阅读说明：本技术 使用温和高压快速制备冷萃咖啡的方法 (Method for rapidly preparing cold-extracted coffee by using mild high pressure ) 是由 劳菲 吴继红 廖小军 吴梦婷 高敏 蔡妍培 于 2021-07-26 设计创作，主要内容包括：本发明公开了一种使用温和高压快速制备冷萃咖啡的方法。该方法包括：(1)将咖啡豆进行研磨,得到咖啡粉；(2)将所述咖啡粉装入滤袋中,然后置于高压二氧化碳处理器中,加入水,进行高压二氧化碳处理,得到咖啡萃取液和咖啡渣；(3)取所述咖啡萃取液进行灌装,得到冷萃咖啡产品。该方法通过对咖啡粉进行高压二氧化碳处理,可以在促进咖啡风味物质有效溶出的同时,完成对产品的初步杀菌,实现“提取、护味、杀菌”三位一体；且可以在高度还原传统冷萃咖啡风味的基础上大大缩短加工时间,并保证咖啡提取得率。(The invention discloses a method for rapidly preparing cold-extracted coffee by using mild high pressure. The method comprises the following steps: (1) grinding coffee beans to obtain coffee powder; (2) filling the coffee powder into a filter bag, then placing the filter bag into a high-pressure carbon dioxide processor, adding water, and performing high-pressure carbon dioxide processing to obtain coffee extract and coffee grounds; (3) and filling the coffee extract to obtain a cold-extracted coffee product. The method can promote effective dissolution of coffee flavor substances and complete preliminary sterilization of the product by performing high-pressure carbon dioxide treatment on the coffee powder, thereby realizing three-in-one of extraction, flavor protection and sterilization; and the processing time can be greatly shortened on the basis of highly reducing the flavor of the traditional cold-extracted coffee, and the extraction yield of the coffee is ensured.)

1. A method for rapidly preparing cold-extracted coffee using mild high pressure, comprising:

(1) grinding coffee beans to obtain coffee powder;

(2) filling the coffee powder into a filter bag, then placing the filter bag into a high-pressure carbon dioxide processor, adding water, and performing high-pressure carbon dioxide processing to obtain coffee extract and coffee grounds;

(3) and filling the coffee extract to obtain a cold-extracted coffee product.

2. The method according to claim 1, wherein the coffee powder has a particle size of 30 to 60 mesh.

3. The method of claim 1, wherein step (1) is further followed by: the coffee powder was sieved using 30 and 60 mesh sieves.

4. The method of claim 1, wherein the filter bag is a 300 mesh filter bag.

5. The method according to claim 1, wherein the mass ratio of the coffee powder to the water is 1 (4-10).

6. The method according to claim 1, wherein in the high pressure carbon dioxide treatment, the carbon dioxide pressure is 5 to 20 MPa.

7. The method according to claim 1, wherein in the high-pressure carbon dioxide treatment, the treatment temperature is 4 to 35 ℃ and the treatment time is 20 to 60 min.

8. The method of claim 1, wherein step (2) is further followed by: washing the coffee grounds with water and combining the resulting wash water with the coffee extract for step (3).

9. The method of claim 1, wherein step (3) is preceded by the further step of: and filtering or centrifuging the coffee extract to clarify.

10. A cold-extracted coffee, characterized in that it is prepared by the method according to any one of claims 1 to 9.

Technical Field

The invention relates to the field of food science, in particular to a method for rapidly preparing cold-extracted coffee by using mild high pressure.

Background

Coffee is one of three major drinks in the world, contains rich chlorogenic acid, caffeine and other components, has the functions of refreshing, invigorating stomach, assisting excitement and the like due to special taste, occupies about one third of the population in the world, and is popular with consumers. Classic cold extract coffee making processes generally undergo long-term processing: after roasting and grinding the coffee beans, the aroma and taste of the roasted coffee powder are extracted after soaking in cold water or ice or dropping overnight. Before drinking, water, milk, syrup and the like can be added to prepare cold extract coffee drinks with different tastes.

Compared with the traditional hot-brewed coffee, the cold-extracted coffee has smoother and softer taste, less bitter taste and lower acidity, but the extraction time of the cold-extracted coffee is longer, and generally 3-24 hours are needed. The hot coffee has obvious efficiency advantage in extraction time, for example, the classic hand-brewed coffee or the hang-filtered coffee generally needs 3-5 min, and the extraction time of the Italian coffee (expresso) with the highest commercialization degree only needs 18-23 s. How to complete the cold extraction of coffee on the basis of no damage to the flavor of the cold-extracted coffee in a relatively short time becomes a technical problem to be solved urgently.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. To this end, it is an object of the present invention to propose a method for the rapid preparation of cold-extracted coffee using mild high pressure. The method can promote effective dissolution of coffee flavor substances and complete preliminary sterilization of the product by performing high-pressure carbon dioxide treatment on the coffee powder, thereby realizing three-in-one of extraction, flavor protection and sterilization; and the processing time can be greatly shortened on the basis of highly reducing the flavor of the traditional cold-extracted coffee, and the extraction yield of the coffee is ensured.

