Method for comprehensively extracting essential oil and pectin from physiological dropped fruit of Jinggang honey pomelo

Abstract

The invention discloses a method for comprehensively extracting essential oil and pectin from physiological dropped fruits of Jinggang honey pomelo, which comprises the following steps: by taking the physiological dropped fruits of Jinggang honey pomelo after enzymolysis as raw materials, extracting essential oil from the physiological dropped fruits of Jinggang honey pomelo by adopting a two-time extraction method, a steam distillation extraction method is adopted for the second extraction, and pectin is extracted from the raw material after essential oil extraction by adopting an acid extraction and alcohol precipitation method. According to the method, physiological fallen fruits instead of mature fruits are used for extracting the grapefruit essential oil and pectin, agricultural product waste can be fully utilized, meanwhile, the essential oil is extracted through a secondary extraction method, the problem that the purity is not high when an organic solvent extraction method is independently adopted for extracting the essential oil is solved, and the method is suitable for industrial production. The defect that the yield is low when the essential oil is extracted by independently adopting a steam distillation method is avoided; and then the pectin is extracted from the raw material subjected to essential oil extraction, so that the problem of insufficient resource utilization caused by separate extraction of a certain component can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of deep processing of agricultural and sideline products, and in particular to a method for comprehensively extracting essential oil and pectin from physiologically fallen fruits of Jinggang pomelo. Background Art

[0002] Jinggang Honey Pomelo is a citrus fruit variety unique to Ji'an City, Jiangxi Province. After a long period of natural selection and artificial domestication, the varieties dominated by Jinsha Pomelo, Jinlan Pomelo and Taoxi Honey Pomelo have been formed. Among them, Jinlan Pomelo has become the leader among "Jinggang Honey Pomelo" with its excellent properties and unique quality. Jinggang Honey Pomelo is rich in various vitamins and minerals, especially vitamin C, which has a content of up to 62.2 mg / 100 g. In addition, Jinggang Honey Pomelo also contains a variety of active substances that are beneficial to the human body, such as naringin and flavonoids, which have a variety of health functions such as digestion, moistening the lungs, resolving phlegm, lowering blood sugar, and lowering blood lipids.

[0003] Grapefruit fruit drop is the phenomenon of natural fruit shedding due to various reasons during the growth of grapefruit trees. Grapefruit fruit drop can be divided into two types: physiological fruit drop and abnormal fruit drop. Physiological fruit drop is a phenomenon in the normal growth process of grapefruit trees, which usually occurs within a period of time after full flowering. It is divided into the first physiological fruit drop and the second physiological fruit drop. The peak of the first physiological fruit drop of Jinggang honey pomelo occurs from April to May, and the peak of the second physiological fruit drop occurs from May to June. Abnormal fruit drop is an abnormal drop caused by factors such as environment, nutrition, pests and diseases. Grapefruit fallen fruit generally only has the peel structure, without the pulp and juice of mature fruit, so it cannot be eaten. It is usually directly returned to the field as agricultural waste. However, the content of active ingredients (such as essential oils, pectin and flavonoids, etc.) in grapefruit fallen fruit is much higher than that in mature fruit. If it is extracted by scientific methods, high value-added products will be obtained, which will bring significant economic benefits to fruit farmers and processing companies.

[0004] The traditional preparation of grapefruit essential oil generally uses the peel of mature grapefruit as raw material, and adopts distillation to extract. The raw material of this process (mature grapefruit peel) is not easy to collect and store on a large scale, and the distillation method has the problems of low extraction efficiency, low purity of essential oil, high equipment and energy consumption cost, and environmental pollution. The traditional preparation of grapefruit pectin is generally also based on the peel of mature grapefruit as raw material, and is directly extracted by acid extraction and alcohol precipitation. Since the raw material is not properly pre-treated, this method also has the problems of low extraction efficiency and poor quality of obtained pectin. At present, there are only patents for extracting bioactive substances from grapefruit physiological fruit drop, "A method for jointly extracting essential oil and hesperidin from navel orange physiological fruit drop" (CN106520372 A) and "A method for preparing new hesperidin in grapefruit physiological fruit drop in an alcohol / salt two-phase system" (CN109293721 B). However, the former only uses steam distillation to extract essential oil, but this method has the problem of low essential oil extraction efficiency, and the raw material is not pre-treated. The latter only extracted neohesperidin from the physiological fruit drop of grapefruit, without extracting essential oil and pectin, and also did not perform any pre-treatment on the raw materials.

