Method for continuously extracting and separating naringin and pectin in shaddock peel

Abstract

The invention discloses a method for continuously extracting and separating naringin and pectin in shaddock peel. The method comprises the following steps: mixing shaddock peel powder with an alcohol amine-alcohol eutectic solvent, ultrasonically extracting naringin, and centrifugally separating to obtain a naringin extracting solution; deionized water is added into the extracting solution, CO gas is introduced, double aqueous phases are formed, and naringin is enriched in the lower phase; collecting a lower-phase solution to obtain a crude extract, heating and dissolving with ethanol, filtering, crystallizing and drying to obtain naringin; the method comprises the following steps: washing and drying residues after naringin extraction, extracting pectin by using a citric acid solution, filtering, precipitating with ethanol, centrifuging, purifying and drying to obtain the pectin. According to the method, the alcohol amine-alcohol eutectic solvent is applied to green extraction of the naringin for the first time, CO is utilized to trigger two aqueous phases to achieve efficient separation and purification of the naringin, meanwhile, multi-component high-value co-production of the naringin and pectin is achieved, the method has the advantages of being green, efficient, simple and convenient and the like, and a new way is provided for high-value utilization of shaddock peel waste.

Description

Technical Field

[0001] This invention belongs to the field of high-value utilization of biomass, specifically relating to a method for continuous extraction and separation of naringin and pectin from grapefruit peel using a CO2-responsive eutectic solvent. Background Technology

[0002] Chrysanthemum core pomelo is a national geographical indication agricultural product unique to Yongding District, Zhangjiajie City, with an annual output of over 50,000 tons. Its peel is about 50% thick, and discarding it not only wastes resources but also pollutes the environment. The peel is rich in various high-value active ingredients such as naringin, pectin, and dietary fiber. Among them, naringin has various biological activities such as anti-oxidation, anti-inflammation, and anti-tumor, and the pectin content is as high as 20%, which is widely used in the food and pharmaceutical industries.

[0003] Currently, the main methods for extracting naringin and pectin from pomelo peel include traditional solvent extraction. Although the stepwise solvent extraction method can achieve the separation of multiple components, it still has problems such as solvent residue and high environmental pressure. In addition, traditional methods often fail to achieve high-value co-production of multiple components in pomelo peel, resulting in low resource utilization. Therefore, developing green, efficient, and precise separation technologies is of great significance for realizing the high-value utilization of pomelo peel, improving agricultural efficiency, and reducing environmental pressure.

[0004] CO2-responsive eutectic solvents (DESs) are a novel type of green solvent that can achieve intelligent phase transitions through reversible reactions, thereby simplifying separation steps and showing great potential in the efficient and selective extraction and separation of plant active ingredients. However, there is currently no technology that combines alkanolamine-alcohol DESs with CO2-triggered aqueous two-phase technology for the continuous extraction and separation of naringin and pectin from grapefruit peel. Summary of the Invention

[0005] The purpose of this invention is to provide a green, efficient, and simple method for continuous extraction and separation of naringin and pectin from grapefruit peel using a CO2-responsive eutectic solvent, in order to solve the problems of low extraction efficiency, solvent residue, environmental pollution, and difficulty in multi-component high-value co-production of naringin and pectin in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for continuous extraction and separation of naringin and pectin from grapefruit peel using a CO2-responsive eutectic solvent, characterized by comprising the following steps: a) Pretreatment of grapefruit peel: Dry and pulverize the grapefruit peel to obtain grapefruit peel powder; b) Naringin extraction: i. The grapefruit peel powder is mixed with an alcoholic amine-alcohol eutectic solvent and subjected to ultrasonic extraction to obtain a mixture containing naringin; ii. Centrifuge the mixture to obtain naringin extract; iii. Add deionized water to the naringin extract and introduce CO2 gas to form an aqueous two-phase mixture, wherein naringin is mainly enriched in the lower phase of the aqueous two-phase mixture; iv. Collect the lower phase solution, dissolve the crude extract in ethanol by heating, filter, crystallize by low-temperature stirring, filter and dry to obtain naringin; c) Pectin extraction: i. Wash the residue after centrifugation in step b)ii with anhydrous ethanol and dry it to obtain the residue powder after naringin extraction. ii. The residue powder after naringin extraction is mixed with a citric acid solution at pH 1.9 for extraction; iii. Filter the extracted mixture and collect the filtrate; iv. Add ethanol to the filtrate to precipitate, and then centrifuge to obtain crude pectin; v. The crude pectin is purified a second time and then freeze-dried to obtain pectin.

