Continuous drying for Antarctic krill and processing of shelled Antartic krill on board

Abstract

The present invention relates to a continuous on-board drying method for Antarctic krill and a continuous on-board processing method of shelled Antarctic krill. The drying method includes the following steps: 1) subjecting fishing materials to cleaning, sorting, and dewatering with a vibrating screen; 2) rapidly heating the krill to the temperature of up to 70 C. using infra-red rays; 3) hot-air drying; 4) impurity removal by vacuum; 5) cooling to obtain dried krill. The processing method includes the following steps: a) subjecting fishing materials to cleaning, sorting, and dewatering with a vibrating screen; b) rapidly heating the krill to the temperature of up to 70 C. using infra-red rays; c) hot-air drying; d) subjecting the dried krill to shelling treatment to separate shell from meat, to obtain shelled krill; e) impurity removal by vacuum to obtain shelled krill product. The methods in the present invention are highly efficient, energy saving, green and environmental protection, and the krill products have high quality and safety.

Claims

1. A continuous on-board drying method for Antarctic krill, which comprises the following steps: 1) cleaning and sorting of fishing materials: the fresh and live krill is cleaned by seawater, sorted, and then dewatered using a vibrating screen; 2) after treated in step 1), the krill is put evenly onto a conveyor belt to enter a multilayer drying cabinet, heated rapidly up to 70 C. using one or several infra-red rays ranging from 1 m to 400 m, which can inactivate the low-temperature proteinase and polyphenoloxidase; 3) after treated in step 2), the krill is subjected to hot-air drying at 55 C.-90 C. until the moisture content of the krill falls to not more than 40%; 4) impurities mixing in the krill obtained in step 3) are removed by vacuum; 5) after treated in step 4), the krill is put into a cooling cabinet and cooled at 15 C.5 C. for 15 min to make the temperature of the krill decrease rapidly to 0 C.10 C. and then dried krill is obtained.

2. The method according to claim 1, further comprising a step as follows, 6) the dried krill obtained in step 5) is screened according to the shape size.

3. The method according to claim 2, further comprising a step as follows, 7) the screened dried krill is subjected to packaging according to its specifications and then to storage at room or cold temperature.

4. The method according to claim 1, which is characterized in that, in step 1), the krill is put onto a vibrating screen with a vibrating frequency of 300 r/min-1150 r/min, to remove the water droplets on the krill.

5. The method according to claim 1, which is characterized in that, in step 2), the krill is heated rapidly up to 70 C. using one or several infrared rays ranging from 1 m to 300 m.

6. The method according to claim 1, which is characterized in that, in step 2), the krill is heated to 70 C.75 C.

7. The method according to claim 1, which is characterized in that, the step 3) includes the following two stage, Stage one includes the drying temperature is controlled between 65 C. and 90 C., the drying air velocity is between 0.5 m/s and 3.5 m/s, and the drying time is between 2 min to 20 min; Stage two includes the drying temperature is controlled between 55 C. and 80 C., the drying air velocity is between 0.5 m/s and 3.0 m/s, and the drying time is between 5 min to 25 min.

8. The method according to claim 1, which is characterized in that: in step 4), impurities mixing in the krill are removed by vacuum, and the relative vacuum degree is controlled to be between 15 kPa and 80 kPa.

9. A continuous on-board processing method of shelled Antarctic krill, which comprises the following steps: a) the fresh and live krill is cleaned by seawater, sorted, and then dewatered using a vibrating screen; b) after treated in step a), the krill is put evenly onto a conveyor belt to enter a multilayer drying cabinet, heated rapidly up to 70 C. using one or several infra-red rays ranging from 1 m to 400 m, which can inactivate the low-temperature proteinase and polyphenoloxidase; c) after treated in step b), the krill is subjected to hot-air drying at 55 C. -90 C. until the moisture content of the krill falls to not more than 40%; d) after treated in step c), the krill, whose moisture content has been not more than 40%, is treated with a shell crusher to separate shell from meat, and finally shelled krill is obtained; e) impurities mixing in the shelled krill obtained in step d) are removed by vacuum to obtain shelled krill product.

