > D > C > B 25°O: A > D > C > B As is clear from the above results, the coffee flavor of Example 2 (A ) exhibited an excellent deterioration prevention effect under any storage conditions, and the coffee flavor of Comparative Example 7 was collected using caramel, which is one of the effective ingredients for preventing flavor deterioration described in JP-A-59-109133. Even when compared with (D), it was significantly superior.

Comparative example 5 collected using concentrated liquid E of the liquid passing through the ultrafiltration membrane
Although a slight effect was observed in the coffee flavor (B) of Comparative Example 6 and the coffee flavor (C) of Comparative Example 6 in which concentrate F, which was obtained by concentrating the coffee extract as it was, was added, there was no practical effect.

(Effects of the Invention) According to the method of the present invention, volatile aroma components of coffee, coffee extracts, blended coffee flavor compositions, etc., are released into roasted coffee through steam and/or inert gas. Flavors and coffee-flavored food and beverages containing these coffee flavors,
By blending as an active ingredient a fraction with a molecular weight cut-off of approximately 6,000 or more, which is obtained by treating an aqueous solvent extract of roasted coffee with an ultrafiltration membrane, we have created a delicious coffee with excellent palatability unique to roasted coffee. Coffee flavor can be stably maintained for a long period of time.

Further, the above-mentioned components having a molecular weight cut off of about 6,000 or more used in the present invention can be added to foods and drinks other than coffee, such as chocolate, cocoa, beer, miso, soy sauce, and delicatessens, as desired. It can also be used as a flavor deterioration inhibitor for food and drink products.

Patent applicant: Hasegawa Fragrance Co., Ltd.

Claims (1)

[Claims] A method for preventing deterioration of coffee flavor, which comprises blending as an active ingredient a fraction having a molecular weight cut off of about 6,000 or more, which is obtained by treating an aqueous solvent extract of roasted coffee with an ultrafiltration membrane.