Method for improving quality of phyllanthus emblica fruit juice through pulsed electric field assisted by enzymolysis

Abstract

The invention discloses a method for improving the quality of phyllanthus emblica fruit juice through an enzymolysis-assisted pulsed electric field, which comprises the following steps: firstly, carrying out preliminary enzymolysis treatment on phyllanthus emblica fruits through a low-concentration compound enzyme solution to form micropores in the surfaces of cell walls; then, the pore diameter of the preliminarily formed micropore area is further expanded under the action of a pulsed electric field, the cell structure is destroyed to form a pore channel, through combined regulation and control of enzymolysis and electric field parameters, efficient release of micromolecular nutritional ingredients such as vitamin C, polyphenol substances, total flavonoids and monosaccharide is achieved through the synergistic effect of the enzymolysis and the electric field parameters, and the effect of improving the nutrient content is achieved. Meanwhile, the excessive precipitation of macromolecular polysaccharide is limited, the taste of the fruit juice is improved, the clarity of the fruit juice and the stability of nutritional ingredients are ensured, the consistency of the taste of the product is maintained, in addition, the enzyme dosage is effectively reduced, the safety problem caused by enzyme residues is reduced, the enzymolysis time and the pulse intensity are also remarkably reduced, and the production cost is reduced; the method meets the requirement of green production and is suitable for industrial large-scale application.

Description

Technical Field:

[0001] The present invention relates to the technical field of Phyllanthus emblica juice preparation, and particularly relates to a method for improving the quality of Phyllanthus emblica juice by enzymatic hydrolysis assisted pulsed electric field. Background Art:

[0002] Phyllanthus emblica L, also known as Indian gooseberry, oil plum, and Yunnan olive, is a plant widely used in traditional Chinese medicine and Ayurvedic medicine, and is also one of the plants with both edible and medicinal uses in the Lingnan region of China. Phyllanthus emblica is rich in a variety of thermosensitive nutrients, especially vitamin C, polyphenols, flavonoids, etc. These components are extremely easy to decompose under high temperature conditions. Traditional thermal processing is used in juice processing to inhibit the activity of browning-related enzymes, soften the fruit tissue, and increase the cell permeability, making the subsequent juice extraction easier. For example, a processing method of Phyllanthus emblica juice disclosed in Chinese Patent Application CN103653149A softens Phyllanthus emblica fruits at a high temperature of 80-95°C, and after long-term soaking (20-24 hours), multi-stage filtration is carried out to obtain a finished juice with a sweet and sour taste. However, high-temperature treatment inevitably leads to the degradation of vitamin C and some phenolic compounds, affecting the nutritional value and antioxidant properties of the juice. In addition, long-term heating will also change the color and flavor of the juice, reducing the sensory quality of Phyllanthus emblica juice. Nowadays, consumers' demand for natural juices that retain the original fruit flavor and nutrition is gradually increasing, and traditional high-temperature processing can no longer meet the market demand.

[0003] The cell wall of Phyllanthus emblica also contains a large amount of cellulose and hemicellulose, and the tissue structure is tight. Traditional mechanical crushing methods are difficult to completely break the cell wall, resulting in the difficulty of releasing some nutrients. Enzymatic hydrolysis can not only effectively prevent the risk of high-temperature degradation of nutrients compared with traditional high-temperature heat treatment technology, but also help decompose the cell wall components, thereby improving the release of nutrients. For example, in the Phyllanthus emblica juice preparation method disclosed in Chinese Patent Application CN116998646A, pectin methylesterase and protease are used as a composite enzyme preparation. This method can prepare Phyllanthus emblica juice with high aftertaste flavor and high polyphenol content, but there are still many problems in enzymatic hydrolysis treatment. First, in order to achieve a high cell wall breaking efficiency, a high concentration of enzyme solution is usually required, which not only increases the production cost, but also may cause safety problems of enzyme residues. In addition, during the enzymatic hydrolysis process, the decomposition of pectin and cellulose easily leads to the excessive release of macromolecular substances such as polysaccharides, making the juice texture viscous and the stability decrease. The bitter taste brought by some polysaccharides will also affect the taste. The simple enzymatic hydrolysis reaction also requires a long time, usually 1-2 hours, which is not conducive to rapid industrial production.

