Film cloth containing opuntia ficus-indica and preparation method of film cloth

Abstract

The invention relates to a film cloth containing opuntia ficus-indica and a preparation method thereof, and belongs to the technical field of skin care products. According to the membrane cloth, sodium carboxymethyl cellulose and sodium alginate ions are cross-linked to form a framework, and composite active ingredients are uniformly dispersed in the framework; the composite active component is composed of an opuntia ficus-indica active extract and rice gelatinized syrup. The film cloth realizes accurate regulation and control of a gradient aperture structure through temperature gradient field curing, and a gradient structure with dense outside and sparse inside is formed. The outer layer is compact, so that the release rate of active ingredients can be slowed down, rapid loss of the ingredients is avoided, and the skin-care persistence is prolonged; and the inner layer is loose and can bear more composite active components.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of skin care products, and relates to a pear cactus membrane cloth and a preparation method thereof. BACKGROUND

[0002] As a natural plant with both medicinal and skin care values, pear cactus is rich in polysaccharides, flavonoids, amino acids and various minerals in its stem pieces, and has excellent antioxidant, moisturizing and skin soothing effects, and thus is highly concerned in the field of cosmetic raw materials. Rice gelatinized syrup is prepared by gelatinization and enzymatic hydrolysis of rice starch, and contains rich oligosaccharides and dextrin. The rice gelatinized syrup not only has good water solubility and moisturizing properties, but also can be used as a natural carrier to improve the stability and skin permeability of other active ingredients.

[0003] As an important carrier for active ingredients, the performance of a membrane cloth directly affects the exertion of skin care effects. Commonly used membrane cloth substrates include natural and synthetic high molecular materials. The preparation of a membrane cloth is usually carried out by a solution film forming method, in which the substrate is dissolved and mixed with active ingredients, and then solidified, demolded and the like to form a membrane cloth. How to improve the uniformity of dispersion of active ingredients in the membrane cloth, control the release rate of the active ingredients, and optimize the adhesion and air permeability of the membrane cloth is a key research direction of the preparation process of the membrane cloth.

[0004] In the prior art, the extraction of pear cactus active ingredients is usually carried out by high-temperature boiling or chemical solvent method, which easily leads to the inactivation of heat-sensitive components and has low extraction efficiency. When rice derivatives are used as carriers, the molecular weight and structure thereof are difficult to be accurately controlled, which affects the loading and synergistic effect of active ingredients. In addition, traditional membrane cloths usually have uniform pore sizes, and either have the problems of too fast release of active ingredients and poor persistence, or have poor air permeability and poor skin feel experience. Moreover, some preparation processes are complex, involve high temperature or toxic reagents, and are not conducive to the preservation and large-scale production of natural active ingredients. SUMMARY

[0005] The present application aims to provide a pear cactus-containing membrane cloth and a preparation method thereof, which has a "dense outside and sparse inside" double-channel slow-release structure and has triple synergistic effects of antioxidant, repair and slow release.

[0006] The object of the present application can be achieved by the following technical solutions: A pear cactus-containing membrane cloth, the material of the formed membrane cloth comprises: a high molecular substrate network formed by ionic crosslinking of carboxymethyl cellulose sodium and sodium alginate; a complex active ingredient dispersed in the high molecular substrate network; the complex active ingredient is formed by pear cactus active extract and rice gelatinized syrup; The material of the forming film cloth is processed into an outer layer and an inner layer, and the average pore size of the outer layer is smaller than that of the inner layer.

[0007] As a preferred technical solution of the present application, the Opuntia dillenii Haw. active extract is prepared by the following steps: A1, after the Opuntia dillenii Haw. stem pieces are removed of spines, freeze-drying and crushing, Opuntia powder is obtained; A2, the Opuntia powder obtained in step A1 is mixed with deionized water at a mass ratio of 1:10-20, the pH is adjusted to 5.5-6.5, and a low-temperature plasma device is used for treatment at 20-30℃ for 1-2min; A3, the broken cell Opuntia slurry obtained in step A2 is centrifuged to obtain the supernatant to obtain the active extract.