[0007] Preferably, in step b)i, the alkanolamine-alcohol eutectic solvent is selected from a mixture of monoethanolamine and n-propanol, isopropanol, n-butanol or isobutanol, or a mixture of diethanolamine and n-butanol or isobutanol, or a mixture of monoethanolamine and n-butanol / n-propanol, n-butanol / isopropanol, n-butanol / ethanol, or a mixture of diethanolamine and n-butanol / n-propanol, n-butanol / isopropanol, n-butanol / ethanol, isobutanol / n-propanol or isobutanol / isopropanol.

[0008] More preferably, the alkanolamine-alcohol eutectic solvent is diethanolamine / isobutanol / ethanol.

[0009] Most preferably, the molar ratio of diethanolamine, isobutanol and ethanol is 2:1:1.

[0010] Preferably, in step b)i, the liquid-to-solid ratio of grapefruit peel powder to eutectic solvent is 25:1 mL / g to 55:1 mL / g.

[0011] More preferably, the liquid-to-solid ratio is 45:1 mL / g.

[0012] Preferably, in step b), the temperature for extracting naringin is 40 °C to 80 °C.

[0013] More preferably, the extraction temperature of naringin is 70 °C.

[0014] Preferably, in step b)i, the ultrasonic extraction time for naringin is 20 min to 60 min.

[0015] More preferably, the ultrasonic extraction time for naringin is 40 min.

[0016] Preferably, in step b)iii, the volume ratio of the deionized water to the naringin extract is 1:2.

[0017] Preferably, in step c)ii, the liquid-to-solid ratio of the residue powder after naringin extraction to the citric acid solution is 40:1 mL / g.

[0018] Preferably, in step c)ii, the pectin extraction temperature is 80 °C and the extraction time is 160 min.

[0019] Compared with the prior art, the beneficial effects of the present invention are: Green and environmentally friendly: This invention is the first to apply alkanolamine-alcohol eutectic solvent to the green extraction of naringin, replacing traditional organic solvents, reducing environmental pollution, and conforming to the principles of green chemistry.

[0020] High-efficiency separation: The introduction of CO2-triggered aqueous two-phase technology enables intelligent phase transition separation of naringin and eutectic solvent, simplifying the separation steps and improving the recovery rate and purity of naringin. The extraction rate of naringin in the lower phase reaches as high as 97.30%, and the final HPLC purity reaches 98.5%.

[0021] Multi-component high-value co-production: This invention realizes the continuous extraction and separation of naringin and pectin from pomelo peel, effectively utilizing multiple active ingredients in pomelo peel waste and improving resource utilization efficiency.

[0022] Improving pectin yield and purity: Experimental results showed that DESs pretreatment can effectively promote pectin dissolution. The pectin yield of residue (25.20%) was significantly higher than that of grapefruit peel pectin (20.60%), and the purity of residue pectin (67.74%) met the food-grade requirements.

[0023] Simple process: The entire process is simple, easy to operate, and easy to promote industrially.

[0024] Adjustability: By adjusting the extraction conditions, high-ester pectin and low-ester pectin can be obtained to meet the needs of different food processing applications. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a flowchart of the continuous extraction process of naringin and pectin from pomelo peel; Figure 2 SEM images of grapefruit peel powder (a) and residue powder (b); Figure 3This is the HPLC chromatogram of the pectin monosaccharide component; Figure 4 The images show the infrared spectra of the two types of pectin. Detailed Implementation

[0026] Please see Figure 1-4 This invention provides a technical solution: a method for the continuous extraction and separation of naringin and pectin from pomelo peel. The pomelo peel was purchased from the Zhangjiajie Chrysanthemum Core Pomelo Professional Cooperative in Hunan Province. The peel was dried to constant weight in a 50℃ oven, pulverized, and sealed in bags for later use in a desiccator. All other reagents were of analytical grade and were untreated before use.

