U.S. patent application number 15/597737 was filed with the patent office on 2018-11-22 for continuous on-board processing of seafood after fishing on the sea.
The applicant listed for this patent is ZHEJIANG UNIVERSITY OF TECHNOLOGY. Invention is credited to Shanping Chen, Yuting Ding, Saiqi Gu, Jianhua Liu, Shulai Liu, Fei Lv, Xia Xu, Jianyou Zhang, Peicheng Zhao, Zhicheng Zheng, Xuxia Zhou.
Application Number | 20180332864 15/597737 |
Document ID | / |
Family ID | 64269510 |
Filed Date | 2018-11-22 |
United States Patent
Application |
20180332864 |
Kind Code |
A1 |
Ding; Yuting ; et
al. |
November 22, 2018 |
Continuous On-Board Processing of Seafood after Fishing on the
Sea
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.degree. 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.degree. 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.
Inventors: |
Ding; Yuting; (Zhejiang,
CN) ; Zhou; Xuxia; (Zhejiang, CN) ; Liu;
Shulai; (Zhejiang, CN) ; Liu; Jianhua;
(Zhejiang, CN) ; Lv; Fei; (Zhejiang, CN) ;
Chen; Shanping; (Zhejiang, CN) ; Zhao; Peicheng;
(Zhejiang, CN) ; Zhang; Jianyou; (Zhejiang,
CN) ; Gu; Saiqi; (Zhejiang, CN) ; Xu; Xia;
(Zhejiang, CN) ; Zheng; Zhicheng; (Zhejiang,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ZHEJIANG UNIVERSITY OF TECHNOLOGY |
Zhejiang |
|
CN |
|
|
Family ID: |
64269510 |
Appl. No.: |
15/597737 |
Filed: |
May 17, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A23L 5/51 20160801; B01D
61/142 20130101; C02F 9/005 20130101; A23V 2250/1614 20130101; B01D
2311/06 20130101; F26B 3/04 20130101; A23L 17/40 20160801; A23V
2250/126 20130101; A23V 2250/1582 20130101; C02F 2103/22 20130101;
C02F 2103/08 20130101; A23V 2250/082 20130101; A23V 2250/60
20130101; B01D 61/422 20130101; A23V 2300/06 20130101; B01D 61/58
20130101; A23L 5/19 20160801; A23V 2002/00 20130101; B63B 35/14
20130101; B01D 61/16 20130101; C02F 1/442 20130101; C02F 1/444
20130101; B01D 61/147 20130101; A22C 29/02 20130101; A23V 2250/214
20130101; A23V 2300/38 20130101; B01D 2311/06 20130101; A23V
2300/34 20130101; A23L 17/00 20160801; A23V 2002/00 20130101; A23V
2250/1618 20130101; B01D 71/58 20130101; C02F 1/441 20130101; A23V
2250/2132 20130101; B01D 61/145 20130101; A23V 2300/31 20130101;
C02F 2103/008 20130101; C02F 1/4693 20130101; B01D 61/025 20130101;
B01D 61/027 20130101; B01D 61/04 20130101; F26B 2200/16 20130101;
C02F 2301/08 20130101; A23V 2250/214 20130101; B01D 2311/2676
20130101; A23V 2250/082 20130101; B01D 2311/2642 20130101; A23V
2250/1618 20130101; A23V 2250/21 20130101; A23V 2250/2132 20130101;
F26B 1/00 20130101; A22C 29/021 20130101; A23L 5/13 20160801; A23V
2250/154 20130101; A23V 2250/21 20130101; C02F 9/00 20130101; B01D
2311/2676 20130101 |
International
Class: |
A22C 29/02 20060101
A22C029/02; A23L 17/40 20060101 A23L017/40; A23L 5/10 20060101
A23L005/10; F26B 3/04 20060101 F26B003/04; B01D 61/58 20060101
B01D061/58; B01D 61/04 20060101 B01D061/04; B01D 61/02 20060101
B01D061/02; B01D 61/14 20060101 B01D061/14; B01D 61/16 20060101
B01D061/16; B01D 61/42 20060101 B01D061/42 |
Claims
1. A cooking soup comprising a quality improver for treating
seafood materials, wherein the cooking soup comprising the quality
improver comprises salt 0.about.6% (w/w), edible alcohol
0.1.about.3% (w/w), glucono-delta-lactone 0.05.about.0.5% (w/w),
tea polyphenol 0.02.about.0.2% (w/w), perilla juice 0.01.about.0.1%
(w/w), sodium hexametaphosphate 0.05.about.0.25% (w/w), and
water.
