A method for steam explosion peeling of green pepper

Abstract

The application provides a steam explosion peeling method of green pepper, which comprises the following steps: picking mature green pepper from the field, transporting the green pepper to a processing site within 24 hours, removing impurities, washing with clean water, and then directly placing the green pepper into a basket of a steam explosion machine; the steam explosion pressure is 1-2.5 MPa, the pressure maintaining time is 60-180 s, then the pressure is released instantaneously, the kernel is left in the basket, and part of the peel is degraded into peel liquid, so that the kernel and the peel residue liquid are automatically separated; the white pepper particle product is dried to obtain the peeled white pepper. The peeled white pepper provided by the application has the advantages of rich pepper aroma, no peculiar smell, complete particles, no broken fruit, gloss, white color, overall harmony, high preference, sufficient retention of the aroma of the pepper while removing the peculiar smell of the white pepper, short peeling time, rich aroma, bright and white color, a peeling rate of more than 99%, no surface skin damage, high content of piperine, clean and safe process, high efficiency, energy saving, no solid waste and liquid waste discharge.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material processing, in particular to a steam explosion peeling method of green pepper. BACKGROUND

[0002] Pepper (Piper nigrum L.) is also known as mali branch, floating pepper and jade pepper. It is a climbing evergreen vine of Piperaceae (Piper Linn) and contains volatile oil, piperine, crude fat, crude protein and other components. After the popularization of pepper planting technology, its yield and output value exceed those of other spices. The traditional processing of pepper fruits includes black pepper and white pepper with peeling, and green pepper and red pepper with color protection. The main product consumed in China is white pepper. The processing method of white pepper is to obtain it by removing stems, peeling, washing and drying mature pepper fruits. The peeling step is a key process in white pepper processing and has an important influence on the quality of the obtained peeled white pepper. Currently, traditional water soaking method, biological enzyme method, solid-state fermentation method and frozen peeling method are used for pepper peeling. The problems of off-flavor generated during the peeling process of white pepper and halving of the aroma of white pepper after peeling are prominent. Moreover, the above-mentioned peeling methods have problems such as low efficiency, long time, high breakage rate, solid and liquid waste discharge, environmental pollution and the like. Under these problems, the peeling technology of white pepper cannot show good market prospects. SUMMARY

[0003] In view of this, the purpose of the present application is to provide a steam explosion peeling method of green pepper. The mature green pepper is picked from the field and transported to the processing site within 24 hours. After impurity removal and water washing, it is directly placed in the explosion material basket of the steam explosion machine. A certain steam pressure is set, the pressure holding time is set, and then the pressure is released instantaneously. The kernel remains in the basket, and part of the peel is degraded into peel liquid, realizing the automatic separation of the kernel and the peel residue liquid. The peel residue liquid can be blended into a pepper beverage. The process is clean and safe, efficient and energy-saving, and has no solid waste and liquid waste discharge.

[0004] The technical scheme of the present application is as follows:

[0005] A steam explosion peeling method of green pepper, comprising the following preparation steps:

[0006] S1 pepper pretreatment: taking green pepper, removing impurities, soaking and washing in water, controlling water, and obtaining pretreated pepper;

[0007] S2 steam explosion: the pretreated pepper is treated by steam explosion at a steam explosion pressure of 1-2.5 MPa and a pressure maintaining time of 60-180 s, the skin residue liquid and the pepper product are separated, the pepper product is dried, and the peeled white pepper is obtained; by controlling the pressure and the pressure maintaining time, effective peeling is achieved while avoiding damage to the quality of the peeled pepper.

[0008] Further, in step S1, the pepper is mature green pepper, and the time for picking the green pepper to obtain the pretreated pepper is 0-24 h.

[0009] Further, in step S2, an ethanol solution is added as a carrying agent before steam explosion, or a certain amount of ethanol / different proportions of ethanol is added as a carrying agent during the peeling process, which is shorter in time and better in effect.

[0010] Further, the mass ratio of the green pepper to the ethanol solution is 1:5-10.

[0011] Further, before the addition of the ethanol solution, the method further comprises soaking the pretreated pepper in a buffer solution, the buffer solution is a citric acid-sodium citrate buffer solution or a disodium hydrogen phosphate-sodium citrate buffer solution, and the pH of the buffer solution is 5.0-6.2.

[0012] Further, the soaking time in the buffer solution is 2-4 h.

[0013] Further, during the soaking in the buffer solution, the buffer solution is heated to 35-45 DEG C and is kept warm for 0.5-1.5 h.

[0014] Further, the drying temperature is 50-55 DEG C, and the drying time is 5-7 h.