In one aspect of the invention, a method for rapidly preparing cold-extracted coffee using mild high pressure is presented. According to an embodiment of the invention, the method comprises: (1) grinding coffee beans to obtain coffee powder; (2) filling the coffee powder into a filter bag, then placing the filter bag into a high-pressure carbon dioxide processor, adding water, and performing high-pressure carbon dioxide processing to obtain coffee extract and coffee grounds; (3) and filling the coffee extract to obtain a cold-extracted coffee product.

According to the method for rapidly preparing cold-extracted coffee using mild high pressure according to the above embodiment of the present invention, after grinding coffee, the resulting coffee powder is subjected to High Pressure Carbon Dioxide (HPCD) treatment. On one hand, the high-pressure carbon dioxide can provide pressure auxiliary extraction, and coffee flavor components are pressed out of coffee by using pressure far greater than atmospheric pressure, so that the coffee flavor components are quickly dispersed in an extraction solution, and the extraction yield of the coffee is improved; on the other hand, the carbon dioxide has the function of adjusting the polarity of the extraction solution and can promote the coffee flavor substances to be quickly dissolved out, thereby greatly improving the extraction efficiency of the coffee at normal temperature. Meanwhile, the carbon dioxide can play a role in protecting the coffee flavor and inhibiting microorganisms in the extraction process, can protect the coffee flavor from oxidative deterioration and microbial pollution, and effectively guarantees the sensory quality and the safety quality of the cold-extracted coffee. In addition, the high-pressure carbon dioxide treatment of the invention can promote the coffee flavor substances to be effectively dissolved out, and simultaneously complete the primary sterilization of the product, thereby realizing the three-in-one of extraction, flavor protection and sterilization, and the obtained product can be directly filled into commercial circulation, and has higher treatment efficiency.

In addition, the method for rapidly preparing cold-extracted coffee using mild high pressure according to the above embodiment of the present invention may further have the following additional technical features:

in some embodiments of the invention, the coffee powder has a particle size of 30-60 mesh.

In some embodiments of the present invention, step (1) is followed by further comprising: the coffee powder was sieved using 30 and 60 mesh sieves.

In some embodiments of the invention, the filter bag is a 300 mesh filter bag.

In some embodiments of the invention, the mass ratio of the coffee powder to the water is 1 (4-10).

In some embodiments of the invention, in the high-pressure carbon dioxide treatment, the pressure of the carbon dioxide is 5-20 MPa.

In some embodiments of the invention, in the high-pressure carbon dioxide treatment, the treatment temperature is 4-35 ℃ and the treatment time is 20-60 min.

In some embodiments of the present invention, step (2) is followed by further comprising: washing the coffee grounds with water and combining the resulting wash water with the coffee extract for step (3).

In some embodiments of the present invention, step (3) is preceded by: and filtering or centrifuging the coffee extract to clarify.

In another aspect of the invention, the invention provides a cold-extracted coffee. According to the embodiment of the invention, the cold-extracted coffee is prepared by the method for quickly preparing the cold-extracted coffee by using the mild high pressure of the embodiment. Thus, the flavor of the cold-extracted coffee is equivalent to that of the traditional cold-extracted coffee, but the making efficiency is far higher than that of the traditional cold-extracted coffee.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a graph of high pressure carbon dioxide cold extract coffee extraction yield over time, according to one embodiment of the present invention.

Detailed Description

The following describes embodiments of the present invention in detail. The following examples are illustrative only and are not to be construed as limiting the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

In one aspect of the invention, a method for rapidly preparing cold-extracted coffee using mild high pressure is presented. The method for rapidly preparing cold-extracted coffee using mild high pressure according to an embodiment of the present invention is further described in detail below.

First, according to an embodiment of the present invention, coffee beans are ground to obtain coffee powder. In this step, coffee beans of a suitable roasting degree may be selected, and it is recommended to use arabica coffee beans of a medium roasting degree. The grinding can be carried out by using a grinding machine, and the grinding process needs to ensure that the grinding machine is clean and dry. In order to ensure the flavor of the coffee powder, the ground coffee powder needs to be extracted within 24 hours.