2-10. (canceled)
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a method of continuous
on-board processing of seafood after fishing on the sea,
specifically relates to a method of continuous on-board processing
of seafood, and high efficient and energy-saving processing of its
wastewater on the sea.
BACKGROUND OF THE INVENTION
[0002] For a long time, the production of seafood adopts the
following traditional ways: firstly, marine fishing; secondly,
salting processing or ice preservation and transportation; finally,
traditional processing on the land. There is a strong seasonality
of marine resources such as fish and shrimp. Especially for the
polar resource, Antarctic krill, is small-size, easy to be
deteriorated, and hard to preserve. According to the traditional
production ways for seafood, the products have several problems
such as low-fresh raw materials, quality decrease after processing
(high-content of TVB-N, colour decrease, etc.). The innovative
on-board fishing and processing model provides a best way solving
these problems. This model not only keeps the freshness for raw
materials by solving the problems of easy to be deteriorated and
hard to transport and preserve for fish and shrimp, but also cuts
the cost for transportation and shortens the time for processing.
This model realizes a continuous on-board value-adding processing
way.
[0003] In the continuous on-board processing, the wastewater
(cooking soup) produced from heat treatment for fish and shrimp
contains abundant nutrients and flavor compounds such as proteins,
polypeptides, amino acids, carbohydrates, and nucleic acids. Due to
technical restriction, these cooking soups with high COD and BOD
value are discharged directly without any treatment, which would
induce water eutrophication, leading to a high risk for red tide
phenomenon.
[0004] Membrane separation includes the processing of reverse
osmosis, nanofiltration, ultrafiltration and microfiltration, etc.
The experimental research indicates that the cooking soup treated
via membrane separation not only recycles all the dissolved
substances, but also makes the water filtrated by membrane reuse in
production. This research lays a solid foundation for the
continuous on-board large-scale processing.
BRIEF SUMMARY
[0005] To solve the problems such as low freshness processing on
the land, and quality and safety decrease for seafood, the present
invention provides a method of continuous on-board processing of
seafood after fishing on the sea, which can keep the freshness for
raw materials, increase products quality, and keep products
safety.
[0006] The present invention adopts the following technical
solution to solve the technical problems:
[0007] a method of continuous on-board processing of seafood after
fishing on the sea, which comprises the following steps:
[0008] 1) after fishing of seafood materials, cleaning the seafood
materials with seawater of 0.about.10.degree. C., wherein the
seafood materials are fish or shrimp;
[0009] 2) cooking the fish or shrimp for 2.about.8 min in a cooking
soup comprising a quality improver, wherein the solid-liquid ratio
is 1 kg: 8.about.20 L, and the cooking soup comprising the quality
improver is composed of salt 0.about.6% (w/w), edible alcohol
0.1.about.3% (w/w), glucono-delta-lactone 0.05.about.0.5% (w/w),
tea polyphenol 0.02.about.0.2% (w/w), perilla juice 0.01.about.0.1%
(w/w), sodium hexametaphosphate 0.05.about.0.25% (w/w), and water;
during the cooking, the cooking soup is replaced at a fixed time
(preferably every 2 hours), and the replaced cooking soup is heat
processing wastewater, which should be treated to become more
suitable for environment;
[0010] 3) putting the cooked fish or shrimp onto vibrating screen,
leaching and dewatering it;
[0011] 4) putting the processed fish or shrimp evenly onto conveyor
belt to go into a multilayer (preferably 3- to 9-layer) hot-air
drying cabinet, and drying it until the moisture content of the
fish or shrimp falls below 40% (w/w);
[0012] 5) removing impurities such as small antennas mixing in the
dried fish or shrimp obtained in step 4) by vacuum;
[0013] 6) cooling the fish or shrimp obtained in step 5) by cold
wind to decrease the temperature to not more than 10.degree. C.,
thereby obtaining dried fish or shrimp product.
