Method for continuously extracting effective components of pericarp by ultrasonic-assisted flash extraction method

Abstract

The invention discloses a method for continuously extracting effective components of fruit peels by an ultrasonic-assisted flash extraction method, and belongs to the technical field of recycling of agricultural and forestry wastes. Comprising the following steps: drying and crushing pericarp into powder, mixing with water, heating, carrying out ultrasonic treatment, carrying out solid-liquid separation, concentrating filtrate I obtained by solid-liquid separation, adding ethanol, standing, centrifuging, precipitating, carrying out alcohol washing, and drying to obtain pericarp pectin; s2, mixing the material residue I obtained by solid-liquid separation in the step S1 with an ethanol solution, then carrying out flash extraction, concentrating an extracting solution II obtained by flash extraction, and freeze-drying to obtain pericarp anthocyanin; and S2, mixing the residue II obtained by solid-liquid separation in the step S2 with water, soaking, and drying to obtain the dietary fiber. The whole process is simple in technology, easy to control and suitable for large-scale production, meanwhile, the extraction rate of the active substances of the pericarp is increased, and the extraction time is shortened.

Description

Technical Field

[0001] The present application relates to a method for continuously extracting effective components from peels using an ultrasound-assisted flash extraction method, and belongs to the technical field of agricultural and forestry waste recycling. Background Art

[0002] The fruit industry has become China's third largest agricultural industry after the grain and vegetable industries, and has obvious advantages and competitiveness in the agricultural industry. In the process of eating and processing fruits, in addition to the edible pulp, the peel part of the fruit also has a high utilization value. The peel of most fruits accounts for a large proportion, and it contains rich nutrients and functional ingredients. However, many discarded fruit peels are not fully utilized. For example, my country's citrus production ranks second in the world, but only the pulp of citrus is used in the processing process. The remaining 40% to 50% of citrus peels have not been fully utilized. Most of them are landfilled or processed into animal feed. For example, bananas, the fourth largest fruit in my country, account for 35% to 40% of banana peels. After eating bananas, a large amount of banana peels are discarded as waste, which also pollutes the environment. Therefore, the comprehensive utilization of peels is of great significance to improving the economic benefits of fruit factories, reducing pollution and protecting the environment. In particular, the extraction and utilization of pectin, anthocyanins, dietary fiber and other components in peels are very important: my country consumes more than 1,500 tons of pectin each year. Although my country has abundant pectin resources, more than 80% relies on imports, and the price is much higher than domestic pectin; flavonoids can promote the disappearance of inflammation and have significant anti-inflammatory, antibacterial and antiviral effects. For example, it can inhibit the activity of influenza virus and polio virus. In addition, flavonoids also have antibacterial effects and help prevent bacterial infections; the application of dietary fiber in the food industry has been very common. In recent years, the structure of global food is adjusting towards fiber food, and the peel is rich in dietary fiber. Although pectin, anthocyanins, dietary fiber and other resources are abundant in peels, they are still limited by low resource utilization and imperfect large-scale production processes.

[0003] In recent years, the research on comprehensive utilization and processing technology of fruit peels has made great progress, and the prospects for comprehensive utilization are good. Traditional methods for extracting active substances from peels mainly include solvent extraction, microwave extraction, ultrasonic extraction, enzymatic hydrolysis and supercritical extraction, but traditional extraction methods have problems such as low efficiency and high energy consumption. For example, although the steam distillation method has simple equipment, easy operation and low cost, its extraction time is long and the temperature is high, which can easily degrade the heat-sensitive components in the peel, resulting in a low extraction rate; taking the extraction of total flavonoids from passion fruit peel as an example, although supercritical extraction technology can improve the extraction rate and reduce the extraction time and temperature, this method still faces the challenge of high cost.

[0004] In recent years, ultrasound-assisted extraction technology and flash extraction technology have been widely used in the extraction of bioactive substances due to their high efficiency and energy saving. However, there is no research on combining ultrasound-assisted and flash extraction for the extraction of active substances from peel. Summary of the invention

[0005] The present application provides a method for continuously extracting effective components from peels by using an ultrasound-assisted flash extraction method, which solves the problems of low extraction rate and long extraction time in the prior art.

