A method for extracting pandan juice, pandan juice and beverage

Abstract

The present invention discloses a method for extracting pandan juice, as well as pandan juice and a beverage. The method for extracting pandan leaves includes the following steps: freezing soaked pandan leaves or pandan powder with a water content greater than 20% to -20°C to -30°C for 10 - 12 hours, thawing, adding water and blending into a paste, adding a complex enzyme for enzymatic hydrolysis, and then separating the enzymatic hydrolysate and enzymatic hydrolysis residue. The enzymatic hydrolysis residue is dehydrated and soaked in a mixed solvent for 12 - 48 hours; separately, chopped pandan leaves are soaked in the mixed solvent for 12 - 48 hours; the soaked enzymatic hydrolysis residue and chopped pandan leaves are respectively loaded into a percolation tank, and the mixed solvent is used for percolation extraction to obtain a percolation extract; the percolation extracts are mixed with the enzymatic hydrolysate, and after removing ethanol, ethyl acetate, and diethyl ether, it is concentrated to obtain pandan juice. The method for extracting pandan leaves of the present invention, through the combined use of wet-state freezing and enzymatic hydrolysis and percolation with a mixed solvent, the obtained pandan juice has a rich and strong aroma, and has both the original flavor of pandan leaves and the enzymatic hydrolysis flavor.

Description

Technical Field

[0001] The invention belongs to the technical field of food, and in particular relates to a method for extracting pandan juice, pandan juice and a beverage. Background Art

[0002] Pandan leaf is a natural spice. Hainan is the origin and dominant production area of pandan leaf in my country. Currently, pandan leaf culture in southern my country is primarily based on Southeast Asian culture and is primarily a form of folk utilisation. Pandan leaf is widely used in specialty restaurants, ornamental gardening, leisure tourism, and other industries. Traditional delicacies such as pandan cake, pandan qingbuliang, and pandan cold drinks are brimming with Southeast Asian influences. Pandan chiffon cake is a global favourite, while pandan nine-layer cake, pandan rolls, and pandan qingbuliang are particularly popular.

[0003] Due to the inconveniences of storing and transporting fresh Pandan leaves, freeze-dried Pandan leaf powder is widely used. However, due to the large amount of water-insoluble matter in freeze-dried Pandan leaf powder, it is only suitable for use in baking and is not suitable for beverages, dairy products, ice cream, jelly, or candy. Existing Pandan juice products are rare, and the aroma and flavor are often lacking the original Pandan leaf fragrance and flavor due to insufficient extraction or loss during processing, resulting in a bland aroma and flavor. Summary of the Invention

[0004] The object of the present invention is to provide a pandan juice which is convenient for use in beverages and has not only the aroma and taste of the pandan leaves themselves but also a richer and more intense aroma and flavor.

[0005] The technical solution of the present invention is:

[0006] A method for extracting pandan juice comprises the following steps:

[0007] Step 1: Freeze the soaked pandan leaves or pandan powder with a water content of not less than 40% to -20°C to -30°C for 10-12 hours, thaw, add water and crush into a paste;

[0008] Step 2: adding a composite enzyme to the paste for enzymatic hydrolysis, inactivating the enzyme, and separating the enzymatic hydrolysis solution and the enzymatic hydrolysis residue;

[0009] Step 3: dehydrate the enzymatic residue with anhydrous ethanol and soak it in a mixed solvent for 12-48 hours;

[0010] Chop another pandan leaf into small pieces and soak it in the mixed solvent for 12-48 hours;

[0011] The enzymatic hydrolysis residue and the crushed Pandan leaves after soaking are placed in a percolation tank, the mixed solvent used for soaking is added, and percolation extraction is performed using the mixed solvent to obtain a percolation extract;

[0012] Among them, the mixed solvent is: ethanol, ethyl acetate and ether are mixed in a volume ratio of 1:0.5 - 1:0.5 - 1;

[0013] Step 4: Mix the percolation extract and the enzymolysis solution, remove ethanol, ethyl acetate and ether, and concentrate to obtain pandan juice.