[0005] In order to make full use of resources and overcome the shortcomings of traditional processes, the present invention comprehensively utilizes the physiological fallen fruits of Jinggang pomelo rich in pomelo essential oil and pomelo pectin, and comprehensively extracts essential oil and pectin through enzymatic pretreatment, two-step extraction method and acid extraction and alcohol precipitation method, thereby realizing high-value utilization of agricultural waste. Summary of the invention

[0006] The purpose of the present invention is to provide a method for comprehensively extracting essential oil and pectin from physiologically fallen fruits of Jinggang pomelo in view of the deficiencies in the prior art, and to comprehensively utilize the physiologically fallen fruits of Jinggang pomelo rich in pomelo essential oil and pectin, and to comprehensively extract essential oil and pectin through enzymatic pretreatment, a two-step extraction method and an acid extraction and alcohol precipitation method, so as to realize the high-value utilization of agricultural waste.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] A method for comprehensively extracting essential oil and pectin from physiologically fallen fruits of Jinggang pomelo, comprising the following steps:

[0009] Step 1, collection and pretreatment of raw materials: collecting physiologically fallen fruits in the orchard during the physiological fruit-dropping period of Jinggang pomelo, washing, cutting, drying, crushing, sieving, and obtaining raw materials;

[0010] Step 2, enzymolysis: adding cellulase and hemicellulase to the raw material, enzymolyzing for a period of time at a certain temperature, filtering the mixture after the enzymolysis is completed, and drying the filter residue as the extraction raw material;

[0011] Step 3, primary extraction of crude essential oil: extraction by organic solvent extraction;

[0012] Step 4, preparation of crude essential oil: after one extraction is completed, rotary evaporation is performed at a certain temperature for a period of time to obtain crude essential oil, and the extracted crude essential oil is immobilized;

[0013] Step 5, secondary extraction of essential oil: secondary extraction of the immobilized crude essential oil by steam distillation;

[0014] Step 6, essential oil purification: After the secondary extraction, extract with an organic solvent, take the upper layer and rotary evaporate it at a certain temperature for a period of time to obtain high-purity essential oil;

[0015] Step 7, pectin extraction: using the filter residue produced after the essential oil is extracted once as a raw material for extracting pectin, and extracting grapefruit pectin by acid extraction and alcohol precipitation method;

[0016] Step 8, pectin preparation: after the extraction is completed, centrifuge for a period of time, dry and crush to obtain the pectin product.

[0017] Specifically, the drying temperature in step 1 is 55-65° C.; and the sieving is through a 40-100 mesh sieve.

[0018] Specifically, in step 2, cellulase and hemicellulase are added to the raw material, the mass ratio of cellulase and hemicellulase is 1:1, and the total amount of cellulase and hemicellulase enzyme powder added: raw material mass = 1:100-1:200; after cellulase and hemicellulase are added to the raw material, the solid-liquid mass ratio = 1:5-1:10, the solid phase is the sum of enzyme powder and raw material powder, and the liquid phase is the added water; the enzymolysis temperature is 40-60°C, and the enzymolysis time is 4.5-6.5h.

[0019] Specifically, the organic solvent extraction method in step 3 is a Soxhlet reflux extraction method, the organic solvent used for extraction is ethanol or petroleum ether, preferably petroleum ether; the material-liquid mass ratio is 1:8-1:12, the extraction time is 10h-50h, and the extraction temperature is 40-50°C.

[0020] Specifically, after the extraction in step 4 is completed, the organic phase is collected and rotary evaporated at 40-45° C. for 1.5 h-5 h to separate the organic phase and the essential oil by evaporation, and the essential oil is collected and immersed in filter paper or cotton to immobilize the extracted crude essential oil.