[0006] This application adopts the following technical solutions:

[0007] A method for continuously extracting effective components from peels, comprising the following steps:

[0008] S1, drying and crushing the peel into powder, mixing with water, heating, ultrasonic treatment, and then solid-liquid separation, concentrating the filtrate I obtained by solid-liquid separation, adding ethanol, standing, and then centrifuging, precipitating, washing with alcohol, and drying to obtain peel pectin;

[0009] S2, mixing the residue I obtained by solid-liquid separation in step S1 with an ethanol solution, and then performing flash extraction, concentrating the filtrate II obtained after the flash extraction, and freeze-drying to obtain peel flavonoids;

[0010] S3, mixing the residue II remaining after the flash extraction in step S2 with water, soaking, and drying to obtain dietary fiber.

[0011] Commonly used extraction methods for peel in the prior art mainly include conventional organic solvent extraction, water decoction, ultrasonic assisted extraction and supercritical fluid extraction, etc. However, these methods have disadvantages such as low extraction efficiency, long extraction time, high equipment price, ultrasonic attenuation, etc. Compared with the aforementioned prior art, the method for continuous extraction of effective components of peel provided by the present application has a simple process and low cost.

[0012] Optionally, in step S1, the size of the powder is 50-150 mesh;

[0013] Optionally, in step S1, the weight ratio of the powder to water and ethanol is 1:2-8:4-16.

[0014] Optionally, the ethanol is preferably ethanol with a mass concentration of 95%.

[0015] Optionally, in step S1, the heating conditions include: a temperature of 40 to 60°C and a heating time of 3 to 10 minutes.

[0016] Optionally, in step S1, the conditions of the ultrasonic treatment include: ultrasonic power of 200 to 700 W, and ultrasonic time of 2 to 12 min.

[0017] Optionally, in step S1, in the ultrasonic treatment conditions, the ultrasonic power is selected from any value of 200 W, 300 W, 400 W, 500 W, 600 W, 700 W or any range between two of them.

[0018] Optionally, in step S1, in the ultrasonic treatment conditions, the ultrasonic time is selected from any value of 2 min, 4 min, 6 min, 8 min, 10 min, 12 min or any range between two values.

[0019] Optionally, in step S1 and step S2, the conditions for concentrating filtrate I and concentrating filtrate II independently include: concentrating until the volume is reduced by 40-60%.

[0020] Optionally, in step S1, the standing time is 6 to 18 hours.

[0021] Optionally, in step S2, the liquid-to-material ratio of the ethanol solution to the slag I is 30-50 mL: 1 g;

[0022] The concentration of the ethanol solution is 40-75%.

[0023] Optionally, in step S2, the residue I is washed with water several times before being mixed with the ethanol solution.

[0024] Optionally, in step S2, the conditions of the flash extraction include: extraction temperature of 50-70°C, pressure of 1-2 MPa, and holding time of 5-30 min.

[0025] Optionally, in step S2, in the flash extraction conditions, the extraction temperature is selected from any value of 50°C, 55°C, 60°C, 65°C, 70°C or any range therebetween.

[0026] Optionally, in step S2, in the flash extraction condition, the pressure is selected from any value among 1 MPa, 1.2 MPa, 1.4 MPa, 1.6 MPa, 1.8 MPa, 2 MPa, or any range between two values.

[0027] Optionally, in step S3, the liquid-to-material ratio of water to slag II is 30-50 mL: 1 g.

[0028] Optionally, in step S3, the soaking time is 5 to 30 minutes.

[0029] Optionally, the conditions for solid-liquid separation in step S1 include: repeating the filtration 2 to 5 times, and mixing the filtrates obtained from each filtration;

[0030] Optionally, the flash extraction conditions in step S2 also include: repeating the extraction 2 to 5 times, and mixing the extracts obtained from each extraction.

[0031] Optionally, the solid-liquid separation method is suction filtration.

[0032] Optionally, the alcohol washing is preferably washing with anhydrous ethanol.

[0033] The beneficial effects of this application include:

[0034] The method for continuously extracting effective ingredients from peel provided by the present application has a simple process, low cost, is environmentally friendly, is suitable for large-scale production, and can bring certain social benefits while creating benefits; and the present invention improves the extraction rate of the obtained peel active substances and shortens the extraction time. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the process of continuously extracting effective ingredients from peels of the present application. DETAILED DESCRIPTION

[0036] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0037] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0038] Unless otherwise specified, conventional methods were used for testing and instrument settings were those recommended by the manufacturer.

