Preparation method of square bamboo shoot superfine powder and product thereof

Abstract

The invention discloses a preparation method of square bamboo shoot superfine powder and a product thereof, and the preparation method comprises the following steps: peeling off bamboo shoot shells on the surfaces of harvested square bamboo shoots, then cutting the square bamboo shoots, cleaning and blanching the square bamboo shoots, cutting the square bamboo shoots into small sections, freezing the cut small sections, grinding the frozen square bamboo shoots, and drying the ground fresh powder to obtain the square bamboo shoot superfine powder. And finally, carrying out superfine grinding on the dry powder to obtain a square bamboo shoot superfine powder product. According to the square bamboo shoot superfine powder product prepared by the preparation method disclosed by the invention, the utilization rate of square bamboo shoot raw materials is greatly improved, the deep processing variety of square bamboo shoots is enriched, the application range of the product is expanded, the utilization rate of nutritional and functional components in the bamboo shoots is improved, the storage life of the product is effectively prolonged, and the dissolution of effective components of the product is improved; therefore, the application range of the square bamboo shoot product is expanded, the prepared product can be used by more people, and popularization and application of the square bamboo shoot superfine powder are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a preparation method of superfine bamboo shoot powder and a product thereof. Background Art

[0002] Bamboo is a perennial plant of the subfamily Bambusoideae of the Poaceae family, widely distributed in tropical, subtropical and warm temperate regions. my country is rich in bamboo resources, mainly distributed in Fujian, Jiangxi, Zhejiang, Anhui and other provinces. Bamboo shoots are swollen buds and tender stems that germinate and differentiate from buds on bamboo whips or culms. Bamboo shoots are rich in nutrients such as protein, amino acids, multiple vitamins, dietary fiber, minerals, monosaccharides and oligosaccharides, which have a certain preventive effect on obesity, hyperlipidemia, hypertension, coronary heart disease, diabetes and arteriosclerosis; in addition, they also contain polysaccharides and flavonoids, which have a certain effect of improving the body's immunity and anti-cancer. In particular, the square bamboo shoots produced in Sichuan, Guizhou and Yunnan provinces in my country are unique bamboo species in southwest my country. The proportion of its nutrients is the most appropriate among the main bamboo shoots, especially the water content and amino acid and essential amino acid content of the human body are the highest, the crude fiber content is the average level of bamboo shoots, and the fat content is the lowest, so it has a good preservation effect, good taste and high quality. According to relevant information, 100g of fresh bamboo shoots contain 91.99g of water, 3.20g of protein, 0.34g of fat, 0.89g of total sugar, 0.53g of soluble sugar, 7.82kj of calories, 0.68g of crude fiber, 76mg of phosphorus, 0.6mg of iron, and 18.4mg of calcium. As bamboo shoots are rich in nutrients, eating them can help the human body's gastrointestinal motility and digestion, and achieve the special effects of weight loss, beauty, and prevention and treatment of gastrointestinal and cardiovascular diseases.

[0003] At present, the products of bamboo shoots are relatively simple. The products generally entering the market can be roughly divided into hairy bamboo shoots, dried bamboo shoots, salted bamboo shoots, fresh bamboo shoots and sulfur bamboo shoots, or used to produce canned bamboo shoots, dried bamboo shoots and bamboo shoot shreds. These products mainly use the tender bamboo shoots in the middle and upper parts, while the middle and lower parts with higher fiber content cannot be used and are discarded. Since the discarded scraps also contain rich nutrients and functional ingredients, the overall utilization rate of bamboo shoot raw materials is low.

[0004] Ultrafine grinding technology is a high-tech in the food processing industry. This technology can grind material particles larger than 3mm into micro powders of about 10μm. The principle of ultrafine grinding is the same as that of ordinary grinding, but the fineness requirement is higher. It uses external mechanical force to destroy the cohesion between material molecules to achieve the purpose of grinding. Due to the micronization of particles, their surface area and porosity will increase, so that the obtained ultrafine powder has unique physical and chemical properties, such as good dispersibility, adsorption, solubility and biological activity. Micronized food also has strong surface adsorption and affinity. Therefore, the ultrafine grinding technology has good color, dispersibility and solubility, and is particularly easy to be digested and absorbed by the human body.