[0021] Specifically, in step 5, the immobilized crude essential oil is subjected to secondary extraction by steam distillation; the extraction solvent is deionized water, the material-liquid mass ratio is 1:8-1:12, the extraction time is 10h-50h, and the extraction temperature is 140-160°C.

[0022] Specifically, after the secondary extraction in step 6 is completed, the aqueous phase is collected, and an organic solvent is added for extraction. The organic solvent is selected from petroleum ether or dichloromethane, preferably petroleum ether; the volume ratio of the petroleum ether to the aqueous phase is 1:3-1:5. After the extraction is completed, the upper organic phase is taken and rotary evaporated at 40-45° C. for 1h-5h, and the organic phase and essential oil are evaporated and separated to obtain high-purity essential oil.

[0023] Specifically, in step 7, the grapefruit pectin is extracted by acid extraction and alcohol precipitation, the raw material after essential oil extraction and water are placed in a container, the material-liquid mass ratio is controlled to be 1:5-1:8, the pH is adjusted to 1.5-2.5, and the extraction is heated to reflux at 80°C-100°C for 10h-50h, and the extraction is centrifuged for 25-35min after the extraction is completed. After the centrifugation is completed, the supernatant is taken, and then 2-4 times the volume of the supernatant is added with 95% ethanol and precipitated at 4°C for 12-24h.

[0024] Specifically, the centrifugation time in step 8 is 25-35 minutes. After centrifugation, the lower layer of pectin is taken out and dried at a temperature of 60-80° C. After drying, the pectin is crushed to obtain pectin powder.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention utilizes physiological fallen fruits instead of mature fruits to extract grapefruit essential oil and pectin, which can make full use of agricultural waste and does not compete with fresh fruits for raw materials. At the same time, it scientifically utilizes the characteristics that the fallen fruits themselves have higher essential oil and pectin contents than mature fruits.

[0027] 2. The present invention first enzymolyzes the raw materials with cellulase and hemicellulase, which can decompose the lignocellulose components surrounding the essential oil cavity and the surrounding cells, thereby promoting the dissolution of the essential oil; at the same time, the degradation and collapse of cellulose and hemicellulose also promote the dissolution of grapefruit pectin adsorbed thereon, thereby improving the extraction efficiency of essential oil and pectin in the later stage.

[0028] 3. Compared with the conventional technology, the present invention adopts a secondary extraction method to extract essential oils, wherein the primary extraction method adopts an organic solvent extraction method and the secondary extraction method adopts a steam distillation method. This can overcome the disadvantages of low purity of essential oils extracted by organic solvent extraction alone and the disadvantage of low yield of essential oils extracted by steam distillation alone.

[0029] 4. The present invention adopts a continuous extraction method to first extract the essential oil from the physiologically fallen fruits of Jinggang pomelo, and then extract the pomelo pectin, which can avoid the disadvantage of insufficient resource utilization caused by extracting a certain component alone. At the same time, the process of first extracting the essential oil and then extracting the pectin can obtain a pectin product with higher purity and better quality than the process of directly extracting pectin. DETAILED DESCRIPTION

[0030] In order to facilitate understanding of the present invention, the present invention is described more fully below, and several embodiments of the present invention are provided. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0031] Example 1

[0032] A method for comprehensively extracting essential oil and pectin from physiologically fallen fruits of Jinggang pomelo, comprising the following steps:

[0033] Step S11, collecting physiologically fallen fruits in the orchard during the physiological fruit-dropping period of Jinggang pomelo, washing, cutting, drying, crushing, and passing through a 40-mesh sieve to obtain a raw material;

[0034] Step S12, weigh 100g of raw material powder into a conical flask, add 1000ml of deionized water, and then add 1% cellulase and hemicellulase (w enzyme: w peel powder) in a ratio of 1:1, adjust pH to 4.5 and stir evenly with a glass rod, seal and heat in a 40℃ water bath for 2h for enzymolysis. After enzymolysis, dry in an oven to obtain the enzymolysis extraction raw material;

[0035] Step S13, weigh 100 g of the raw material powder after enzymatic hydrolysis into a Soxhlet extractor, add 800 ml of petroleum ether into a round-bottom flask, open the condensation water, and extract at 40° C. for 10 h;

