TW202142126A - Instant adzuki bean and preparation method thereof wherein the instant adzuki bean has high solidity and excellent rehydration ability - Google Patents

Abstract

The present invention discloses a method for preparing instant adzuki bean, which comprises the following steps of performing a pre-drying treatment for the adzuki bean including at least one of freeze-drying treatment and superheated vapor drying treatment; ripening the adzuki bean treated by the pre-drying treatment; and performing a reduced pressure drying treatment and a hot-air puffing treatment in sequence for the ripened adzuki bean, thereby obtaining the instant adzuki bean. The pre-drying treatment is performed to reduce the water content by 10 to 30%. The freeze-drying treatment includes a freezing treatment and a reduced pressure drying treatment that are performed sequentially. The ripening treatment is performed by at least one of boiling, steaming and baking. The reduced pressure drying treatment is performed so that the water content is less than 30 to 15%. The hot-air puffing treatment is performed until the bulk density is 0.60 to 0.96 g/mL. The hot-air puffing treatment is performed at a temperature of 200 to 550DEG C and a wind speed of 30 to 90 m/s. The instant adzuki bean prepared by the above-described method has a solidity of 0.9 to 1.0 and a rehydration ratio of 1.6 to 2.2. The instant adzuki bean has a porosity of 0.3 to 0.5. Before the pre-drying treatment, the adzuki bean can be blanched at 80 to 105 DEG C for 1 to 10 minutes to deactivate most of the enzymes in the adzuki bean. The freezing treatment is performed at -12 to -30 DEG C for 1 to 12 hours. The reduced pressure drying treatment is performed at 30~70 DEG C and 0.1 to 100 Torr. The superheated vapor drying treatment is performed by using superheated vapor at 120 to 180° C for 1 to 10 minutes. Therefore, the instant adzuki bean of the present invention has high solidity and excellent rehydration ability.

Description

Instant red beans and preparation method thereof

The present invention relates to an instant adzuki bean with both high integrity and excellent rehydration ability and a preparation method thereof. The present invention also relates to a food product containing the instant red beans.

Red beans are a kind of high-nutrient cereals with high protein and low fat. However, due to the structural composition of red beans, it takes a long time to cook red beans. With the changes in modern eating habits and lifestyles, speed and convenience have become one of the important considerations for consumers today. Therefore, researchers in food-related fields have tried to develop instant adzuki beans. Ready-to-eat red beans are mainly prepared by cooking red beans until they are matured and then dried. When consumers want to eat them, they only need to soak them in hot water and eat them after they are rehydrated. However, all the instant red beans on the market have the shortcomings of incomplete crushing of red beans and poor taste, and these shortcomings are mainly caused by the manufacturing process of instant red beans. Therefore, how to prepare instant red beans with complete granules and better taste is the research direction in this technical field.

Some prior technologies have tried to use chemicals such as carbonate and bicarbonate for upgrading (for example, CN 1265283 A, CN 104822275 A), but the use of such chemical treatments in the manufacturing process may cause health concerns. On the other hand, some prior technologies introduce additional pressurization (for example, CN 109527408 A, CN 1068187 C). However, the additional pressurization during the manufacturing process causes a problem of higher energy consumption.

Therefore, there is still a need in the art to develop a method for preparing instant red beans with complete granules, better taste and no health concerns without pressure to meet the needs of the industry.

Summary of the invention

Therefore, in the first aspect, the present invention provides a method for preparing an instant red bean, which comprises the following steps: A red bean is subjected to a pre-drying treatment, which includes at least one of the following: freeze-drying treatment and superheated steam drying treatment; Subject the red beans that have been pre-dried to a maturation process; and The matured red beans are sequentially subjected to a reduced pressure drying treatment and a hot air puffing treatment, thereby obtaining the instant red beans.

In the second aspect, the present invention provides an instant red bean, which is prepared by a method as described above. Preferably, the instant red beans have a completeness rate of 0.9 to 1.0 and a rehydration rate of 1.6 to 2.2.

In a third aspect, the present invention provides a food product comprising an instant red bean as described above.

Detailed description of the invention

It should be understood that if any previous case publication is quoted here, the previous case publication does not constitute a recognition: in Taiwan or any other country, the previous case publication forms a common general in this art. Part of knowledge.

