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CN-122004325-A - Peanut leaf tea and preparation method thereof

CN122004325ACN 122004325 ACN122004325 ACN 122004325ACN-122004325-A

Abstract

The invention relates to the technical field of agricultural product deep processing and substitute tea preparation, and discloses peanut leaf tea and a preparation method thereof, wherein the method comprises the steps of selecting tender peanut leaves, spreading the tender peanut leaves and carrying out microwave de-enzyming; and rolling the de-enzymed leaves, spraying metastable state interface inducing liquid containing low methoxyl pectin, citric acid, sodium citrate, sodium ascorbate, L-glutamic acid and trehalose in the spraying amount of 3.0-5.0%, and final low temperature curing at 60-70 deg.c and high temperature fragrance raising gradient drying at 110-120 deg.c to obtain the product. The invention utilizes the in-situ gelation reaction of the induced liquid and endogenous calcium ions to construct a barrier film on the leaf surface, reduces the loss of active ingredients such as anthocyanin and the like, combines gradient drying and Maillard reaction, improves the tight knot degree of strip ropes, removes green and astringent taste, endows the finished product with unique nut caramel fragrance, and obviously improves the sensory quality and nutritive value of peanut leaf tea.

Inventors

  • YIN DONGMEI
  • ZHAO KUNKUN

Assignees

  • 河南农业大学

Dates

Publication Date
20260512
Application Date
20260317

Claims (10)

  1. 1. The preparation method of the peanut leaf tea is characterized by comprising the following steps of: S1, preprocessing raw materials, namely selecting tender peanut leaves, cleaning and draining; s2, spreading and de-enzyming, namely spreading the processed leaves for de-enzyming, and then performing microwave de-enzyming; S3, twisting the de-enzymed leaves by coupling chemical and mechanical, and spraying metastable interface induction liquid to the surfaces of the leaves in the twisting process, wherein the spraying amount of the metastable interface induction liquid is 3.0-5.0% of the mass of the leaves, and the metastable interface induction liquid comprises the following components in percentage by mass: 0.30% -0.50% of low methoxy pectin; sodium citrate 0.10-0.15%; citric acid 0.20% -0.25%; Sodium ascorbate 0.30-0.40%; 1.0% -1.2% of L-glutamic acid; trehalose 2.0% -3.0%; Deionized water is the balance; S4, gradient phase change drying, namely performing low-temperature solidification drying on the rolling leaves at 60-70 ℃, and then heating to 110-120 ℃ for high-temperature aroma extraction drying to obtain the peanut leaf tea.
  2. 2. A method of preparing a peanut leaf tea according to claim 1, wherein the step of preparing the metastable interface inducing liquid comprises: preparing a base solution, namely heating deionized water to 45 ℃, and adding and dissolving citric acid, sodium citrate, sodium ascorbate, L-glutamic acid and trehalose; colloid dispersion, namely, increasing the stirring rotation speed to form vortex, and adding low methoxy pectin powder; Homogenizing and defoaming, namely stirring at a high speed until the mixture is transparent and has no particles, and standing for defoaming.
  3. 3. The method for preparing peanut leaf tea according to claim 1, wherein the raw materials selected in the step S1 are peanut plant top heart leaf and 1-2 tender leaves below the top heart leaf in the period of needle setting.
  4. 4. The method for preparing peanut leaf tea according to claim 1, wherein the condition of spreading in the step S2 is that the temperature is 20-25 ℃, the relative humidity is 60-70%, and the time is 1.5-2.5 hours.
  5. 5. The preparation method of peanut leaf tea according to claim 1, wherein the microwave de-enzyming power in the step S2 is 500-600W, the total duration is 45-50 seconds, and an intermittent heating mode is adopted.
  6. 6. A method of preparing a peanut leaf tea according to claim 1 wherein the low methoxyl pectin has a DE value of 25% to 35%.
  7. 7. The method of claim 1, wherein the twisting in step S3 is divided into initial twisting and re-twisting, wherein the initial twisting is performed for 60-90 seconds, and the re-twisting is continued for 2.0-3.0 minutes after the induced liquid is sprayed.
  8. 8. The method for preparing peanut leaf tea according to claim 1, wherein the moisture content of the low-temperature cured and dried control leaf in the step S4 is reduced to 25% -30%, and the moisture content of the high-temperature aroma-improving and dried control leaf is reduced to 8% -10%.
  9. 9. The method of preparing peanut leaf tea according to claim 1, wherein the flipping frequency of the low temperature curing stage in step S4 is 20-30 times/min and the flipping frequency of the high temperature aroma raising stage is 40-50 times/min.
  10. 10. A peanut leaf tea prepared by the preparation method of any one of claims 1 to 9.