[0014] Further, the method of continuous on-board processing of
seafood after fishing on the sea includes a step as follows: 7)
screening: screening the dried fish or shrimp product according to
the shape size.
[0015] More further, the method of continuous on-board processing
of seafood after fishing on the sea includes a step as follows: 8)
packaging and storage: subjecting the screened dried fish or shrimp
to packaging according to its specifications and then to storing at
room or cold temperature.
[0016] In step 2) mentioned above, after leached on a stainless
steel net, the cooked fish or shrimp is put onto a vibrating screen
with vibrating frequency of 300.about.1150 r/min (the optimal is
750 r/min), to remove the water droplets on the fish or shrimp.
[0017] In step 4) mentioned above, the drying includes the
following three stages:
[0018] stage one: the drying temperature is controlled between
50.degree. C. and 60.degree. C., the drying air velocity is between
1.2 m/s and 3.5 m/s, and the drying time is between 5 min to 15
min;
[0019] stage two: the drying temperature is controlled between
65.degree. C. and 75.degree. C., the drying air velocity is between
0.8 m/s to 2.3 m/s, and the drying time is between 10 min and 25
min;
[0020] stage three: the drying temperature is controlled between
55.degree. C. and 65.degree. C.; the drying air velocity is between
0.5 m/s to 2.0 m/s; and the drying time is between 8 min and 15
min.
[0021] In step 5) mentioned above, impurities such as small
antennas mixing in dried fish or shrimp are removed by vacuum, and
relative vacuum degree is controlled at -15 kPa.about.-80 kPa. If
the relative vacuum degree is less than -15 kPa, impurities such as
small antennas cannot be removed. If the relative vacuum degree is
more than 80 kPa, the impurities and the fish or shrimp would be
all removed, therefore the purpose of separation can not be
achieved.
[0022] In step 6) mentioned above, the fish or shrimp obtained in
step 5) is cooled by cold wind at a temperature of
-5.about.5.degree. C. for 1.about.15 min, to rapidly decrease the
temperature to not more than 10.degree. C.
[0023] Further, the method of continuous on-board processing of
seafood after fishing on the sea includes the high efficient and
energy-saving treatment of the replaced cooking soup, which is
carried out as follows:
[0024] (a) the replaced cooking soup (i.e., the cooking wastewater)
produced in step 2) is cooled down to 0.about.70.degree. C., the
cooled cooking wastewater is subjected to filtration or
centrifugation to remove the suspended substances, then a
flocculant is added and stirred for 5.about.60 min, and then the
resulted floccule is removed by filtration or centrifugation;
wherein the flocculant is diatomite, and the addition amount of the
diatomite is 50.about.1000 mg/L;
[0025] (b) microfiltration treatment: a microfiltration membrane
with aperture of 0.1.about.2 .mu.m is used for filtration of the
cooking wastewater obtained in step (a), and a permeate solution
"a" is obtained;
[0026] (c) ultrafiltration treatment: a ultrafiltration membrane
with aperture of 10000.about.100000 Da is used for filtration of
the permeate solution "a", and a permeate solution "b" is
obtained;
[0027] (d) purification treatment: the permeate solution "b" is
subjected to one of the following treatments: {circle around (1)}
nanofiltration treatment: the permeate solution "b" flows into a
nanofiltration membrane device with aperture of 90.about.1000 Da,
and is subjected to filtration under conditions of 0.5.about.2 MPa
and 0.about.70.degree. C. to obtain a permeate solution "c", and
the solution "c" can be recycled or discharged directly; {circle
around (2)} reverse osmosis treatment: the permeate solution "b"
flows into a reverse osmosis device, and is subjected to reverse
osmosis treatment under conditions of 1.about.6 MPa and
0.about.70.degree. C. to obtain a permeate solution "d", and the
solution "d" can be recycled or discharged directly.
