Method for dewaxing and drying wolfberry

Abstract

The application belongs to the technical field of drying processing pretreatment, and particularly relates to a method for dewaxing and promoting drying of wolfberry, which comprises the following steps: (1) soaking wolfberry with a liquid enzyme preparation, wherein the liquid enzyme preparation comprises water and at least one enzyme, and the enzyme is an enzyme having the function of decomposing plant wax layer; and (2) placing the wolfberry soaked in step (1) into a drying chamber and drying under the conditions of a temperature of 20-85 DEG C and a humidity of 10-80%. The method for dewaxing and promoting drying of wolfberry effectively solves the problems of chemical residues and quality damage of the current wolfberry dried products, and maximally maintains the nutritional ingredients of wolfberry pulp. In addition, the method can further reduce drying energy consumption and improve drying rate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of drying processing pretreatment, and particularly relates to a dewaxing and drying method for wolfberry. BACKGROUND

[0002] Drying is an important link in wolfberry processing. Although the components of wolfberry are slightly different between different regions and different varieties, the drying process of wolfberry is usually based on dewaxing.

[0003] Traditional dewaxing processes usually use salt solution to soak wolfberry. During the dewaxing process, the exosmosis of components such as polysaccharides causes the product to be sticky and hard, and browning and deterioration occur during the processing. Soaking wolfberry in salt solution increases the amount of water, which increases the energy consumption during the drying process. In addition, the contact between water and the wound of the fruit stem is one of the causes of deterioration. At the same time, the use of chemical drying methods causes chemical residues in the product, which has a great impact on the aroma and multivitamins of wolfberry, and the quality of wolfberry cannot be guaranteed, which affects the commodity rate. In order to solve the above problems, it is urgent to find a dewaxing process for wolfberry without chemical residues. After dewaxing, combined with the current low-energy drying process, the energy consumption can be effectively reduced, and technical services can be provided to improve the quality of wolfberry dried products. SUMMARY

[0004] The purpose of the present application is to provide a dewaxing and drying method for wolfberry, which effectively solves the problems of chemical residues and quality damage in the current wolfberry dried products, and maximizes the retention of the nutritional components of wolfberry pulp. In addition, it can further reduce the energy consumption of drying and improve the drying rate.

[0005] Specifically, the present application provides a dewaxing and drying method for wolfberry, comprising the following steps:

[0006] (1) soaking wolfberry with liquid enzyme preparation, wherein the liquid enzyme preparation comprises water and at least one enzyme, and the enzyme is a wax enzyme, a chitinase or other enzyme with the function of decomposing plant wax layer;

[0007] (2) placing the wolfberry soaked in step (1) into a drying chamber and drying at a temperature of 20-85℃ and a humidity of 10-80%.

[0008] The enzyme dewaxing and drying technology for wolfberry provided by the present application has the following advantages. First, the wolfberry to be dried is soaked in enzyme preparation for a period of time for the first dewaxing. Second, the soaked wolfberry is placed in a drying chamber, and the temperature and humidity in the drying chamber are controlled for warm and humid drying, so that the enzyme activity in the enzyme preparation reaches the best state, the second dewaxing is carried out, and the decomposition and destruction ratio of different components of the wax layer is improved.

[0009] In the present application, the enzymes having the function of decomposing the plant wax layer, such as the wax enzyme and the chitinase, are not limited to the manufacturers, and all the enzymes or enzyme preparations produced by the regular manufacturers, the laboratory purification production, or the genetically engineered enzyme variants are within the scope of the present application. Specifically, it includes but is not limited to the wax enzyme and the chitinase.

[0010] As preferred, in the step (1) of the above-mentioned dewaxing and drying method of wolfberry, the enzyme is the wax enzyme and / or the chitinase. The present application finds that the dewaxing speed is faster by using the liquid enzyme preparation containing the above-mentioned enzyme.

[0011] More preferably, the enzyme is the mixed enzyme of the wax enzyme and the chitinase with the mass ratio of 1:0.8-1.2, and the most preferred mass ratio is 1:1. The present application finds that the drying time can be significantly shortened and the quality can be improved by using the mixed enzyme of the above-mentioned wax enzyme and chitinase with the above-mentioned ratio.

[0012] Further preferably, in the step (2), the temperature is 37-40℃ and the humidity is 40-60%. The present application finds that the enzyme activity of the mixed enzyme of the above-mentioned wax enzyme and chitinase with the above-mentioned ratio is the highest under the above-mentioned temperature and humidity conditions.

[0013] As preferred, in the step (1) of the above-mentioned dewaxing and drying method of wolfberry, the concentration of the enzyme in the liquid enzyme preparation is 0.01-1g / mL. The present application finds that the excellent dewaxing effect can be ensured by using the liquid enzyme preparation with the above-mentioned enzyme ratio to soak the wolfberry, and the enzyme dosage is further increased, but the dewaxing effect does not change significantly, and the production cost is increased instead.