For the purpose of this specification, it will be clearly understood that the word "comprising" means "including but not limited to", and the word "comprises" has a corresponding meaning.

Unless otherwise defined, all technical and scientific terms used in this article have meanings commonly understood by those familiar with the art of the present invention. A person familiar with the art will recognize that many methods and materials similar or equivalent to those described herein can be used to implement the present invention. Of course, the present invention is by no means restricted by the described methods and materials.

As used herein, the term "instant adzuki bean" means that it can be rehydration or reconstitution by mixing with an aqueous liquid (for example, water, milk, etc.) and selectively heating it. ) And converted to red beans in a cometible state.

In order to prepare instant red beans with complete particles and better taste, the applicant tried various pretreatments before the ripening treatment of the red beans, and tried various drying treatments after ripening, and found that: the pre-drying treatment was carried out before the ripening treatment And after the maturation treatment, the reduced-pressure drying treatment and the hot-air puffing treatment can be performed to obtain instant red beans with complete granules and better taste and aroma.

Therefore, the present invention provides a method for preparing an instant red bean, which comprises the following steps: A red bean is subjected to a pre-drying treatment, which includes at least one of the following: freeze-drying treatment and superheated steam drying treatment; Subject the red beans that have been pre-dried to a maturation process; and The matured red beans are sequentially subjected to a reduced pressure drying treatment and a hot air puffing treatment, thereby obtaining the instant red beans.

The method according to the present invention is carried out using whole red bean particles.

According to the present invention, the red beans can come from various varieties (cultivar). Preferably, the red bean varieties can be selected from the group consisting of Kaohsiung No. 8, Kaohsiung No. 9, Kaohsiung No. 10, and combinations thereof. In a preferred embodiment of the present invention, the red bean variety is Gaoxiong No. 9.

According to the present invention, before drying, the red beans can be blanched at 80 to 105° C. for 1 to 10 minutes to deactivate most of the enzymes in the red beans.

According to the present invention, the water content of the red beans can be adjusted to a desired level before drying, preferably 44 to 65%, more preferably 55 to 60%.

Preferably, the pre-drying treatment is performed to reduce the water content by 10 to 30%, more preferably, 10 to 15%, thereby generating cracks on the surface of the red beans.

In a preferred embodiment of the present invention, the pre-drying treatment is freeze-drying treatment.

According to the present invention, the freeze-drying treatment includes a freezing treatment and a reduced-pressure drying treatment performed sequentially. According to the present invention, the freezing treatment and the reduced-pressure drying treatment can be carried out using a technique well known and commonly used by those skilled in the art. It can be understood that the operating conditions related to the freezing treatment and the reduced-pressure drying treatment will be further changed according to the number of red beans used, the water content and other factors, so as to achieve the best freezing and drying effect. The choice of these operating conditions is routinely determined by those who are familiar with the art.

Preferably, the freezing treatment is performed at -12 to -30°C for 1 to 12 hours.

Preferably, the reduced-pressure drying treatment is performed at 30 to 70° C. and 0.1 to 100 Torr.

In another preferred embodiment of the present invention, the pre-drying treatment is a superheated steam drying treatment.

According to the present invention, the superheated steam drying treatment can be carried out using a technique well known and commonly used by those skilled in the art. In this regard, one can refer to, for example, Patent Publication No. TW M536331 U. In a preferred embodiment of the present invention, the superheated steam drying treatment is performed by using the superheated steam equipment disclosed in Patent Publication No. TW M536331 U.

It can be understood that the operating conditions related to the superheated steam drying treatment will be further changed with factors such as the amount of red beans used and the water content in order to achieve the best drying effect. The choice of these operating conditions is routinely determined by those who are familiar with the art.

Preferably, the superheated steam drying treatment is performed using superheated steam at 120 to 180° C. for 1 to 10 minutes.

According to the present invention, the aging treatment can be carried out using a technique well known and used by those skilled in the art. Preferably, the maturation treatment is performed by at least one of the following: boiling, steaming, and baking. In a preferred embodiment of the present invention, the aging treatment is cooking.

It can be understood that the operating conditions related to the maturation treatment will be further changed with factors such as the amount of red beans used and the water content in order to achieve the best maturation effect. The choice of these operating conditions is routinely determined by those who are familiar with the art.