According to some embodiments of the invention, the ground coffee powder has a particle size of 30 to 60 mesh. By controlling the particle size of the coffee powder within the range, the cold-extracted coffee with soft flavor and full mouthfeel can be obtained. If the particle size of the coffee powder is too large, extension of extraction time and reduction of extraction efficiency may be caused because flavor extraction is incomplete; if the particle size of the coffee powder is too small, it may cause the coffee powder to adsorb other off-flavors to degrade the sensory quality of the finished product.

According to some embodiments of the invention, step (1) is followed by further comprising: the coffee powder was sieved using 30 and 60 mesh sieves. Specifically, the screen material of 30-mesh and 60-mesh screens can be taken for subsequent extraction. And (4) sealing and storing the screened coffee powder in a dark place. In order to improve the utilization rate of raw material beans, oversize materials can be ground and sieved again.

Further, according to an embodiment of the present invention, coffee powder is packed in a filter bag, and then placed in a high pressure carbon dioxide processor, water is added, and high pressure carbon dioxide processing is performed to obtain coffee extract and coffee grounds. Wherein, the coffee extract can be led out by a high-pressure carbon dioxide processor to realize the separation from the coffee grounds.

According to some embodiments of the present invention, the filter bag is a 300-mesh filter bag.

According to some embodiments of the invention, in the high-pressure carbon dioxide treatment, the mass ratio of the coffee powder to the water is 1 (4-10), such as 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, and the like. By controlling the amount of water within the above range, cold-extracted coffee with full flavor can be obtained. If the amount of water is too much, the flavor of the finished product is possibly weak; if the amount of water is too small, flavor extraction may be incomplete and raw materials may be wasted.

According to some embodiments of the invention, in the high pressure carbon dioxide treatment, the carbon dioxide pressure may be 5 to 20MPa, such as 5MPa, 10MPa, 15MPa, 20MPa, etc., preferably 5 to 6 MPa. Under the pressure condition, the accelerated extraction of the cold-extracted coffee can be finished, and the requirements and the cost of the method for extracting the cold-extracted coffee on equipment are far lower than those of a method for extracting the cold-extracted coffee by utilizing ultrahigh pressure (such as 300-500 MPa).

According to some embodiments of the present invention, in the high pressure carbon dioxide treatment, the treatment temperature may be 4 to 35 ℃ (e.g., 4 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, etc.), and the treatment time may be 20 to 60min (e.g., 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, 60min, etc., preferably 20 to 30 min). Thereby, accelerated extraction of cold-extracted coffee can be guaranteed to be accomplished under mild conditions.

According to some embodiments of the invention, the completion of the high pressure carbon dioxide treatment may further comprise: washing the coffee grounds with water, and combining the obtained washing water with the coffee extract for the subsequent filling step. Specifically, the coffee grounds may be washed several times (e.g., 2 to 3 times) with water having an extraction amount of about 1/3, and then the obtained washing water may be mixed with the coffee extract.

Further, according to an embodiment of the present invention, the coffee extract is filled to obtain a cold-extracted coffee product.

For cold-extracted coffee products with a desired clarity, according to some embodiments of the present invention, the coffee extract may be subjected to a filtration or centrifugation clarification process before filling, and the specific filtration or centrifugation clarification process conditions may be selected according to actual needs.

In another aspect of the invention, the invention provides a cold-extracted coffee. According to the embodiment of the invention, the cold-extracted coffee is prepared by the method for quickly preparing the cold-extracted coffee by using the mild high pressure of the embodiment. Thus, the flavor of the cold-extracted coffee is equivalent to that of the traditional cold-extracted coffee, but the making efficiency is far higher than that of the traditional cold-extracted coffee.

In addition, it should be noted that all the features and advantages described above for the method for rapidly preparing cold-extracted coffee using mild pressure and high pressure are also applicable to the cold-extracted coffee product, and are not described in detail herein.

The invention will now be described with reference to specific examples, which are intended to be illustrative only and not to be limiting in any way.

Example 1

Comparing the extraction yield of cold-extracted coffee extracted by the method (HPCD) of the invention with the extraction yield of cold-extracted coffee extracted by different traditional methods. The results are shown in Table 1.

TABLE 1 comparison of extraction yields of different methods for extracting cooled coffee

The results show that the HPCD method can achieve the same extraction yield as the traditional cold extraction method, but the extraction efficiency is far higher than that of the traditional cold extraction method. In addition, compared with ultrahigh pressure extraction, the method of the invention requires lower processing pressure and has higher coffee extraction yield.