[0014] In the above-mentioned method for extracting pandan juice of the present invention, in Step 1, the pandan leaves or pandan powder containing moisture are frozen at -20°C to -30°C, and the water freezes. The low temperature and the extrusion of water molecules damage the integrity of the cell walls and cell membranes of the pandan leaves. This enables the nutrients and aroma substances inside the cell membranes to be fully exposed after being mechanically broken into a paste, allowing the enzymolysis reaction to occur at the intracellular substance level during the enzymolysis process, making the enzymolysis more thorough and sufficient, and the aroma and fragrance of the enzymolysis solution to be richer and more intense. Before freezing, the pandan leaves need to be soaked in water or the pandan powder needs to be moistened to contain a certain amount of moisture. The freezing of this moisture plays a role in fixing and restricting the expansion of the cells in the pandan leaves or pandan powder, causing the water in the cells to be fully compressed when expanding outwards, thereby making the cell walls and cell membranes incomplete and exposing the nutrients and aroma substances. Pandan leaves or pandan powder with too little water content cannot be well extruded during the freezing process, resulting in poor effects. After dehydrating the enzymolysis residue in Step 3, ethyl acetate and ether in the mixed solvent can more easily and fully penetrate into the interior of the enzymolysis residue, thus easily dissolving the aroma and fragrance molecules in it and further being extracted into the mixed solvent during percolation.

[0015] In the method of the present invention, the enzymolysis residue after sufficient enzymolysis is mixed with unenzymolyzed pandan leaves for percolation. The obtained percolation extract contains both the aroma and fragrance substances obtained by enzymolysis and the original aroma and fragrance substances contained in the unenzymolyzed pandan leaves, making the aroma and fragrance richer and more layered. In addition, the mixed solvent used for percolation is a mixture of ethanol, ethyl acetate and ether in a volume ratio of 1:0.5 - 1:0.5 - 1. The three act synergistically to extract the aroma substances in the unenzymolyzed pandan leaves and the enzymolysis residue more fully and efficiently. After the obtained extract is mixed with the enzymolysis solution and ethanol, ethyl acetate and ether are removed, the resulting pandan juice has both the aroma and fragrance of the original pandan leaves and the aroma and fragrance generated by enzymolysis, making the aroma and fragrance richer, more intense and more delicious.

[0016] Preferably, when loading the enzymolysis residue and crushed pandan leaves into the percolation tank, it is carried out in layers, separated by filter cloth between each layer. Each layer is filled with enzymolysis residue and crushed pandan leaves, and the total volume of the enzymolysis residue filled in each layer, when converted into height, does not exceed 1 / 4 of the layer height.

[0017] In the percolation tank, the enzymolysis residue and crushed pandan leaves are loaded in layers, and filter cloth is arranged between each layer. Such a loading method can decompose the percolation tank into multiple series-connected percolation units, and there are enzymolysis residues and crushed pandan leaves in each unit. In this way, the mixed solvent in each layer is in full contact with the enzymolysis residue and crushed pandan leaves respectively, which is conducive to the reasonable gradient distribution of the concentrations of the substances to be extracted in the mixed solvent in the same layer, thus giving play to the synergistic effect of the mixed solvent; in addition, since the enzymolysis residue is separated into multiple longitudinally distributed layers by the filter cloth, the thickness of the enzymolysis residue precipitated in each layer is appropriate, preventing the too thick fine enzymolysis residue from blocking the percolation channel; furthermore, the enzymolysis residue with an appropriate thickness appropriately blocks and decelerates the mixed solvent in each layer, which is conducive to the full extraction of aroma substances and flavor substances.

[0018] Preferably, the loading sequence of each layer in the percolation tank from bottom to top is enzymolysis residue and crushed pandan leaves, and the height of the enzymolysis residue does not exceed 1.0 cm.

[0019] Setting the loading sequence of each layer from bottom to top as enzymolysis residue and crushed pandan leaves is conducive to the appropriate residence of the mixed solvent in the same layer and better extraction of the crushed pandan leaves and enzymolysis residue. Of course, the enzymolysis residue and crushed pandan leaves after soaking and swelling can also be mixed evenly and loaded in each layer. In this way, the percolation speed will be faster at the initial stage of percolation. As the percolation proceeds, the fine enzymolysis residue will flow to the lower layer, and finally, the lower layer is the enzymolysis residue and the upper layer is the crushed pandan leaves. Too thick enzymolysis residue will affect the percolation speed.