[0004] Pulsed Electric Field (PEF), as a new non-thermal processing technology, acts on fruits through high-voltage electric field pulses, generating an electroporation effect, thereby promoting the release of nutrients. The advantages of pulsed electric field technology, such as non-thermal treatment, high-efficiency extraction, and low energy consumption, avoid the destruction of heat-sensitive nutrients by high temperature and improve the extraction efficiency of small-molecule nutrients (such as vitamin C and polyphenolic compounds). It is also more environmentally friendly compared to traditional treatment methods. CN118303564A discloses a method for preparing Phyllanthus emblica fresh squeezed juice with enhanced sweet aftertaste flavor, innovatively using a multi-stage pulsed electric field to separately treat the Phyllanthus emblica fruit peel and pulp after skin-pulp separation. Specific pulsed electric field treatment conditions are used in static treatment and flow-through treatment, mainly including: the first-stage static pulsed electric field treatment uses an electric field strength of 2 - 6 kV / cm, the number of pulses is 100 - 200 times, the pulse frequency is 1 - 5 Hz, to soften the Phyllanthus emblica fruit peel, and to a certain extent, destroy the cell walls and cell membranes of the peel cells, which is beneficial to the subsequent extraction of sweet aftertaste substances during juicing; the second-stage flow-through pulsed electric field treatment uses an electric field strength of 10 - 20 kV / cm, a frequency of 50 - 200 Hz, a duration of 1 - 4 min, and a pulse width of 6 - 10 μs to treat the juice obtained by mixing and squeezing the Phyllanthus emblica fruit peel and pulp, aiming to accelerate the collision of substances inside it, such as tannin substances with astringent taste, organic acid substances with sour taste, sugar substances with sweet taste, and phenolic substances with sweet aftertaste characteristic flavor, enhance the interaction of these substances, achieve mutual association, not only weaken the unacceptable sour and astringent taste of Phyllanthus emblica juice, but also significantly improve the sweet aftertaste flavor of Phyllanthus emblica. However, the prior art does not disclose a method for improving the quality of Phyllanthus emblica juice by enzymatic hydrolysis assisted pulsed electric field. Summary of the Invention:

[0005] The object of the present invention is to provide a method for improving the quality of Phyllanthus emblica juice by enzymatic hydrolysis assisted pulsed electric field, which solves the problems of loss of heat-sensitive components, insufficient environmental protection, poor juice taste consistency, and insufficient flavor in the prior art for preparing Phyllanthus emblica juice.

[0006] The present invention is achieved by the following technical solutions:

[0007] A method for improving the quality of Phyllanthus emblica juice by enzymatic hydrolysis assisted pulsed electric field, the method comprising the following steps:

[0008] 1) Take fresh, intact, uniformly sized Phyllanthus emblica fruits with 90% maturity, remove the stalks and pedicles, and wash them clean;

[0009] 2) Mix the fruits with a complex enzyme solution composed of cellulase and pectinase in a mass ratio of 1:4, and carry out enzymatic hydrolysis at 40 - 50 °C for 15 - 30 minutes to generate initial micropores on the fruit peel;

[0010] 3) Treat the enzymatically hydrolyzed Phyllanthus emblica fruits in a pulsed electric field device. The conditions of the electric field action are: electric field strength of 1 - 3 kV / cm, number of pulses of 1,200 - 4,000 times, pulse frequency of 10 - 30 Hz, and pulse width of 2 - 10 μs. Then remove the fruit cores and perform juice extraction to obtain the quality - enhanced fresh - squeezed Phyllanthus emblica juice.