According to the present invention, the curing treatment is performed until fully cooked, or the birefringence of the starch granules disappears completely, that is, fully gelatinized.

According to the present invention, the reduced-pressure drying treatment of the matured red beans can be carried out in the same or different manners.

Preferably, the reduced-pressure drying treatment is performed at 30 to 70° C. and 0.1 to 100 Torr until the water content is less than 30 to 15%, more preferably, less than 20%.

According to the present invention, the term "hot-air puffing" can be used interchangeably with "hot-air puffing".

According to the present invention, the hot-air puffing treatment can be carried out using a technique well known and commonly used by those skilled in the art. In this regard, you can refer to, for example, Patent Publication Nos. TW I626895 and TW M548447 U. In a preferred embodiment of the present invention, the hot air puffing treatment is performed by using the puffing heater disclosed in Patent Publication No. TW M548447 U.

It can be understood that the operating conditions related to the hot-air puffing treatment will be further changed with factors such as the amount of red beans used and the water content in order to achieve the best puffing drying effect. The choice of these operating conditions is routinely determined by those who are familiar with the art.

Preferably, the hot air puffing treatment is performed at a temperature of 200 to 550° C. and a wind speed of 30 to 90 m/s.

More preferably, the hot air puffing treatment is performed until the bulk density is 0.60 to 0.96 g/mL.

The present invention provides an instant red bean, which is prepared by a method as described above. Preferably, the instant red beans have a solidity of 0.9 to 1.0 and a rehydration ratio of 1.6 to 2.2.

The present invention also provides an instant red bean, which has a completeness rate of 0.9 to 1.0 and a rehydration rate of 1.6 to 2.2.

Preferably, the instant red beans have a porosity of 0.3 to 0.5.

According to the present invention, the instant red beans can be rehydrated by conventional means such as hot water and microwave-assisted heating for immediate consumption, or can be further formulated into food together with any edible material.

Therefore, the present invention provides a food product, which contains an instant red bean as described above.

According to the present invention, the food product may further include an instant food, which includes, but is not limited to: soluble drink powder, instant soup, instant noodle, and instant cereal (instant cereal) (such as instant rice), other instant beans, and prepared food. Detailed description of the preferred embodiment

The present invention will be further described with the following embodiments, but it should be understood that these embodiments are for illustrative purposes only, and should not be interpreted as limitations on the implementation of the present invention. EXAMPLES Example 1. Preparation of the instant adzuki bean experimental materials of the present invention: 1. The Vigna angularis variety used in the following experiments was Kaohsiung No. 9, purchased from Wandan Township, Pingtung. experimental method:

First, the red beans are washed and placed in 95-100℃ water for 3 minutes for blanching, and then moved to 25℃ water for soaking until the water content reaches 55-60% [Quick moisture determination using halogen lamps Instrument (MA100, Sartorius AG)], and then divided into 2 experimental groups (ie, experimental groups 1 and 2) and 7 comparative experimental groups (ie, comparative experimental groups 1 to 7), the weight of each group is 1 kg. After that, the red beans of each group were processed as shown in Table 1 below to prepare instant red beans.

Specifically, the processing treatment of the comparative experimental group 1 was carried out according to the following steps: First, the red beans were placed in boiling water at 100°C and cooked by boiling until the red beans were completely cooked. Cooked [judged by the complete disappearance of the birefringence of the starch granules]. After that, the cooked red beans (with water content of about 55-60%) are taken out and evenly spread on a stainless steel plate, and then heated at 30°C under a hot-air dryer (manufactured by Shengyang Industrial Factory) The hot air is used for drying until the water content of the cooked red beans is less than 10%.

The processing of comparative experimental group 2 is basically carried out with reference to the steps of comparative experimental group 1 above. The difference is that the curing treatment is carried out by steaming in a steamer set at 95℃ (the brand is Marupin). (steaming) method, and the drying process is performed by 85°C hot air.

The processing of the comparative experimental group 3 is basically carried out with reference to the steps of the comparative experimental group 2 above. The difference is that: before the maturation treatment, the red beans are subjected to a freeze-drying treatment as follows: at -18 The freezing process was performed at ℃ for 4 hours to obtain frozen red beans. Next, use a rotary vacuum concentrator (R-2000V, Fanqun Technology Co., Ltd.) to perform reduced pressure drying (reduced pressure drying) at 60°C and 60 Torr until the water content is reduced by approximately 15%.