[0039] The process diagram of Examples 1 to 6 is as follows: Figure 1 shown.

[0040] Example 1

[0041] Take 10kg of dried and crushed citrus peel, add 40kg of distilled water respectively, heat in a water bath at 50℃, keep for 5min, ultrasonic power is 400W, ultrasonic time is kept for 4min, filter, filter residue repeatedly twice, combine 3 filtrates, concentrate until the volume is reduced by 50%, add 95% ethanol 4 times the weight of the concentrate and let stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extraction temperature is 60℃, pressure is 1.5MPa, keep time for 10min, separate, extract the residue repeatedly twice, combine 3 extracts, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-liquid ratio of 40:1, soak for 10min, filter, dry, and obtain dietary fiber.

[0042] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 9.3 mg / g and the anthocyanin content was 11.6 mg / g.

[0043] The pectin content in the extract Ⅰ obtained by ultrasonic-assisted flash extraction is 6.7 mg / g, and the pectin extraction rate is 72.1%; the anthocyanin content in the extract Ⅱ is 9.8 mg / g, and the anthocyanin extraction rate is 84.4%; the obtained dietary fiber is placed in an oven for drying and crushed to obtain 5337 grams of powder.

[0044] The extraction time is 35min.

[0045] Comparative Example 1

[0046] Take 10kg of dried and crushed citrus peel, add 40kg of distilled water respectively, heat in a water bath at 50℃, keep for 10min, filter by suction, repeat the operation twice for the filter residue, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol with 4 times the weight of the concentrate and let it stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60℃, pressure of 1.5MPa, keep for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0047] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 9.3 mg / g and the anthocyanin content was 11.6 mg / g.

[0048] The pectin content in the extract I was 3.9 mg / g, and the pectin extraction rate was 41.9%. The anthocyanin content in the extract II was 6.3 mg / g, and the anthocyanin extraction rate was 54.3%.

[0049] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 30.2% and the anthocyanin extraction rate by 30.1%.

[0050] The extraction time was 45 min.

[0051] Comparative Example 2

[0052] Take 10kg of dried and crushed citrus peel, add 40kg of distilled water respectively, heat in a water bath at 50℃, keep for 20min, filter by suction, repeat the operation twice for the filter residue, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol with a weight of 5 times that of the concentrate and let it stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60℃, pressure of 1.5MPa, keep for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0053] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 9.3 mg / g and the anthocyanin content was 11.6 mg / g.

[0054] The pectin content in the extract I was 4.3 mg / g, and the pectin extraction rate was 46.2%. The anthocyanin content in the extract II was 5.9 mg / g, and the anthocyanin extraction rate was 50.9%.

[0055] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 25.9% and the anthocyanin extraction rate by 33.5%.

[0056] The extraction time was 1 h.

[0057] Comparative Example 3

[0058] Take 10kg of dried and crushed citrus peel, add 40kg of distilled water respectively, heat in a water bath at 50℃, keep for 30min, filter by suction, repeat the operation twice for the filter residue, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol 6 times the weight of the concentrate and let stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60℃, pressure of 1.5MPa, keep for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0059] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 9.3 mg / g and the anthocyanin content was 11.6 mg / g.

[0060] The pectin content in the extract I was 3.5 mg / g, and the pectin extraction rate was 37.6%. The anthocyanin content in the extract II was 5.7 mg / g, and the anthocyanin extraction rate was 49.1%.

[0061] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 34.4% and the anthocyanin extraction rate by 35.3%.

[0062] The extraction time was 1.5 h.

[0063] Example 2

[0064] Take 10kg of passion fruit peel that has been dried and crushed, add 40kg of distilled water, heat in a water bath at 50°C, keep it for 5min, apply ultrasonic power of 200W, keep ultrasonic time for 2min, filter by suction, repeat the operation of filter residue twice, combine 3 filtrates, concentrate until the volume is reduced by 50%, add 95% ethanol of 4 times the weight of the concentrate and let it stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol for several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60°C, pressure of 1.5MPa, keep it for 10min, separate, extract the residue repeatedly twice, combine 3 extracts, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0065] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 6.3 mg / g and the anthocyanin content was 7.9 mg / g.