Description

Peanut leaf tea and preparation method thereof Technical Field The invention relates to the technical field of agricultural product deep processing and substitute tea preparation, in particular to peanut leaf tea and a preparation method thereof. Background Peanuts are used as important oil crops, and the biomass of stems and leaves of overground parts of the peanuts is huge. Researches show that the peanut leaf contains rich active ingredients such as flavonoid compounds, resveratrol, triterpenoid saponins and the like, particularly anthocyanin and volatile ingredients with the functions of resisting oxidation, calming and aiding sleep, and has the potential of being developed into functional substituted tea. However, the current development and production of peanut leaf tea is faced with significant technical bottlenecks. Because peanut leaves have thicker cuticle and lack of self-oxidation polymerase systems such as tea polyphenol, the ideal quality is difficult to obtain by adopting the traditional green tea or black tea processing technology. In the de-enzyming link, high temperature is extremely easy to cause a large amount of degradation of heat-sensitive components such as anthocyanin and the like, so that the color of the finished tea soup is dull and the nutritional value is lost. In the rolling step, the peanut leaf has high fiber content and poor viscosity, and is difficult to curl into strips, so that the finished tea strips have loose cables and high breakage rate, and the appearance quality is poor and the tea strips are not beneficial to transportation and storage. In addition, peanut leaf raw materials have heavy green and astringent taste and grass fishy smell, are difficult to remove effectively by means of physical drying alone, and lack mellow fragrance similar to traditional tea leaves, so that consumer acceptance is low. Although the prior art attempts to improve the quality by adding exogenous flavoring agents or adopting low-temperature drying, the methods often cannot combine the retention of active ingredients and the flavor improvement, or have the problems of original taste masking by additives, excessive process cost and the like, and are difficult to realize large-scale production. Therefore, the development of a processing method capable of efficiently retaining the functional components of peanut leaves and improving the morphology and the sensory flavor of the peanut leaves is a problem to be solved in the field of comprehensive utilization of peanut resources. Disclosure of Invention Aiming at the defects of the prior art, the invention provides the peanut leaf tea and the preparation method thereof, and solves the problems that active ingredients such as anthocyanin and the like are poor in thermal stability and easy to run off in the de-enzyming and twisting stages in the existing peanut leaf tea processing process, and the finished product tea is loose in strip, heavy in green taste and insufficient in fragrance. In order to achieve the above purpose, the invention is realized by the following technical scheme: In a first aspect, the invention provides a preparation method of peanut leaf tea, which adopts the following technical scheme: a preparation method of peanut leaf tea comprises the following steps: S1, preprocessing raw materials, namely selecting tender peanut leaves, cleaning and draining; s2, spreading and de-enzyming, namely spreading the processed leaves for de-enzyming, and then performing microwave de-enzyming; s3, twisting the de-enzymed leaves by coupling chemistry and machinery, and spraying metastable interface induction liquid to the surfaces of the leaves in the twisting process, wherein the spraying amount of the metastable interface induction liquid is 3.0% -5.0% of the mass of the leaves; wherein the metastable state interface inducing liquid comprises the following components in percentage by mass: 0.30 to 0.50 percent of low methoxy pectin, 0.10 to 0.15 percent of sodium citrate, 0.20 to 0.25 percent of citric acid, 0.30 to 0.40 percent of sodium ascorbate, 1.0 to 1.2 percent of L-glutamic acid, 2.0 to 3.0 percent of trehalose and the balance of deionized water; S4, gradient phase change drying, namely performing low-temperature solidification drying on the rolling leaves at 60-70 ℃, and then heating to 110-120 ℃ for high-temperature aroma extraction drying to obtain the peanut leaf tea. By adopting the technical scheme, the quality of the peanut leaf tea is improved by utilizing the synergistic effect of chemical components and a processing technology, and the specific principle is as follows: In the invention, metastable interface induced liquid is introduced in the rolling stage, and endogenous calcium ions flowing out by crushing peanut leaf cells are utilized to carry out ionic crosslinking reaction with low methoxy pectin in the induced liquid. The galacturonic acid residues of low methoxyl pectin combine under the action of calcium ions