Example 2

Compared with the flavor of cold-extracted coffee extracted by the traditional cold extraction method and the method (HPCD) of the invention. Through a sensory similarity test (GB/T12311-: there was no difference at the 90% confidence level, and only no more than 30% of panelists were able to identify the difference.

Volatile aroma substance analysis is carried out on cold-extracted coffee obtained by adopting a gas chromatography-mass spectrometry combined technology and adopting a method of the invention (HPCD treatment parameter is 25 ℃, 6MPa, 30min extraction)) and a traditional cold-extraction method (25 ℃, normal pressure, 8h extraction), and the flavor spectra of the cold-extracted coffee are basically similar, as shown in table 2, the concentrations of most flavor substances in the two extraction methods are very close.

TABLE 2 comparison of typical flavor volatiles content of conventional and HPCD cold-extracted coffee

Example 3

The influence of different high-pressure carbon dioxide treatment pressures on the extraction effect of cold-extracted coffee is researched.

(1) Grinding the roasted coffee beans to the granularity of 30 meshes, then filling the ground coffee beans into a 300-mesh filter bag, sealing the filter bag, putting the filter bag into a high-pressure carbon dioxide processor, adding drinking purified water with the weight 10 times that of the coffee powder, and closing the hatch door of the high-pressure carbon dioxide processor.

(2) Setting the temperature of the circulating water tank at 25 deg.C, extracting for 60min, respectively setting high pressure carbon dioxide extraction pressure at 5MPa, 10MPa, and 15MPa for coffee extraction, measuring soluble solid content of each group of samples with Abbe refractometer, and calculating extraction yield. Under the conditions of 25 ℃ and 60min, the extraction yields of 5MPa, 10MPa and 15MPa are respectively 24.6%, 24.6% and 25.3%, and analysis shows that the pressure has no significant influence on the extraction rate of coffee (p is greater than 0.05). Therefore, the accelerated extraction of the cold-extracted coffee can be finished by using a milder high pressure (5-15 MPa).

Example 4

The influence of different high-pressure carbon dioxide treatment temperatures on the extraction effect of cold-extracted coffee is researched.

(1) Grinding the roasted coffee beans to the granularity of 30 meshes, then filling the ground coffee beans into a 300-mesh filter bag, sealing the filter bag, putting the filter bag into a high-pressure carbon dioxide processor, adding drinking purified water with the weight 10 times that of the coffee powder, and closing the hatch door of the high-pressure carbon dioxide processor.

(2) Setting high pressure carbon dioxide extraction pressure at 6MPa, extracting time at 60min, respectively setting circulating water tank temperature at 15 deg.C, 25 deg.C, and 35 deg.C for coffee extraction, measuring soluble solid content of each group of samples with Abbe refractometer, and calculating extraction yield. Under the conditions of 6MPa and 60min, the extraction yields at the three temperatures of 15 ℃, 25 ℃ and 35 ℃ are respectively 25.0%, 25.3% and 25.3%, and analysis shows that the temperature has no significant influence on the extraction rate of coffee (p is more than 0.05). Therefore, the accelerated extraction of cold-extracted coffee can be completed at normal temperature (15-35 ℃), and the energy consumption caused by refrigeration and temperature rise in the production process is greatly reduced.

Example 5

The influence of different high-pressure carbon dioxide treatment time on the extraction effect of cold-extracted coffee is researched.

(1) Grinding the roasted coffee beans to the granularity of 30 meshes, then filling the ground coffee beans into a 300-mesh filter bag, sealing the filter bag, putting the filter bag into a high-pressure carbon dioxide processor, adding drinking purified water with the weight 10 times that of the coffee powder, and closing the hatch door of the high-pressure carbon dioxide processor.

(2) Setting the high-pressure carbon dioxide extraction pressure at 6MPa and the temperature of a circulating water tank at 25 ℃, respectively preparing coffee samples with extraction time of 20min, 30min, 40min, 50min and 60min, measuring the soluble solid content of each group of samples by using an Abbe refractometer, and calculating the extraction yield. The extraction yield of high pressure carbon dioxide cold-extracted coffee under the conditions of 6MPa and 25 ℃ and different extraction time is shown in figure 1. The extraction yield of coffee is continuously improved with the increase of the extraction time. However, when the time is longer than 30min, the extraction rate of coffee increases and slows down significantly. This is mainly because the longer the extraction time, the more complete the extraction, and when the extraction time reaches a certain value, most of the soluble solids in the coffee are already extracted, so that the coffee extraction rate increases slowly as the extraction time continues to increase. The extraction rate of HPCD cold-extracted coffee reaches 23.7% at 30min, and exceeds 21% of the extraction rate of traditional cold-extracted coffee for 8 h.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.