阅读说明：本技术 一种低频超声-射频复合协同定向钝酶提升玫瑰花干燥品质的方法 (Method for improving rose drying quality by virtue of low-frequency ultrasonic-radio frequency composite coordinated oriented inactive enzyme ) 是由 张慜 孙亚男 王彬 昌鲁 于 2020-04-15 设计创作，主要内容包括：一种低频超声-射频复合协同定向钝酶提升玫瑰花干燥品质的方法,属于食品加工技术领域。先将挑选、清洗好的原料放入柠檬酸浸渍液中进行浸泡；之后将其进行超声波处理3-5min,然后置于射频装置传送带上,射频处理装置谐振频率为27.12MHz,功率为3.5-8.0kW,极板间距为90-160mm,处理时间为50-90s,射频处理装置内温度为50-70℃。钝酶后的玫瑰花沥干后,迅速冷冻干燥。所述处理方法能钝化过氧化物酶、多酚氧化酶80-90％的活性,保留超氧化物歧化酶的40-60％相对残余活力。相比普通热水法钝酶,玫瑰花干燥后的花色苷含量提高10-16％,主要风味成分香茅醇的保存率提高14-20％。(A method for improving rose drying quality by low-frequency ultrasonic-radio frequency composite coordinated oriented inactive enzyme belongs to the technical field of food processing. Firstly, soaking the selected and cleaned raw materials in a citric acid soaking solution; then carrying out ultrasonic treatment for 3-5min, and then placing on a conveyer belt of a radio frequency device, wherein the resonance frequency of the radio frequency treatment device is 27.12MHz, the power is 3.5-8.0kW, the distance between polar plates is 90-160mm, the treatment time is 50-90s, and the internal temperature of the radio frequency treatment device is 50-70 ℃. And (4) draining the enzyme-inactivated rose, and quickly freezing and drying. The treatment method can inactivate 80-90% of activities of peroxidase and polyphenol oxidase, and retain 40-60% of relative residual activity of superoxide dismutase. Compared with common hot water enzyme inactivation, the anthocyanin content of the dried rose is improved by 10-16%, and the preservation rate of the main flavor component citronellol is improved by 14-20%.)

1. A method for improving rose drying quality by low-frequency ultrasonic-radio frequency composite coordinated oriented blunt enzyme is characterized by comprising the following steps:

(1) pretreatment of raw materials: selecting fresh roses, removing defective products, cleaning, putting rose petals into a citric acid soaking solution, and draining water on the surface after soaking for a period of time;

(2) low-frequency ultrasonic treatment: mixing the roses treated in the step (1) according to the mass ratio of material to water of 1: 10, starting ultrasonic waves, wherein the action frequency of the ultrasonic waves is 20kHz, and the action intensity is 0.30-0.40W/cm²The pulse mode is 6s action, 4s pause and the low-frequency ultrasonic treatment time is 3-5 min;

(3) placing the sample treated in the step (2) on a conveyor belt of a radio frequency device, wherein the resonant frequency of the radio frequency treatment device is 27.12MHz, the internal size of a heating cavity is 1300mm, × 1000mm, × 750mm, the power is 3.5-8.0kW, the distance between polar plates is 90-160mm, the treatment time is 50-90s, the temperature in the radio frequency treatment device is 50-70 ℃, and the sample is rapidly cooled after the radio frequency treatment is finished;

(4) drying the rose: quickly draining the roses treated in the step (3), and quickly transferring to a low-temperature refrigerator at minus 80 ℃ for freezing for 4 hours; drying until the final water content of the rose is below 8%, and finishing the drying process.

2. The method for improving the rose drying quality by the low-frequency ultrasonic-radio frequency composite synergetic oriented blunt enzyme according to claim 1, wherein the citric acid immersion liquid in the step (1) has a mass concentration of 5%; the immersion time was 2 h.

3. The method for improving the drying quality of roses by the low-frequency ultrasonic-radio frequency composite coordinated oriented blunt enzyme according to claim 1 or 2, wherein in the step (2), the roses are mixed according to the mass ratio of material to water of 1: 10, and the volume of the solution does not exceed 2/3 of a container.

4. The method for improving the dry quality of rose flowers by using the low-frequency ultrasonic-radio frequency composite synergistic oriented blunt enzyme as claimed in claim 1 or 2, wherein the action intensity of the ultrasonic waves in the step (2) is 0.35W/cm²And the low-frequency ultrasonic treatment time is 4 min.