[0020] Preferably, the layer height of each layer in the percolation tank decreases successively from top to bottom. Since the liquid pressure in the percolation tank gradually increases from top to bottom, designing the layer height of each layer in the percolation tank to decrease successively from top to bottom is conducive to controlling the percolation speed and preventing the occurrence of air intake phenomenon.

[0021] Preferably, the percolation speed of the percolation tank is 10 - 20 ml / min / kg.

[0022] Preferably, the complex enzyme is cellulase, pectinase and protease; wherein, based on the total mass of pandan leaves or pandan powder, cellulase is 0.01 - 0.1%, pectinase is 0.01 - 0.05%, and protease is 0.01 - 0.05%.

[0023] Preferably, the enzymolysis conditions in step two are: enzymolysis at 45°C - 50°C for 50 - 60 min under stirring.

[0024] The present invention also provides a kind of pandan juice prepared by the above method.

[0025] The present invention also provides a kind of beverage containing the above pandan juice.

[0026] The beneficial effects of the present invention are:

[0027] The extraction method of pandan leaves of the present invention combines wet freezing and enzymatic hydrolysis to fully enzymatically hydrolyze pandan leaves or pandan powder, so as to obtain as many enzymatically hydrolyzed aroma and flavor substances as possible; a mixed solvent composed of ethanol, ethyl acetate and ether is used for multi-component percolation of the enzymatically hydrolyzed residue and crushed pandan leaves in a coordinated manner, so that both the aroma and flavor substances after enzymatic hydrolysis and the aroma and flavor substances that have not been enzymatically hydrolyzed are fully extracted; therefore, the pandan juice obtained by mixing the extract and the enzymatically hydrolyzed solution not only has a strong aroma and flavor, but also has a rich layer, and has both the original flavor of pandan leaves and the enzymatically hydrolyzed flavor. Specific Embodiments

[0028] The present invention will be described in detail below in conjunction with embodiments.

[0029] Example 1

[0030] Extract a kind of pandan juice, and the method is as follows:

[0031] Step 1: Take pandan powder, spray and add water evenly under stirring to make the water content reach 40%, freeze the wetted pandan powder to -30°C, thaw after 12 hours of freezing, add water to make the total water content 2 times the mass of the pandan powder, and break it into a paste.

[0032] Step 2: Add cellulase, pectinase and protease to the above paste, and the addition amounts are: based on the mass of the pandan powder before wetting, cellulase is 0.1%, pectinase is 0.05%, and protease is 0.05%. Keep the temperature at 50°C and enzymatically hydrolyze for 60 min under stirring, then quickly heat to 85°C and keep it for 15 minutes to inactivate the enzyme, and centrifuge after cooling to obtain the enzymatically hydrolyzed solution and the enzymatically hydrolyzed residue.

[0033] Step 3: Immerse the enzymatically hydrolyzed residue in absolute ethanol, stir and then quickly centrifuge to dry.

[0034] Prepare a mixed solvent according to the volume ratio of ethanol: ethyl acetate; ether = 1:1:1, and soak the enzymatically hydrolyzed residue in the mixed solvent for 48 hours.

[0035] Cut another pandan leaf and soak it in the above-prepared mixed solvent for 48 hours.

[0036] After laying a filter cloth at the bottom of the percolation tank, load the enzymatically hydrolyzed residue and shredded pandan leaves after the above soaking. The loading is carried out in layers, and the method is as follows: First, load the enzymatically hydrolyzed residue with a thickness of 0.5 cm, and then compactly load the shredded pandan leaves with a thickness of 2 cm. Lay a layer of filter cloth on the shredded pandan leaves to complete the loading of one layer. Carry out multi-layer loading according to the above method. When loading upwards, for each layer increased, the thickness of the enzymatically hydrolyzed residue increases layer by layer within 1 cm or remains unchanged, and the thickness of the shredded pandan leaves increases by 0.5 cm per layer until the entire percolation tank is loaded. Add the mixed solvent used for soaking the above pandan leaves and enzymatically hydrolyzed residue, then fill it with the mixed solvent and let it stand for soaking for 12 hours. Open the liquid inlet and outlet of the percolation tank, and use the mixed solvent for percolation extraction. Control the percolation speed at a flow rate of 15 ml / min / kg, and collect the liquid flowing out from the liquid outlet. In order to ensure the concentration of the percolation extract, the liquid flowing out in the first 30 minutes of percolation is returned to the inlet for use, and the liquid collected from 30 minutes to 3 hours is used as the percolation extract.