[0011] The total mass fraction of pectinase and cellulase in the complex enzyme solution is 0.1% - 0.5%, preferably 0.2 - 0.4%, and most preferably 0.4%. The mass ratio of pectinase to cellulase is 1:1.

[0012] Preferably, the conditions of the electric field action are: electric field strength of 2 kV / cm, 4,000 pulses, pulse frequency of 20 Hz, and pulse width of 10 μs.

[0013] The juice extraction device is a residue - juice separation juicer.

[0014] In the present invention, the Phyllanthus emblica fruits are first subjected to preliminary enzymatic hydrolysis treatment with a low - concentration complex enzyme solution (cellulase, pectinase) to form micropores on the cell wall surface. Then, the pore diameter of the initially formed micropore region is further expanded and the cell structure is destroyed to form channels under the action of a pulsed electric field, promoting the release of nutrients inside the fruits. By adjusting different electric field strengths, the size of the pore diameter is controlled, thereby controlling the precipitation ability of large and small molecular substances. Through the combined regulation of enzymatic hydrolysis and electric field parameters, the two act synergistically to achieve the efficient release of small - molecule nutritional components (such as vitamin C, polyphenols, total flavonoids, and monosaccharides), while limiting the excessive precipitation of macromolecular polysaccharides, ensuring the texture of the juice and the stability of nutritional components, and maintaining the consistency of the product taste and sensory characteristics. The pulsed electric field in the present invention assists the enzymatic reaction, effectively reducing the enzyme dosage, significantly reducing the enzymatic hydrolysis time and pulse intensity, reducing production costs, and meeting the requirements of green production.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1) In the present invention, the Phyllanthus emblica fruits are first subjected to preliminary enzymatic hydrolysis treatment with a low - concentration complex enzyme solution to form micropores on the cell wall surface. Then, the pore diameter of the initially formed micropore region is further expanded and the cell structure is destroyed to form channels under the action of a pulsed electric field. Through the combined regulation of enzymatic hydrolysis and electric field parameters, the two act synergistically to achieve the efficient release of small - molecule nutritional components (such as vitamin C, polyphenols, total flavonoids, and monosaccharides), significantly improving the release ability and efficiency of small - molecule nutrients. At the same time, the excessive precipitation of macromolecular polysaccharides is limited, improving the taste of the juice, ensuring the clarity of the juice and the stability of nutritional components, and maintaining the consistency of the product taste.

[0017] 2) The pulsed electric field-assisted enzymatic hydrolysis reaction of the present invention effectively reduces the enzyme dosage, reduces the safety problems caused by enzyme residues, significantly reduces the enzymatic hydrolysis time and pulse intensity, reduces the production cost, meets the requirements of green production, and is suitable for large-scale industrial applications. Description of the Drawings:

[0018] Figure 1 It is a scanning electron microscope image of Phyllanthus emblica fruits in Example 1. Among them, (a) is the scanning electron microscope image of Phyllanthus emblica fruits without any treatment, (b) is the scanning electron microscope image of Phyllanthus emblica fruits after enzymatic hydrolysis treatment with low concentration, and (c) is the scanning electron microscope image of Phyllanthus emblica after secondary treatment with pulsed electric field after enzymatic hydrolysis treatment. Detailed Implementation Modes:

[0019] The following is a further description of the present invention, rather than a limitation to the present invention.

[0020] All pulsed electric field equipment in the examples is the PEF-SY-2 type pulsed electric field equipment of Guangzhou Paihu Technology Co., Ltd.

[0021] All Phyllanthus emblica fruits in the examples are freshly picked Phyllanthus emblica fruits; the source is Phyllanthus emblica of Shibintian variety from Shanwei City.

[0022] Example 1:

[0023] (1) Take fresh, intact, uniformly sized Phyllanthus emblica fruits with 90% maturity, remove the stalks and pedicles, and wash them clean.