The processing of comparative experiment group 4 is basically carried out with reference to the steps of comparative experiment group 3 above. The difference is that the drying treatment after maturation is performed by hot air-assisted frequency radio dryer (hot air-assisted frequency radio dryer). EDB-5D, Yida Biotechnology Co., Ltd.) is performed with a radio frequency (radio frequency) with a hot air auxiliary power of 5 kW and a frequency of 40.68 MHz at 85°C.

The processing of comparative experiment group 5 is basically carried out with reference to the steps of comparative experiment group 3 above. The difference is that the drying treatment after maturation is performed by a microwave dryer (NN-ST651, Panasonic) with a power of 600 W is performed with microwaves with a frequency of 2450 MHz.

The processing of comparative experiment group 6 is basically carried out with reference to the steps of comparative experiment group 3 above. The difference is that the drying treatment after aging is done by superheated steam equipment (Patent Announcement No. TW M536331 U, Food Industry Consortium) Development Research Institute) is carried out with superheated vapor at 160°C.

The processing of comparative experiment group 7 is basically carried out with reference to the steps of comparative experiment group 3 above. The difference is that the drying treatment after maturation is performed by vacuum drying at 60°C and 60 Torr under a rotary vacuum concentrator. To proceed.

The processing of the experimental group 1 is basically carried out with reference to the steps of the comparative experimental group 3 above. The difference is that the drying treatment after maturation is carried out by the following: Torr is dried under reduced pressure to make the water content about 20%, and then it is carried out under the air-flow type micro-expansion equipment (Patent Announcement No. TW M548447 U, Food Industry Development Research Institute) at a temperature of 220°C and a wind speed of 48 m/s The hot-air puffing (also known as hot-air puffing) lasts 10 to 90 seconds (this method can shorten the traditional drying time by 30-60%).

The processing of experimental group 2 is basically carried out with reference to the steps of experimental group 1 above. The difference is that the pre-drying treatment is carried out by superheated steam at 140°C under the superheated steam equipment until the water content is reduced by approximately 15%. %. Table 1. Processing methods used by each group Group Treatment before drying Maturation treatment Drying treatment after aging Comparative experimental group 1 no Boiled Hot air drying (30℃) Comparative Experimental Group 2 no Cooking Hot air drying (85℃) Comparative Experimental Group 3 Freeze-dry Cooking Hot air drying (85℃) Comparative experimental group 4 Freeze-dry Cooking Hot air assisted radio frequency drying (5 kW, 40.68 MHz, 85°C) Comparative experimental group 5 Freeze-dry Cooking Microwave drying (600 W, 2450 MHz) Comparative experimental group 6 Freeze-dry Cooking Superheated steam drying (160℃) Comparative experimental group 7 Freeze-dry Cooking Dry under reduced pressure (60℃, 60 torr) Experimental group 1 Freeze-dry Cooking Drying under reduced pressure (60℃, 60 torr) Hot air puffing (220℃, 48 m/s) Experimental group 2 Superheated steam drying (140℃) Cooking Drying under reduced pressure (60℃, 60 torr) Hot air puffing (220℃, 48 m/s) Texture Example 2. The instant invention bean Analysis (texture analysis)

In this example, the bulk density, expansion ratio, complete grain ratio, and solidity of the instant red beans prepared in Example 1 above were measured. To analyze the effect of processing on the expansion and completeness of instant red beans. Then, the rehydration ratio and sensory evaluation of the instant red beans after rehydration were performed to analyze the rehydration ability and rehydration status of the instant red beans. Finally, the structure of instant red beans was analyzed by electron microscope observation and porosity measurement.