5. The method according to claim 3, wherein the rose drying quality is improved by the low-frequency ultrasonic-radio frequency composite synergistic directional blunt enzymeThe method is characterized in that the action intensity of the ultrasonic waves in the step (2) is 0.35W/cm²And the low-frequency ultrasonic treatment time is 4 min.

6. The method for improving the rose drying quality by the low-frequency ultrasonic-radio frequency composite coordinated orientation blunt enzyme according to the claim 1, 2 or 5, characterized in that the input value of the radio frequency power in the step (3) is set to 6kW, and the plate spacing is 120 mm.

7. The method for improving the rose drying quality by the low-frequency ultrasonic-radio frequency composite coordinated orientation blunt enzyme according to claim 3, wherein the input value of the radio frequency power in the step (3) is set to 6kW, and the plate spacing is 120 mm.

8. The method for improving the rose drying quality by the low-frequency ultrasonic-radio frequency composite coordinated orientation blunt enzyme according to claim 4, wherein the input value of the radio frequency power in the step (3) is set to 6kW, and the plate spacing is 120 mm.

9. The method for improving the drying quality of roses by the low-frequency ultrasonic-radio frequency composite coordinated orientation blunt enzyme according to claim 1, 2, 5, 7 or 8, wherein the treatment time in the step (3) is 70s, and the temperature in the radio frequency treatment device is 60 ℃.

10. The method for improving the drying quality of rose flowers by using the low-frequency ultrasonic-radio frequency composite coordinated orientation blunt enzyme as claimed in claim 6, wherein the treatment time in the step (3) is 70s, and the temperature in the radio frequency treatment device is 60 ℃.

Technical Field

The invention relates to a method for improving rose drying quality by low-frequency ultrasonic-radio frequency coordinated oriented blunt enzyme, belonging to the technical field of food processing.

Background

The rose is a perennial evergreen or deciduous shrub belonging to Rosaceae and Rosa, is rich in nutrients such as protein, dietary fiber, phenols and flavonoids, and has important ornamental, medicinal and edible values. Fresh edible roses are easy to deteriorate in color, fragrance and taste and reduce in nutritive value when stored at normal temperature (about 20 ℃), and can also deteriorate in putrefaction and the like when placed for a long time.

The petals are easy to brown in the drying process, and proper enzyme inactivation treatment is necessary, which influences the moisture diffusion rate and the quality after drying in the whole drying process. The enzymes causing browning in edible flos Rosae Rugosae are mainly Peroxidase (POD) and polyphenol oxidase (PPO), POD catalyzes phenolic substances to generate browning, and H is firstly digested in the process of cell metabolism₂O₂By means of H₂O₂The released oxygen deoxidizes phenolic substances to generate quinone, then a series of dehydration and polymerization reactions are carried out, and finally black brown substances are formed and are gathered at the reaction part to cause browning. PPO catalyzes and oxidizes phenolic substances, anthocyanidin and degradation products thereof in the edible rose to generate corresponding quinone substances, and the quinone substances further oxidize anthocyanin to cause anthocyanin fading or discoloration. The superoxide dismutase (SOD) can catalyze the superoxide in the cell to generate H₂O₂And O₂Active oxygen generated in the metabolic process is eliminated, the content of active oxygen required by enzymatic browning reaction is reduced, and the browning reaction is inhibited. Therefore, the browning of the rose is mainly influenced by POD and PPO enzyme, so that the browning of the rose can be effectively prevented by properly keeping the SOD enzyme activity while the activities of the POD and PPO enzyme are passivated, and the quality of a dried product is ensured.

The enzyme inactivation can effectively improve the quality of the dried fruit and vegetable products, and the traditional enzyme inactivation method mainly adopts high-temperature hot water and normal-pressure steam, but the method is easy to cause the reduction of the drying quality of the fruit and vegetable, the loss of partial nutrient components and the like. In order to achieve a better enzyme inactivation effect, low-frequency ultrasonic wave is used for directionally inactivating enzyme of rose petals in cooperation with radio frequency treatment, the enzyme is inactivated through two stages, the enzyme stability is reduced in the first stage under the action of ultrasonic waves, and instant high temperature, high pressure and shock waves are generated by the formation and explosion of cavitation bubbles along with the increase of the propagation time of the ultrasonic waves in a medium, so that the heat sensitivity of the enzyme is enhanced; the second stage material causes the inside charged ion oscillation of material and polar molecule rotation through absorbing electromagnetic radiation, and these ion and molecule produce the friction at the inside high-speed motion of material to internally generate heat, have quick and bulk heating's unique advantage, the penetration depth is big, and heating efficiency is high, and it is effectual to go out enzyme.