[0024] (2) Mix the fruits with a composite enzyme solution (containing equal masses of cellulase and pectinase, with a total concentration of 0.2 wt%) at a mass ratio of 1:4 and perform enzymatic hydrolysis at 50 °C for 20 minutes.

[0025] (3) Treat the enzymatically hydrolyzed Phyllanthus emblica fruits in a pulsed electric field equipment. The electric field application conditions are: electric field strength 3 kV / cm, number of pulses 2000 times, pulse frequency 20 Hz, and pulse width 10 μs.

[0026] (4) Remove the fruit cores from the Phyllanthus emblica fruits treated as above (take samples and analyze the hardness using a texture analyzer), and perform juicing using a residue-juice separator for subsequent analysis.

[0027] Example 2

[0028] (1) Take fresh, intact, uniformly sized Phyllanthus emblica fruits with 90% maturity, remove the stalks and pedicles, and wash them clean.

[0029] (2) Mix the fruits with a composite enzyme solution (containing equal masses of cellulase and pectinase, with a total concentration of 0.5 wt%) at a mass ratio of 1:4 and perform enzymatic hydrolysis at 50 °C for 30 minutes.

[0030] (3) Treat the enzymatically hydrolyzed Phyllanthus emblica fruits in a pulsed electric field device. The electric field application conditions are: electric field strength of 1 kV / cm, number of pulses of 3000 times, pulse frequency of 20 Hz, and pulse width of 10 μs;

[0031] (4) Remove the seeds from the Phyllanthus emblica fruits after the above treatment and juice them using a residue-juice separation juicer for subsequent analysis.

[0032] Example 3

[0033] (1) Take fresh, undamaged Phyllanthus emblica fruits of uniform size and 90% maturity, remove the stems and pedicels, and wash them clean;

[0034] Mix the fruits with a complex enzyme solution (containing equal masses of cellulase and pectinase, with a total concentration of 0.4 wt%) at a mass ratio of 1:4 and enzymatically hydrolyze for 20 minutes at 50 °C;

[0035] (2) Treat the enzymatically hydrolyzed Phyllanthus emblica fruits in a pulsed electric field device. The electric field application conditions are: electric field strength of 2 kV / cm, number of pulses of 4000 times, pulse frequency of 20 Hz, and pulse width of 10 μs;

[0036] (3) Remove the seeds from the Phyllanthus emblica fruits after the above treatment (take samples and analyze the hardness using a texture analyzer), and juice them using a residue-juice separation juicer for subsequent analysis.

[0037] Comparative Example 1

[0038] Refer to Example 1, with the difference that there is no enzymatic hydrolysis treatment and electric field treatment, serving as a blank control.

[0039] It includes the following steps: Take fresh, undamaged Phyllanthus emblica fruits of 90% maturity, remove the stems and pedicels, and wash them clean; Remove the seeds from the washed Phyllanthus emblica fruits (take samples and analyze the hardness using a texture analyzer), and juice them using a residue-juice separation juicer for subsequent analysis.

[0040] Comparative Example 2

[0041] Refer to Example 1, with the difference that there is no electric field treatment. The steps are as follows:

[0042] Take fresh, undamaged Phyllanthus emblica fruits of uniform size and 90% maturity, remove the stems and pedicels, and wash them clean; Mix the fruits with an enzyme solution (containing cellulase and pectinase, with a total concentration of 0.2%) at a mass ratio of 1:4 and enzymatically hydrolyze for 20 minutes at 50 °C; Remove the seeds from the Phyllanthus emblica fruits after the above treatment (take samples and analyze the hardness using a texture analyzer), and juice them using a residue-juice separation juicer for subsequent analysis.

[0043] Comparative Example 3

[0044] Referring to Example 1, the difference is that there is no enzymatic hydrolysis treatment.

[0045] (1) Take fresh, undamaged, evenly sized and 90% mature Phyllanthus emblica fruits, remove the stalks and pedicles, and wash them clean.