In addition, for comparison, the unprocessed red beans were used as the control group, and the commercially available instant red beans (from the red bean rice sold by Osai Foods) were used as the commercial group, and the same experiment was performed together. A. Determination of bulk density, expansion rate, intact grain rate and intact rate:

The bulk density is generally determined with reference to the master's thesis (2011) by Zhan Yiping from the Department of Food and Applied Biotechnology, National Chung Hsing University The method described is slightly modified. In short, put each group of red beans (10 g) in a 500 mL graduated cylinder, then add 100 mL of salt, and then tap the graduated cylinder until the height of the salt in the graduated cylinder no longer changes to calculate the amount of red beans in each group. The total volume (bulk volume). The bulk density is calculated by substituting the total weight and total volume of each group into the following formula (I): Formula (I) : A = B/C where: A = bulk density (g/mL) B = each group The total weight (g) C = the total volume of each group (mL)

The expansion rate is calculated by referring to Hoke K. et al. (2006), Journal of Food engineering , 80:1016-1022, and substituting the measured bulk density of each group into the following formula (II): Formula (II) : D = E/F where: D = expansion rate E = volume density of the control group (g/mL) F = volume density of each group (g/mL)

The complete grain rate is based on the "Rice Verification Specification" of Taiwan's Certified Agricultural Standards (CAS) and the definition of "complete grain" in the National Standards of the People's Republic of China-Soybeans. If the cotyledon of the red bean is less than 1/4 of the volume of the grain, it is regarded as a whole grain and weighed, and then substituted into the following formula (III) to be calculated: Formula (III) : G = H/I × 100( %) Wherein: G = complete grain rate (%) H = total weight of intact grains of each group (g) I = total weight of each group (g)

The bulk density, expansion ratio, and intact grain ratio of each group are shown in Table 2 below. Table 2. Bulk density, expansion rate and intact grain rate of each group Group Bulk density (g/mL) Expansion rate Complete grain rate (%) Control group 1.44±0.06 - - Comparative experimental group 1 0.83±0.08 1.73 87.3±1.9 Comparative Experimental Group 2 0.76±0.07 1.90 39.5±1.1 Comparative Experimental Group 3 1.01±0.00 1.43 95.2±1.4 Comparative experimental group 4 1.07±0.06 1.35 96.1±0.7 Comparative experimental group 5 0.99±0.03 1.45 97.8±0.3 Comparative experimental group 6 0.98±0.06 1.47 93.0±0.3 Comparative experimental group 7 1.03±0.02 1.40 97.4±0.4 Experimental group 1 0.90±0.06 1.60 94.0±1.5 Experimental group 2 0.88±0.06 1.64 93.8±1.3 Commercial Group 0.89±0.08 1.62 9.4±1.2

It can be seen from Table 2 that the expansion ratios of the comparative experimental groups 1 to 7 and experimental groups 1 to 2 are similar to or higher than those of the commercial group, which means that the expansion degree of red beans after the above-mentioned various processing treatments can all be Achieve those similar to or higher than those of commercially available products. Among them, compared to the comparative experimental group 1, the comparative experimental group 2 has a slightly lower bulk density and a slightly higher expansion rate, but has a greatly reduced intact grain rate (but still significantly higher than that of the commercial group). This means that although cooking is easier to increase the swelling degree of red beans than boiled in water, this kind of maturation treatment has seriously damaged the integrity of red beans. However, the intact grain rate of the comparative experimental group 3 to 7 and the experimental group 1 to 2 was significantly higher than that of the comparative experimental group 2 and the commercial group, and it was also observed that the cooking loss was reduced by 70-90 %. This means that the pre-drying treatment performed before the maturation treatment can effectively protect the red beans from the integrity of the maturation treatment, and is significantly better than the commercially available products. In particular, only experimental groups 1 and 2 have both a higher expansion rate and a complete grain rate at the same time, which means that the pre-drying treatment combined with the specific drying treatment after aging can achieve more excellent effects.

In addition, in order to further verify the above results, the applicant refers to the method described in Matsumoto et al . (2015), Journal of Medical Ultrasonics , 42:505-512 to perform the completeness rate of the instant red beans in the experimental group 1 and the commercial group. The determination. In short, a CCD auto-zoom camera (USB3 uEye ^® XC, Imaging Development Systems, Germany) and ImageJ imaging software (ImageJ Imaging Software, version 1.52) were used to determine the area and convexity of the instant red beans in the experimental group 1 and the commercial group. Convex area. The integrity rate is calculated by substituting the measured area and convex area of each group into the following formula (IV): Formula (IV) : J = K/L where: J = integrity rate K = area of each group (mm ² ) L = convex area of each group (mm ² )

