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CN-121971490-A - Gallnut de-enzyming method with high tannic acid retention rate

CN121971490ACN 121971490 ACN121971490 ACN 121971490ACN-121971490-A

Abstract

The invention discloses a method for deactivating enzyme of gallnut with high tannic acid retention rate, belonging to the technical field of preliminary processing of gallnut. The method comprises grading fresh times according to diameter, sterilizing with 110-120deg.C saturated steam for 1-4 min at the first stage, adjusting temperature to 95-105deg.C, continuously treating for 2-6 min to dehydrate the times, cooling forcibly after de-enzyming, cooling to below 40deg.C within 5-10 min, and drying to below water content of 12%. Aiming at the characteristics of a galling double-layer structure, the invention adopts a two-stage temperature changing process, combines the double aims of thoroughly killing internal insects and efficiently retaining external tannins, avoids the excessive heating of small fruits and the insufficient fixation of large fruits by size grading matching and differentiating treatment time, and reduces the degradation of tannins caused by waste heat by rapid cooling after fixation. The tannic acid retention rate of the invention is obviously higher than that of the traditional water boiling method, the water content after fixation is moderate, and the energy consumption for subsequent drying is reduced.

Inventors

  • CHEN YONGCHAO
  • HU YAN
  • YU JIAQI
  • LUO YONG
  • SHI CHANG
  • FENG WEI
  • Zhou Dingqin

Assignees

  • 遵义华邦农业科技开发有限公司

Dates

Publication Date
20260505
Application Date
20260323

Claims (9)

  1. 1. A method for deactivating enzyme of Galla chinensis with high tannic acid retention rate is characterized by comprising the following steps: (1) Fresh-time pretreatment, namely collecting fresh gallnut, removing damaged and mildewed gallnut, grading according to the diameter size, and carrying out fixation treatment within 24 hours after collection; (2) The first stage of enzyme deactivation, namely placing the graded gallnut into steam enzyme deactivation equipment, introducing saturated steam for treatment at 110-120 ℃ for 1-4 minutes; (3) The second stage of enzyme deactivation, namely after the first stage of enzyme deactivation is finished, adjusting the steam temperature to 95-105 ℃ and continuously treating for 2-6 minutes; (4) Quick cooling, namely taking out the gallnut immediately after fixation, and reducing the temperature of the gallnut to below 40 ℃ within 5-10 minutes by adopting a forced cooling mode; (5) And (5) drying the cooled gallnut until the final water content is below 12%.
  2. 2. The method of claim 1, wherein in the step (1), the small fruits are classified according to the diameter, the diameter is smaller than or equal to 1.5cm, the diameter of the medium fruits is 1.5-2.5cm, the diameter of the large fruits is larger than or equal to 2.5cm, and each type of the classified seeds is subjected to subsequent enzyme deactivation treatment respectively.
  3. 3. The method according to claim 2, wherein the first stage deactivation time of the small fruits is 1-2 minutes, the second stage deactivation time is 2-4 minutes, the first stage deactivation time of the medium fruits is 2-3 minutes, the second stage deactivation time is 3-5 minutes, and the first stage deactivation time of the large fruits is 3-4 minutes, and the second stage deactivation time is 4-6 minutes.
  4. 4. The method of claim 1, wherein a rapid pressure relief or ventilation transition is provided between step (2) and step (3) for a period of 30-60 seconds.
  5. 5. The method according to claim 1, wherein in the step (4), the forced cooling mode is vacuum cooling or cold air forced cooling, and the cold air temperature is 15-25 ℃ and the wind speed is 3-5m/s during the cold air forced cooling.
  6. 6. The method according to claim 1, wherein in the step (5), the drying is performed by hot air at a drying temperature of 50-70 ℃ for 8-24 hours.
  7. 7. The method of claim 1, further comprising a de-enzyming degree judging step, wherein in the de-enzyming process of the second stage of the step (3) or after the end, the gallnut is sampled and split to observe the internal insect body state, and the insect body is grey white or light brown, and the de-enzyming is qualified without transparent sense.
  8. 8. The method of claim 1, wherein the water content of the seeds after the fixation is controlled to be 45% -55%.
  9. 9. The method of claim 1, wherein the gallnut is one or more of a horny, a tripe, or a flower.