[0015] The application further provides a green pepper beverage, which is prepared from the skin residue liquid obtained by the above separation, coconut milk, honey, and dragon fruit stem pectin, and is obtained by colloid milling, homogenization, and pasteurization.

[0016] Compared with the prior art, the application has the following beneficial effects:

[0017] The application uses steam explosion for the peeling of pepper after soaking treatment, effectively shortens the peeling time of pepper, and has a peeling rate of more than 99%, basically no skin damage, and a high content of piperine.

[0018] The peeled white pepper provided by the application has a strong pepper aroma, no odor, complete particles, basically no broken fruit, luster, white color, overall harmony, and high preference, removes the odor of white pepper while fully retaining the aroma of pepper, has a short peeling time, strong aroma, bright color, clean and safe process, high efficiency and energy saving, no solid waste and liquid waste discharge, and meets the needs of modern agriculture and consumers.

[0019] The steam explosion type peeling provided by the present application, after steam explosion treatment, the fruit kernels remain in the basket, and part of the peel is degraded into peel liquid, which can effectively realize the automatic separation of the fruit kernels and the peel residue liquid, reduce the labor cost, and at the same time, the peel residue liquid of the green pepper after steam explosion peeling can be mixed with coconut milk, honey and fruit pectin of the big fruit stem to prepare a green pepper beverage after colloid milling, homogenization and pasteurization, and the peel residue liquid can be mixed to become a pepper beverage, thereby fully improving the recycling rate of the material. DETAILED DESCRIPTION

[0020] In order to better understand the technical content of the present application, the following specific examples are provided to further illustrate the present application.

[0021] The experimental methods used in the embodiments of the present application are conventional methods unless otherwise specified.

[0022] The materials, reagents and the like used in the embodiments of the present application can be obtained from commercial channels unless otherwise specified.

[0023] Example 1

[0024] Mature green peppers are picked from the field and transported to the processing site within 24 hours for processing, impurity removal and water washing, and then soaked in a pH 6.2 sodium citrate buffer for 2 hours. During the soaking process, the sodium citrate buffer is heated to 40℃ for 1 hour. The green peppers are then taken out, water is controlled, and ethanol solution is added as a carrying agent at a material-liquid mass ratio of 1:8. Steam explosion is performed at a steam explosion pressure of 2.1 MPa and a pressure holding time of 125 s. After steam explosion, the pressure is released instantly to open the discharge valve, the fruit kernels remain in the basket, and part of the peel is degraded into peel liquid, thereby realizing the automatic separation of the fruit kernels and the peel residue liquid. The peel residue liquid and the pepper product are separated, the pepper product is taken out, dried at 55℃ for 6 hours, and white pepper with the peel removed is obtained.

[0025] Example 2

[0026] Mature green peppers are picked from the field and transported to the processing site within 24 hours for processing, impurity removal and water washing, and then soaked in a pH 6.2 sodium citrate buffer for 2 hours. During the soaking process, the sodium citrate buffer is heated to 40℃ for 1 hour. The green peppers are then taken out, water is controlled, and ethanol solution is added as a carrying agent at a material-liquid mass ratio of 1:8. Steam explosion is performed at a steam explosion pressure of 2.1 MPa and a pressure holding time of 125 s. After steam explosion, the pressure is released instantly to open the discharge valve, the fruit kernels remain in the basket, and part of the peel is degraded into peel liquid, thereby realizing the automatic separation of the fruit kernels and the peel residue liquid. The peel residue liquid and the pepper product are separated, the pepper product is taken out, dried at 55℃ for 6 hours, and white pepper with the peel removed is obtained.

[0027] Example 3

[0028] The ripe green pepper is picked from the field, and 24 kg is transported to the processing site for processing. After impurity removal and water cleaning, steam explosion is performed at a steam explosion pressure of 2.1 MPa and a pressure holding time of 125 s. After steam explosion, the pressure is instantaneously released to open the discharge valve, the fruit kernels remain in the basket, and part of the peel is degraded into peel liquid, thereby achieving automatic separation of the fruit kernels and the peel residue liquid. The peel residue liquid and the pepper product are separated, the pepper product is taken, dried at 55°C for 6 h, and white pepper with the peel removed is obtained.

[0029] Comparative Example 1

[0030] Traditional peeling method: fresh pepper is taken, washed, and de-stemmed and de-germinated. After soaking in clean water for 10 days, mechanical peeling is performed, the peel residue and the pepper product are separated, the pepper product separated from the peel residue is taken, dried at 55°C for 6 h, and white pepper with the peel removed is obtained.