[0066] The pectin content in the extract Ⅰ obtained by ultrasonic-assisted flash extraction is 4.8 mg / g, and the pectin extraction rate is 76.2%; the anthocyanin content in the extract Ⅱ is 6.1 mg / g, and the anthocyanin extraction rate is 77.2%; the obtained dietary fiber is placed in an oven for drying and crushed to obtain 5559 grams of powder.

[0067] The extraction time is 35min.

[0068] Comparative Example 4

[0069] Take 10kg of passion fruit peel that has been dried and crushed, add 40kg of distilled water respectively, heat in a water bath at 50℃, keep for 10min, filter by suction, repeat the operation of filter residue twice, combine the filtrate three times, concentrate until the volume is reduced by 50%, add 95% ethanol with 4 times the weight of the concentrate, stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60℃, pressure of 1.5MPa, keep for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0070] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 6.3 mg / g and the anthocyanin content was 7.9 mg / g.

[0071] The pectin content in the extract I was 2.7 mg / g, and the pectin extraction rate was 42.9%. The anthocyanin content in the extract II was 3.6 mg / g, and the anthocyanin extraction rate was 54.3%.

[0072] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 33.3% and the anthocyanin extraction rate by 22.9%.

[0073] The extraction time was 45 min.

[0074] Comparative Example 5

[0075] Take 10kg of passion fruit peel that has been dried and crushed, add 40kg of distilled water respectively, heat in a water bath at 50℃, keep it for 20min, filter by suction, repeat the operation of filter residue twice, combine the filtrate three times, concentrate until the volume is reduced by 50%, add 95% ethanol with 5 times the weight of the concentrate, stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60℃, pressure of 1.5MPa, keep it for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0076] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 6.3 mg / g and the anthocyanin content was 7.9 mg / g.

[0077] The pectin content in the extract I was 3.1 mg / g, and the pectin extraction rate was 49.2%. The anthocyanin content in the extract II was 4.1 mg / g, and the anthocyanin extraction rate was 51.9%.

[0078] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 27.0% and the anthocyanin extraction rate by 25.3%.

[0079] The extraction time was 1 h.

[0080] Comparative Example 6

[0081] Take 10kg of passion fruit peel that has been dried and crushed, add 40kg of distilled water respectively, heat in a water bath at 50℃, keep for 35min, filter by suction, repeat the operation of filter residue twice, combine the filtrate three times, concentrate until the volume is reduced by 50%, add 95% ethanol with 6 times the weight of the concentrate, stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60℃, pressure of 1.5MPa, keep for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0082] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 6.3 mg / g and the anthocyanin content was 7.9 mg / g.

[0083] The pectin content in the extract I was 2.5 mg / g, and the pectin extraction rate was 39.7%. The anthocyanin content in the extract II was 3.9 mg / g, and the anthocyanin extraction rate was 49.4%.

[0084] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 36.5% and the anthocyanin extraction rate by 27.8%.

[0085] The extraction time was 1.5 h.

[0086] Example 3

[0087] Take 5kg of dried and crushed banana peel, add 40kg of distilled water, heat in a water bath at 50°C, keep for 5min, ultrasonic power is 500W, ultrasonic time is kept for 6min, filter by suction, filter residue repeatedly for 2 times, combine 3 filtrates, concentrate until the volume is reduced by 50%, add 95% ethanol 4 times the weight of the concentrate and let stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol for several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60°C, pressure of 1.5MPa, keep for 10min, separate, extract the residue repeatedly for 2 times, combine 3 extracts, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0088] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 7.4 mg / g and the anthocyanin content was 8.7 mg / g.

[0089] The pectin content in the extract Ⅰ obtained by ultrasonic-assisted flash extraction is 5.2 mg / g, and the pectin extraction rate is 70.3%; the anthocyanin content in the extract Ⅱ is 6.3 mg / g, and the anthocyanin extraction rate is 72.4%; the obtained dietary fiber is placed in an oven for drying and crushed to obtain 2513 grams of powder.

[0090] The extraction time is 35min.