Tang Yong Cheng et al discloses a method for preparing dried mango by combining ultrasonic osmotic dehydration with microwave drying (Chinese patent application No. CN201711465138.9), wherein a mango slice is placed in an ultrasonic instrument for osmotic dehydration for 50-120 min; and (4) drying by microwave to remove water until the water content of the mango slices is 6-10%. Compared with the prior art, the method has the advantages that the roses are pretreated by the cooperation of the ultrasonic waves and the radio frequency, so that the anthocyanin content of the dried roses can be kept, and the problems of nutrient component loss and the like caused by browning in the drying process are solved.

Wang Su Xin et al disclose a microwave-assisted method for inactivating enzyme in soybean (Chinese patent application No. CN201810552295.1), soaking soybean in citric acid aqueous solution, placing the soybean and the soaking solution together in a microwave reactor for microwave treatment, which can effectively reduce the activity of lipoxygenase in the soybean, improve the taste of bean products, and reduce the loss of nutrients. Compared with the prior art, the method has the advantages that the selective passivation of various enzymes is realized by combining various electromagnetic fields, the efficient directional inactive enzymes are realized, and the flavor and color of the rose tea are retained to the maximum extent.

Schlemongtong et al disclose a process for preparing crisp string of sweet pea (Chinese patent application No. CN201910778104.8), in which sweet pea is blanched with hot water to inactivate enzyme, then cooled to protect color, and the sweet pea soaked in color-protecting liquid is vacuum dried. Compared with the rose enzyme, the rose enzyme-inactivating method adopts high-efficiency physical field treatment, has large penetration depth, high heating efficiency and good enzyme-inactivating effect, and effectively preserves antioxidant active functional components of the rose.

Lanhongjian et al disclose a process for producing green zanthoxylum bungeanum enzyme-deactivating enzyme (Chinese patent application No. CN201610486705.8), preheating green zanthoxylum bungeanum, performing continuous microwave treatment at high temperature, then performing cold water spray cooling treatment, recovering aromatic essential oil through a draught fan, and the treatment can keep the fragrance and the numb taste of the green zanthoxylum bungeanum and prolong the shelf life. Compared with the prior art, the method utilizes the physical field to coordinate and orient the inactive enzyme, effectively inhibits the activity of the browning enzyme, obviously increases the penetration depth under the radio frequency, and effectively improves the quality of the dried final product.

Wangyuchuan et al discloses a processing and self-disinfection integrated device for directional inactivated enzyme of fruits and vegetables (Chinese patent application No. CN201910311723.6), wherein raw materials of fruits and vegetables enter an infrared irradiation cavity, a radio frequency irradiation cavity, a microwave irradiation cavity and an ultraviolet irradiation cavity through a conveyer belt to carry out inactivation and disinfection. Compared with the prior art, the invention utilizes the low-frequency ultrasonic radio frequency to coordinate with the directional inactive enzyme, so that the superoxide dismutase can keep higher components while the activities of peroxidase and polyphenol oxidase are effectively inhibited, thereby realizing the high-efficiency directional inactive enzyme and ensuring the quality of the dried final product.

Wangyuan et al discloses an integrated device for directional inactivation and sterilization of liquid food and a processing method thereof (Chinese patent application No. CN201910940554.2), wherein the liquid food generates fog drops with high charges at the outlet of a capillary under the action of a high-voltage direct-current electric field, and the fog drops with high charges kill enzymes and microorganisms in the liquid food. The directional inactive enzyme of the liquid food is realized according to the size distribution characteristic difference of various enzyme atomized liquid drops in the liquid food. Compared with the method, the coordinated orientation enzyme inactivation method is not only suitable for liquid materials, but also suitable for solid materials, and has higher universality.

Ruiz et al, which adopts microwave (650-900W) method to treat mung beans, found that the time required for enzyme deactivation is short (150s) and the vitamin C retention rate is higher than that of the traditional enzyme deactivation (48%), and can reach 64% under 650W condition. Delfiya et al treated carrot slices with microwaves (0.0-3.0 min), and found that with the increase of microwave treatment time, the rehydration performance and carotene content of the treated carrot slices are improved, and the influence on the quality, structure and color of the carrot slices is small.