The results showed that the integrity rates of experimental group 1 and the commercial group were 0.97±0.03 and 0.66±0.11, respectively. It can be seen that the method according to the present invention can indeed enable instant red beans to have significantly excellent integrity even with a high degree of swelling. B. Determination of rehydration rate and sensory evaluation:

The rehydration rate is determined with reference to the method described in Doymaz I. et al. (2015), Czech J. Food Sci. , 33:367-376. In short, the ready-to-eat red beans of the commercial group, the comparative experimental groups 1 to 7 and the experimental groups 1 to 2 were rehydrated with 95℃ hot water for 20 minutes, and the weight before and after rehydration (ie dry weight and wet weight) was measured. Heavy). The rehydration rate is calculated by substituting the measured dry weight and wet weight of each group into the following formula (V): Formula (V) : M = (O - N)/O where: M = rehydration Rate N = the dry weight of each group (g) O = the wet weight of each group (g)

The sensory evaluation is conducted by the panelists on the appearance, texture and flavor of each group of ready-to-eat red beans after rehydration.

The rehydration rate and sensory evaluation results of each group are shown in Table 3 below. Table 3. Rehydration rate and sensory evaluation results of each group Group Rehydration rate Sensory evaluation results Comparative experimental group 1 1.74±0.02 Broken particles, bean aroma, dense taste Comparative Experimental Group 2 2.23±0.01 Broken particles, no bean fragrance, dense taste Comparative Experimental Group 3 1.31±0.03 Complete granules, no bean fragrance, hard taste Comparative experimental group 4 1.10±0.01 Complete granules, no bean fragrance, hard taste Comparative experimental group 5 1.26±0.04 Complete granules, no bean fragrance, hard taste Comparative experimental group 6 1.05±0.02 Complete granules, no bean fragrance, hard taste Comparative experimental group 7 1.35±0.02 Complete granules, bean aroma, hard taste Experimental group 1 1.86±0.02 Complete granules, bean aroma, dense taste Experimental group 2 1.73±0.03 Complete granules, bean aroma, dense taste Commercial Group 2.16±0.04 Broken particles, no bean fragrance, soft taste

It can be seen from Table 3 that although the comparative experimental groups 1 and 2 without pre-drying treatment and the commercial group have relatively high rehydration rates and accompanied by a softer taste, they all have particle breakage after rehydration The situation has a poor appearance. In contrast, the comparative experimental groups 3 to 7 and experimental groups 1 to 2 that have undergone the pre-drying treatment have no such crushing, which means that the pre-drying treatment before the maturation treatment can effectively avoid the crushing of the rehydrated instant red beans. . Furthermore, in the comparative experimental groups 3 to 7 and experimental groups 1 to 2, only the experimental groups 1 to 2 have a rehydration rate similar to that of the commercially available group and a softer mouthfeel while retaining the aroma of red beans. This means that the pre-drying treatment combined with the specific drying treatment after aging can achieve a more excellent effect.

In addition, in order to further verify the above results, the applicant generally used the above method to determine the rehydration rate and sensory evaluation of the instant red beans in experimental group 1. The difference is that the rehydration method was changed to the instant red beans at 95°C The water was heated by microwave at 600 W for 5 minutes. The results show that the measured rehydration rate is 2.12±0.02, and the sensory evaluation results are complete particles, bean flavor, and dense mouthfeel. It can be seen that, according to the method of the present invention, the instant red beans can indeed have excellent rehydration ability and good appearance, texture and flavor after rehydration, even if different rehydration methods are used, it will not be affected. C. Electron microscope analysis and determination of porosity:

The red bean structure of the experimental group 1 and the control group was observed with a scanning electron microscope (Hitachi 4700) at a magnification of 20 times.

Figure 1 and Figure 2 show the external surface and internal structure of red beans in the control group and experimental group 1, respectively. It can be seen from Figure 1 and Figure 2 that the outer surface of the red beans in the control group is relatively smooth, while the internal structure is relatively compact and complete. On the contrary, the instant red beans in the experimental group 1 have many small cracks on the outer surface, while the internal structure has many small cracks. It appears porous, and there are gaps between the cotyledons and the seed coat. Based on this, the applicant believes that the instant red beans of the present invention, due to the cracks on the surface and the porous internal structure, can facilitate the ingress of liquid into the red beans particles during rehydration, thereby improving the rehydration efficiency and at the same time resulting in a denser mouthfeel.