[0027] Example 1: Effect of different types of DESs on the extraction yield of naringin Preparation of DESs Hydrogen bond acceptors and hydrogen bond donors were mixed in different molar ratios, and the mixtures were stirred at room temperature until homogeneous and transparent to prepare binary or ternary DESs. The mixtures were then stored in sealed containers at room temperature. The molar ratios, densities, pH values, and viscosities of all prepared DESs are shown in Table 1.

[0028] Table 1. Composition, molar ratio and physicochemical properties of DESs

[0029] The experiment used DESs including six binary DES systems (component molar ratio 1:1) and nine ternary DES systems (component molar ratio 2:1:1), detailed information is shown in Table 1. 0.2 g of grapefruit peel powder was weighed and extracted under the conditions of a liquid-to-solid ratio of 25:1 mL / g, an extraction temperature of 60℃, and an extraction time of 30 min. The effects of different types of DESs on the extraction yield of naringin were systematically investigated, and their applicability as a green extraction solvent was evaluated. The experimental results are shown in Table 2.

[0030] Table 2. Effects of different types of DESs on the extraction yield and partition coefficient of naringin

[0031] Example 2: Effect of component molar ratio on the extraction yield of naringin Preparation of naringin 10 g of grapefruit peel was weighed and extracted for naringin under the following conditions: a DESs molar ratio of 2:1:1 (diethanolamine:isobutanol:ethanol), a liquid-solid ratio of 45:1 mL / g, an extraction temperature of 70 ℃, and an extraction time of 40 min. Water (water:DESs = 1:2, v / v) was then added to the extract and mixed thoroughly. CO2 was bubbled through the mixture until the phases separated. The extraction rate of naringin in the lower phase was 97.30%. The lower phase solution was collected, dried, and dissolved in 95% (v / v) ethanol by heating. After hot filtration, the filtrate was collected and subjected to low-temperature stirring for crystallization. After filtration and drying, 3.0 g of naringin with an HPLC purity of 98.5% was finally obtained.

[0032] HPLC determination method for naringin The content of naringin was determined by HPLC. 2.30 mg of naringin standard was accurately weighed and placed in a 10 mL volumetric flask. Methanol was added to dissolve and dilute to volume, preparing a standard stock solution with a concentration of 230 μg / mL. The solution was then serially diluted with deionized water, filtered through a 0.45 μm filter membrane, and subjected to HPLC quantitative analysis. A standard regression curve (5) was plotted with mass concentration as the x-axis and peak area as the y-axis to calculate the naringin concentration.

[0033] y1=6.9003x1+0.0657, R2=0.9998 (5) Method for determining pectin galacturonic acid content The purity of pectin was determined by the carbazole-sulfuric acid method. 5 mg of galacturonic acid standard was accurately weighed and diluted to 50 mL with deionized water to prepare a 0.1 mg / mL stock solution. 1.0 mL of standard solutions at concentration gradients of 0, 20, 40, 60, 80, and 100 mg / L were placed in 25 mL test tubes, and 0.25 mL of 1 g / L carbazole-ethanol solution and 5.0 mL of concentrated sulfuric acid were added sequentially. After mixing, the mixture was immediately heated in an 85 ℃ water bath for 20 min. After cooling, the absorbance was measured at 525 nm using an Evolution220 UV spectrophotometer. A standard curve (6) was plotted with galacturonic acid concentration (x) as the abscissa and absorbance (y) as the ordinate, and the galacturonic acid content in the pectin sample was calculated. The formula (7) for calculating pectin purity (X, %, calculated as galacturonic acid) is as follows: y2=0.0104x2+0.0089, R2=0.9990 (6)

[0034] In the formula, C is the galacturonic acid concentration (mg / L), V is the volume of the pectin solution (50 mL), N is the dilution factor (N=10), and M is the mass of the pectin sample (mg). Extraction and separation experiment of naringin from grapefruit peel 0.2 g of grapefruit peel powder was placed in a 10 mL centrifuge tube, and a certain amount of DESs was added according to the ratio. After shaking and mixing, naringin was extracted using an XO-5200DT ultrasonic cleaner. The experimental factors investigated included liquid-to-solid ratio, molar ratio, temperature, and time. Each experiment was repeated three times. After extraction, the extract was centrifuged for 5 min to obtain the naringin extract. Then, 50 μL of the extract was pipetted and diluted 100 times with deionized water. After filtration through a 0.45 μm filter membrane, the concentration of naringin in the extract was determined by HPLC. The extraction yield (Y, mg / g) of naringin was calculated using the following formula (1):

[0035] In the formula, C and V are the concentration (mg / mL) and volume (mL) of naringin in the extract, respectively, and M is the mass (mL) of dried grapefruit peel.