[0091] Comparative Example 7

[0092] Take 5kg of dried and crushed banana peels, add 40kg of distilled water respectively, heat in a water bath at 50°C, keep for 10 minutes, filter by suction, repeat the operation of filtering residues twice, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol 4 times the weight of the concentrate and let stand for 12 hours, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60°C, pressure of 1.5MPa, keep for 10 minutes, separate, extract the residue repeatedly twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10 minutes, filter, and dry to obtain dietary fiber.

[0093] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 7.4 mg / g and the anthocyanin content was 8.7 mg / g.

[0094] The pectin content in the extract I was 3.1 mg / g, and the pectin extraction rate was 41.9%. The anthocyanin content in the extract II was 4.2 mg / g, and the anthocyanin extraction rate was 48.3%.

[0095] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 28.4% and the anthocyanin extraction rate by 24.1%.

[0096] The extraction time was 45 min.

[0097] Comparative Example 8

[0098] Take 5kg of dried and crushed banana peels, add 40kg of distilled water respectively, heat in a water bath at 50°C, keep for 20min, filter by suction, repeat the operation twice for the filter residue, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol 5 times the weight of the concentrate and let stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60°C, pressure of 1.5MPa, keep for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0099] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 7.4 mg / g and the anthocyanin content was 8.7 mg / g.

[0100] The pectin content in the extract I was 3.5 mg / g, and the pectin extraction rate was 47.3%. The anthocyanin content in the extract II was 4.6 mg / g, and the anthocyanin extraction rate was 52.9%.

[0101] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 17.4% and the anthocyanin extraction rate by 19.5%.

[0102] The extraction time was 1 h.

[0103] Comparative Example 9

[0104] Take 5kg of dried and crushed banana peels, add 40kg of distilled water respectively, heat in a water bath at 50°C, keep for 35 minutes, filter by suction, repeat the operation twice for the filter residue, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol 5 times the weight of the concentrate and let stand for 12 hours, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60°C, pressure of 1.5MPa, keep for 10 minutes, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10 minutes, filter, and dry to obtain dietary fiber.

[0105] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 7.4 mg / g and the anthocyanin content was 8.7 mg / g.

[0106] The pectin content in the extract I was 2.8 mg / g, and the pectin extraction rate was 37.8%. The anthocyanin content in the extract II was 3.9 mg / g, and the anthocyanin extraction rate was 44.8%.

[0107] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 32.5% and the anthocyanin extraction rate by 27.6%.

[0108] The extraction time was 1.5 h.

[0109] Example 4

[0110] Take 5kg of dried and crushed apple peel, add 40kg of distilled water, heat in a water bath at 50℃, keep for 5min, ultrasonic power is 600W, ultrasonic time is kept for 10min, filter, filter residue repeatedly for 2 times, combine 3 filtrates, concentrate until the volume is reduced by 50%, add 95% ethanol with 4 times the weight of the concentrate and let stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol for several times, dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60℃, pressure of 1.5MPa, keep for 10min, separate, extract the residue repeatedly for 2 times, combine 3 extracts, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, dry, and obtain dietary fiber.

[0111] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 8.1 mg / g and the anthocyanin content was 9.2 mg / g.

[0112] The pectin content in the extract Ⅰ obtained by ultrasonic-assisted flash extraction is 6.4 mg / g, and the pectin extraction rate is 79.0%; the anthocyanin content in the extract Ⅱ is 7.1 mg / g, and the anthocyanin extraction rate is 77.2%; the obtained dietary fiber is placed in an oven for drying and crushed to obtain 2739 grams of powder.

[0113] The extraction time is 35min.

[0114] Comparative Example 10

[0115] Take 5kg of dried and crushed apple peel, add 40kg of distilled water respectively, heat in a water bath at 50℃, keep for 10min, filter by suction, repeat the operation of filtering residue twice, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol with 4 times the weight of the concentrate and let it stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60℃, pressure of 1.5MPa, keep for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0116] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 8.1 mg / g and the anthocyanin content was 9.2 mg / g.

[0117] The pectin content in the extract I was 3.6 mg / g, and the pectin extraction rate was 44.4%. The anthocyanin content in the extract II was 5.2 mg / g, and the anthocyanin extraction rate was 56.5%.

[0118] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 34.6% and the anthocyanin extraction rate by 20.7%.

[0119] The extraction time was 45 min.