[0008] As a preferred technical solution of the present application, the rice gelatinized syrup is prepared by the following steps: B1, the rice is crushed and mixed with deionized water, and gelatinized at 85-95℃ for 15-30min until the slurry is translucent and viscous; B2, the gelatinized slurry obtained in step B1 is cooled to 60-75℃, the pH is adjusted to 5.5-6.5, and α-amylase is added for enzymatic hydrolysis for 30-90min; B3, the enzyme hydrolysis mixture of step B2 is boiled in water for 10min to inactivate the enzyme, and the supernatant is obtained by centrifugation.

[0009] As a preferred technical solution of the present application, the amount of α-amylase added is 0.5-2% of the dry weight of the rice.

[0010] Further, the preparation method of the Opuntia dillenii Haw. film cloth comprises the following steps: (1) the Opuntia dillenii Haw. active extract is mixed with the rice gelatinized syrup, and then high-pressure homogenization is performed; (2) the mixture of step (1) is subjected to ultrasonic nanodispersion for 10-30min to obtain a composite active ingredient solution; (3) carboxymethyl cellulose sodium and sodium alginate are dissolved in deionized water to form a film-forming base solution; (4) the composite active ingredient solution obtained in step (2) is mixed with the film-forming base solution obtained in step (3), and a crosslinking agent Ca 2+ solution is added and mixed uniformly; (5) the mixture of step (4) is divided into a first mixture and a second mixture, the first mixture is solidified and formed at a first temperature to obtain an inner layer, and the second mixture is solidified and formed on the surface of the inner layer at a second temperature to obtain an outer layer, and the first temperature is lower than the second temperature.

[0011] As a preferred technical scheme of the present application, the mass ratio of the Opuntia dillenii Haw active extract to the rice gelatinized syrup in step (1) is 1:0.5-2; and the high-pressure homogenization pressure is 500-1500 bar.

[0012] As a preferred technical scheme of the present application, the dispersion particle size of the composite active ingredient solution obtained in step (2) is 50-200 nm.

[0013] As a preferred technical scheme of the present application, the mass ratio of the sodium carboxymethyl cellulose, sodium alginate and deionized water in step (3) is 1.5-3:0.5-1:90-95.

[0014] As a preferred technical scheme of the present application, the Ca 2+ solution is a 2-5% CaCl2 solution; and the mass ratio of the composite active ingredient solution, the film-forming base solution and the Ca 2+ solution is 10-25:75-90:4.25-13.5.

[0015] As a preferred technical scheme of the present application, the first temperature in step (5) is 15-25℃ lower than the second temperature.

[0016] In the present application, the first temperature is high, the polymer chain movement is intensified, the crosslinking rate is slow, a loose porous structure is formed, the skin-friendly feeling and the active ingredient release rate are improved; and the second temperature is low, the calcium ion crosslinking is accelerated, a dense layer is formed to realize the function of reducing water evaporation.

[0017] The present application has the following beneficial effects: (1) The present application adopts the freeze-drying and low-temperature plasma treatment process, compared with the traditional high-temperature extraction or chemical solvent method, can maximize the retention of the polysaccharide, flavone and other antioxidant and moisturizing active ingredients in the Opuntia dillenii Haw, and improve the skin care efficacy basis; by controlling the gelatinization temperature and using α-amylase to prepare the rice gelatinized syrup, the rice gelatinized syrup not only plays a role as a natural moisturizing agent, but also stably loads the Opuntia dillenii Haw active ingredients as a carrier, and through high-pressure homogenization and ultrasonic nanodispersion, the uniform mixing and nanoscale dispersion of the two are realized, and the skin permeability of the active ingredients is enhanced.

[0018] (2) The present application forms a substrate network by calcium ion crosslinking of sodium carboxymethyl cellulose and sodium alginate, which can firmly lock the composite active ingredients; and by curing the film cloth outer layer at different temperatures, the average pore size of the outer layer is smaller than that of the inner layer, forming a structure of "dense outside and loose inside". The dense outer layer can slow down the release rate of the active ingredients, avoid the rapid loss of the ingredients, and prolong the skin care efficacy; and the loose inner layer can carry more composite active ingredients, and at the same time, improve the air permeability of the film cloth, reduce the stuffy feeling during use, and enhance the skin comfort. DETAILED DESCRIPTION

[0019] To further illustrate the technical means and effects taken by the present application to achieve the predetermined object of the invention, the following embodiments are combined to explain the specific embodiments, structures, features and effects of the present application in detail.