[0037] Step 4: Mix the percolation extract obtained in Step 3 and the enzymolysis solution obtained in Step 2 in a volume ratio of 1:1, and remove ethanol, ethyl acetate, and diethyl ether to obtain pandan juice.

[0038] Example 2

[0039] Extract a kind of pandan juice, and the method is as follows:

[0040] Step 1: Freeze the soaked pandan leaves to -25 °C, thaw them after freezing for 11 hours, and add 2 times the mass of water of the pandan leaves and break them into a paste.

[0041] Step 2: Add cellulase, pectinase, and protease to the above paste. The addition amounts are: based on the mass of the pandan leaves before soaking, cellulase is 0.01%, pectinase is 0.01%, and protease is 0.01%. Keep the temperature at 45 °C and enzymatically hydrolyze for 50 minutes under stirring, then quickly heat to 85 °C and keep it for 15 minutes to inactivate the enzyme, and centrifuge to obtain the enzymolysis solution and the enzymatically hydrolyzed residue.

[0042] Step 3: Immerse the enzymatically hydrolyzed residue in absolute ethanol, stir it a few times and immediately centrifuge and spin dry.

[0043] Prepare a mixed solvent according to a volume ratio of ethanol:ethyl acetate; diethyl ether = 1:0.5:0.5, and soak the enzymatically hydrolyzed residue with the mixed solvent for 30 hours.

[0044] Take another part of shredded pandan leaves, and soak them with the above-prepared mixed solvent for 30 hours.

[0045] After laying a filter cloth at the bottom of the percolation tank, load the enzymatically hydrolyzed residue and shredded pandan leaves after the above soaking. The loading is carried out in layers as follows: First, load the enzymatically hydrolyzed residue with a thickness of 1 cm, and then compactly load the shredded pandan leaves with a thickness of 3 cm. Lay a layer of filter cloth on the shredded pandan leaves, thus completing the loading of the first layer. Carry out multi-layer loading according to the above method until the entire percolation tank is filled. Add the mixed solvent used for soaking the pandan leaves and enzymatically hydrolyzed residue, and then add the mixed solvent until it is full. Let it stand and soak for 12 hours. Open the inlet and outlet of the percolation tank, and use the mixed solvent for percolation extraction. Control the percolation speed at a flow rate of 10 ml / min / kg, and collect the liquid flowing out of the outlet. In order to ensure the concentration of the percolation extract, the liquid flowing out in the first 30 minutes before percolation is returned to the inlet for use, and the liquid flowing out collected within 30 minutes to 3 hours is used as the percolation extract.

[0046] Step 4, mix the percolation extract obtained in Step 3 and the enzymatic hydrolysate obtained in Step 2 according to a volume ratio of 1:1. After removing ethanol, ethyl acetate, and diethyl ether, pandan juice is obtained.

[0047] Example 3

[0048] Extract a kind of pandan juice, and the method is as follows:

[0049] Step 1, freeze the soaked pandan leaves to -30 °C, thaw after 10 hours of freezing, and add water twice the mass of the pandan leaves and break them into a paste.

[0050] Step 2, add cellulase, pectinase, and protease to the above paste. The addition amounts are: based on the mass of the pandan leaves before soaking, cellulase is 0.01%, pectinase is 0.05%, and protease is 0.01%. Keep the temperature at 45 °C and enzymatically hydrolyze for 60 min under stirring, then quickly heat to 85 °C and keep it for 15 minutes to inactivate the enzyme. After cooling, centrifuge to obtain the enzymatic hydrolysate and the enzymatically hydrolyzed residue.

[0051] Step 3, add anhydrous ethanol to submerge the enzymatically hydrolyzed residue, stir, and then quickly centrifuge and spin dry.