[0005] After searching, a patent document with application publication number CN102715470A discloses a method for preparing bamboo shoot ultrafine powder. From the content disclosed in the retrieved patent document, it can be seen that color protection treatment is required during the preparation process. In view of the problems of low utilization rate of existing square bamboo shoot raw materials, single product and small product application range, a preparation method of square bamboo shoot ultrafine powder different from that disclosed in the prior art is provided. The product prepared by this method can meet the usage needs of more consumers, thereby expanding its application range. Summary of the invention

[0006] The technical problem to be solved by the present invention is to solve the problems existing in the background technology. In order to improve the utilization rate of square bamboo shoot raw materials, improve the application range of products, and at the same time, to extend the shelf life of products and improve the dissolution of effective ingredients of products, thereby expanding the application range of square bamboo shoot products, a preparation method for producing square bamboo shoot ultrafine powder is provided, so that the prepared product can meet the use of more people. Specifically, it is a preparation method of square bamboo shoot ultrafine powder and its product.

[0007] In order to solve the above technical problems, the technical scheme adopted by the present invention is: a method for preparing superfine powder of bamboo shoots, the preparation method comprises the following steps: peeling off the bamboo shoot shells on the surface of the harvested bamboo shoots, then cutting them, washing and blanching them, cutting them into small sections, freezing the cut small sections, grinding them after freezing, drying the ground fresh powder, and finally superfinely grinding the dried powder to obtain the superfine powder of bamboo shoots, and the preparation method comprises the following steps: S1. The harvested bamboo shoots are peeled off the bamboo shoots on the surface by mechanical or manual methods, and then cut along the length direction to obtain bamboo shoots; S2. The bamboo shoots obtained in step S1 are washed in clean water to remove dust, dirt and impurities from the surface. After washing, remove and drain the water; S3. After draining the bamboo shoots in step S2, blanch them in hot water at a temperature of 90 to 100 ℃ for 3 to 6 minutes, and then remove them from the pot; S4. After the bamboo shoots are blanched in step S3, they are quickly placed in clean water and cooled to room temperature. After cooling, they are removed and drained; S5. The cooled bamboo shoots in step S4 are cut into small sections of 0.1 to 0.5 cm in length; S6. The small pieces of bamboo shoots cut in step S5 are placed in liquid nitrogen for freezing for 25 to 35 minutes; S7. The frozen bamboo shoots in step S6 are ground into small segments using a frozen grinder, the frozen grinding time is 30 to 40min, and after frozen grinding, fresh powder is obtained; S8. The fresh powder obtained in step S7 is sent to a freeze dryer for freeze vacuum drying. The freeze vacuum drying method is as follows: the fresh powder is placed in a tray, first evacuated to 10-20 Pa, filled with nitrogen to atmospheric pressure, precooled to 0-10° C., maintained for 30-50 minutes, then evacuated to 10-20 Pa, heated and sublimated to 0-10° C., and then cooled to 0--10° C. to freeze the fresh powder into ice solid. After maintaining for 2.5-3.5 hours, nitrogen is passed to 20-30 Pa, and the temperature is kept for 3-5 hours to obtain dry powder; S9. The dried powder obtained in step S8 and the freeze-dried nitrogen are injected into an ultrafine pulverizer and pulverized by high-speed airflow for 40 to 60 minutes until the particle size is below 15 μm, thereby obtaining the square bamboo shoot ultrafine powder.

[0008] Furthermore, in the method for preparing the superfine powder of bamboo shoots of the present invention, the bamboo shoots harvested in step S1 refer to fresh bamboo shoots dug from September to October each year. The bamboo shoots can be dug when they are 15 to 20 cm long after they are unearthed. When digging, just dig 5 to 8 cm of soil at the base of the bamboo shoots and break them off.

[0009] Furthermore, the method for preparing the superfine powder of bamboo shoots of the present invention is adopted, and the small bamboo shoot segments in step S6 are placed in a liquid nitrogen tank for liquid nitrogen freezing, and the freezing time is 30 minutes.

[0010] Furthermore, in the method for preparing the square bamboo shoot ultrafine powder described in the present invention, during the freeze-grinding in step S7, before the freeze-grinding, the freeze-grinding machine is pre-cooled with liquid nitrogen for 5 to 10 minutes. At the same time, during the freeze-grinding process, liquid nitrogen needs to be added again every 3 to 5 minutes, and the ground bamboo shoots are required to be kept wet with liquid nitrogen at all times.

[0011] Furthermore, a preparation method of the square bamboo shoot ultrafine powder described in the present invention is adopted. During the freeze-vacuum drying in step S8, the freeze dryer is a vacuum dryer, and the freeze-vacuum drying method is as follows: fresh powder is loaded into a plate, first evacuated to 15Pa, filled with nitrogen to atmospheric pressure, pre-cooled to 5°C, kept for 40 minutes, then evacuated to 15Pa, heated and sublimated to 5°C, and then cooled to -4°C to freeze the fresh powder of the square bamboo shoots into ice solid. After keeping for 3 hours, nitrogen is passed to 25Pa and kept warm for 4 hours.