[0020] Example 1 A pear cactus membrane cloth is provided, and the material of the shaped membrane cloth comprises: a high-molecular substrate network formed by ion cross-linking of sodium carboxymethyl cellulose and sodium alginate; a complex active ingredient dispersed in the high-molecular substrate network; the complex active ingredient is formed by a pear cactus active extract and a rice gelatinized syrup; wherein the material of the shaped membrane cloth is processed into an outer layer and an inner layer, and the average pore size of the outer layer is smaller than that of the inner layer.

[0021] The pear cactus active extract is prepared by the following steps: A1, after removing the spines of the pear cactus stem pieces, freeze-drying and crushing to obtain cactus powder; A2, mixing the cactus powder prepared in step A1 with deionized water at a mass ratio of 1:15, adjusting the pH to 6, and treating with a low-temperature plasma device at 25°C for 2 min; A3, centrifuging the broken cell cactus slurry prepared in step A2 to obtain the supernatant to obtain the active extract.

[0022] The rice gelatinized syrup is prepared by the following steps: B1, crushing the rice and mixing with deionized water, and gelatinizing at 90°C for 20 min until the slurry is translucent and viscous; B2, cooling the gelatinized slurry prepared in step B1 to 65°C, adjusting the pH to 6, adding α-amylase, and enzymatic hydrolysis for 60 min; B3, boiling water bath for 10 min to inactivate the enzyme, and centrifuging to obtain the supernatant.

[0023] The amount of α-amylase added is 1% of the dry weight of the rice.

[0024] The preparation method of the pear cactus membrane cloth comprises the following steps: (1) uniformly mixing the pear cactus active extract and the rice gelatinized syrup, and then performing high-pressure homogenization; (2) ultrasonic nanodispersion of the mixture of step (1) for 20 min to obtain a complex active ingredient liquid; (3) dissolving sodium carboxymethyl cellulose and sodium alginate in deionized water to form a film-forming base solution; (4) mixing the complex active ingredient liquid obtained in step (2) with the film-forming base solution obtained in step (3), adding a cross-linking agent Ca2+ The solution is mixed evenly; (5) The mixture of step (4) is divided into a first mixture and a second mixture, the first mixture is solidified and formed at a first temperature to obtain an inner layer, and the second mixture is solidified and formed at a second temperature on the surface of the inner layer to obtain an outer layer, the first temperature is lower than the second temperature.

[0025] The mass ratio of the pear cactus active extract to the rice gelatinized syrup in step (1) is 1:0.5-2; and the high-pressure homogenization pressure is 1000 bar.

[0026] The dispersion particle size of the obtained composite active ingredient solution in step (2) is 50-200 nm.

[0027] The mass ratio of the sodium carboxymethyl cellulose, the sodium alginate and the deionized water in step (3) is 2:0.7:92.

[0028] The Ca 2+ The solution is a 3% CaCl2 solution; the mass ratio of the composite active ingredient solution, the film-forming base solution and the Ca 2+ The solution is 18:80:9.

[0029] The second temperature of the temperature gradient field in step (5) is 45℃, and the first temperature is 20℃.

[0030] Example 2 A pear cactus film cloth is provided, and the material for forming the film cloth comprises: A high-molecular base material network formed by ion cross-linking of sodium carboxymethyl cellulose and sodium alginate; A composite active ingredient dispersed in the high-molecular base material network; The composite active ingredient is formed by a pear cactus active extract and a rice gelatinized syrup. The material for forming the film cloth is processed into an outer layer and an inner layer, and the average pore size of the outer layer is smaller than that of the inner layer.

[0031] The pear cactus active extract is prepared by the following steps: A1, after removing the spines of the pear cactus stem pieces, the pear cactus stem pieces are freeze-dried and crushed to obtain cactus powder; A2, the cactus powder obtained in step A1 is mixed with deionized water at a mass ratio of 1:10, the pH is adjusted to 5.5, and a low-temperature plasma device is used to treat at 20℃ for 1 min; A3, the broken cell cactus pulp obtained in step A2 is centrifuged to obtain the supernatant to obtain the active extract.