Gamboa and the like adopt ultrasonic-assisted heat treatment (40-70 ℃) to inactivate enzymes of carrots, and researches show that the activity of Peroxidase (POD) is reduced to 6.7% at 60 ℃, the total phenol substances in the product are slightly damaged in the treatment process, and the carrot has better rehydration performance after treatment. Ren and other researches find that ultrasonic-assisted (20kHz, 70 ℃, 1.0-3.0 min) enzyme deactivation can improve retention rate of bioactive substances and antioxidant activity of freeze-dried onions, and ultrasonic-assisted has certain advantages in color protection performance.

The reports relate to the research of the physical field on the aspect of enzyme inactivation of fruits and vegetables, and the results show that the physical field has a good effect on the inactive enzyme of food materials, but the research fields do not relate to the low-frequency ultrasonic composite synergistic radio frequency directional inactive enzyme.

Disclosure of Invention

The invention aims to provide a method for improving the drying quality of roses by using low-frequency ultrasonic-radio frequency coordinated oriented enzyme inactivation, and mainly solves the problem that the color, the flavor, the functional components and the nutritional quality of a dried product are reduced due to hot water blanching enzyme inactivation before the existing fruit and vegetable drying. The method can realize directional inactivation of flos Rosae Rugosae, improve quality of dried product, and promote development of edible flower dried product.

The technical scheme of the invention is as follows:

a method for improving rose drying quality by low-frequency ultrasonic-radio frequency composite coordinated oriented blunt enzyme comprises the following steps:

(1) pretreatment of raw materials: selecting fresh roses, removing defective products, cleaning, putting rose petals into a citric acid soaking solution, and draining water on the surface after soaking for a period of time;

(2) low frequency ultrasonic treatment: mixing the roses treated in the step (1) according to the mass ratio of material to water of 1: 10, starting ultrasonic waves, wherein the action frequency of the ultrasonic waves is 20kHz, and the action intensity is 0.30-0.40W/cm²The pulse mode is 6s action, 4s pause and the low-frequency ultrasonic treatment time is 3-5 min;

(3) and (3) carrying out radio frequency treatment on the oriented inactive enzyme, namely placing the sample treated in the step (2) on a conveyor belt of a radio frequency device, wherein the resonance frequency of the radio frequency treatment device is 27.12MHz, the internal size of a heating cavity is 1300mm, × 1000mm, × 750mm and 750mm, the power is 3.5-8.0kW, the distance between electrode plates is 90-160mm, the treatment time is 50-90s, the temperature in the radio frequency treatment device is 50-70 ℃, and the sample is rapidly cooled after the radio frequency treatment is finished.

(4) And (3) drying: quickly draining the roses treated in the step (3), and quickly transferring to a low-temperature refrigerator at minus 80 ℃ for freezing for 4 hours; drying until the final water content of the rose is below 8%, and finishing the drying process.

The mass concentration of the citric acid immersion liquid in the step (1) is 5%; the immersion time was 2 h.

In the step (2), the roses are mixed according to the mass ratio of the materials to the water of 1: 10, and the volume of the solution is not more than 2/3 of the container.

The action intensity of the ultrasonic wave in the step (2) is 0.35W/cm²And the low-frequency ultrasonic treatment time is 4 min.

In the step (3), the input value of the radio frequency power is set to be 6kW, and the distance between the polar plates is 120 mm.

In the step (3), the treatment time is 70s, and the temperature in the radio frequency treatment device is 60 ℃.

The invention has the beneficial effects that: according to the invention, the low-frequency ultrasonic wave is used for assisting the blunt enzyme, and the covalent bonds among macromolecules are destroyed by using the mechanical effect of the ultrasonic wave, so that the activity of the enzyme is reduced; the cavitation effect of the ultrasonic wave effectively removes micro bubbles in water, thereby reducing the dissolved oxygen and further slowing down the oxidation. The invention adopts the synergistic effect of radio frequency and low-frequency ultrasound, and under the premise that the enzyme stability is reduced by ultrasound, the material absorbs electromagnetic radiation to cause charged ion oscillation and polar molecule rotation in the material, so that heat is generated in the material, the penetration depth is large, the heating efficiency is high, and the invention has the unique advantages of rapid and integral heating. The invention can passivate the activity of peroxidase and polyphenol oxidase by 80-90%, and retain 40-60% of relative residual activity of superoxide dismutase. Compared with common hot water enzyme inactivation, the anthocyanin content of the dried rose is improved by 10-16%, and the preservation rate of the main flavor component citronellol is improved by 14-20%.

Detailed Description