[0120] Comparative Example 11

[0121] Take 5kg of dried and crushed apple peel, add 40kg of distilled water respectively, heat in a water bath at 50℃, keep for 20min, filter by suction, repeat the operation of filtering residue twice, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol with a weight of 5 times of the concentrate and let stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60℃, pressure of 1.5MPa, keep for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0122] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 8.1 mg / g and the anthocyanin content was 9.2 mg / g.

[0123] The pectin content in the extract I was 3.9 mg / g, and the pectin extraction rate was 48.1%. The anthocyanin content in the extract II was 5.4 mg / g, and the anthocyanin extraction rate was 58.7%.

[0124] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 30.8% and the anthocyanin extraction rate by 18.5%.

[0125] The extraction time was 1 h.

[0126] Comparative Example 12

[0127] Take 5kg of dried and crushed apple peel, add 40kg of distilled water respectively, heat in a water bath at 50℃, keep for 35min, filter by suction, repeat the operation of filtering residue twice, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol 6 times the weight of the concentrate and let stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60℃, pressure of 1.5MPa, keep for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0128] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 8.1 mg / g and the anthocyanin content was 9.2 mg / g.

[0129] The pectin content in the extract I was 3.3 mg / g, and the pectin extraction rate was 40.7%. The anthocyanin content in the extract II was 4.9 mg / g, and the anthocyanin extraction rate was 53.3%.

[0130] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 38.3% and the anthocyanin extraction rate by 23.9%.

[0131] The extraction time was 1.5 h.

[0132] Example 5

[0133] Take 15kg of dried and crushed grape peels, add 60kg of distilled water, heat in a water bath at 50°C, keep for 5min, ultrasonic power is 700W, ultrasonic time is kept for 12min, filter by suction, filter residue repeatedly for 2 times, combine 3 filtrates, concentrate until the volume is reduced by 50%, add 95% ethanol 4 times the weight of the concentrate and let stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol for several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extraction temperature is 60°C, pressure is 1.5MPa, keep for 10min, separate, extract the residue repeatedly for 2 times, combine 3 extracts, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0134] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 10.2 mg / g and the anthocyanin content was 8.5 mg / g.

[0135] The pectin content in the extract Ⅰ obtained by ultrasonic-assisted flash extraction is 8.3 mg / g, and the pectin extraction rate is 81.4%; the anthocyanin content in the extract Ⅱ is 6.3 mg / g, and the anthocyanin extraction rate is 72.4%; the obtained dietary fiber is placed in an oven for drying and crushed to obtain 4618 grams of powder.

[0136] The extraction time is 35min.

[0137] Comparative Example 13

[0138] Take 15kg of dried and crushed grape peels, add 40kg of distilled water respectively, heat in a water bath at 50°C, keep for 10 minutes, filter by suction, repeat the operation of filtering residue twice, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol 4 times the weight of the concentrate and let stand for 12 hours, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60°C, pressure of 1.5MPa, keep for 10 minutes, separate, extract the residue repeatedly twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10 minutes, filter, and dry to obtain dietary fiber.

[0139] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 10.2 mg / g and the anthocyanin content was 8.5 mg / g.

[0140] The pectin content in the extract I was 5.2 mg / g, and the pectin extraction rate was 50.9%. The anthocyanin content in the extract II was 4.4 mg / g, and the anthocyanin extraction rate was 51.7%.

[0141] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 30.5% and the anthocyanin extraction rate by 24.1%.

[0142] The extraction time was 45 min.

[0143] Comparative Example 14

[0144] Take 15kg of dried and crushed grape peels, add 40kg of distilled water respectively, heat in a water bath at 50°C, keep for 20min, filter by suction, repeat the operation of filtering residue twice, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol with a weight of 5 times of the concentrate and let it stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60°C, pressure of 1.5MPa, keep for 10min, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0145] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 10.2 mg / g and the anthocyanin content was 8.5 mg / g.

[0146] The pectin content in the extract I was 5.7 mg / g, and the pectin extraction rate was 55.9%. The anthocyanin content in the extract II was 4.8 mg / g, and the anthocyanin extraction rate was 56.5%.

[0147] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 25.5% and the anthocyanin extraction rate by 15.9%.

[0148] The extraction time was 1 h.