[0052] Prepare a mixed solvent according to a volume ratio of ethanol:ethyl acetate:diethyl ether = 1:0.5:1, and soak the enzymatically hydrolyzed residue with the mixed solvent for 12 hours.

[0053] Cut another batch of pandan leaves, and soak them with the above-prepared mixed solvent for 12 hours.

[0054] After laying a filter cloth at the bottom of the percolation tank, the enzymatic residue and crushed pandan leaves after soaking are loaded. The loading is carried out in layers as follows: the enzymatic residue and crushed pandan leaves are mixed evenly in a thickness of 1:3 after compaction, and a total of 4 cm thick is loaded. Then, a layer of filter cloth is laid on top to complete the first layer of loading. Multi-layer loading is carried out according to the above method until the entire percolation tank is filled. Add the mixed solvent used for soaking the pandan leaves and enzymatic residue, then fill up the mixed solvent and let it stand for 12 hours. Open the liquid inlet and outlet of the percolation tank, use the mixed solvent for percolation extraction, control the percolation speed at a flow rate of 20 ml / min / kg, and collect the effluent from the outlet. In order to ensure the concentration of the percolation extract, the effluent from the first 30 minutes of percolation is returned to the inlet for use, and the effluent collected from 30 minutes to 3 hours is used as the percolation extract.

[0055] Step 4: Mix the percolation extract obtained in step 3 with the enzymatic hydrolyzate obtained in step 2 in a volume ratio of 1:1, remove ethanol, ethyl acetate and ether, and obtain a colorful juice.

[0056] Example 4

[0057] Extract a kind of pandan juice, the method is as follows:

[0058] Step 1: Take the pandan powder, stir and evenly spray it with water until the water content reaches 55%, freeze the wet pandan powder to -20°C, thaw it after 10 hours of freezing, add water to the total water content to 2 times the mass of the pandan powder, and crush it into a paste.

[0059] Step 2: Add cellulase, pectinase, and protease to the paste. The added amounts are: 0.05% cellulase, 0.05% pectinase, and 0.05% protease, based on the weight of the Pandan leaves before soaking. Enzymatic hydrolysis is performed at 50°C with stirring for 50 minutes. The mixture is then rapidly heated to 85°C and held for 15 minutes to inactivate the enzymes. The hydrolyzed liquid and hydrolyzed residue are separated by centrifugation.

[0060] Step 3: Add anhydrous ethanol to the enzymatic hydrolysis residue, immerse it, stir it a few times and immediately centrifuge to dry it.

[0061] A mixed solvent was prepared according to the volume ratio of ethanol: ethyl acetate; ether = 1:1:0.5, and the enzymatic hydrolysis residue was soaked in the mixed solvent for 30 hours.

[0062] Chop another set of Pandan leaves into small pieces and soak them in the above-prepared mixed solvent for 30 hours.

[0063] After laying a filter cloth at the bottom of the percolation tank, load the enzymatically hydrolyzed residue and crushed pandan leaves after the above soaking. The loading is carried out in layers, and the method is as follows: First, load 1 cm thick enzymatically hydrolyzed residue, and then compact and load 3 cm thick crushed pandan leaves. Lay a layer of filter cloth on the crushed pandan leaves, thus completing the loading of the first layer. Carry out multi-layer loading according to the above method until the entire percolation tank is loaded. Add the mixed solvent used for soaking the pandan leaves and enzymatically hydrolyzed residue, and then add the mixed solvent until it is full. Let it stand and soak for 12 hours. Open the inlet and outlet of the percolation tank, and use the mixed solvent for percolation extraction. Control the percolation speed at a flow rate of 10 ml / min / kg, and collect the effluent from the outlet. In order to ensure the concentration of the percolation extract, the effluent in the first 30 minutes of percolation is returned to the inlet for use, and the effluent collected within 30 minutes to 3 hours is used as the percolation extract.

[0064] Step 4: Mix the percolation extract obtained in Step 3 and the enzymatic hydrolysate obtained in Step 2 in a volume ratio of 1:1, and remove ethanol, ethyl acetate, and ether to obtain pandan juice.

[0065] Comparative Example 1

[0066] Extract a kind of pandan juice.

