DD291919A5 - PROCESS FOR THE QUALITY IMPROVEMENT OF ROASTED BEAN COFFEE AND EXTRACTS OBTAINED THEREFROM - Google Patents

Abstract

The subject matter of the process according to the invention is the quality improvement of roasted coffee beans and extractives obtained therefrom. It is about the refinement of less high-quality coffees in terms of sensory and bekokemmlichkeit. Pre-shredded and roasted coffee beans are subjected to mechanolytic treatment by vibratory grinding with the addition of small amounts of quality regulators. The additives are preferably hydrothermally digested and shelled legume seeds. Coffee extract; mechanolytic comminution; Robusta coffee finishing; Quality improvement}

Description

Field of application of the invention

The invention relates to a process for improving the quality of roasted coffee beans and extractives obtained therefrom. Preferred field of application of the invention is the refinement of less high-quality coffees with regard to sensory characteristics and their salubriousness.

Characteristic of the known state of the art

The patent as well as scientific literature contains numerous information on new procedural principles of upgrading the quality of coffee beans, on the one hand the refinement of inferior varieties, on the other hand the sensory improvement of such products, which result in modern technologies of short-term roasting. In addition, a wide range of rooms adopt variants that intend to decaffeinize or eliminate irritants. The first problem described include, for example, the patents üE-OS 3130346 and DD-PS 264142, after which an aroma intensification or a shift of the aroma profile by wet or dry mechanical micro-crushing on particle sizes <100 μιτι, followed by fractionation by air classification and / or extraction. The ground substance thus obtained is the basis for the production of Turkish coffee or cappuccino drinks. Other related patent applications relate to the treatment of coffee with specific additives such as carbohydrates, mineral salts or edible acids.

The latter solutions are based i.a. on a binding of caffeine or phenolic acid to certain additives, such as chitosans or caffeic acid with formation of insoluble complexes., Which are separated separatively in the production of instant coffee.

Object of the invention

The aim of the invention is to develop an economical method for improving the quality of roasted coffee, preferably from less high-quality Robusta varieties. The invention is therefore the object of demonstrating process conditions of an effective treatment of roasted coffee beans with a one-sided flavor profile and high caffeine content in terms of flavor harmonization and / or intensification while increasing the general digestibility and digestive compatibility.

Explanation of the essence of the invention

According to the invention, the sensory and physiological quality improvement of coffee beans and extracted therefrom extracts, preferably from less high-quality Robusta varieties, by mechanolytic treatment, preferably vibratory grinding, over 0.5 to 5h, preferably 1 to 2h, of roasted pre-crushed coffee beans to particle size of 100 to 400μιη, preferably 150 to 250μ, with the addition of quality regulators in the form of legume seeds, preferably hydrothermally digested and shelled, optionally also partially defatted field beans and soybeans in amounts of 2 to 20, preferably 5 to 10%.

Surprisingly, as has been found, such a treatment not only leads to an intensification, but also to a harmonization of the sensory overall impression in the direction of an emphasis on the quality parameter "fine acid" at the expense of the undesirable "dull acid", and in addition a weakening of the bitter note is characteristic , The extent of the displacement of the flavor profile due to an opposite release and binding quality-determining components depends both on the grinding and roasting conditions of the raw materials, as well as the type and concentration of the additives.

As has also been found, the treatment according to the invention also allows a more or less marked reduction in the content of caffeine and free phenolic acids by forming insoluble complexes with the biopolymer matrix, thereby achieving a further increase in salubriousness.

Process variants within the scope of the invention, which allow additional quality control, concern the joint or separate roasting of the raw materials and additives in a uniform or different Röstregime, the inventive solution, the gentle isolation and concentration of aqueous extractives from the roasted mechanolytisch raw materials and additives includes.

Finally, it has been found that the solution according to the invention can also be applied to quality-reduced Arabica varieties with low flavor intensity and / or on one side in the flavor profile, so that their field of application is not limited to Robusta varieties.

The invention will be explained in more detail by means of embodiments which include four tables for examination.

Implementation Example a

example 1

According to the Kurzzeittrommelröstverfahren roasted coffee beans (Coffea canephora, Provenance Laos) after Vorzerkleinerung (cross-beater mill) together with peeled, likewise separately roasted (4min at 24O ⁰ C), pre-shredded (beater mill) field beans (mixture of 90 parts pre-crushed coffee beans and 10 parts pre-shredded field beans) in a vibrating mill "Vibrüiiom ,, (Siebtechnik GmbH, Mühheim / Rohr) at a filling ratio (weight ratio between grinding stock and grinding media) of 3%, inert filling ratio (ratio between bulk volume of the balls and the total volume of the grinding container) of 70% at an amplitude of 2.0 mm and an angular velocity of 1420 rpm in the presence of 10 mm diameter porcelain balls a) 0.5 h; b) 1 h; c) 2h; d) 5H; e) 10h; f) treated for 20h (mechanolysed).