[0012] Furthermore, the method for preparing the superfine powder of bamboo shoots of the present invention is adopted. In the superfine grinding process of step S9, the temperature of the nitrogen after freeze-drying is 5-6° C., and the pressure of the nitrogen injected into the superfine grinder is 20-30 Pa.

[0013] The invention also discloses a bamboo shoot superfine powder product prepared by the preparation method.

[0014] The preparation method of a kind of square bamboo shoots superfine powder of the present invention is adopted, compared with the prior art, and its beneficial effect is: fresh square bamboo shoots are washed and blanched, and then cut into small segments, ground after being frozen with liquid nitrogen, to fresh powder, and then freeze-dried, and finally ultrafinely crushed by high-speed airflow, so that the dissolution of the effective ingredients of the product can be improved, which is beneficial to human body absorption, and greatly increases the utilization of square bamboo shoots. It can be seen that the preparation method of the present invention is adopted, the utilization rate of square bamboo shoots raw materials is greatly improved, the deep-processing varieties of square bamboo shoots are enriched, the application range of products is expanded, the utilization rate of nutrition and efficacy components in bamboo shoots is improved, the shelf life of products is effectively extended, and the dissolution of effective ingredients of products is improved, thereby expanding the application range of square bamboo shoots products, so that the prepared products can meet the use of more people, which is beneficial to the promotion and application of square bamboo shoots superfine powder. DETAILED DESCRIPTION

[0015] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0016] The method for preparing the superfine powder of bamboo shoots described in this embodiment comprises the following steps: S1. In September and October every year, after the bamboo shoots are unearthed and the length reaches 15 to 20 cm, the bamboo shoots can be harvested. The best time to harvest is within 3 to 4 days after the rain, which is the best time to harvest bamboo shoots. When digging, just dig 5 to 8 cm of soil at the base of the bamboo shoots and break them off. Then, the harvested bamboo shoots are peeled off the bamboo shoot shell on the surface by mechanical or manual methods, and then cut into two parts along the length direction to obtain bamboo shoots; S2. The bamboo shoots obtained in step S1 are washed in clean water to remove dust, dirt and impurities from the surface. After washing, remove and drain the water; S3. After draining the bamboo shoots in step S2, blanch them in hot water at a temperature of 90 to 100 ℃ for 3 to 6 minutes, and then remove them from the pot; S4. After the bamboo shoots are blanched in step S3, they are quickly placed in clean water and cooled to room temperature. After cooling, they are removed and drained; S5. The cooled bamboo shoots in step S4 are cut into small sections of 0.1 to 0.5 cm in length; S6. The bamboo shoots cut in step S5 are placed in a liquid nitrogen tank for freezing in liquid nitrogen, and the freezing time is 25 min; S7. The frozen bamboo shoots in step S6 are ground using a cryo-grinder. Before the cryo-grinder, the cryo-grinder is pre-cooled with liquid nitrogen for 5 minutes. At the same time, during the cryo-grinder process, liquid nitrogen needs to be added again every 3 minutes. The ground bamboo shoots are required to be kept wet with liquid nitrogen at all times. The cryo-grinder time is 30 minutes. After the cryo-grinder, fresh powder is obtained. S8. The fresh powder obtained in step S7 is sent to a freeze dryer for freeze vacuum drying. The freeze vacuum drying method is as follows: the fresh powder is placed in a tray, first evacuated to 10Pa, filled with nitrogen to atmospheric pressure, precooled to 0°C, kept for 50 minutes, then evacuated to 10Pa, heated to sublimate to 0°C, and then cooled to -2°C to freeze the fresh powder into ice solid. After keeping for 3.5 hours, nitrogen is passed to 20Pa, and kept warm for 5 hours to obtain dry powder; S9. The dry powder obtained in step S8 and the freeze-dried nitrogen are injected into an ultrafine pulverizer, and pulverized by high-speed airflow for 40 minutes until the particle size is below 15 μm, thereby obtaining the square bamboo shoot ultrafine powder. The temperature of the freeze-dried nitrogen is required to be 5-6°C, and the pressure of the nitrogen injected into the ultrafine pulverizer is 20 Pa. Finally, the obtained square bamboo shoot ultrafine powder is weighed and packaged to obtain the square bamboo shoot ultrafine powder product. Example 2