[0046] (2) Treat the Phyllanthus emblica fruits in a pulsed electric field device, and the electric field action conditions are: electric field strength 3 kV / cm, number of pulses 2000 times, pulse frequency 20 Hz, and pulse width 10 μs.

[0047] (3) After the Phyllanthus emblica fruits are treated by pulsed electric field (sampling and using a texture analyzer to analyze the hardness), remove the fruit cores and perform juicing treatment.

[0048] Comparative Example 4:

[0049] Referring to Example 1, the difference is that the electric field action conditions are electric field strength 5 kV / cm, number of pulses 4000 times, pulse frequency 40 Hz, and pulse width 10 μs.

[0050] (1) Take fresh, undamaged, evenly sized and 90% mature Phyllanthus emblica fruits, remove the stalks and pedicles, and wash them clean.

[0051] (2) Mix the fruits with a complex enzyme solution (containing equal masses of cellulase and pectinase, with a total concentration of 0.2 wt%) at a mass ratio of 1:4 and enzymatically hydrolyze for 60 minutes at 50 °C.

[0052] (3) Treat the enzymatically hydrolyzed Phyllanthus emblica fruits in a pulsed electric field device, and the electric field action conditions are: electric field strength 5 kV / cm, number of pulses 4000 times, pulse frequency 40 Hz, and pulse width 10 μs.

[0053] (4) After the above treatment, the Phyllanthus emblica fruits (sampling and using a texture analyzer to analyze the hardness) remove the fruit cores and are juiced in a residue-juice separation juicer for subsequent analysis.

[0054] Comparative Example 5:

[0055] Referring to Example 2, the difference is that the electric field treatment is performed first and then the enzymatic hydrolysis treatment.

[0056] (1) Take fresh, undamaged, evenly sized and 90% mature Phyllanthus emblica fruits, remove the stalks and pedicles, and wash them clean.

[0057] (2) Treat the washed Phyllanthus emblica fruits in a pulsed electric field device, and the electric field action conditions are: electric field strength 1 kV / cm, number of pulses 3000 times, pulse frequency 20 Hz, and pulse width 10 μs.

[0058] (3) Mix the fruits treated with pulsed electric field with the complex enzyme solution (containing equal masses of cellulase and pectinase, with a total concentration of 0.5 wt%) at a mass ratio of 1:4, and enzymatically hydrolyze for 30 minutes at 50 °C;

[0059] (4) Remove the fruit stones from the Phyllanthus emblica fruits after the above treatment and juice them using a residue-juice separator, and the juice is subjected to subsequent analysis.

[0060] The total phenol content of the juice was determined by the Folin-Ciocalteu colorimetric method; the total flavonoid content of the juice was determined by the aluminum salt colorimetric method; the contents of free monosaccharides and polysaccharides in the juice were determined by the enzymatic hydrolysis method combined with the DNS method; the vitamin C content of the juice was detected by the 2,6-dichlorophenolindophenol titration method; its physical properties were analyzed using a rheological analyzer, a color difference meter, etc.; the antioxidant capacity of the final juice was determined through in vitro antioxidant experiments, including the DPPH radical scavenging rate, the ABTS radical scavenging rate, and the hydroxyl radical (·OH) scavenging rate, to comprehensively characterize the antioxidant performance of the juice. The results are shown in Tables 1 - 3.