Description

Gallnut de-enzyming method with high tannic acid retention rate Technical Field The invention relates to the technical field of preliminary processing of galls, in particular to a gallnut de-enzyming method with high tannic acid retention rate. Background Gallnut is a gall formed by parasitizing gallnut aphids on host plants such as sumac, is rich in tannic acid (tannic acid), and is widely applied to the fields of medicines, chemical industry, foods and the like. After the gallnut is picked, the enzyme deactivation treatment must be performed in time, and the main purposes are that firstly, aphids and ova in the gallnut are killed, so that the cavity is prevented from being caused by continuously taking the gallnut, and secondly, endogenous enzyme activities such as polyphenol oxidase in the gallnut are passivated, so that the tannic acid is prevented from being subjected to enzymolysis in the subsequent storage and processing processes. At present, the Chinese gall is generally treated by a traditional water boiling method, namely fresh times are put into boiling water to be boiled for 3-5 minutes. The method has the problems that tannic acid is easy to dissolve in water in the actual production process to cause dissolution loss, tannic acid is degraded by heating after long-time water boiling, particularly loss is more serious after the gemini skin is broken, the water content of the gemini after water boiling is greatly increased, subsequent drying energy consumption is high, the de-enzyming degree lacks objective judgment standards, the method is mainly operated by experience, the insect body is not dead when the de-enzyming is insufficient, and the loss of tannic acid is aggravated when the de-enzyming is excessive. The gallnut has a unique double-layer structure, wherein the outer layer is a compact double-meat tissue and rich in tannic acid, and the inner layer is a gall chamber and contains aphids and ova. The structure has special requirements on the fixation process, namely, the heat is ensured to penetrate through the outer layer to reach the inner cavity to kill the insects, and the degradation of tannic acid caused by long-time heating of the meat on the outer layer is avoided. However, the existing fixation method cannot achieve the two purposes well. Disclosure of Invention The invention aims to provide a method for removing green of gallnut with high tannic acid retention rate, which aims to solve the technical problems that in the existing water boiling and removing green process, tannic acid is seriously dissolved and pyrolyzed, the water content after removing green is high, and both the killing of insects and the retention of tannic acid are difficult to achieve. In order to achieve the technical purpose, the following technical scheme is adopted: a method for deactivating enzyme of Galla chinensis with high tannic acid retention rate comprises the following steps: (1) Fresh-time pretreatment, namely collecting fresh gallnut, removing damaged and mildewed gallnut, grading according to the diameter size, and carrying out fixation treatment within 24 hours after collection; (2) The first stage of enzyme deactivation, namely placing the graded gallnut into steam enzyme deactivation equipment, introducing saturated steam for treatment at 110-120 ℃ for 1-4 minutes; (3) The second stage of enzyme deactivation, namely after the first stage of enzyme deactivation is finished, adjusting the steam temperature to 95-105 ℃ and continuously treating for 2-6 minutes; (4) Quick cooling, namely taking out the gallnut immediately after fixation, and reducing the temperature of the gallnut to below 40 ℃ within 5-10 minutes by adopting a forced cooling mode; (5) And (5) drying the cooled gallnut until the final water content is below 12%. In the step (1), the seeds are classified according to the diameter, the diameter of the seeds is smaller than or equal to 1.5cm, the diameter of the seeds is between 1.5 and 2.5cm, the diameter of the seeds is larger than or equal to 2.5cm, and the seeds are subjected to subsequent fixation treatment after classification. Further, the first stage de-enzyming time of the small fruits is 1-2 minutes, the second stage de-enzyming time is 2-4 minutes, the first stage de-enzyming time of the medium fruits is 2-3 minutes, the second stage de-enzyming time is 3-5 minutes, the first stage de-enzyming time of the large fruits is 3-4 minutes, and the second stage de-enzyming time is 4-6 minutes. Further, a rapid decompression or ventilation transition is arranged between the step (2) and the step (3), and the transition time is 30-60 seconds. In the step (4), the forced cooling mode is vacuum cooling or cold air forced cooling, wherein the temperature of the cold air is 15-25 ℃ and the wind speed is 3-5m/s when the cold air is forced cooling. Further, in the step (5), the drying is performed by hot air, the drying temperature is 50-70 ℃, and the drying time is 8-24 hours. Further