[0036] Step S14: after the extraction is completed, rotary evaporation is performed at 45° C. for 1 hour to obtain the crude essential oil of Jinggang pomelo fruit, the crude essential oil is collected on filter paper, and the crude essential oil is immobilized;

[0037] Step S15, 100 g of the crude essential oil prepared once was immobilized and placed in a Soxhlet extractor, 900 ml of deionized water was added to the flask, condensation water was turned on, the oil bath temperature was 160° C., and reflux extraction was performed for 10 h;

[0038] Step S16: After the reflux extraction is completed, the aqueous phase is placed in a separatory funnel, and 30 ml of petroleum ether is added to the separatory funnel. After standing, after stratification, the upper organic phase is taken and rotary evaporated at 40° C. for 1 h to separate the organic phase and essential oil by evaporation. The yield of essential oil is 1.5%.

[0039] Step S17, taking 100 g of grapefruit powder from which essential oil has been extracted into a conical flask, adding 500 ml of deionized water, adjusting pH to 1.5 with 0.2 mM hydrochloric acid, and then heating and extracting at 80° C. for 10 h, cooling after extraction, centrifuging the filtrate in a centrifuge for 30 min, taking the supernatant, adding 1000 ml of 95% ethanol, and precipitating at 4° C. for 12 h for alcohol precipitation;

[0040] Step S18: After the alcohol precipitation is completed, centrifuge in a centrifuge for 30 minutes, take out the lower layer of pectin, dry it in an oven at 60°C, and crush it to obtain pectin powder. The pectin yield is 14%.

[0041] Example 2

[0042] A method for comprehensively extracting essential oil and pectin from physiologically fallen fruits of Jinggang pomelo, comprising the following steps:

[0043] Step S21, collecting physiologically fallen fruits in the orchard during the physiological fruit-dropping period of Jinggang pomelo, washing, cutting, drying, crushing, and passing through a 60-mesh sieve to obtain an extraction raw material;

[0044] Step S22, weigh 2.5 kg of raw material powder into a high-temperature enzymolysis tank, add 20 L of deionized water, then add 1.5% of cellulase and hemicellulase (w enzyme: w peel powder) in a ratio of 1:1, adjust pH to 5.5, enzymolyze for 3 hours, and dry in a rotary dryer after enzymolysis to obtain a raw material after enzymolysis;

[0045] Step S23, taking 2 kg of the raw material powder after enzymatic hydrolysis and 19 L of petroleum ether into a reaction kettle, and extracting at 45° C. for 20 h;

[0046] Step S24: After the extraction is completed, the oil is evaporated in an industrial rotary evaporator at 45°C for 2 hours to obtain the crude essential oil of Jinggang pomelo fruit. The crude essential oil is immobilized;

[0047] Step S25, placing 10 L of crude essential oil prepared once and 10 L of deionized water in a reaction kettle at a temperature of 150° C. and reflux extraction for 20 h;

[0048] Step S26: After the reflux extraction, the aqueous phase was taken into the extraction tower, and 10L of petroleum ether was added into the extraction tower. After stratification, the upper organic phase was taken and rotary evaporated at 40°C for 2h to separate the organic phase and essential oil. The yield of essential oil was 2%.

[0049] Step S27, taking 2 kg of grapefruit powder after essential oil extraction into a reactor, adding 20 L of deionized water, adjusting pH to 2 with hydrochloric acid, heating and extracting at 90° C. for 20 h, cooling after extraction, centrifuging the filtrate in an industrial centrifuge, taking the supernatant, adding 20 L of 95% ethanol, and precipitating at 4° C. for 18 h for alcohol precipitation;

[0050] Step S28: After the alcohol precipitation is completed, centrifuge in an industrial centrifuge, take out the lower layer of pectin, dry it in a rotary dryer at 70°C, and crush it to obtain pectin powder with a yield of 14.5%.

[0051] Example 3

[0052] A method for comprehensively extracting essential oil and pectin from physiologically fallen fruits of Jinggang pomelo, comprising the following steps:

[0053] Step S31, collecting physiologically fallen fruits in the orchard during the physiological fruit-dropping period of Jinggang pomelo, washing, cutting, drying, crushing, and passing through a 60-mesh sieve to obtain an extraction raw material.