[0036] Subsequently, a certain amount of deionized water was added to the extract, and high-purity CO2 was bubbled through at a flow rate of 100 mL / min until the solution became turbid. After standing for 5 min, the solution phases were separated, and the volumes of the upper and lower phases were recorded. The concentrations of naringin in the upper and lower phases were then determined using HPLC. Most of the naringin was enriched in the lower organic phase. The extraction efficiency of naringin in the lower phase (E0) was [not specified]. b The ,% and the allocation coefficient (K) are calculated according to formulas (2) and (3) respectively:

[0037]

[0038] In the formula C t C b V represents the concentration (mg / mL) of naringin in the upper and lower phases, respectively. t V b The values ​​represent the volumes (mL) of the upper and lower phases, respectively.

[0039] The experiment selected DES-15 (diethanolamine / isobutanol / ethanol) as the optimal extraction solvent and systematically evaluated the effect of different molar ratios on the extraction rate of naringin. 0.2 g of grapefruit peel powder was weighed, and the experiment was conducted under fixed extraction conditions (liquid-to-solid ratio 25:1 mL / g, extraction temperature 60 ℃, extraction time 30 min). By changing the molar ratio of each component in DESs, the effect of these ratios on the yield of naringin was investigated. The experimental results are shown in Table 3.

[0040] Table 3. Effect of component molar ratio on the extraction yield and partition coefficient of naringin

[0041] Example 3: Effect of liquid-to-solid ratio on the extraction yield of naringin The effect of liquid-to-solid ratio (15:1–55:1 mL / g) on ​​the extraction yield of naringin was systematically investigated. 0.2 g of grapefruit peel powder was weighed out, and the experiment was conducted under fixed extraction conditions of 60 ℃, 30 min, and a DESs component molar ratio of 2:1:1 (diethanolamine:isobutanol:ethanol). The focus was on exploring the effect of different liquid-to-solid ratios on the extraction efficiency of naringin. Detailed experimental results are shown in Table 4.

[0042] Table 4. Effect of liquid-to-solid ratio on the extraction yield and partition coefficient of naringin

[0043] Example 4: Effect of extraction temperature The effect of extraction temperature (40–80 °C) on the extraction yield of naringin was systematically investigated. 0.2 g of grapefruit peel powder was weighed out, and the experiment was conducted under the conditions of a fixed DES component molar ratio of 2:1:1 (diethanolamine:isobutanol:ethanol), a liquid-to-solid ratio of 45:1 mL / g, and an extraction time of 30 min. The focus was on investigating the effect of different temperatures on the extraction efficiency. Detailed experimental results are shown in Table 5.

[0044] Table 5. Effect of extraction temperature on the extraction yield and partition coefficient of naringin

[0045] Example 5: The Influence of Extraction Time The effect of ultrasonic time (20–60 min) on the extraction yield of naringin was systematically investigated to clarify the relationship between ultrasonic time and extraction efficiency. 0.2 g of grapefruit peel powder was weighed, and the experiment was conducted under the conditions of a fixed DES component molar ratio of 2:1:1 (diethanolamine:isobutanol:ethanol), a liquid-to-solid ratio of 45:1 mL / g, and an extraction temperature of 70 ℃. Detailed experimental results are shown in Table 6.