[0028] More further, in step (a) mentioned above, the pH of the
cooking wastewater is adjusted to 4.0.about.5.5 before the addition
of the flocculant. The optimal option for adjusting pH is using
citric acid or acetic acid.
[0029] More further, in step (b) mentioned above, the membrane for
microfiltration is ceramic microfiltration membrane with aperture
of 0.22 .mu.m, and the running pressure and temperature are 0.2 MPa
and 20.about.50.degree. C., respectively.
[0030] More further, in step (c) mentioned above, the aperture of
the ultrafiltration membrane is 50000 Da, and the running pressure
and temperature are 0.6 MPa and 20.about.40.degree. C.,
respectively.
[0031] More further, in step (d) mentioned above, the aperture of
the nanofiltration membrane is below 200 Da, and the running
pressure and temperature are 1.5 MPa and 20.about.40.degree. C.,
respectively.
[0032] More further, in step (d) mentioned above, the membrane for
reverse osmosis is cellulose triacetate (CTA) membrane with
aperture of 5.about.10 nm, and the running pressure and temperature
are 2.5 MPa and 20.about.40.degree. C., respectively.
[0033] More further, in step (d) mentioned above, if the salt
content of the solution before reverse osmosis treatment is over
2.5%, the solution has to be subjected to electrodialysis treatment
due to high osmotic pressure of itself. The electrodialysis device
adopted in the present invention consists of 8 cation and 7 anion
membranes placed at regular intervals. Both of the cation and anion
membrane are homogeneous membrane, optimally provided by Zhejiang
Circle-tech Membrane Technology Co., Ltd. with cation membrane CMX
and anion membrane AMX. These membranes have the following
properties such as high desalting efficiency, strong limiting
current (I=6.5 A), less loss of soluble proteins (25.55%) and free
amino acids (13.77%), which makes them suitable for desalting by
electrodialysis treatment for the cooking wastewater from fish or
shrimp. What's more, the present invention establishes a prediction
model for predicting the desalting ratio by electrodialysis
treatment, with this model, the desalting ratio can be effectively
predicted:
P = 1 - ( .theta. e - .alpha. Et 5 / 3 Q 2 / 3 N .theta. - + e -
.alpha. Et 5 / 3 Q 2 / 3 N ) 2 ##EQU00001##
[0034] wherein .alpha. is obtained by SPSS software regression
fitting, it can be calculated with flow rate, voltage and feed
concentration according to the following formula:
.alpha.=1.766.times.10.sup.-7C.sub.0+2.213.times.10.sup.-7E+1.476.times.-
10.sup.-7Q-7.657.times.10.sup.-6
[0035] C.sub.0 is feed concentration (mol/m.sup.3); .theta. is
ionic limiting molar conductivity of NaCl solution; ismolar
conductivity of NaCl; Q is flow rate (m.sup.3/h); t is time for
electrodialysis treatment (h); E is dc voltage (V); N is the number
of pairs for cation and anion membrane; and e is mathematic
constant, and the value is 2.71828.
[0036] The permeate solutions "a", "b", "c" and "d" described in
the present invention are permeate solutions produced in different
filtration treatments. These letters "a", "b", "c" and "d"
following the permeate solutions are used for distinguishing the
permeate solutions produced in different filtration treatments and
themselves have no meanings.
[0037] Compared with the traditional technologies, the advantages
of the present invention are as follows:
[0038] 1. The present invention provides a method that is suitable
for continuous on-board processing of seafood after fishing on the
sea. The method adopts the formulation with a new quality improver,
which can effectively keep the colour, flavor, texture and quality
of the processed fish or shrimp. Accordingly, the present
technology has a promising value for popularization and
application.