10. The method according to claim 9, further comprising steps as follows: f) the shelled krill obtained in step e) is screened according to the shape size. g) the screened shelled krill is subjected to packaging according to its specifications and then to storage at room or cold temperature.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 describes the flow chart of a continuous onboard drying method for Antarctic krill.

(2) FIG. 2 describes the flow chart of a continuous on-board processing for shelled Antarctic krill.

DETAILED DESCRIPTION

(3) The further description of the present invention is made with figures.

EXAMPLE 1

(4) Referring to FIG. 1, a continuous on-board drying method for fresh and live Antarctic krill after fishing, is executed as follows:

(5) 1) Cleaning and sorting of fishing materials: the fresh and live krill is cleaned by seawater, sorted, and then the water droplets on the krill are removed using a vibrating screen at a vibrating frequency of 1050 r/min;

(6) 2) Heating using infra-red: after processed in step 1), krill is put evenly onto a conveyor belt to go into a seven-layer drying cabinet. It is heated for 3.5 min using a strong-penetration-force near infra-red ray at a wavelength of 1 m. After the center temperature of the krill reaching 75 C., the activities of low-temperature proteinase and polyphenoloxidase are inhibited and starts to disappear;

(7) 3) Hot-air drying: after processed in step 2), krill goes to the first stage of hot-air drying: the temperature of hot air is controlled at 75 C., and the drying air velocity is 1.0 m/s. After drying for 10 min, the low-temperature proteinase and polyphenoloxidase are inactivated completely. Then it comes to the second stage of hot-air drying: the temperature of hot air is controlled at 65 C., and the drying air velocity is 3.0 m/s. After drying for 25 min, the final moisture content of the krill is down to 38%, and the weight is decreased by two times.

(8) 4) Impurity removal by vacuum: Impurities such as small antennas mixing in the krill obtained in step 3) are removed by vacuum at relative vacuum degree of 30 kPa.

(9) 5) Cooling: after processed in step 4), the Krill is put into a cooling cabinet and cooled at 5 C. for 3 min. The temperature of the krill decreased rapidly to 5 C., and then the dried krill is obtained. The fluorine content in the meat of the dried krill is 235 ppm (based on dry matter).

(10) 6) Vibrating screening: after processed in step 5), the dried krill is screened according to the shape size.

(11) 7) Packaging and cold storage: The screened dried krill is subjected to packaging according to its specifications and then to storage at a temperature not more than 18 C.

EXAMPLE 2

(12) Referring to FIG. 1, a continuous and efficient on-board drying method for fresh and live Antarctic krill after fishing at polar area, is executed as follows:

(13) 1) Cleaning and sorting of fishing materials: The fresh and live krill is cleaned by seawater and sorted, and then the water droplets on the krill are removed using a vibrating screen at a vibrating frequency of 1050 r/min.

(14) 2) Heating using infra-red: after processed in step 1), the krill is put evenly onto a conveyor belt to go into a seven-layer drying cabinet. It is heated for 3.0 min using a strong-penetration -force far infra-red ray at a wavelength of 20 m. After the center temperature of the krill reaches 72 C., the activities of low-temperature proteinase and polyphenoloxidase are inhibited and starts to disappear.

(15) 3) Hot-air drying: after processed in step 2), the krill goes to the first stage of hot-air drying: the temperature of the hot air is controlled at 72 C., and the drying air velocity is 2.0 m/s. After drying for 15 min, the low-temperature proteinase and polyphenoloxidase are inactivated completely. Then it comes to the second stage of hot-air drying: the temperature of hot air is controlled at 70 C., and the drying air velocity is 3.5 m/s. After drying for 22 min, the final moisture content of the krill is down to 30%, and the weight is decreased by 2.5 times.

(16) 4) Impurity removal by vacuum: impurities such as small antennas mixing in the krill obtained in step 3) are removed by vacuum at a relative vacuum degree of 50 kPa.

(17) 5) Cooling: after processed in step 4), the krill is put into a cooling cabinet and cooled at 0 C. for 3 min. The temperature of the krill decreased rapidly to 10 C., and then the dried krill is obtained. The fluorine content in the meat of the dried krill is 192 ppm (based on dry matter).

(18) 6) Screening: after processed in step 5), the dried krill is screened according to the shape size.

