JPH09154502A - Bean roasting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently obtain a roasted product excellent in taste, smell and hue, additionally having strong anti-oxidant action by roasting a food raw material suitable for roasting under oxygen-free conditions. SOLUTION: A food raw material suitable for roasting such as plant leaves such as tea leaf, plant seeds such as coffee beans or residue after oil squeezing such as raw lees of sesame after oil squeezing is roasted under substantially oxygen-free conditions, under substantially vacuum condition or in the presence of an inert gas. The roasting temperature is 180-250 deg.C and the time is 5-20 minutes in the case of sesame seeds.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for roasting food materials.

[0002]

2. Description of the Related Art In manufacturing, processing, and cooking various foods, it is necessary to roast food materials, particularly materials derived from plants.
This technology has been widely used worldwide since ancient times. For example, a typical example of this is roasted sesame seeds and sesame oil obtained from the roasted sesame seeds, which have long been used in the Orient. Roasted and crushed soybeans are eaten as Kinako. In the West and the Middle East, coffee and cocoa are also obtained by roasting. Also, one type of beer uses roasted malt as a raw material. By roasting, raw ones can be used for food, and in addition, foods with good odor, taste and color can be obtained. What is conventionally said in performing this roasting is that the most important thing is the temperature for the production of characteristics such as flavor, and the other time is the time, heating method, water content and the like. Considering other important conditions besides the above, changes in flavor and the like due to roasting are due to chemical reactions of food components, and the raw material in a dry state with low water content is heated at high temperature, for example, 1
Since the heating is performed at a temperature higher than 00 ° C., the change is considered to be significantly influenced by oxygen, including generation and reaction of radicals. In particular, when roasting at a slightly high temperature, a burnt odor is generated, and it is considered that the presence of oxygen has a great influence.

Taking sesame as an example, when oil is taken from roasted sesame, conventionally, sesame seeds are roasted in a pan or a rotary kiln in the presence of air at 180 to 190 ° C., but from around 200 ° C. A so-called burnt odor occurs and the color becomes dark brown. These changes are judged as quality deterioration according to the sensory evaluation of the product. However, the antioxidant effect of oil rapidly increases from around this temperature, and
Those heated at ℃ have a very high antioxidant effect. Therefore, it is necessary to heat the sesame seeds to a temperature higher than about 200 ° C. in order to obtain an oil having an excellent antioxidant action, but on the other hand, there is a contradiction that the deterioration of color and aroma cannot be avoided. Roasting of sesame seeds is also usually performed in a pan or rotary kiln in the presence of air.
It is also necessary to improve the aroma and taste of this roasted product.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a method having excellent effects as compared with the above-mentioned conventional methods. That is, the present invention relates to a roasting method of roasting a food material suitable for roasting under substantially oxygen-free conditions. According to the present invention, by performing roasting under a substantially oxygen-free condition which has not been conventionally performed, as described below, it is possible to obtain an excellent effect which cannot be obtained by the conventional technique. As the food material used in the present invention, any food material that can be used for processing by roasting can be used, and examples thereof include plant leaves, plant seeds, and oil extraction residues thereof. Examples thereof include tea leaves, Japanese tea, malt, wheat germ, sesame seeds, rapeseed seeds, barley, soybeans, coffee beans, cocoa beans, and oil extraction residues thereof. Examples of the oil extraction residue used in the present invention include raw sesame meal and rapeseed meal. Raw sesame meal is a meal that has been crushed by an expeller without roasting sesame seeds and still contains about 10% oil. This lees are roasted at a constant temperature, organic solvents such as hexane, ethyl acetate, lower alcohols such as methanol,
Those extracted with ethanol etc. have a strong antioxidant effect. In this case, the oil contained in the meal can be extracted with a solvent, and the meal can be almost completely defatted. However, the completely degreased product is apt to be burnt by roasting and the antioxidant action is weakened. Therefore, the presence of a certain amount of oil content is preferable in order to enhance the antioxidant action and to obtain a good quality product. The roasting method of the present invention is performed under substantially oxygen-free conditions. Specifically, it is carried out by removing the air in the roasting device to make it substantially vacuum and / or filling or flowing an inert gas such as nitrogen gas or carbon dioxide gas. The other conditions for roasting in the present invention are substantially the same as the conditions conventionally used. For example, the roasting temperature depends on the raw material to be roasted. For example, 180-250 ° C for sesame seeds, 200-250 ° C for coffee beans, and 95-1 for cocoa beans.
For example, 50 ° C. The roasting time also differs depending on the raw material to be roasted. For example, 5-20 minutes for sesame seeds, 5-20 minutes for coffee beans, and 15-75 minutes for cocoa beans.