[0149] Comparative Example 15

[0150] Take 15kg of dried and crushed grape peels, add 40kg of distilled water respectively, heat in a water bath at 50°C, keep for 35 minutes, filter by suction, repeat the operation of filtering residue twice, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol 6 times the weight of the concentrate and let stand for 12 hours, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60°C, pressure of 1.5MPa, keep for 10 minutes, separate, extract the residue repeatedly twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10 minutes, filter, and dry to obtain dietary fiber.

[0151] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 10.2 mg / g and the anthocyanin content was 8.5 mg / g.

[0152] The pectin content in the extract I was 4.9 mg / g, and the pectin extraction rate was 48.1%. The anthocyanin content in the extract II was 3.8 mg / g, and the anthocyanin extraction rate was 44.7%.

[0153] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 30.9% and the anthocyanin extraction rate by 32.4%.

[0154] The extraction time was 1.5 h.

[0155] Example 6

[0156] Take 15kg of dried and crushed pitaya peel, add 60kg of distilled water, heat in a water bath at 50°C, keep for 5min, ultrasonic power is 400W, ultrasonic time is kept for 8min, filter, filter residue repeatedly twice, combine 3 filtrates, concentrate until the volume is reduced by 50%, add 95% ethanol 4 times the weight of the concentrate and let stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol for several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extraction temperature is 60°C, pressure is 1.5MPa, holding time is 10min, separate, extract the residue repeatedly twice, combine 3 extracts, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0157] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 11.4 mg / g and the anthocyanin content was 9.6 mg / g.

[0158] The pectin content in the extract Ⅰ obtained by ultrasonic-assisted flash extraction is 8.7 mg / g, and the pectin extraction rate is 76.31%; the anthocyanin content in the extract Ⅱ is 7.1 mg / g, and the anthocyanin extraction rate is 73.9%; the obtained dietary fiber is placed in an oven for drying and crushed to obtain 2314 grams of powder.

[0159] The extraction time is 35min.

[0160] Comparative Example 16

[0161] Take 15kg of dried and crushed pitaya peel, add 40kg of distilled water respectively, heat in a water bath at 50°C, keep for 10 minutes, filter by suction, repeat the operation of filter residue twice, combine the filtrate three times, concentrate until the volume is reduced by 50%, add 95% ethanol 4 times the weight of the concentrate and let stand for 12 hours, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60°C, pressure of 1.5MPa, keep for 10 minutes, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanin; then add distilled water to the remaining residue at a solid-liquid ratio of 40:1, soak for 10 minutes, filter, and dry to obtain dietary fiber.

[0162] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 11.4 mg / g and the anthocyanin content was 9.6 mg / g.

[0163] The pectin content in the extract I was 6.1 mg / g, and the pectin extraction rate was 53.5%. The anthocyanin content in the extract II was 4.9 mg / g, and the anthocyanin extraction rate was 51.1%.

[0164] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 22.81% and the anthocyanin extraction rate by 22.8%.

[0165] The extraction time was 45 min.

[0166] Comparative Example 17

[0167] Take 15kg of dried and crushed pitaya peel, add 40kg of distilled water respectively, heat in a water bath at 50°C, keep for 20min, filter by suction, repeat the operation twice for the filter residue, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol with a weight of 5 times that of the concentrate and let it stand for 12h, centrifuge, wash the precipitate with anhydrous ethanol for several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at a temperature of 60°C, a pressure of 1.5MPa, and a holding time of 10min, separate, extract the residue twice repeatedly, combine the extracts three times, concentrate, and freeze-dry to obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10min, filter, and dry to obtain dietary fiber.

[0168] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 11.4 mg / g and the anthocyanin content was 9.6 mg / g.

[0169] The pectin content in the extract I was 6.5 mg / g, and the pectin extraction rate was 57.0%. The anthocyanin content in the extract II was 5.3 mg / g, and the anthocyanin extraction rate was 55.2%.

[0170] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 19.31% and the anthocyanin extraction rate by 18.7%.

[0171] The extraction time was 1 h.