In addition, in order to further verify the above inference, the applicant refers to the method described in Koua et al . (2019), Journal of the Saudi Society of Agricultural Sciences, 18:72-82 to compare experimental groups 3 to 7 and experimental groups The porosity of instant red beans from 1 to 2 was measured. In short, place the control group red beans (10 g) in a 500 mL graduated cylinder, and then add 100 mL of pure water to calculate the total volume of the control group red beans and calculate the true density. The porosity is calculated by substituting the actual density of the red beans in the control group with the bulk density of the instant red beans in the experimental groups 3 to 7 and the experimental groups 1 to 2 as measured in item A above into the following formula (VI) Out: Formula (VI) : P = (R - Q)/R where: P = porosity Q = bulk density of each group (g/mL) R = true density of the control group (g/mL)

The porosity results of the comparison experiment groups 3 to 7 and the experiment groups 1 to 2 are shown in Table 4 below. Table 4. Porosity of each group Group Porosity Comparative Experimental Group 3 0.29 Comparative experimental group 4 0.25 Comparative experimental group 5 0.30 Comparative experimental group 6 0.31 Comparative experimental group 7 0.28 Experimental group 1 0.37 Experimental group 2 0.38

It can be seen from Table 4 that compared with the comparative experimental groups 3 to 7, the experimental groups 1 to 2 have significantly higher porosity. It can be seen that, according to the method of the present invention, the instant red beans can indeed have more tiny pores and cracks without destroying the integrity of the structure.

Based on the above experimental results, the applicant believes that the method according to the present invention can produce a special structure of red beans with high integrity and high porosity, which is different from the prior art, and has excellent rehydration ability, resulting in excellent Sensory properties.

All patents and documents cited in this specification are incorporated into this case as reference materials in their entirety. If there is a conflict, the detailed description of the case (including the definition) will prevail.

Although the present invention has been described with reference to the above specific specific examples, it is obvious that many modifications and changes can be made without departing from the scope and spirit of the present invention. Therefore, it is intended that the present invention is only limited by the scope of the patent application attached hereto.

The above and other objectives, features and advantages of the present invention will become apparent with reference to the following detailed description, preferred embodiments and drawings attached with the text, among which: Figure 1 shows the surface and internal structure of the red beans in the control group observed by scanning electron microscope; and Figure 2 shows the surface and internal structure of the instant red beans of experimental group 1 observed by scanning electron microscope.

Claims (12)

A method for preparing an instant red bean, which comprises the following steps: A red bean is subjected to a pre-drying treatment, which includes at least one of the following: freeze-drying treatment and superheated steam drying treatment; Subject the red beans that have been pre-dried to a maturation process; and The matured red beans are sequentially subjected to a reduced pressure drying treatment and a hot air puffing treatment, thereby obtaining the instant red beans. The method of claim 1, wherein the pre-drying treatment is performed to reduce the water content by 10 to 30%. The method of claim 1, wherein the freeze-drying treatment includes a freezing treatment and a reduced-pressure drying treatment performed in sequence. The method of claim 1, wherein the aging treatment is performed by at least one of the following: boiling, steaming, and baking. The method of claim 1, wherein the reduced-pressure drying treatment is performed so that the water content is less than 30 to 15%. The method of claim 1, wherein the hot air puffing treatment is performed until the bulk density is 0.60 to 0.96 g/mL. Such as the method of claim 1, wherein the hot air expansion treatment is performed at a temperature of 200 to 550°C and a wind speed of 30 to 90 m/s. An instant red bean prepared by the method as described in any one of claims 1 to 7. Such as the instant red beans of claim 8, which has a completeness rate of 0.9 to 1.0 and a rehydration rate of 1.6 to 2.2. An instant red bean with a completeness rate of 0.9 to 1.0 and a rehydration rate of 1.6 to 2.2. The instant red beans of claim 8 or 10 have a porosity of 0.3 to 0.5. A food product comprising the instant red beans according to any one of Claims 8 to 11.

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