(19) Packaging and storage: The screened dried krill is subjected to packaging according to its specifications and then to storage at room or cold temperature.

EXAMPLE 3

(20) Referring to FIG. 1, a continuous on-board drying method for fresh and live Antarctic krill after fishing, is executed as follows:

(21) 1) Cleaning and sorting of fishing materials: The fresh and live krill is cleaned by seawater and sorted, and then the water droplets on the krill are removed using a vibrating screen at a vibrating frequency of 600 r/min.

(22) 2) Heating using infra-red: after processed in step 1), the krill is put evenly onto a conveyor belt to go into a seven-layer drying cabinet. It is heated continuously for 2.5 min using strong -penetration-force near infra-red rays at a wavelength of 1 m and weak-penetration-force far infra-red rays at a wavelength of 290 m, wherein these rays are with a parallel or crossing distribution above the conveyor belt. After the center temperature of krill reaches 73 C., the activities of the low-temperature proteinase and polyphenoloxidase are inhibited and starts to disappear.

(23) 3) Hot-air drying: after processed in step 2), the krill goes to the first stage of hot-air drying: the temperature of the hot air is controlled at 85 C., and the drying air velocity is 2.0 m/s. After drying for 10 min, the low-temperature proteinase and polyphenoloxidase are inactivated completely. Then it comes to the second stage of hot-air drying: the temperature of hot air is controlled at 75 C., and the drying air velocity is 2.5 m/s. After drying for 10 min, the final moisture content of the krill is down to 20%, and the weight is decreased by 3 times.

(24) 4) Impurity removal by vacuum: impurities such as small antennas mixing in the krill obtained in step 3) are removed by vacuum at a vacuum degree of 40 kPa.

(25) 5) Cooling: after processed in step 4), the krill is put into a cooling cabinet and cooled at 2 C. for 4 min. The temperature of the krill decreased rapidly to 5 C., and then the dried krill is obtained. The fluorine content in the meat of the dried krill is 158 ppm (based on dry matter).

(26) 6) Screening: The dried Krill is screened according to the shape size.

(27) 7) Packaging and storage: The screened dried krill is subjected to packaging according to its specifications and then to storage at room or cold temperature.

EXAMPLE 4

(28) Referring to FIG. 2, a continuous on-board processing method for fresh and live shelled Antarctic krill after fishing, is executed as follows:

(29) Steps 1), 2) and 3) are the same to example 1.

(30) 4) Shelling treatment: after processed in step 3), the krill. with a moisture content of 38% is beaten, rubbed, collided repeatedly with steel rods of a differential roll on roll krill shelling machine produced by Heibei Runlian Mechanical Equipment Company Limited. The krill shell is blown away using a fan to separate shell from meat. And finally the shelled krill is obtained. The fluorine content in the shelled krill is 245 ppm (based on. dry matter).

(31) 5) Impurity removal by vacuum: impurities such as small antennas and shell mixing in the shelled krill are removed by vacuum at a vacuum degree of 40 kPa.

(32) 6) Screening: after processed in step 5), the shelled krill is screened according to the shape size.

(33) 7) Packaging and storage: The screened shelled krill is subjected to packaging according to its specifications and then to storage at 18 C.

EXAMPLE 5

(34) Referring to FIG. 2, a continuous on-board processing method for fresh and live shelled Antarctic krill after fishing is executed as follows:

(35) Step 1), 2) and 3) are the same to example 3.

(36) 4) Shelling treatment: after processed in step 3), the krill with a moisture content of 20% is beaten, rubbed, collided repeatedly with steel rods of a differential roll on roll krill shelling machine produced by Heibei Runlian Mechanical Equipment Company Limited. The krill shell is blown away using a fan to separate shell from meat. And finally the shelled krill is obtained. The fluorine content in the shelled krill is 165 ppm (based on dry matter).

(37) 5) Impurity removal by vacuum: impurities such as small antennas and shell mixing in the shelled krill are removed by vacuum at a vacuum deuce of 20 kPa.

(38) 6) Screening: after processed in step 5), the shelled Krill is screened according to the shape size.

(39) 7) Packaging and storage: The screened shelled krill is subjected to packaging according to its specification and then to storage at room temperature.