[0054] Step S32, weigh 10.5 kg of raw material powder into a high-temperature enzymolysis tank, add 100 L of deionized water, then add 1.5% cellulase and hemicellulase (w enzyme: w peel powder) in a 1:1 ratio, adjust pH = 5.5, enzymolysis for 5 hours, and dry in a rotary dryer after enzymolysis to obtain the enzymolysis raw material.

[0055] Step S33, taking 10 kg of the raw material powder after enzymatic hydrolysis and 100 L of petroleum ether into a reaction kettle, and extracting at 45° C. for 50 h;

[0056] Step S34: after the extraction is completed, rotary evaporation is performed in an industrial rotary evaporator at 45° C. for 5 hours to obtain the Jinggang pomelo fruit crude essential oil, and the crude essential oil is immobilized;

[0057] Step S35, placing 100 L of crude essential oil prepared once and 100 L of deionized water in a reaction kettle at a temperature of 150° C. and reflux extraction for 50 h;

[0058] Step S36: After the reflux extraction, the aqueous phase was taken into the extraction tower, and 100L of petroleum ether was added into the extraction tower. After stratification, the upper organic phase was taken and rotary evaporated at 40°C for 5h to separate the organic phase and essential oil. The yield of essential oil was 2.5%.

[0059] Step S37, taking 10 kg of grapefruit powder after essential oil extraction into a reactor, adding 100 L of deionized water, adjusting pH to 2 with hydrochloric acid, heating and extracting at 90° C. for 50 h, cooling after extraction, centrifuging the filtrate in an industrial centrifuge, taking the supernatant, adding 100 L of 95% ethanol, and precipitating at 4° C. for 24 h for alcohol precipitation;

[0060] Step S38: After the alcohol precipitation is completed, centrifuge in an industrial centrifuge, take out the lower layer of pectin, dry it in a rotary dryer at 70°C, and crush it to obtain pectin powder with a yield of 15%. The pectin yield is increased by 50% compared with the traditional extraction method.

[0061] In summary, compared with the traditional technology, the method of the present invention adopts a secondary extraction method to extract essential oil, the primary extraction adopts an organic solvent extraction method, and the secondary extraction adopts a steam distillation method, which can overcome the disadvantages of low purity of essential oil extracted by using only an organic solvent extraction method, and the disadvantage of low yield of essential oil extracted by using only a steam distillation method; at the same time, a continuous extraction method is adopted to first extract the essential oil in the physiological fallen fruits of Jinggang pomelo, and then extract pomelo pectin, which can avoid the disadvantage of insufficient resource utilization caused by extracting a certain component alone. At the same time, the process of first extracting the essential oil and then extracting the pectin has a higher purity and better quality than the process of directly extracting pectin.

[0062] It should be understood that the above description of the preferred embodiment is relatively detailed and cannot be regarded as limiting the scope of patent protection of the present invention. Under the enlightenment of the present invention, ordinary technicians in this field can also make substitutions or modifications without departing from the scope of protection of the claims of the present invention, which all fall within the scope of protection of the present invention. The scope of protection requested for the present invention shall be based on the attached claims.

Claims

1. A method for comprehensive extraction of essential oil and pectin from physiologically fallen fruit of Jinggang pomelo, characterized in that: The following steps are involved: Step 1, collection and pretreatment of raw materials: collecting physiologically fallen fruits in the orchard during the physiological fruit-dropping period of Jinggang pomelo, washing, cutting, drying, crushing, sieving, and obtaining raw materials; Step 2, enzymolysis: adding cellulase and hemicellulase to the raw material, enzymolyzing for a period of time at a certain temperature, filtering the mixture after the enzymolysis is completed, and drying the filter residue as the extraction raw material; Step 3, primary extraction of crude essential oil: extraction by organic solvent extraction; Step 4, preparation of crude essential oil: after one extraction is completed, rotary evaporation is performed at a certain temperature for a period of time to obtain crude essential oil, and the extracted crude essential oil is immobilized; Step 5, secondary extraction of essential oil: secondary extraction of the immobilized crude essential oil by steam distillation; Step 6, essential oil purification: After the secondary extraction, extract with an organic solvent, take the upper layer and rotary evaporate it at a certain temperature for a period of time to obtain high-purity essential oil; Step 7, pectin extraction: using the filter residue produced after the essential oil is extracted once as a raw material for extracting pectin, and extracting grapefruit pectin by acid extraction and alcohol precipitation method; Step 8, pectin preparation: after the extraction is completed, centrifuge for a period of time, dry and crush to obtain the pectin product.