[0172] Comparative Example 18

[0173] Take 15kg of dried and crushed pitaya peel, add 40kg of distilled water respectively, heat in a water bath at 50°C, keep for 35 minutes, filter by suction, repeat the operation twice for the filter residue, combine the filtrates three times, concentrate until the volume is reduced by 50%, add 95% ethanol 6 times the weight of the concentrate and let stand for 12 hours, centrifuge, wash the precipitate with anhydrous ethanol several times, and dry to obtain peel pectin; repeatedly rinse the residue after extracting pectin with distilled water, add 50% ethanol at a liquid-to-solid ratio of 40:1, flash extract at 60°C, pressure of 1.5MPa, keep for 10 minutes, separate, extract the residue twice, combine the extracts three times, concentrate, freeze-dry, and obtain peel anthocyanins; then add distilled water to the remaining residue at a solid-to-liquid ratio of 40:1, soak for 10 minutes, filter, and dry to obtain dietary fiber.

[0174] The extract and the original sample were subjected to HPLC to determine the anthocyanin content. The HPLC results showed that the pectin content in the original sample was 11.4 mg / g and the anthocyanin content was 9.6 mg / g.

[0175] The pectin content in the extract I was 5.6 mg / g, and the pectin extraction rate was 49.1%. The anthocyanin content in the extract II was 4.8 mg / g, and the anthocyanin extraction rate was 50.0%.

[0176] Compared with the flash extraction method, the ultrasonic-assisted flash extraction method increased the pectin extraction rate by 27.2% and the anthocyanin extraction rate by 23.9%.

[0177] The extraction time was 1.5 h.

[0178] The pectin extracted from the peel in the above embodiments 1 to 6 can be used as a food additive in beverages, candies, and bread, and can also be prepared into tablets, capsules, and granules as health foods. The anthocyanins extracted from the peel can be used as natural plant pigments; they can also be used in medical fields such as anti-aging, anti-cancer and improving vision; the remaining dietary fiber can be used to make fiber beverages, low-energy chocolate and nutrition bars, sports drinks, lactic acid bacteria beverages, milk tablets, etc.

[0179] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for continuously extracting effective ingredients from peels, characterized in that: The steps include: S1, drying and crushing the peel into powder, mixing with water, heating, ultrasonic treatment, and then solid-liquid separation, concentrating the filtrate I obtained by solid-liquid separation, adding ethanol, standing, and then centrifuging, precipitating, washing with alcohol, and drying to obtain peel pectin; S2, mixing the residue I obtained by solid-liquid separation in step S1 with an ethanol solution, and then performing flash extraction, concentrating the filtrate II obtained after the flash extraction, and freeze-drying to obtain peel anthocyanins; S3, mixing the residue II remaining after the flash extraction in step S2 with water, soaking, and drying to obtain dietary fiber.

2. The method according to claim 1, characterized in that In step S1, the size of the powder is 50-150 mesh; Preferably, in step S1, the weight ratio of the powder to water and ethanol is 1:2-8:4-16.

3. The method according to claim 1, characterized in that In step S1, the heating conditions include: a temperature of 40 to 60°C and a heating time of 3 to 10 minutes.

4. The method according to claim 1, characterized in that: In step S1, the conditions of the ultrasonic treatment include: ultrasonic power of 200 to 700 W, and ultrasonic time of 2 to 12 min.

5. The method according to claim 1, characterized in that In step S1 and step S2, the conditions for concentrating the filtrate I and the filtrate II independently include: concentrating until the volume is reduced by 40-60%.

6. The method according to claim 1, characterized in that In step S2, the liquid-to-material ratio of the ethanol solution to the slag I is 30-50 mL: 1 g; The concentration of the ethanol solution is 40-75%.

7. The method according to claim 1, characterized in that In step S2, the conditions of the flash extraction include: extraction temperature of 50-70°C, pressure of 1-2 MPa, and holding time of 5-30 min.

8. The method according to claim 1, characterized in that In step S3, the liquid-to-material ratio of water to slag II is 30-50 mL: 1 g.

9. The method according to claim 1, characterized in that: In step S3, the soaking time is 5 to 30 minutes.

10. The method according to claim 1, characterized in that The conditions for solid-liquid separation in step S1 include: repeating the filtration 2 to 5 times and mixing the filtrates obtained from each filtration; Preferably, the flash extraction conditions in step S2 further include: repeating the extraction 2 to 5 times, and mixing the extracts obtained from each extraction.

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