In the present invention, by performing roasting under the above conditions, it is possible to obtain a product which has an excellent odor, color and taste and which has an antioxidant action, which cannot be obtained by conventional techniques. .

【Example】

Example 1 120 g of sesame seeds were roasted by flowing nitrogen into the roasting device. On the other hand, the same amount of sesame seeds was roasted in the presence of air. Both roasting conditions were 200 ° C. and 10 minutes. The properties of the obtained seeds were as follows. The roasted product in the presence of air had a blackish brown color, and had the odor of roasting oil containing an irritating odor and a burning odor. On the other hand, the product roasted under a nitrogen stream had a brown color, had little irritating odor and burning odor, and had a unique odor different from roasted oil.
The roasted product was squeezed with a hand press to obtain about 20 g of oil. The oil obtained in the presence of air was dark brown in color and tasted bitter. On the other hand, the oil obtained under a nitrogen stream was brown and had a bitter taste.

Example 2 500 g of coffee beans (Brazil) were introduced while flowing nitrogen.
Roasted at 200 ° C. for 10 minutes. On the other hand, the same amount of coffee beans was roasted at the same temperature and time as above without flowing nitrogen. The resulting roasted coffee beans were milled separately and ground. 5 L of hot water was added to the obtained powder, and the powder was filtered using filter paper. The odors and tastes of the obtained extracts were compared. When roasted under a nitrogen stream, the sweetness of the extract was stronger, the bitterness was weaker, the sourness and astringency were weaker than those roasted in the air, and therefore the taste was mild.

Example 3 125 g of raw sesame seed meal was roasted at 200 ° C. for 10 minutes in the presence of air or a nitrogen stream. Those roasted in a nitrogen stream were less likely to be charred and hardened in a tar-like form and roasted with less odor than those roasted in the presence of air. The product obtained by roasting in the presence of air or under a stream of nitrogen was extracted for 30 minutes using a Soxhlet extractor. The obtained extract was concentrated to give concentrate (A) 6.82.
g was obtained. 200 cc of ethyl acetate was added to the extraction residue,
Let stand overnight at room temperature. The extract is concentrated to concentrate (B) 4.
56 g were obtained. The extraction residue is further treated with hot ethanol to 1
-Extracted for 2 hours. The extract is concentrated to concentrate (C) 4.
87 g were obtained. The extraction residue is reheated with hot ethanol 1-
Extracted for 2 hours. The extract was concentrated to give concentrate (D) 0.
94 g were obtained. The concentrate (C) and the concentrate (D) were combined to give a concentrate (G) (5.81 g). The antioxidant effect of the obtained concentrate was investigated using linoleic acid. 0.02 g of the concentrate was added to 1.0 g of linoleic acid, and the mixture was allowed to stand at 60 ° C. and the weight change was observed. 4.5% increase in weight
Table 1 shows the number of days to reach.

[0008]

[Table 1]

From the results shown in Table 1, the hexane category has the weakest antioxidant activity, the ethyl acetate category has the stronger antioxidant activity, and the ethanol category has the stronger antioxidant activity. In any case, roasting under a nitrogen stream is significantly more effective than roasting in the presence of air.

Example 4 The method of Example 3 was carried out using rapeseed meal instead of sesame raw meal. Also in this case, the one roasted under a nitrogen stream was less likely to be scorched than the one roasted in the presence of air, and when it was extracted with an organic solvent, the antioxidant action was stronger. However, the antioxidant effect was weaker in the one obtained from rapeseed meal than in the one obtained from sesame raw meal.

Example 5 The ethanol extract from the sesame raw squeezed lees obtained in the present invention was added to a conventionally used antioxidant such as tocophenol or BHA, and its antioxidant action was examined. 0.2-1% by weight of ethanol extract, 0.01-0.05% by weight of tocophenol and 0.01-0.02% by weight of BHA were added to linoleic acid, and the weight increase was measured. Table 2 shows the number of days when the weight increase reached 5%.

[0012]

[Table 2]

From Table 2 it can be seen that the organic solvent extract of the one obtained by the roasting process of the present invention is combined with conventional antioxidants, especially tocophenol, to have a synergistic effect which is superior to each alone.

Claims (3)

[Claims] 1. A roasting method in which a food material suitable for roasting is roasted under substantially oxygen-free conditions. 2. The method according to claim 1, wherein the food material suitable for roasting is plant leaves, plant seeds, or an oil extraction residue thereof. 3. The method of claim 1, wherein the food material suitable for roasting is roasted substantially under vacuum or in the presence of an inert gas.