[0032] The rice gelatinized syrup is prepared by the following steps: B1, rice is crushed, mixed with deionized water, gelatinized at 85℃ for 15 min to a semi-transparent viscous state; B2, the gelatinized slurry prepared in step B1 is cooled to 60℃, the pH is adjusted to 5.5, and alpha-amylase is added, and enzymatic hydrolysis is carried out for 30 min; B3, the enzymatic hydrolysis mixture of step B2 is boiled in a water bath for 10 min to inactivate the enzyme, and the supernatant is obtained by centrifugation.

[0033] The amount of alpha-amylase added is 0.5% of the dry weight of rice.

[0034] The preparation method of the pear cactus film cloth comprises the following steps: (1) mixing the pear cactus active extract with the rice gelatinized syrup uniformly and then performing high-pressure homogenization; (2) performing ultrasonic nanodispersion on the mixture of step (1) for 10 min to obtain a composite active ingredient solution; (3) dissolving carboxymethyl cellulose sodium and sodium alginate in deionized water to form a film-forming base solution; (4) mixing the composite active ingredient solution obtained in step (2) with the film-forming base solution obtained in step (3), adding a crosslinking agent Ca 2+ solution, and uniformly mixing; (5) dividing the mixture of step (4) into a first mixture and a second mixture, allowing the first mixture to solidify and form an inner layer at a first temperature, and allowing the second mixture to solidify and form an outer layer on the surface of the inner layer at a second temperature, wherein the first temperature is lower than the second temperature.

[0035] In step (1), the mass ratio of the pear cactus active extract to the rice gelatinized syrup is 1:0.5-2, and the high-pressure homogenization pressure is 500 bar.

[0036] In step (2), the dispersion particle size of the composite active ingredient solution is 50-200 nm.

[0037] In step (3), the mass ratio of carboxymethyl cellulose sodium, sodium alginate, and deionized water is 1.5:0.5:90.

[0038] In step (4), the Ca 2+ solution is a 2% CaCl2 solution; and the mass ratio of the composite active ingredient solution, the film-forming base solution, and the Ca 2+ solution is 10:75:4.25.

[0039] In step (5), the temperature gradient field second temperature is 40℃, and the first temperature is 15℃.

[0040] Example 3 The pear cactus film cloth comprises: A high molecular matrix network formed by ionic cross-linking of sodium carboxymethyl cellulose and sodium alginate; A complex active ingredient dispersed in the high molecular matrix network; The complex active ingredient is formed by Opuntia tuna active extract and rice gelatinized syrup; Wherein, the material of the forming film cloth is processed into an outer layer and an inner layer, the average pore size of the outer layer is smaller than that of the inner layer.

[0041] The Opuntia tuna active extract is prepared by the following steps: A1, after removing the spines of Opuntia tuna stem pieces, freeze-drying and crushing to obtain cactus powder; A2, mixing the cactus powder prepared in step A1 with deionized water according to a mass ratio of 1:20, adjusting the pH to 6.5, and treating with low-temperature plasma equipment at 30°C for 2 min; A3, centrifuging the broken cell cactus slurry prepared in step A2 to obtain the supernatant to obtain the active extract.

[0042] The rice gelatinized syrup is prepared by the following steps: B1, crushing rice and mixing with deionized water, and gelatinizing at 95°C for 30 min until the slurry is translucent and viscous; B2, cooling the gelatinized slurry prepared in step B1 to 75°C, adjusting the pH to 6.5, adding α-amylase, and enzymatic hydrolysis for 90 min; B3, boiling water bath enzyme inactivation of the enzymatic hydrolysis mixture for 10 min, and centrifuging to obtain the supernatant.

[0043] The amount of α-amylase added is 2% of the dry weight of rice.

[0044] The preparation method of the Opuntia tuna film cloth comprises the following steps: (1) uniformly mixing the Opuntia tuna active extract and the rice gelatinized syrup, and then high-pressure homogenizing; (2) ultrasonic nanodispersion of the mixture of step (1) for 30 min to obtain a complex active ingredient liquid; (3) dissolving sodium carboxymethyl cellulose and sodium alginate in deionized water to form a film-forming base solution; (4) mixing the complex active ingredient liquid obtained in step (2) with the film-forming base solution obtained in step (3), adding a cross-linking agent Ca 2+ and mixing uniformly; (5) dividing the mixture of step (4) into a first mixture and a second mixture, solidifying the first mixture at a first temperature to form an inner layer, and solidifying the second mixture on the surface of the inner layer at a second temperature to form an outer layer, wherein the first temperature is lower than the second temperature.