[0039] 2. The protein flocculation technology is adopted in the
present invention to pre-treat the cooking wastewater, which
effectively decreases the concentration polarization, enhances
running time for membrane, decreases washing times for membrane,
and prolongs the usage of membrane.
[0040] 3. The electrodialysis technology is used for desalting for
the cooking wastewater in the present invention. For the specific
electrodialysis device, a prediction model for the desalting ratio
by electrodialysis treatment is established. According to this
model, the desalting ratio can be effectively predicted.
[0041] 4. The present invention effectively solves the problem of
discharging of the wastewater produced by on-board heat processing
on the sea, and reduces the environmental pollution. The water
after treatment can be discharged directly or recycled for usage.
The present invention provides a "green" processing method for some
sea areas such as Antarctic area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] FIG. 1 describes the flow chart of the method of continuous
on-board processing of seafood after fishing on the sea.
DETAILED DESCRIPTION
[0043] The present invention is further described with examples
together with the FIGURE. However, the protection range of the
present invention is not limited to the examples.
[0044] The electrodialysis device adopted in the present invention
consists of a membrane stack of 8 cation and 7 anion membranes
placed at regular intervals. Both of the cation membrane CMX and
anion membrane AMX are provided by Zhejiang Circle-tech Membrane
Technology Co., Ltd.
Example 1
[0045] Referring to FIG. 1, a continuous on-board processing of
fish or shrimp after fishing on the sea is executed as follows:
[0046] 1) Cleaning and sorting of fishing shrimp: The fresh and
live shrimp is cleaned by seawater, sorted. The temperature of
seawater is controlled between 0.degree. C. to 10.degree. C.
[0047] 2) Cooking: 2000 L of cooking soup containing a quality
improver are put into a cooking tank. The cooking soup containing
the quality improver is composed of edible alcohol (2 kg, produced
by Jiangsu Donghai Shuntai Alcohol Co. Ltd.), glucono-delta-lactone
(1 kg), tea polyphenol (4 kg), perilla juice (2 kg, produced by
Zhejiang Shizi Bio-tech Co. Ltd.), hexametaphosphate (5 kg), and
water. The cooking soup in the tank is heated until the temperature
is up to 90.degree. C. The shrimp is added into the tank to cook
for 6 min, with the purpose of inactivation of enzyme (mainly
endogenous proteases), reduction of microorganism, and meat
dewatering. The solid-liquid ratio is controlled at 1:10. The
cooking soup is replaced with new one every 2 hours. The replaced
cooking soup (i.e., heat processing wastewater) should be treated
to become more suitable for environment.
[0048] 3) After leached on a stainless steel net, the cooked shrimp
is put onto a vibrating screen with a vibrating frequency of 750
r/min, to remove the water droplets on the shrimp.
[0049] 4) Drying: the shrimp is put evenly onto conveyor belt to go
into a 7-layer hot-air drying cabinet for gradually drying: stage
one: the drying temperature is controlled at 60.degree. C., the
drying air velocity is 2.6 m/s, and the drying time is 5 min; stage
two: the drying temperature is controlled at 65.degree. C., the
drying air velocity is 1.0 m/s, and the drying time is 25 min;
stage three: the drying temperature is controlled at 60.degree. C.,
the drying air velocity is 0.8 m/s, and the drying time is 15
min.
[0050] 5) Impurity removal by vacuum: Impurities such as small
antennas mixing in dried shrimp are removed by vacuum at a relative
vacuum degree of -15 kPa.
[0051] 6) Cooling: the shrimp is put into a cooling cabinet at
-5.degree. C. for 3 min. The temperature of the shrimp decreased
rapidly to 0.about.10.degree. C. The dried shrimp product is
obtained.
[0052] 7) Screening: The dried shrimp product is screened according
to the shape size.
[0053] 8) Packaging and storage: the screened dried shrimp is
subjected to packaging according to its specifications and then to
storing at -18.degree. C.
[0054] The dried shrimp obtained according to the method mentioned
above displays natural colour, uniform texture, and original flavor
and taste.