[0017] The method for preparing the bamboo shoots ultrafine powder described in this embodiment is the same as steps S1 to S5 of Example 1, and the difference is mainly reflected in steps S6 to S9. The specific differences are as follows: S6. The small pieces of bamboo shoots cut in step S5 are placed in a liquid nitrogen tank for freezing in liquid nitrogen, and the freezing time is 30 min; S7. The small segments of bamboo shoots frozen in step S6 are ground using a freeze grinder. Before freeze grinding, the freeze grinder is precooled with liquid nitrogen for 8 minutes. At the same time, during the freeze grinding process, liquid nitrogen needs to be added again every 4 minutes. The ground bamboo shoots are required to be kept wet with liquid nitrogen at all times. The freeze grinding time is 35 minutes. After freeze grinding, fresh powder is obtained; S8. The fresh powder obtained in step S7 is sent to a freeze dryer for freeze vacuum drying. The freeze vacuum drying method is as follows: the fresh powder is placed in a tray, first evacuated to 15Pa, filled with nitrogen to atmospheric pressure, precooled to 5°C, kept for 40 minutes, then evacuated to 15Pa, heated to sublimate to 5°C, and then cooled to -4°C to freeze the fresh powder of bamboo shoots into ice solid. After keeping for 3 hours, nitrogen is passed to 25Pa and kept warm for 4 hours to obtain dry powder; S9. The dry powder obtained in step S8 and the freeze-dried nitrogen are injected into an ultrafine pulverizer and pulverized by high-speed airflow for 50 minutes until the particle size is below 15 μm to obtain the square bamboo shoot ultrafine powder. The temperature of the freeze-dried nitrogen is required to be 5-6°C and the pressure of the nitrogen injected into the ultrafine pulverizer is 25 Pa. Finally, the obtained square bamboo shoot ultrafine powder is weighed and packaged to obtain the square bamboo shoot ultrafine powder product. Example 3

[0018] The method for preparing the bamboo shoots ultrafine powder described in this embodiment is the same as steps S1 to S5 of Example 1, and the difference is mainly reflected in steps S6 to S9. The specific differences are as follows: S6. The small pieces of bamboo shoots cut in step S5 are placed in a liquid nitrogen tank for freezing in liquid nitrogen, and the freezing time is 35 min; S7. The small segments of bamboo shoots frozen in step S6 are ground using a freeze grinder. Before freeze grinding, the freeze grinder is precooled with liquid nitrogen for 10 minutes. At the same time, during the freeze grinding process, liquid nitrogen needs to be added again every 5 minutes. The ground bamboo shoots are required to be kept wet with liquid nitrogen at all times. The freeze grinding time is 40 minutes. After freeze grinding, fresh powder is obtained; S8. The fresh powder obtained in step S7 is sent to a freeze dryer for freeze vacuum drying. The freeze vacuum drying method is as follows: the fresh powder is placed in a tray, first evacuated to 20Pa, filled with nitrogen to atmospheric pressure, precooled to 10°C, kept for 50 minutes, then evacuated to 20Pa, heated to sublimate to 10°C, and then cooled to -10°C to freeze the fresh powder of bamboo shoots into ice solid. After keeping for 2.5 hours, nitrogen is passed to 30Pa, and kept warm for 3 hours to obtain dry powder; S9. The dried powder obtained in step S8 and the freeze-dried nitrogen are injected into an ultrafine pulverizer and pulverized by high-speed airflow for 60 minutes until the particle size is below 15 μm to obtain the square bamboo shoot ultrafine powder. The temperature of the freeze-dried nitrogen is required to be 5-6°C and the pressure of the nitrogen injected into the ultrafine pulverizer is 30 Pa. Finally, the obtained square bamboo shoot ultrafine powder is weighed and packaged to obtain the square bamboo shoot ultrafine powder product.

[0019] The equipment used in the preparation method of the present invention are all common equipment in the prior art, and thus no detailed description is given therefor. Other unexplained aspects of the present invention are all conventional technologies known to those skilled in the art.

[0020] The square bamboo shoot ultrafine powder obtained by the preparation method described in Examples 1 to 3 was subjected to a stability test. After being placed in an environment at a temperature of 25° C. for 24 months, the powder did not show any agglomeration or aggregation phenomenon, indicating that the prepared square bamboo shoot ultrafine powder has stable properties. The ultrafine grinding process not only greatly extends the shelf life of the product, but also improves the dissolution of the effective ingredients of the product, so that the prepared product can meet the use of more people, which is conducive to the promotion and application of the square bamboo shoot ultrafine powder.