[0045] The mass ratio of the pear cactus active extract to the rice gelatinized syrup in step (1) is 1:2; and the high-pressure homogenization pressure is 1500 bar.

[0046] The dispersion particle size of the obtained composite active ingredient liquid in step (2) is 50-200 nm.

[0047] The mass ratio of the sodium carboxymethyl cellulose, the sodium alginate and the deionized water in step (3) is 3:1:95.

[0048] The Ca 2+ The solution is a 5% CaCl2 solution; and the mass ratio of the composite active ingredient liquid, the film-forming base liquid and the Ca 2+ solution is 25:90:13.5.

[0049] The second temperature of the temperature gradient field in step (5) is 50℃, and the first temperature is 25℃.

[0050] Comparative Example 1 On the basis of Example 1, the pear cactus active extract is extracted by water boiling method, the cactus powder is mixed with deionized water at a mass ratio of 1:15, boiled at 80℃ for 2h, and then filtered to obtain the supernatant, and the rest is consistent with Example 1.

[0051] Comparative Example 2 On the basis of Example 1, the pear cactus active extract is extracted by alcohol, and 60% ethanol is used for extraction at 50℃, and the rest is consistent with Example 1.

[0052] Comparative Example 3 On the basis of Example 1, the rice gelatinized syrup is omitted in step B2 enzymatic treatment, and the rest is consistent with Example 1.

[0053] Comparative Example 4 On the basis of Example 1, the preparation method of the pear cactus film cloth is omitted in step (1) high-pressure homogenization treatment, and the rest is consistent with Example 1.

[0054] Comparative Example 5 On the basis of Example 1, the preparation method of the pear cactus film cloth is omitted in step (2) ultrasonic nanodispersion treatment, and the rest is consistent with Example 1.

[0055] Comparative Example 6 On the basis of Example 1, the preparation method of the pear cactus film cloth is not set to temperature gradient, and is solidified at constant temperature of 32℃, and the rest is consistent with Example 1.

[0056] Performance test: Antioxidant: 1 g of the sample of the examples and comparative examples was cut into pieces and soaked in 10 mL of PBS (pH 7.4) for 24 h (37°C), centrifuged to obtain the supernatant, and the active ingredient extract was obtained; 10 μg / mL, 50 μg / mL, 100 μg / mL and 200 μg / mL sample solutions were prepared and mixed with 0.1 mM DPPH ethanol solution (1:1), and reacted in the dark for 30 min, and the absorbance was measured at 517 nm, and the DPPH clearance rate was calculated; Skin barrier repair: 80 volunteers with impaired skin barrier (aged 20-35 years old, no history of skin disease) were recruited and randomly divided into 8 groups to use the samples prepared in the examples and comparative examples, and the film cloth was applied for 15 min in the morning and evening every day, and the treatment was continuously used for 7 days; the TEWL of the face was measured by Tewameter before and after the use.

[0057] Sustained release effect: 2 cm 2 The sample was soaked in 10 mL of PBS with pH 7.4, and the liquid samples soaked for 10 min, 1 h and 2 h were taken, and the concentration of polyphenols (using gallic acid as a standard) was detected by high performance liquid chromatography.

[0058] It can be seen from the test results that the water boiling method of the comparative example destroys the active substances of the Opuntia dillenii Haw. at high temperature, resulting in a decrease in antioxidant capacity; the ethanol extraction of the comparative example 2 may result in incomplete dissolution of polyphenols, and the improvement rate of TEWL is significantly decreased, which may be due to the stimulation of ethanol to the skin; the comparative example 3 omits the enzyme hydrolysis step, and the macromolecular syrup blocks the membrane pores and hinders the penetration and release of active substances; the comparative example 4 does not perform high-pressure homogenization, and the comparative example 5 does not perform ultrasonic nanodispersion treatment, which may cause the aggregation of active ingredients, uneven dispersion and an increase in particle size, resulting in a decrease in penetration efficiency; the comparative example 6 does not have temperature difference solidification, and uniform pore size is lost, resulting in a loss of sustained release and long-acting repair.