Example 2
[0055] 1) 200 kg of clove fish are cleaned by seawater, and sorted.
The temperature of seawater is controlled between 0.degree. C. and
10.degree. C.
[0056] 2) 1000 L of cooking soup containing a quality improver are
put into cooking tank. The cooking soup containing the quality
improver is composed of salt (60 kg), edible alcohol (2 kg,
produced by Jiangsu Donghai Shuntai Alcohol Co. Ltd.),
glucono-delta-lactone (4.5 kg), tea polyphenol (200 g), perilla
juice (1 kg, produced by Zhejiang Shizi Bio-tech Co. Ltd.),
hexametaphosphate (500 g) and water. The cooking soup in the tank
is heated until the temperature is up to 100.degree. C. The clove
fish (200 kg) is added into the tank to cook for 2 min. The cooking
soup is replaced with new one every 2 hours. The replaced cooking
soup (i.e., heat processing wastewater) should be treated to become
more suitable for environment.
[0057] 3) After leached on a stainless steel net, the cooked clove
fish is put onto a vibrating screen with vibrating frequency of 750
r/min, to remove the water droplets on the clove fish.
[0058] 4) Drying: the clove fish is put evenly onto conveyor belt
to go into a 7-layer hot-air drying cabinet for gradually drying:
stage one: the drying temperature is controlled at 60.degree. C.,
the drying air velocity is 1.5 m/s, and the drying time is 5 min;
stage two: the drying temperature is controlled at 75.degree. C.,
the drying air velocity is 2.0 m/s, and the drying time is 10 min;
stage three: the drying temperature is controlled at 60.degree. C.,
the drying air velocity is 2.0 m/s, and the drying time is 12 min.
The moisture content of the final dried clove fish is controlled
not more than 40%.
[0059] 5) Impurity removal by vacuum: Impurities mixing in the
dried clove fish are removed by vacuum at a relative vacuum degree
of -80 kPa.
[0060] 6) Cooling: the clove fish is put into a cooling cabinet at
-5.degree. C. for 3 min. The temperature of the clove fish
decreased rapidly to 0.about.10.degree. C. The dried clove fish
product is obtained.
[0061] 7) Screening: The dried clove fish product is screened
according to the shape size.
[0062] 8) Packaging and storage: the screened dried clove fish is
subjected to packaging according to its specifications and then to
storing at -18.degree. C.
[0063] The dried clove fish obtained according to the method
mentioned above displays natural colour, uniform texture, and
original flavor and taste.
Example 3
[0064] 1) 250 kg of acete chinensis with 2 cm length are cleaned by
seawater, and sorted. The temperature of seawater is controlled
within 0.about.10.degree. C.
[0065] 2) the acete chinensis is brought into cooking tank with a
bucket elevator. 2000 L of cooking soup containing a quality
improver is put into cooking tank. The cooking soup containing the
quality improver is composed of salt (50 kg), edible alcohol (6 kg,
produced by Jiangsu Donghai Shuntai Alcohol Co. Ltd.),
glucono-delta-lactone (5 kg), tea polyphenol (2 kg), perilla juice
(1 kg, produced by Zhejiang Shizi Bio-tech Co. Ltd.),
hexametaphosphate (5 kg), and water. The cooking soup in the tank
is heated to 98.degree. C. and maintained for 4 min. The cooking
soup is replaced with new one every 2 hours. The replaced cooking
soup (i.e., heat processing wastewater) should be treated to become
more suitable for environment.
[0066] 3) After leached on a stainless steel net, the cooked acete
chinensis is put onto a vibrating screen with vibrating frequency
of 750 r/min, to remove the water droplets on the acete
chinensis.
[0067] 4) the acete chinensis is put evenly onto conveyor belt to
go into a 7-layer hot-air drying cabinet for gradually drying:
stage one: the drying temperature is controlled at 60.degree. C.,
the drying air velocity is 2.5 m/s, and the drying time is 15 min;
stage two: the drying temperature is controlled at 70.degree. C.,
the drying air velocity is 2.0 m/s, and the drying time is 20 min;
stage three: the drying temperature is controlled at 60.degree. C.,
the drying air velocity is 1.5 m/s, and the drying time is 15 min.