[0061] Table 1. Nutritional component contents of Phyllanthus emblica juice with different treatment methods

[0062]

[0063]

[0064] Table 2. Physical property contents of Phyllanthus emblica with different treatment methods

[0065]

[0066] Table 3. Influence of radical scavenging rates of Phyllanthus emblica juice with different treatment methods

[0067]

[0068]

[0069] As can be seen from the comparison of Example 1 and Comparative Examples 1 - 3 in Table 1, the combined regulation of enzymatic hydrolysis and electric field parameters, with their synergistic effect, realizes the efficient release of small-molecule nutrients such as vitamin C, total phenols, and total flavonoids, significantly improves the release ability and efficiency of small-molecule nutrient monosaccharides, while restricting the excessive precipitation of macromolecular polysaccharides, improves the taste of the juice, ensures the clarity of the juice and the stability of nutritional components, and maintains the consistency of product taste. As can be seen from the comparison of Example 1 and Comparative Examples 1 - 3 in Table 2, the combined regulation of enzymatic hydrolysis and electric field parameters, with their synergistic effect, significantly reduces the hardness of Phyllanthus emblica fruits, which helps to remove the fruit stones.

[0070] Comparing Comparative Example 4 with Examples 1-3, it can be seen that when the pulsed electric field strength is higher than 3 kV / cm, although it is beneficial to the release ability and efficiency of small molecule monosaccharides and vitamin C, it is not conducive to the release of total phenols and total flavonoids, and it is also easy to cause excessive release of macromolecular substances such as polysaccharides, making the texture of the juice viscous and the stability decrease. The bitter taste brought by some polysaccharides will also affect the taste, which is not conducive to the clarity and taste of the juice. Therefore, the electric field strength is selected to be 1-3 kV / cm.

[0071] Comparing Comparative Example 5 with Example 2, it can be seen that in Example 2, low-concentration enzymatic hydrolysis treatment is carried out first and then pulsed electric field treatment. Compared with Comparative Example 5 where electric field treatment is carried out first and then enzymatic hydrolysis treatment, it can effectively increase the content of small molecule monosaccharides and has a certain restrictive effect on the precipitation of macromolecular polysaccharides.

[0072] The above results show that: through the combined application of low-concentration enzymatic hydrolysis (0.1%-0.5%) and pulsed electric field (1-3 kV / cm), after forming initial micropores on the surface of the fruit cell wall, the electric field further expands the pore size, significantly reducing the hardness of Phyllanthus emblica fruits, helping to remove the fruit cores, and at the same time improving the release efficiency of small molecule nutrients such as vitamin C, total phenols, total flavonoids and monosaccharides, enhancing the antioxidant capacity, while inhibiting the excessive precipitation of macromolecular polysaccharides, ensuring the clarity and stability of the juice. The optimal parameter combination (enzymatic hydrolysis 0.4% + electric field 2 kV / cm + pulse 4000 times in Example 3) has both economy and high efficiency in industrial production, providing a green technical solution for the development of high-value-added functional juices.

Claims

1. A method for improving the quality of emblica fruit juice by enzymatic hydrolysis assisted by pulsed electric field, characterized in that: The method comprises the following steps: 1) Take fresh, intact, uniform-sized, 90% mature Phyllanthus emblica fruits, remove the stems and stalks, and wash them clean; 2) Mix the fruit with a complex enzyme solution consisting of cellulase and pectinase in a mass ratio of 1:4, and perform enzymolysis at 40-50°C for 15-30 minutes to produce initial micropores in the peel; 3) treating the enzymatically hydrolyzed emblica fruit in a pulsed electric field device, wherein the electric field action conditions are: electric field intensity 1-3 kV / cm, pulse number 1200-4000 times, pulse frequency 10-30 Hz, pulse width 2-10 μs, and then removing the core for juicing to obtain the emblica fresh juice with enhanced quality.

2. The method according to claim 1, characterized in that The total mass percentage of pectinase and cellulase in the complex enzyme solution is 0.1%-0.5%, wherein the mass ratio of pectinase to cellulase is 1:

1.

3. The method according to claim 2, characterized in that The total mass percentage of pectinase and cellulase in the complex enzyme solution is 0.2-0.4%.

4. The method according to claim 1, characterized in that the electric field Action conditions: electric field strength 2kV / cm, pulse 4000 times, pulse frequency 20Hz, pulse width 10μs.

5. The method according to claim 1, characterized in that The juice extraction processing equipment is a residue-juice separation juicer.

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