Each of a portion of the resulting mixtures are prepared by pouring boiling water (according to recipe 6.5 g of mixture and 150ml of water) coffee drinks and using a üblicherwei? Prepared coffee sample (standard) of the same batch of roast (after crushing the roasted coffee beans in a beater mill by pouring boiling water according to specified recipe) assessed comparatively sensory. In addition, the dry mechanolyzed samples were analyzed with regard to their comminution spectrum as well as the caffeine content.

Result Difference to the deviation " default a) Sensory evaluation (difference test) -Table 1 - yes + Mechanolysezeit yes + (Hours) Yes 0.5 Yes 1.0 Yes 2.0 Yes 5.0 10.0 20.0 1 + = improvement. - = deterioration.

By a short-term mechanolysis (0.5 and 1.0 hour) of a mixture of previously separately roasted and pre-shredded coffee beans and field beans carried out under the conditions described results in an improvement of the sensory Ggsamteindrucks of the prepared coffee beverage. There is a harmonization of the "Sauer" note, which leads to a characteristic for highland varieties of "fine" caffeic acid. At the same time, a significant reduction in the "metallic" bitter taste is achieved, and with extension of the mechanolysis time (2.5 and 10 hours) of the mixture, a further change in the quality of the drinks made therefrom is noted, but in an increasing "emptiness" or "flatness" of the beverage Coffee aromas expresses.

b) Grinding spectrum-Tabello2 particle size distribution as a function of the mechanolysis time

Mechanolysis time Particle size distribution (%)

(h)> 1000pm <1000pm <630pm <500pm <400pm <200pm <125pm <100μηι <50μηι

Control" 3.7 7.4 18.5 11.1 48.1 11.1 - - 0.5 13.8 1.7 6.9 8.6 55.2 13.8 - - 5.0 11.5 1.8 6.7 2.4 46.7 21.8 3.6 3.6 10.0 5.5 2.8 2.8 5.5 19.4 36.1 16.7 11.1 20.0 2.6 5.1 3.2 54.6 2.3 29.1

1 Crushed in a beater mill.

control Mechanolysezeit " 5 10 20 -3- 291919 10 c) Caffeine Content Table 3- (Hours) 0.5 3 · 4 29.8 30.2 Mechanolysis time ²¹ 24.5 (Hours) 29.6 28.3 4.2 4.6 • 4.4 0.5 4.6 Total extractives 1.3 1.4 1.3 1.1 (% I.t.) 6.0 4.9 25.2 Caffeine (% i. T.) 1.8 1.4 70.4 76.6 72.6 76.6 in the extract 74.6 76.8 74.6 4.6 63.8 total· 100 81.1 1.1 caffeine reduction 100 78.0 extract reference 73.9 raw material supply 61.6

1 roasted, pre-shredded coffee sample (standard) mechanolyysed without additives.

2 Roasted mixture (90 parts pre-shredded coffee bean and 10 parts pre-shredded field bean) mechanolyised.

Example 2

A mixture of 90 parts of coffee beans and 10 parts peeled, defatted soybeans is subjected to a roasting process (drum roasting, 3 min 22O ⁰ C), then pre-crushed (beater mill) and treated under the conditions given in Example 1 (mechanolysed).

The sensory examination of the resulting patterns in comparison to the standard in the opinion of the experts in turn results in a clear preference of short-time mechanolyzed (0.5 h, 1 h) samples.

The sensory characteristics of the prepared coffee beverages from this mixture are similar to those of Example 1. Here, too, a reduction of the caffeine content of the mixture is detectable by the mechanolysis of roasted, pre-shredded coffee beans in the presence of roasted, pre-shredded soybeans (Table 4).

Caffeine content - Table 4 -

control Mechanolysezeit 10 (Hours) 0.5 26.6 Total extractives (% I.t.) 29.6 26.3 4.3 Caffeine (% i. T.) 1.2 in the extract 6.0 4.3 total 1.8 1.1 caffeine reduction 72.1 (% rel.) 65.5 extract reference 100 70.8 raw material supply 100 63.3

Claims (4)

1. A process for improving the quality of roasted coffee beans and extracted therefrom, preferably the variety Robusta, characterized in that pre-shredded and roasted coffee beans of a mechanolytic treatment by vibratory grinding to particle sizes in the range of 100 to 400 μηη, preferably 150 to 250 μπι, with addition of quality regulators based on legume seeds, preferably hydrothermally digested and shelled, optionally also partially defatted field and soybeans, in quantities of 2 to 20%, preferably 5 to 10%. 2. The method according to claim 1, characterized in that the raw materials and additives are subjected to a common or separate roasting process. 3. The method according to claim 1 and 2, characterized in that the raw materials and additives are subjected to a different Röstregime. 4. The method according to claim 1 to 3, characterized in that extracted from the roasted and mechanolytically treated raw materials and additives by means of aqueous media extractives and concentrated by gentle drying.