JPH0443613B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides a novel method for producing roasted coffee beans,
In particular, the present invention relates to a method for producing roasted coffee beans that uses heating oil as a heat medium to increase heating efficiency and improve the quality of the roasted coffee beans themselves. [Conventional technology] Conventional methods for roasting coffee beans include coal, kerosene,
There are two types of methods: the direct heat method, in which green coffee beans are directly heat-treated using a heat source such as electricity, and the hot-air method, in which green coffee beans are heat-treated using combustion gas or heated air. As a direct-fire type device, a Shirotsuko type roasting machine is generally known, and the roasting machine is composed of a cylindrical can containing green coffee beans and a combustion section provided below the can. The can is rotated horizontally to stir the green coffee beans while roasting them over an open flame. On the other hand, in the hot air method, green coffee beans are roasted in a vertical fixed container using hot air blown from the bottom of the container, and most large-scale roasting machines in recent years have adopted this hot air method. It is known that in the hot air method, the degree of expansion of the roasted beans is higher because there is less contact between the coffee beans than in the direct flame method. In addition, the hot air method is superior in that the transition from the roasting process to the discharge cooling process can be performed quickly, making the end point of roasting more clear and making it easier to control the degree of roasting. [Problem to be solved by the invention] However, the conventional method of roasting coffee beans uses gas as a heat medium, which has low heating efficiency and takes time to roast, and it is difficult to evenly roast individual coffee beans. Heat treatment was difficult, and uneven heating was likely to occur, resulting in so-called roasting spots. Furthermore, since conventional roasting methods heat coffee beans in an open system, it is true that some volatile components (coffee flavor) of roasted coffee beans are inevitably lost during the roasting process. [Means for Solving the Problems] The present invention has been made in view of the above, and is intended to prevent the occurrence of uneven roasting through uniform heat treatment and to prevent the loss of volatile components of roasted coffee beans. Coffee consists of a roasting process in which beans are brought into contact with oil heated to a predetermined temperature and heated for a predetermined time, and a process in which the coffee beans obtained by the roasting process are cooled and the oil adhering to the coffee beans is separated. A method for producing roasted beans is provided. [Function] That is, the present invention uses heated oil (edible fats and oils) as a heat medium, which is completely different from the heat treatment that uses gas as a heat medium in the conventional roasting process, and thereby enables uniform heat treatment. It imparts effects to coffee beans, such as preventing the loss of volatile components (flavors), not hindering the expansion of the coffee beans, and allowing oil to remain on the surface of the roasted beans, improving their shelf life. Note that the heat treatment of coffee beans in the method for producing roasted coffee beans of the present invention does not involve the use of thermal power, so it is different from the original "roasting," but in this specification, for convenience, "roasting" is interpreted in a broad sense. This term is used to refer to all heat treatments used to produce roasted beans. [Example] Hereinafter, an example of the method for producing roasted coffee beans according to the present invention will be described in detail. The raw coffee beans used are those that have been refined in advance. This is to prevent the oil used in the roasting process from becoming colored and deteriorating due to contaminants mixed into the green coffee beans. Purification is carried out by methods such as air blowing, brushing, and water washing. The fats and oils used in the roasting process are selected from among edible fats and oils. However, substances that adversely affect the flavor of the produced roasted coffee beans (coffee extract), such as oils and fats that have a unique flavor that affects the flavor, oils and fats that tend to thermally decompose and generate off-flavor components, etc., are not suitable. For example, commercially available fats and oils such as salad oil and corn oil, general adjusted fats and oils, hydrogenated oils, coconut oil, cacao oil, and the like are preferred. Fat-soluble vitamins, fat-soluble substances such as emulsifiers, antioxidants such as tocopherols, etc. are added to the fats and oils as necessary. The roasting process is carried out by placing the green coffee beans directly into an oil tank containing oil set at a predetermined temperature and allowing the green coffee beans to come into contact with the heated oil for a predetermined period of time. Note that the contact between green coffee beans and heated oil is not limited to the above-mentioned direct injection method, but can also be applied to all other solid-liquid contact methods, for example, for green coffee beans stored in a basket, etc. A method such as pouring heated oil into contact can be applied. Further, the main roasting step may be performed in either a batch method or a continuous method. Oil temperature is 180-260℃, preferably
The temperature should be 200 to 240℃. Oil temperatures below 200℃ will take too long to reach the desired degree of roasting;
This is because oil temperatures of 240°C or higher may exceed the oil's smoking point and become dangerous. The roasting time will vary depending on the desired degree of roasting of the coffee beans and the oil temperature, but the target roasting time will be achieved in 12 to 15 minutes at an oil temperature of 200℃, and about 2 to 3 minutes at an oil temperature of 240℃. reach. This is extremely short compared to the traditional roasting time for coffee beans.
This indicates high thermal efficiency (see Table 1). The degree of roasting is mainly determined by the oil temperature and roasting time, but it also depends on conditions such as the structure and performance of the roasting device (oil tank), and the amount of coffee beans processed.

〔Effect of the invention〕

As explained in detail above, the method for producing roasted coffee beans of the present invention includes a roasting process in which green coffee beans are brought into contact with oil heated to a predetermined temperature and heated for a predetermined time; Since it consists of a process of cooling the coffee beans and separating the oil content attached to the coffee beans, it is possible to perform uniform heat treatment, prevent the occurrence of uneven roasting, and prevent the loss of volatile components of the roasted coffee beans. . On the other hand, by using heating oil as a heat medium, the roasting time can be significantly shortened, and the yield and degree of expansion of the resulting roasted coffee beans are both improved.

Claims (1)

[Scope of Claims] 1. A roasting process in which green coffee beans are heated for a predetermined period of time in oil heated to a predetermined temperature in an amount sufficient to bathe the green coffee beans, and coffee beans obtained by the roasting process. A method for producing roasted coffee beans, comprising the steps of cooling the coffee beans and separating oil adhering to the coffee beans. 2.Claim 1, wherein the green coffee beans are purified in advance by air blowing, brushing and/or water washing.
The method for producing roasted coffee beans described. 3. The method for producing roasted coffee beans according to claim 1 or 2, wherein the predetermined temperature is 180 to 260°C. 4. Claims 1 and 2, wherein the oil is salad oil, tempura oil, coconut oil, cacao oil, hydrogenated oil, or other edible fats and oils.
Or the method for producing roasted coffee beans according to 3. 5. The method for producing roasted coffee beans according to claim 1, 2, 3 or 4, wherein vitamin E and other antioxidants are added to the oil. 6. The method for producing roasted coffee beans according to claim 1, 2, 3, 4 or 5, wherein the oil content is separated using a centrifuge.