[0067] The only difference between this comparative example and Example 1 is that the pandan powder in Step 1 is not frozen. In this comparative example, the pandan powder is directly added to the same amount of water as in Example 1 and directly broken into a paste. The rest of Step 1 is exactly the same as in Example 1.

[0068] Comparative Example 2

[0069] Extract a kind of pandan juice.

[0070] The only difference between this comparative example and Example 1 is in Steps 3 and 4. In this comparative example, absolute ethanol is used instead of the mixed solvent in Steps 3 and 4, and the rest is exactly the same as in Example 1.

[0071] Comparative Example 3

[0072] Extract a kind of pandan juice.

[0073] The only difference between this comparative example and Example 1 is in Steps 3 and 4. In this comparative example, ethyl acetate is used instead of the mixed solvent in Steps 3 and 4, and the rest is exactly the same as in Example 1.

[0074] Comparative Example 4

[0075] Extract a kind of pandan juice.

[0076] The only difference between this comparative example and Example 1 is in Steps 3 and 4. In this comparative example, ether is used instead of the mixed solvent in Steps 3 and 4, and the rest is exactly the same as in Example 1.

[0077] Comparative Example 5

[0078] Prepare a pandan juice. The pandan juice in this comparative example is prepared by taking a part of the pandan juices prepared in Comparative Example 2, Comparative Example 3 and Comparative Example 4 and mixing them in a volume ratio of 1:1:1.

[0079] Example 5

[0080] The pandan juices prepared in Examples 1 - 4 and the pandan juices prepared in Comparative Examples 1 - 5 were made into beverages respectively according to the following methods:

[0081] Take 1 part by mass of pandan juice, add 10 parts by mass of water, and add 0.2 part by mass of granulated sugar and dissolve it to make a beverage.

[0082] Detection:

[0083] The pandan juices prepared in Examples 1 - 4 and the pandan juices prepared in Comparative Examples 1 - 4 were detected, and the mass percentage content of volatile substances in the pandan juices was measured. The results are shown in Table 1. The test method is as follows:

[0084] Solid phase extraction - gas chromatography / mass spectrometry (SPE - GC / MS) was used. Instrument and equipment: Agilent GC / MS8890 / 5976B combined instrument; 500mg silica gel solid phase extraction column.

[0085] Accurately pipette 5 mL of pandan juice into the activated solid phase extraction column (activation of the column: first wash the solid phase extraction column with 5 mL of ethanol, and then wash it with 10 mL of cyclohexane). After separation, elute with 30 mL of cyclohexane at an elution speed of 0.8 - 1.0 mL / min. Collect all the eluates for GC / MS analysis.

[0086] Chromatographic conditions Chromatographic column; carrier gas He; flow rate 1.1 mL / min constant pressure Column temperature: initial temperature 35°C, rising to 240°C at 5°C / min and holding for 10 min Injection port temperature 200°C; split ratio 20:1; transfer line temperature 280°C

[0087] Mass spectrometry conditions Electron impact (EI) ion source; electron energy 70 eV; electron multiplier voltage 1300 V; solvent delay 0 min; ion source temperature 150°C; quadrupole temperature 230°C; full spectrum scan; mass scan range m / z29 - 350.

[0088] Table 1

[0089]

[0090] Sensory evaluation:

[0091] The beverage prepared in Example 5 was subjected to a sensory evaluation by 30 sensory evaluation professionals. The sensory evaluation criteria are shown in Table 2, and the evaluation results are shown in Table 3.

[0092] Table 2

[0093]

[0094] Table 3

[0095] Project Aroma Flavor Total Score Example 1 49 48 97 Example 2 47 48 95 Example 3 48 45 93 Example 4 47 46 93 Comparative Example 1 30 32 62 Comparative Example 2 25 21 46 Comparative Example 3 28 23 51 Comparative Example 4 27 22 49 Comparative Example 5 33 35 68