2. A method for comprehensive extraction of essential oil and pectin from physiologically fallen fruits of Jinggang pomelo according to claim 1, characterized in that: The drying temperature in step 1 is 55-65° C.; the sieving is through a 40-100 mesh sieve.

3. A method for comprehensive extraction of essential oil and pectin from physiologically fallen fruits of Jinggang pomelo according to claim 1, characterized in that: In step 2, cellulase and hemicellulase are added to the raw material, the mass ratio of cellulase and hemicellulase is 1:1, and the total amount of cellulase and hemicellulase enzyme powder added: raw material mass = 1:100-1:200; after adding cellulase and hemicellulase to the raw material, the solid-liquid mass ratio = 1:5-1:10, the solid phase is the sum of enzyme powder and raw material powder, and the liquid phase is the added water; the enzymolysis temperature is 40-60°C, and the enzymolysis time is 4.5-6.5h.

4. A method for comprehensive extraction of essential oil and pectin from physiologically fallen fruits of Jinggang pomelo according to claim 1, characterized in that: The organic solvent extraction method in step 3 is a Soxhlet reflux extraction method, the organic solvent used for extraction is ethanol or petroleum ether, the material-liquid mass ratio is 1:8-1:12, the extraction time is 10h-50h, and the extraction temperature is 40-50°C.

5. The method for comprehensive extraction of essential oil and pectin from physiologically fallen fruits of Jinggang pomelo according to claim 1, characterized in that: After the extraction in step 4 is completed, the organic phase is collected and rotary evaporated at 40-45° C. for 1.5 h-5 h to separate the organic phase and the essential oil by evaporation. The essential oil is collected and immersed in filter paper or cotton to immobilize the extracted crude essential oil.

6. The method for comprehensive extraction of essential oil and pectin from physiologically fallen fruits of Jinggang pomelo according to claim 1, characterized in that: In step 5, the immobilized crude essential oil is subjected to secondary extraction by steam distillation; the extraction solvent is deionized water, the material-liquid mass ratio is 1:8-1:12, the extraction time is 10h-50h, and the extraction temperature is 140-160°C.

7. The method for comprehensive extraction of essential oil and pectin from physiologically fallen fruits of Jinggang pomelo according to claim 1, characterized in that: After the secondary extraction in step 6 is completed, the aqueous phase is collected, and an organic solvent is added for extraction. The organic solvent is selected from petroleum ether or dichloromethane, and the volume ratio of the petroleum ether to the aqueous phase is 1:3-1:

5. After the extraction is completed, the upper organic phase is taken and rotary evaporated at 40-45° C. for 1h-5h, and the organic phase and essential oil are evaporated and separated to obtain high-purity essential oil.

8. The method for comprehensive extraction of essential oil and pectin from physiologically fallen fruits of Jinggang pomelo according to claim 1, characterized in that: In step 7, the grapefruit pectin is extracted by acid extraction and alcohol precipitation. The raw material after essential oil extraction and water are placed in a container, the material-liquid mass ratio is controlled to be 1:5-1:8, the pH is adjusted to 1.5-2.5, and the extraction is heated to reflux at 80°C-100°C for 10h-50h. After the extraction is completed, centrifuge for 25-35min. After the centrifugation is completed, the supernatant is taken, and then 2-4 times the volume of the supernatant is added with 95% ethanol and precipitated at 4°C for 12-24h.

9. The method for comprehensive extraction of essential oil and pectin from physiologically fallen fruits of Jinggang Pomelo according to claim 1, characterized in that: The centrifugation time in step 8 is 25-35 minutes. After centrifugation, the lower layer of pectin is taken out and dried at a temperature of 60-80° C. After drying, the pectin powder is obtained by crushing.

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