[0021] The protection scope of the present invention is not limited to the technical solutions disclosed in the specific implementation methods. The above description is only a preferred implementation method of the present invention and does not limit the present invention. Any minor modifications, equivalent substitutions and improvements made according to the technical solutions of the present invention should be included in the protection scope of the technical solutions of the present invention.

Claims

1. A method for preparing superfine powder of bamboo shoots, characterized in that: The preparation method comprises the following steps: peeling off the bamboo shoot shells on the surface of the harvested bamboo shoots, cutting them, washing and blanching them, cutting them into small sections, freezing the cut sections, grinding them after freezing, drying the ground fresh powder, and finally ultrafine grinding the dried powder to obtain the bamboo shoot ultrafine powder. The method specifically comprises the following steps: S1. The harvested bamboo shoots are peeled off the bamboo shoots on the surface by mechanical or manual methods, and then cut along the length direction to obtain bamboo shoots; S2. The bamboo shoots obtained in step S1 are washed in clean water to remove dust, dirt and impurities from the surface. After washing, remove and drain the water; S3. After draining the bamboo shoots in step S2, blanch them in hot water at a temperature of 90 to 100 ℃ for 3 to 6 minutes, and then remove them from the pot; S4. After the bamboo shoots are blanched in step S3, they are quickly placed in clean water and cooled to room temperature. After cooling, they are removed and drained; S5. The cooled bamboo shoots in step S4 are cut into small sections of 0.1 to 0.5 cm in length; S6. The small pieces of bamboo shoots cut in step S5 are placed in liquid nitrogen for freezing for 25 to 35 minutes; S7. The frozen bamboo shoots in step S6 are ground into small segments using a frozen grinder, the frozen grinding time is 30 to 40min, and after frozen grinding, fresh powder is obtained; S8. The fresh powder obtained in step S7 is sent to a freeze dryer for freeze vacuum drying. The freeze vacuum drying method is as follows: the fresh powder is placed in a tray, first evacuated to 10-20 Pa, filled with nitrogen to atmospheric pressure, precooled to 0-10° C., maintained for 30-50 minutes, then evacuated to 10-20 Pa, heated and sublimated to 0-10° C., and then cooled to 0--10° C. to freeze the fresh powder into ice solid. After maintaining for 2.5-3.5 hours, nitrogen is passed to 20-30 Pa, and the temperature is kept for 3-5 hours to obtain dry powder; S9. The dried powder obtained in step S8 and the freeze-dried nitrogen are injected into an ultrafine pulverizer and pulverized by high-speed airflow for 40 to 60 minutes until the particle size is below 15 μm, thereby obtaining the square bamboo shoot ultrafine powder.

2. The method for preparing superfine powder of bamboo shoots according to claim 1, characterized in that: The square bamboo shoots harvested in step S1 refer to fresh square bamboo shoots dug from September to October each year. The square bamboo shoots can be dug when they are 15 to 20 cm long after they are unearthed. When digging, just dig 5 to 8 cm of soil at the base of the shoot and break it off.

3. The method for preparing superfine powder of bamboo shoots according to claim 1, characterized in that: The bamboo shoot segments in step S6 are placed in a liquid nitrogen tank for liquid nitrogen freezing, and the freezing time is 30 minutes.

4. The method for preparing the superfine powder of bamboo shoots according to claim 1, characterized in that: During the freeze grinding in step S7, liquid nitrogen is first used to pre-cool the freeze grinder for 5 to 10 minutes before freeze grinding. At the same time, during the freeze grinding process, liquid nitrogen needs to be added again every 3 to 5 minutes, and the ground bamboo shoots are required to be kept moistened with liquid nitrogen at all times.

5. The method for preparing the superfine powder of bamboo shoots according to claim 1, characterized in that: In the freeze-vacuum drying step S8, the freeze dryer is a vacuum dryer, and the freeze-vacuum drying method is: put the fresh powder in a plate, first evacuate to 15Pa, fill with nitrogen to atmospheric pressure, pre-cool to 5°C, keep for 40 minutes, then evacuate to 15Pa, heat and sublimate to 5°C, and then cool to -4°C to make the fresh powder of square bamboo shoots freeze into ice solid, keep for 3 hours, pass nitrogen to 25Pa, and keep warm for 4 hours.

6. The method for preparing the superfine powder of bamboo shoots according to claim 1, characterized in that: During the ultrafine grinding process of step S9, the temperature of the freeze-dried nitrogen is 5-6° C., and the pressure of the nitrogen injected into the ultrafine grinder is 20-30 Pa.

7. The superfine powder product of bamboo shoots prepared according to the preparation method according to any one of claims 1 to 6.