[0014] As preferred, in the step (1) of the above-mentioned dewaxing and drying method of wolfberry, the soaking time is 10 minutes-144 hours. Under the above-mentioned soaking time, the excellent first dewaxing effect can be ensured, and the soaking time is further increased, but the dewaxing effect does not change significantly, and there is the disadvantage that the epidermis is easy to be damaged in the subsequent process.

[0015] As preferred, in the step (1) of the above-mentioned dewaxing and drying method of wolfberry, the soaking temperature is 25-76℃. If the temperature is too low, the expected dewaxing effect cannot be achieved, and if the temperature is too high, the biological enzyme is inactivated and the quality of wolfberry is negatively affected.

[0016] As preferred, in the step (2) of the above-mentioned dewaxing and drying method of wolfberry, the drying time is 40min-80min. Under the above-mentioned drying time, the excellent second dewaxing effect can be ensured, and the drying time is further increased, but the dewaxing effect does not change significantly, and there is the disadvantage that the fruit may absorb too much enzyme liquid and the consumption required in the drying process is increased.

[0017] The dewaxed wolfberry obtained through the above dewaxing and drying method can be directly subjected to further drying treatment using the conventional drying process in the art, and the high temperature in the drying process inactivates the enzyme; or the enzyme can be inactivated through the conventional enzyme inactivation process (for example, infrared rays) in the art, and then subjected to subsequent drying treatment.

[0018] Based on the above scheme, the beneficial effects of the present application are as follows:

[0019] The dewaxing and drying method for wolfberry provided by the present application uses enzyme preparation for primary dewaxing, and then uses the temperature and humidity synergistic drying technology to perform secondary dewaxing treatment on the wax layer on the surface of wolfberry by adjusting the temperature and humidity. Compared with the existing dewaxing using chemical reagents, on the one hand, the quality of wolfberry is greatly guaranteed without the action of chemical drying accelerators; on the other hand, the drying rate is improved, and the energy consumption required in the drying process is greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the dried wolfberry after dewaxing and drying according to the embodiment of the present application; wherein the left picture is the dried wolfberry after mixed enzyme dewaxing according to example 1, and the right picture is the dried wolfberry after single enzyme dewaxing according to example 2.

[0021] Figure 2 is the wolfberry directly subjected to drying without dewaxing according to comparative example 1.

[0022] Figure 3 is the dried wolfberry after chemical dewaxing according to comparative example 2. DETAILED DESCRIPTION

[0023] The following examples are used to illustrate the present application, but are not used to limit the scope of the present application. If the specific technology or condition is not specified in the examples, the technology or condition is performed according to the technology or condition described in the literature in the art, or according to the product instruction.

[0024] In the following examples, the instruments and the like without the manufacturer noted are all the conventional products that can be purchased through the regular channel. The methods are all the conventional methods without special instructions, and the raw materials are all available from the public commercial channels without special instructions.

[0025] In the following examples, the manufacturers of the enzymes are as follows:

[0026] Novozymes cutinase: from Hangzhou Chuangke Biological Technology Co., Ltd., product number: 43115; an industrial grade cutinase obtained by high-density fermentation of genetically engineered bacteria Aspergillus oryzae, and then isolated, purified and refined, yellow to light brown aqueous solution, enzyme content about 6%, enzyme activity higher than 15000 LU / g, density about 1.2 g / mL;

[0027] Chitinase: from Guangdong Yunxing Biotechnology Co., Ltd., CAS No: 9001-06-3; BR, 200u / g, enzyme activity higher than 100000 LU / g;

[0028] Example 1

[0029] (1) First dewaxing: Novozymes cutinase 1 g, chitinase 1 g, prepare liquid enzyme preparation 200 mL, enzyme concentration is 0.01 g / mL, immerse 100 g wolfberry in the liquid enzyme preparation, constant temperature 40℃, 50 rpm speed shock incubation for 30 minutes, take out the wolfberry and drain, wherein the liquid enzyme preparation contains 1 g cutinase, 1 g chitinase and 200 mL water;

[0030] (2) Second dewaxing: put the drained wolfberry of step (1) into a drying room, dry at 37℃ temperature and 40% humidity for 50 min to obtain dewaxed wolfberry;

[0031] (3) Drying: adjust the temperature in the drying room to 38℃, relative humidity 60%, maintain for 120 min; then adjust to 43℃, relative humidity 42%, maintain for 180 min; then adjust to 48℃, relative humidity 30%, maintain for 300 min; then adjust to 52℃, relative humidity 15%, maintain for 360 min; finally adjust to 58℃, relative humidity 10%, after 120 min, the water content of wolfberry reaches about 10%, and the drying is completed. The dried wolfberry after enzymatic dewaxing is shown in the left image of Figure 1 , which has uniform color and no obvious quality damage.