[0046] Table 6. Effects of extraction time on the extraction yield and partition coefficient of naringin

[0047] Example 6: Pectin Yield and Purity Analysis Pectin extraction experiment The grapefruit peel residue was washed with anhydrous ethanol until colorless and dried in an oven at 50 ℃ for later use. Grapefruit peel powder was used as a control for pectin extraction. Citric acid solution with pH = 1.9 was prepared as the extraction solvent and extracted in a DF-101S magnetic stirrer with a heat-collecting constant temperature for 160 min at a liquid-to-solid ratio of 40:1 mL / g. The extract was then filtered through gauze while hot to obtain the pectin extract. Two volumes of 95% (v / v) ethanol were added to the extract and the mixture was refrigerated for 12 h. The extract was then centrifuged for 5 min using a Cenlee 18K centrifuge to obtain crude pectin. The crude pectin was then purified by secondary precipitation with three volumes of anhydrous ethanol and freeze-dried to obtain high-purity pectin. The formula (4) for calculating the pectin extraction yield (W, %) is shown below:

[0048] In the formula, M1 is the mass of the pectin sample (mg), and M0 is the mass of the grapefruit peel raw material (mg). Method for determining the degree of pectin esterification The degree of esterification (DE) of pectin was determined by titration. 0.2 g of pectin sample was accurately weighed and dissolved in 20.0 mL of deionized water, stirred until completely dissolved. Three drops of phenolphthalein indicator were added, and titration was performed with 0.1 mol / L NaOH standard solution until a pale pink endpoint was reached. The volume consumed (V1) was recorded. Then, 10 mL of 0.1 mol / L NaOH solution was added, and stirring was continued for 20 min to carry out the saponification reaction. Next, 10 mL of 0.1 mol / L HCl solution was added, and stirring was performed until the pale pink color disappeared. Finally, titration was performed with 0.1 mol / L NaOH standard solution until a stable pale pink endpoint reappeared, and the volume consumed (V2) was recorded. The degree of esterification (DE) was calculated according to the following formula (8):

[0049] Table 7. Yield and properties of pectin under different extraction conditions

[0050] (1) Effect of DESs pretreatment on pectin yield Experimental results showed that DESs treatment effectively promoted pectin dissolution, and the pectin yield of the residue (25.20%) was significantly higher than that of grapefruit peel pectin (20.60%). SEM analysis showed that untreated grapefruit peel powder ( Figure 2 a) It has a complete and compact structure, which restricts pectin release; while the residue powder after DESs treatment ( Figure 2 b) shows obvious structural changes, with microcracks and hollow openings appearing in its cell walls.

[0051] (2) Effect of DESs pretreatment on pectin purity The results showed that the purity of pectin in the residue (67.74%) was significantly higher than that in grapefruit peel pectin (55.67%), meeting food-grade requirements. This indicates that DESs ultrasound-assisted extraction effectively removed impurities such as flavonoids from the residue, improving pectin purity.

[0052] (3) Effect of DESs pretreatment on pectin esterification degree The results showed that the degree of esterification of pectin in grapefruit peel (53.22%) met the characteristics of high-ester pectin (DE>50%), making it suitable for processing high-sugar foods such as jams and jellies; while the degree of esterification of pectin in the residue (49.54%) was slightly lower than 50%, classifying it as low-ester pectin.

[0053] (4) Effect of DESs pretreatment on pectin molecular weight HP-GPC analysis showed that the weight-average molecular weight of pectin from grapefruit peel (Mw=48.14 kDa) was significantly higher than that of pectin from the residue (Mw=14.05 kDa). This may be because the residual pectin underwent a β-elimination reaction induced by alkaline DES ultrasonic treatment, leading to molecular chain breakage, while grapefruit peel pectin extracted by the conventional acid method maintained a more complete molecular structure. Furthermore, the polydispersity index of grapefruit peel pectin (2.85) was lower than that of the residual pectin (3.64), indicating a more uniform molecular weight distribution and better structural homogeneity.

[0054] (5) Effect of DESs pretreatment on pectin monosaccharide composition Monosaccharide composition analysis showed that ( Figure 3 Grapefruit peel pectin and pectin residue are highly similar in chemical composition, both using galacturonic acid (GalA>85%) as the main structural unit and containing small amounts of arabinose (Ara), galactose (Gal), rhamnose (Rha), and glucose (Glc), indicating that both possess typical rhamnose-galacturonic acid polysaccharide type I (RG-I) domains. However, pectin residue has a higher Ara / Gal ratio, suggesting that its RG-I side chain structure may differ from that of grapefruit peel pectin, leading to different functional properties.

[0055] The monosaccharide composition of grapefruit peel pectin is: 86.83% galacturonic acid (GalA), 5.80% arabinose (Ara), 3.06% galactose (Gal), 2.67% glucose (Glc) and 1.64% rhamnose (Rha). The monosaccharide composition of the pectin residue is: 6.31% arabinose, 1.57% rhamnose, 2.30% galactose, 2.20% glucose and 87.63% galacturonic acid.

