Method of preparing paprika red pigment with low polycyclic aromatic hydrocarbons

Abstract

A method of preparing paprika red pigment with low polycyclic aromatic hydrocarbons includes (1) drying, crushing and granulating mature peppers to obtain pepper particles; (2) extracting the pepper particles with a vegetable oil in a rotocel extractor to obtain a paprika red pigment solution; (3) extracting the paprika red pigment solution with an ethanol solution in a liquid-liquid extractor to remove spicy substances; (4) running the paprika red pigment solution through a low-pressure chromatography column to remove polycyclic aromatic hydrocarbons; and (5) concentrating the paprika red pigment solution to obtain the paprika red pigment with low polycyclic aromatic hydrocarbons.

Claims

1. A method of preparing paprika red pigment consisting of: (1) drying, crushing and granulating mature peppers to obtain pepper particles; (2) extracting the pepper particles with a vegetable oil in a rotocel extractor to obtain a paprika red pigment vegetable oil solution; (3) extracting the paprika red pigment vegetable oil solution with an ethanol solution in a liquid-liquid extractor to remove spicy substances; (4) running the paprika red pigment vegetable oil solution through a chromatography column to remove polycyclic aromatic hydrocarbons; and (5) concentrating the paprika red pigment vegetable oil solution to obtain the paprika red pigment, wherein in step (1), the mature peppers are dried, crushed, and granulated at 30? C.; wherein in step (2), the pepper particles are extracted with the vegetable oil at 40? C. and at a spraying volume of 1,000 L/h; wherein in step (3), the paprika red pigment vegetable oil solution is extracted continuously with the ethanol solution with a paprika red pigment vegetable oil solution flow rate of 1 m.sup.3/h and an ethanol solution flow rate of 2 m.sup.3/h, and the ethanol solution is a 70% (v/v) ethanol solution; wherein in step (4), the chromatography column includes a filler that includes 200 mesh activated carbon and 80 mesh activated white clay mixed at a weight ratio of 7:1, and a weight ratio of the filler and the pepper particles is 7:30; and wherein in step (5), the paprika red pigment vegetable oil solution is concentrated at 74? C. and a pressure of 0.09 mPa, the paprika red pigment has a polycyclic aromatic hydrocarbons concentration of 10.4 mg/Kg, and the paprika red pigment has a benzopyrene concentration of 1.9 mg/Kg.

Description

DETAILED DESCRIPTION

Example 1

(1) a) Mature red peppers were dried, crushed, and granulated at 30? C. to obtain pepper particles. 3,000 Kg pepper particles (color value: 16.6) were extracted with vegetable oil as extraction solvent in a horizontal continuous rotocel extractor. The extraction was conducted at 45? C. and a spray volume of 1,000 L/h to obtain a paprika red pigment solution. The paprika red pigment solution was continuously extracted with 70% ethanol in a liquid-liquid extractor at 45? C. and 200 r/min to remove spicy substances. The paprika red pigment solution has a flow rate of 1 m.sup.3/h and 70% ethanol has a flow rate of 2 m.sup.3/h.

(2) b) The paprika red pigment solution was adsorbed at a flow rate of 1 By/h on a chromatography column with a filler of 100 mesh activated carbon and 100 mesh diatomaceous earth mixed at a ratio of 5:1. The amount of the filler of the chromatography column is 30 kg. The eluent was collected, and polycyclic aromatic hydrocarbons were removed from the paprika red pigment solution.

(3) c) The paprika red pigment solution was concentrated under reduced pressure 0.08 mPa at 60? C. to recover the extraction solvent. The paprika red pigment solution was further dried at 78? C. and 0.08 mPa for 3.5 hours to obtain 183.8 kg of paprika red pigment with low polycyclic aromatic hydrocarbons.

Example 2

(4) a) Mature red peppers were dried, crushed, and granulated at 30? C. to obtain pepper particles. 3,000 Kg pepper particles (color value: 17.6) were extracted with vegetable oil as extraction solvent in a horizontal continuous rotocel extractor. The extraction was conducted at 45? C. and a spray volume of 1,000 L/h to obtain a paprika red pigment solution. The paprika red pigment solution was continuously extracted with 70% ethanol in a liquid-liquid extractor at 45? C. and 200 r/min to remove spicy substances. The paprika red pigment solution has a flow rate of 1 m.sup.3/h and 70% ethanol has a flow rate of 2 m.sup.3/h.

(5) b) The paprika red pigment solution was adsorbed at a flow rate of 1.5 By/h on a chromatography column with a filler of 100 mesh activated carbon, 100 mesh activated white clay, and 100 mesh diatomaceous earth mixed at a ratio of 4:1:1. The amount of the filler of the chromatography column is 50 kg. The eluent was collected, and polycyclic aromatic hydrocarbons were removed from the paprika red pigment solution.