[0032] Example 2

[0033] (1) First dewaxing: Novozymes cutinase 2 g is used to prepare liquid enzyme preparation 200 mL, enzyme concentration is 0.01 g / mL, immerse 100 g wolfberry in the liquid enzyme preparation, constant temperature 40℃, 50 rpm speed shock incubation for 30 minutes, take out the wolfberry and drain, wherein the liquid enzyme preparation contains 200 mL water and 2 g cutinase;

[0034] (2) Second dewaxing: put the drained wolfberry of step (1) into a drying room, dry at 37℃ temperature and 40% humidity for 50 min to obtain dewaxed wolfberry;

[0035] (3) drying: the temperature in the drying chamber is adjusted to 38°C, the relative humidity is 60%, and the adjustment is maintained for 120 min; then the temperature is adjusted to 43°C, the relative humidity is 42%, and the adjustment is maintained for 180 min; then the temperature is adjusted to 48°C, the relative humidity is 30%, and the adjustment is maintained for 300 min; then the temperature is adjusted to 52°C, the relative humidity is 15%, and the adjustment is maintained for 360 min; finally, the temperature is adjusted to 58°C, the relative humidity is 10%, and the adjustment is maintained for 200 min, so that the moisture content of the wolfberry is about 10%, and the drying is completed. The dried wolfberry obtained after enzymatic dewaxing is shown in the right image of Fig. 1, which is uniform in color and has no obvious quality damage. Figure 1

[0036] Comparative Example 1

[0037] Compared with Example 1, the difference is that steps (1) and (2) of dewaxing are not performed, and drying is directly performed:

[0038] The wolfberry is placed in the drying chamber, the temperature in the drying chamber is adjusted to 38°C, the relative humidity is 60%, and the adjustment is maintained for 120 min; then the temperature is adjusted to 43°C, the relative humidity is 42%, and the adjustment is maintained for 180 min; then the temperature is adjusted to 48°C, the relative humidity is 30%, and the adjustment is maintained for 300 min; then the temperature is adjusted to 52°C, the relative humidity is 15%, and the adjustment is maintained for 360 min; finally, the temperature is adjusted to 58°C, the relative humidity is 10%, and the adjustment is maintained for 420 min, so that the moisture content of the wolfberry is about 10%, and the drying is completed. The dried wolfberry obtained without dewaxing is shown in Fig. 2, which is not easy to dry, and oil fruits, black fruits, and uneven color may occur. Figure 2

[0039] Comparative Example 2

[0040] Compared with Example 1, the difference is that the enzymatic dewaxing of steps (1) and (2) is replaced by chemical dewaxing:

[0041] (1) The chemical dewaxing component is: 5-10% of ethanol, 0.2-0.5% of sodium metabisulfite, 0.5-1% of potassium sorbate, and the rest is alkali metal carbonate; the use method is: according to the above-mentioned components, the sodium metabisulfite, the potassium sorbate, and the alkali metal carbonate are uniformly mixed, and are dissolved in water at a solid-liquid ratio of 1-2g:100ml, stirred uniformly, then the ethanol is added and mixed uniformly, to obtain a wolfberry drying and color protection agent solution, the fresh wolfberry fruits are soaked for 0.5-1 min, and the fresh fruits are taken out and drained;

[0042] ​​(2) After chemical dewaxing of step (1), the wolfberry is put into a drying chamber, the temperature in the drying chamber is adjusted to 38°C, the relative humidity is 60%, and the temperature is maintained for 120 minutes; then the temperature is adjusted to 43°C, the relative humidity is 42%, and the temperature is maintained for 180 minutes; then the temperature is adjusted to 48°C, the relative humidity is 30%, and the temperature is maintained for 300 minutes; then the temperature is adjusted to 52°C, the relative humidity is 15%, and the temperature is maintained for 360 minutes; finally, the temperature is adjusted to 58°C, the relative humidity is 10%, and the temperature is maintained for 300 minutes, and the moisture content of the wolfberry is about 10% after drying is completed. The dried wolfberry obtained by chemical dewaxing is shown in Fig. 2. Although the treatment accelerates the drying rate, the chemical residues on the dried fruit are obvious, and the quality is damaged to a certain extent. Figure 3

[0043] Finally, the method of the present application is only a preferred embodiment, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.​

Claims

1. A method for dewaxing and drying of wolfberry, characterized in that, The method comprises the following steps: (1) soaking wolfberry with a liquid enzyme preparation, wherein the liquid enzyme preparation comprises water and an enzyme having a function of decomposing a plant wax layer; (2) placing the wolfberry soaked in step (1) into a drying chamber and drying the wolfberry at a temperature of 37-40 DEG C and a humidity of 40-60%; the enzyme is a mixed enzyme of waxase and chitinase at a mass ratio of 1:1; the concentration of the enzyme is 0.01-1 g / mL; the drying time is 40-80 min.

2. The wolfberry dewaxing and expedited drying method of claim 1, wherein, In step (1), the soaking time is 10 min-144 h.

3. The wolfberry dewaxing and expedited drying method of claim 1, wherein, In step (1), the soaking temperature is 25-76 DEG C.

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