The moisture content of the final dried acete chinensis is 22%.
[0068] In the present example, the steps 5) to 8) are the same to
Example 1.
[0069] The dried acete chinensis obtained according to the method
mentioned above displays natural colour, uniform texture, and
original flavor and taste.
Example 4
[0070] 1) 300 kg of clove fish with 2 cm length are cleaned by
seawater, and sorted. The temperature of seawater is controlled
between 0.degree. C. and 10.degree. C.
[0071] 2) 3000 L of cooking soup containing a quality improver are
put into a cooking tank. The cooking soup containing the quality
improver is composed of salt (9 kg), edible alcohol (15 kg,
produced by Jiangsu Donghai Shuntai Alcohol Co. Ltd.),
glucono-delta-lactone (6 kg), tea polyphenol (3 kg), perilla juice
(2.4 kg, produced by Zhejiang Shizi Bio-tech Co. Ltd.),
hexametaphosphate (3 kg), and water. 300 kg of clove fish with 2 cm
length are put into the cooking soup in the tank. The cooking soup
is heated to 95.degree. C. and maintained for 4.5 min. The cooking
soup is replaced with new one every 2 hours. The replaced cooking
soup (i.e., heat processing wastewater) should be treated to become
more suitable for environment.
[0072] 3) After leached on a stainless steel net, the cooked clove
fish is put onto a vibrating screen with vibrating frequency of 750
r/min, to remove the water droplets on the clove fish.
[0073] 4) The clove fish after dewatering is put evenly onto
conveyor belt to go into 7-layer hot-air drying cabinet, the drying
parameters are controlled as follows: stage one: the drying
temperature is controlled at 60.degree. C., the drying air velocity
is 1.2 m/s, and the drying time is 8 min; stage two: the drying
temperature is controlled at 70.degree. C., the drying air velocity
is 2.2 m/s, and the drying time is 15 min; stage three: the drying
temperature is controlled at 60.degree. C., the drying air velocity
is 2.0 m/s, and the drying time is 15 min.
[0074] In the present example, the steps 5) to 8) are the same to
Example 2.
[0075] The dried clove fish obtained according to the method
mentioned above displays natural colour, uniform texture, and
original flavor and taste.
Example 5
[0076] During the processing mentioned above, a huge number of
cooking wastewater is produced. The cooking wastewater contains
abundant nutrients and flavor compounds such as polypeptides, amino
acids, carbohydrates, and nucleic acids.
[0077] 1) Cooling and removal of suspended substances: An aliquot
of 2000 L of cooking wastewater from shrimp in Example 1 is cooled
down to 55.degree. C., and then filtrated by a cloth bag.
[0078] 2) Flocculationand precipitation: The pH of the filtrated
cooking wastewater is adjusted by citric acid or acetic acid to
5.5. Then 800 g of flocculant (i.e. diatomite, produced by Kunming
Shuixiao Sci-tech Co. Ltd.) are added. The waste is stirred for 8
min and standing for 10 min until the floccule appears.
[0079] 3) Centrifugation and separation: The precipitate is
obtained by centrifugation separation with a centrifuge (DBSDH5,
Yixing Haide Separation Machinery Co. Ltd.). The supernatant is
cooking wastewater after pre-treatment, with the salt content of
1.44 g/100 mL, the amino acid nitrogen content of 20.15 mg/100 mL,
and the soluble protein content of 1.46 mg/100 mL.
[0080] 4) Microfiltration separation: The ceramic membrane with
aperture of 0.22 .mu.m is used for microfiltration membrane. 1800 L
of the cooking wastewater after pre-treatment is subjected to
microfiltration with the running pressure and temperature of 0.2
MPa and 25.about.30.degree. C., respectively. The permeate solution
after microfiltration treatment flows into the ultrafiltration
device.