(6) c) The paprika red pigment solution was concentrated under reduced pressure 0.07 mPa at 70? C. to recover the extraction solvent. The paprika red pigment solution was further dried at 74? C. and 0.07 mPa for 4 hours to obtain 170.9 kg of paprika red pigment with low polycyclic aromatic hydrocarbons.

Example 3

(7) a) Mature red peppers were dried, crushed, and granulated at 30? C. to obtain pepper particles. 3,000 Kg pepper particles (color value: 16.9) were extracted with vegetable oil as extraction solvent in a horizontal continuous rotocel extractor. The extraction was conducted at 45? C. and a spray volume of 1,000 L/h to obtain a paprika red pigment solution. The paprika red pigment solution was continuously extracted with 70% ethanol in a liquid-liquid extractor at 45? C. and 200 r/min to remove spicy substances. The paprika red pigment solution has a flow rate of 1 m.sup.3/h and 70% ethanol has a flow rate of 2 m.sup.3/h.

(8) b) The paprika red pigment solution was adsorbed at a flow rate of 1.5 By/h on a chromatography column with a filler of 200 mesh activated carbon and 80 mesh activated white mixed at a ratio of 7:1. The amount of the filler of the chromatography column is 70 kg. The eluent was collected, and polycyclic aromatic hydrocarbons were removed from the paprika red pigment solution.

(9) c) The paprika red pigment solution was concentrated under reduced pressure 0.09 mPa at 74? C. to recover the extraction solvent. The paprika red pigment solution was further dried at 74? C. and 0.08 mPa for 3 hours to obtain 194.1 kg of paprika red pigment with low polycyclic aromatic hydrocarbons.

Comparative Example 1

(10) a) Mature red peppers were dried, crushed, and granulated at 30? C. to obtain pepper particles. 3,000 Kg pepper particles (color value: 16.8) were extracted with vegetable oil as extraction solvent in a horizontal continuous rotocel extractor. The extraction was conducted at 45? C. and a spray volume of 1,000 L/h to obtain a paprika red pigment solution. The paprika red pigment solution was continuously extracted with 70% ethanol in a liquid-liquid extractor at 45? C. and 200 r/min to remove spicy substances. The paprika red pigment solution has a flow rate of 1 m.sup.3/h and 70% ethanol has a flow rate of 2 m.sup.3/h.

(11) b) The paprika red pigment solution was concentrated under reduced pressure 0.08 mPa at 60? C. to recover the extraction solvent. The paprika red pigment solution was further dried at 78? C. and 0.09 mPa for 3 hours to obtain 188.9 kg of paprika red pigment.

Comparative Example 2

(12) 3,000 Kg mature pepper particles (color value: 16.5) were extracted with vegetable oil as extraction solvent in a horizontal continuous rotocel extractor. The extraction was conducted at 40? C. and a spray volume of 1,500 L/h to obtain a paprika red pigment solution.

(13) The paprika red pigment solution was concentrated under reduced pressure 0.06 mPa to obtain 250.86 kg concentrated paprika red pigment solution. The concentrated solution was extracted with 500 kg of 70% ethanol, and then dried at 75? C. and 0.08 mPa for 3.5 hours to obtain 190.6 kg of paprika red pigment.

(14) The paprika red pigment prepared in the Examples and Comparative Examples was tested. The absorbance was detected according to the method of GB/10783-2008. The absorbance ratio was a ratio of A470 nm to A454 nm in the same paprika red pigment solution. PAHs were detected by HPLC. The test results are shown in Table 1.

(15) TABLE-US-00001 TABLE 1 Test results of paprika red pigment prepared in Examples 1 to 3 and Comparative Examples 1-2 Experimental Nos. Test Results Ex. 1 Ex. 2 Ex. 3 Comp. Ex. 1 Comp. Ex. 2 Color value 258.2 287.6 246.7 255.6 239.7 Absorbance 0.986 0.991 0.982 0.990 0.978 PAHs, mg/kg 9.1 12.6 10.4 96.3 89.2 benzopyrene, mg/kg 4.6 2.9 1.9 43.7 62.1 Yield % 95.3 93.1 94.4 95.8 92.3

(16) As shown in Table 1, the paprika red pigment in the example and the comparative example are close in color value and yield, but the PAHs and benzopyrene contents in the examples 1-3 are significantly lower than those in the comparative examples 1-2. The method of the present application has a good removal effect on PAHs and benzopyrene while ensuring a high yield of the paprika red pigment.

(17) Finally, it should be noted that the above-mentioned embodiments are only examples for clearly illustrating the present invention, rather than limiting the implementation manners. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. There is no need and cannot give an exhaustive list of all implementation methods. The obvious changes or modifications derived from this are still within the protection scope of the present invention.