[0056] (6) Molecular structure of pectin FT-IR analysis shows that ( Figure 4 ), two types of pectin at 3365 cm-1 (OH stretching vibration), 2933 cm -1 (CH stretching vibration), 1732 cm -1 (Esterified carboxyl group C=O) and 1626 cm -1 The positions of characteristic peaks such as (carboxylate C=O) are basically consistent, confirming that DES treatment did not change the basic skeletal structure of pectin. Among them, 1732 cm⁻¹ -1 With 1626 cm -1 The relative intensity difference of the absorption peaks reflects the difference in the degree of esterification between the two, which is consistent with the results of the esterification degree determination. Fingerprint region (1200-900 cm⁻¹) -1 The characteristic absorption peaks further verified that both samples have typical pectin polysaccharide structures and contain RG-I domain features.

[0057] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for continuous extraction and separation of naringin and pectin from grapefruit peel, characterized in that, Includes the following steps: S1. Grapefruit peel pretreatment: Dry and crush the grapefruit peel to obtain grapefruit peel powder; S2, Naringin Extract: a) The grapefruit peel powder is mixed with an alcohol amine-alcohol eutectic solvent and subjected to ultrasonic extraction to obtain a mixture containing naringin; b) Centrifuge the mixture to obtain naringin extract; c) Add deionized water to the naringin extract and introduce CO2 gas to form an aqueous two-phase solution, wherein naringin is mainly enriched in the lower phase of the aqueous two-phase solution; d) Collect the lower phase solution, dissolve the crude extract in ethanol by heating, filter, crystallize by low-temperature stirring, filter and dry to obtain naringin; S3, Pectin Extraction: a) The residue after centrifugation in the naringin extraction step is washed with anhydrous ethanol and dried to obtain the residue powder after naringin extraction. b) The residue powder after the extraction of naringin is mixed with a citric acid solution with a pH of 1.9 for extraction; c) Filter the extracted mixture and collect the filtrate; d) Add ethanol to the filtrate to precipitate, and then centrifuge to obtain crude pectin; e) The crude pectin is purified a second time and then freeze-dried to obtain pectin.

2. The method for continuous extraction and separation of naringin and pectin from grapefruit peel according to claim 1, characterized in that: The alkanolamine-alcohol eutectic solvent is a mixture of diethanolamine, isobutanol, and ethanol.

3. The method for continuous extraction and separation of naringin and pectin from grapefruit peel according to claim 2, characterized in that: The molar ratio of diethanolamine, isobutanol and ethanol is 2:1:

1.

4. The method for continuous extraction and separation of naringin and pectin from grapefruit peel according to claim 3, characterized in that: In the naringin extraction step, the liquid-solid ratio of grapefruit peel powder to eutectic solvent is 25:1 mL / g to 55:1 mL / g.

5. The method for continuous extraction and separation of naringin and pectin from grapefruit peel according to claim 4, characterized in that: The liquid-to-solid ratio is 45:1 mL / g.

6. The method for continuous extraction and separation of naringin and pectin from grapefruit peel according to claim 1, characterized in that: In the naringin extraction step, the temperature for naringin extraction is controlled at 40 ℃ to 80 ℃; the ultrasonic extraction time for naringin is 20 min to 60 min.

7. The method for continuous extraction and separation of naringin and pectin from grapefruit peel according to claim 6, characterized in that: The extraction temperature of naringin was 70 ℃, and the ultrasonic extraction time was 40 min.

8. The method for continuous extraction and separation of naringin and pectin from grapefruit peel according to claim 1, characterized in that: In the naringin extraction step, the volume ratio of deionized water to the naringin extract is 1:

2.

9. The method for continuous extraction and separation of naringin and pectin from grapefruit peel according to claim 1, characterized in that: In the pectin extraction step, the liquid-to-solid ratio of the residue powder after naringin extraction to the citric acid solution is 40:1 mL / g.

10. The method for continuous extraction and separation of naringin and pectin from grapefruit peel according to claim 1, characterized in that: In the pectin extraction step, the pectin extraction temperature is 80 ℃ and the extraction time is 160 min.

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