[0031] Comparative Example 2

[0032] Fresh pepper is taken, washed, and de-stemmed and de-germinated. After soaking in a citric acid-sodium citrate buffer solution with a pH of 6.2 for 2 h, the citric acid-sodium citrate buffer solution is heated to 40°C for 1 h, the pepper is taken out, water is controlled, pectinase liquid is sprayed while vibrating (solid-liquid ratio of 1:0.02), stirred uniformly, and enzyme hydrolysis is performed at 28-30°C for 20 h. The peel residue and the pepper product are separated, the pepper product separated from the peel residue is taken, dried at 55°C for 6 h, and white pepper with the peel removed is obtained.

[0033] Test Example 1

[0034] About 100 g of white pepper with the peel removed in the above examples and comparative examples is randomly selected, weighed, and the weight is recorded as M2. The white pepper with the peel completely removed is selected, weighed, and the weight is recorded as M1. The peeling rate is calculated according to the formula: peeling rate % = M1 / M2 x 100%. The white pepper with the damaged skin is selected, weighed, and the weight is recorded as M3. The damage rate is calculated according to the formula: damage rate % = M3 / M2 x 100%.

[0035] The piperine content of the white pepper with the peel removed in each treatment group is determined according to GB / T 17528-2009 High Performance Liquid Chromatography Method for Determining Piperine Content.

[0036] Table 1 Peeling rate and piperine results of pepper in each group

[0037] Item Peeling rate / % Damage rate / % Piperine / % Example 1 100.0 0.80 5.62 Example 2 99.3 0.65 5.56 Example 3 96.9 1.21 5.50 Comparative Example 1 92.2 5.67 4.52 Comparative Example 2 95.8 2.72 5.08

[0038] As seen from the above Table 1, the green pepper treated in Examples 1 and 2 has a peeling rate of more than 99%, the minimum broken skin rate is 0.65%, and the content of piperine is 5.56-5.62%, compared with the traditional peeling method, the green pepper is treated by soaking and then subjected to steam explosion for peeling, the peeling efficiency is high, the broken skin degree is low, and the content of piperine in the peeled pepper is also high, the green pepper is treated by steam explosion in the present application, the high-efficiency peeling is realized, the automatic separation of the kernel and the skin residue liquid is realized, the process is clean and safe, high-efficiency, energy-saving, no solid waste and liquid waste is discharged; compared with Example 3, the cells of the skin are ruptured and degraded when the steam explosion releases pressure instantaneously, and are separated from the kernel, the ethanol solution is added before steam explosion, which can increase the penetration speed of water in the skin during steam explosion treatment and improve the peeling efficiency; compared with Comparative Example 2, the steam explosion is used for peeling the pepper, which can soften the pectin more quickly, further improve the peeling efficiency, and reduce the broken skin degree.

[0039] Test Example 2

[0040] 30 professional personnel with high sensory sensitivity are selected to form a sensory evaluation group, 10 people in each group, the peeled white pepper obtained in each treatment group is subjected to sensory evaluation according to the scoring standard of quality evaluation in Table 2.

[0041] Table 2 Scoring standard of quality evaluation

[0042]

[0043] Table 3 Quality evaluation results of the peeled pepper in each group

[0044]

[0045] As seen from the above Table 2, compared with Comparative Example 2, the pepper is treated by soaking and then subjected to steam explosion for peeling in Example 1, the peculiar smell of the white pepper is removed, and the aroma of the pepper is fully retained, Example 1 is better than Comparative Example 2 in odor and tissue appearance, the white pepper obtained in Example 1 has rich pepper aroma, no peculiar smell, complete particles, basically no broken fruit, luster, white color, basically no black fruit, overall harmony, and high preference.

[0046] The above only describes the preferred embodiments of the present application, and is not used to limit 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 steam-exploding and peeling green peppercorns, characterized in that, The preparation steps include the following: S1 Pepper Pretreatment: Take green peppers, remove impurities, soak them in clean water to wash, drain the water, and obtain pretreated peppers; S2 Steam Explosion: The pretreated pepper is subjected to steam explosion treatment at a steam explosion pressure of 1~2.5MPa and a holding time of 60~180s to separate the peel residue liquid and pepper products. The pepper products are then dried to obtain peeled white pepper. In step S2, an ethanol solution is added as an entrainer before steam explosion; the mass ratio of green pepper to ethanol solution is 1:5~10. Before adding the ethanol solution, the peppers are soaked in a buffer solution, which is either citrate-sodium citrate buffer or disodium hydrogen phosphate-sodium citrate buffer with a pH of 5.0-6.2 and a soaking time of 2-4 hours. During the soaking process, the buffer solution is heated to 35-45°C and kept at that temperature for 0.5-1.5 hours. In step S1, the pepper is mature green pepper, and the time from harvesting the green pepper to obtaining the pre-treated pepper is 0~24h; The drying temperature is 50~55℃, and the drying time is 5~7 hours.

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