[0096] The data in Table 1 demonstrate that the Banlan juice prepared by the method of the present invention contains a wide variety of naturally fragrant components at relatively high levels, particularly dihydroactin and ryegrass lactones. These aroma-imparting components are successfully extracted into the prepared Banlan juice, resulting in an aroma and flavor that more closely resembles that of natural Banlan leaves. This conclusion is also drawn from the sensory evaluation results in Table 2. Beverages formulated with the Banlan juice prepared by the method of the present invention exhibit a richer, more harmonious, richer, and more layered aroma and flavor, more closely resembling the aroma and flavor of natural Banlan leaves. In contrast, the Banlan juice prepared in Comparative Example 1, unlike Example 1, did not undergo a freezing step. As a result, some aroma and flavor components within the Banlan leaf cells were not fully released and could not be effectively absorbed into the extract during the subsequent extraction step. This resulted in a smaller variety of aroma-imparting components and lower content in the prepared Banlan juice. Consequently, beverages formulated with this Banlan juice were significantly inferior to those in Example 1 in terms of aroma and flavor. Comparative Examples 2, 3, and 4, respectively, used only one of ethanol, ethyl acetate, or ether in place of the mixed solvent for soaking and extraction in the preparation of pandan juice. The test results in Table 1 indicate that this resulted in poor extraction of dihydroactinol, vanillin, and ryegrass lactone from the pandan juice. This suggests that the mixed solvent of ethanol, ethyl acetate, and ether exerted a synergistic effect during the extraction process, effectively extracting a greater amount of aroma and flavor compounds from the pandan juice.

[0097] It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described above can be combined with each other as long as they do not conflict with each other. In addition, the above are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Claims

1. A method for extracting pandan juice, characterized in that, It includes the following steps: Step 1: Freeze the soaked pandan leaves or pandan powder with a water content of not less than 40% to -20°C to -30°C for 10 - 12 hours, then thaw and add water to break it into a paste; Step 2: Add a complex enzyme to the above paste for enzymatic hydrolysis, inactivate the enzyme after hydrolysis, and separate the enzymatic hydrolysate and enzymatic hydrolysis residue; Step 3: Dehydrate the enzymatic hydrolysis residue with absolute ethanol and soak it in a mixed solvent for 12 - 48 hours; Separate the chopped pandan leaves and soak them in the above mixed solvent for 12 - 48 hours; Load the above soaked enzymatic hydrolysis residue and chopped pandan leaves into a percolation tank, add the mixed solvent used for soaking, and perform percolation extraction with the mixed solvent to obtain a percolation extract; Wherein, the mixed solvent is a mixture of ethanol, ethyl acetate and ether in a volume ratio of 1:0.5 - 1:0.5 - 1; Step 4: Mix the percolation extract with the enzymatic hydrolysate, remove ethanol, ethyl acetate and ether, and concentrate to obtain pandan juice.

2. The extraction method of the colorful juice according to claim 1, characterized in that When loading the enzymatic hydrolysis residue and chopped pandan leaves into the percolation tank, it is carried out in layers, separated by filter cloth between each layer. Both the enzymatic hydrolysis residue and chopped pandan leaves are loaded in each layer, and the total volume of the enzymatic hydrolysis residue loaded in each layer, when converted into height, does not exceed 1 / 4 of the layer height.

3. The extraction method of the colorful juice according to claim 2, characterized in that, The loading order of each layer in the percolation tank from bottom to top is the enzymatic hydrolysis residue and chopped pandan leaves respectively, and the height of the enzymatic hydrolysis residue does not exceed 1.0 cm.

4. The extraction method of the colorful juice according to claim 3, characterized in that, The layer height of each layer in the percolation tank decreases sequentially from top to bottom.

5. The extraction method of the colorful juice according to claim 1, characterized in that, The percolation speed of the percolation tank is 10 - 20 ml / min / kg.

6. The extraction method of the colorful juice according to claim 1, characterized in that, The complex enzyme is cellulase, pectinase and protease; wherein, based on the total mass of pandan leaves or pandan powder, cellulase is 0.01 - 0.1%, pectinase is 0.01 - 0.05%, and protease is 0.01 - 0.05%.

7. The extraction method of the colorful juice according to claim 1, characterized in that The enzymatic hydrolysis conditions in Step 2 are: enzymatic hydrolysis at 45°C - 50°C for 50 - 60 min under stirring.

8. A pandan juice, characterized in that, Prepared by the method according to any one of claims 1 to 7.

9. A beverage, characterized in that, Containing the pandan juice according to claim 8.

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