[0059] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, and any indirect modification, equivalent change and modification of the above examples according to the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. A membrane containing prickly pear cactus, characterized in that: The materials of formed membrane cloth include: A polymer matrix network formed by ionic crosslinking of sodium carboxymethyl cellulose and sodium alginate; a composite active ingredient dispersed in the polymer matrix network; The composite active ingredient is formed by the active extract of Opuntia pyrifolia and rice gelatinized syrup; The material of the formed membrane cloth is processed into an outer layer and an inner layer, and the average pore size of the outer layer is smaller than the average pore size of the inner layer.

2. The membrane cloth containing prickly pear cactus according to claim 1, characterized in that: The active extract of Opuntia pomegranate is prepared by the following steps: A1. Remove the spines from Opuntia cactus stem slices, freeze-dry them, and then grind them into cactus powder; A2. Mix the cactus powder prepared in step A1 with deionized water in a mass ratio of 1:10-20, adjust the pH to 5.5-6.5, and treat with a low-temperature plasma device at 20-30°C for 1-2 minutes; A3. Prepare the broken cactus pulp in step A2, centrifuge and collect the supernatant to obtain the active extract.

3. The membrane cloth containing prickly pear cactus according to claim 1, characterized in that: The rice gelatinized syrup is prepared by the following steps: B1. Grind the rice, add deionized water and mix, and gelatinize at 85-95°C for 15-30 minutes until the slurry becomes translucent and viscous; B2. Cool the gelatinized slurry obtained in step B1 to 60-75°C, adjust the pH to 5.5-6.5, add α-amylase, and perform enzymatic hydrolysis for 30-90 minutes; B3. Inactivate the enzyme in the enzymatic hydrolysis mixture obtained in step B2 by boiling water, and centrifuge to obtain the supernatant.

4. The membrane cloth containing prickly pear cactus according to claim 3, characterized in that: The α-amylase is added in an amount of 0.5-2% of the dry weight of the rice.

5. A method for preparing a membrane containing prickly pear cactus according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) Mix the active extract of Opuntia pyrifolia and rice gelatinized syrup and homogenize; (2) subjecting the mixture from step (1) to ultrasonic nanodispersion for 10-30 minutes to obtain a composite active ingredient liquid; (3) Dissolve sodium carboxymethyl cellulose and sodium alginate in deionized water to form a membrane-forming base liquid; (4) Mix the composite active ingredient liquid obtained in step (2) with the film-forming base liquid obtained in step (3), and add the crosslinking agent Ca 2+ The solution was mixed evenly; (5) The mixed liquid in step (4) is divided into a first mixed liquid and a second mixed liquid, the first mixed liquid is solidified at a first temperature to obtain an inner layer, and the second mixed liquid is solidified at a second temperature on the surface of the inner layer to obtain an outer layer, wherein the first temperature is lower than the second temperature.

6. The method for preparing a membrane containing Opuntia cactus according to claim 5, characterized in that: In step (1), the mass ratio of the active extract of Opuntia pyrifolia to the rice gelatinized syrup is 1:0.5-2; and the high-pressure homogenization pressure is 500-1500 bar.

7. The method for preparing a membrane containing Opuntia pomegranate according to claim 5, characterized in that: The dispersed particle size of the composite active ingredient liquid obtained in step (2) is 50-200 nm.

8. The method for preparing a membrane containing Opuntia pomegranate according to claim 5, characterized in that: The mass ratio of sodium carboxymethyl cellulose, sodium alginate and deionized water in step (3) is 1.5-3:0.5-1:90-95.

9. The method for preparing a membrane containing Opuntia pomegranate according to claim 5, characterized in that: Step (4) Ca 2+ The solution is 2-5% CaCl2 solution; composite active ingredient solution, film-forming base solution and Ca 2+ The mass ratio of the solution is 10-25:75-90:4.25-13.

5.

10. The method for preparing a membrane containing Opuntia cactus according to claim 5, characterized in that: The first temperature is 15-25°C lower than the second temperature.

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