[0081] 5) Ultrafiltration separation: The ultrafiltration membrane
with aperture of 50000 Da is used, and the running pressure and
temperature of 0.6 MPa and 25.about.30.degree. C., respectively.
The permeate solution after ultrafiltration treatment flows into
the nanofiltration device.
[0082] 6) Nanofiltration separation: The nanofiltration membrane
device with aperture of 90 Da is used for nanofiltrate the permeate
solution after ultrafiltration treating, and the operation pressure
and temperature are 1.5 MPa and 25.about.30.degree. C.,
respectively. The permeate and retention solutions are obtained.
The retention solution has the salt content of 1.67 g/100 mL, the
amino acid nitrogen content of 152.4 mg/100 mL, and the soluble
protein content of 10.77 mg/100 mL. Compared with the cooking
wastewater after pre-treatment, the cooking wastewater is
concentrated by around 7 times. The treated permeate solution can
be reused for shrimp cooking, to achieve recycling usage
standard.
Example 6
[0083] 1) Cooling and removal of suspended substances: 2000 L of
cooking wastewater from clove fish in Example 2 are cooled down to
40.degree. C., and then filtrated by a cloth bag.
[0084] 2) Flocculation and precipitation: The pH of the filtrated
cooking wastewater is adjusted by citric acid to 4.8. Then 800 g of
flocculant (diatomite, produced by Kunming Shuixiao Sci-tech Co.
Ltd.) are added. The wastewater is stirred for 8 min and standing
for 10 min until floccule appears.
[0085] 3) Centrifugation and separation: The precipitate is
obtained by centrifugation separation with a centrifuge (DBSDH5,
Yixing Haide Separation Machinery Co. Ltd.). The supernatant is
cooking wastewater after pre-treatment, with the salt content of
3.22 g/100 mL, the amino acid nitrogen content of 32.71 mg/100 mL,
and the soluble protein content of 4.1 mg/100 mL.
[0086] 4) Microfiltration separation: The ceramic membrane with
aperture of 0.22 .mu.m is used for microfiltration separation. 1800
L of the cooking wastewater after pre-treatment are subjected to
microfiltration with the running pressure and temperature of 0.2
MPa and 25.about.30.degree. C., respectively. The permeate solution
after microfiltration treatment flows into the ultrafiltration
device.
[0087] 5) Ultrafiltration separation: The ultrafiltration membrane
with aperture of 50000 Da is used, and the running pressure and
temperature are 0.6 MPa and 25.about.30.degree. C., respectively.
The permeate solution after ultrafiltration treatment flows into
the electrodialysis device. The permeate solution after
ultrafiltration has the salt content of 3.50 g/100 mL, the amino
acid nitrogen content of 128.53 mg/100 mL, and the soluble protein
content of 16.5 mg/100 mL. Compared with the cooking wastewater
after pre-treatment, the cooking wastewater is concentrated by
around 4 times.
[0088] 6) The permeate solution after ultrafiltration is subjected
to electrodialysis treatment. The parameters for electrodialysis
treatment are as follows: temperature 20.degree. C., current 3 A,
flow rate 40 L/h. According to the prediction model for the
desalting ratio, the desalting ratio is 85.3%. In the practical
desalted solution after electrodialysis treatment, its salt content
is 0.49 g/100 mL, and the desalting ratio is 86%. The result
indicates the present invention of the prediction model for the
desalting ratio can accurately predict the desalting ratio.
[0089] The desalted solution flows into reverse osmosis device,
which adopts cellulose triacetate (CTA) membrane (produced by
Japanese Toyobo Co. Ltd.) with aperture of 5.about.10 nm, and the
running pressure and temperature of 2.5 MPa and 26.degree. C.,
respectively. The permeate and retention solutions are obtained.
The retention solution has the salt content of 2.83 g/100 mL, the
amino acid nitrogen content of 190.53 mg/100 mL, and the soluble
protein content of 13.2 mg/100 mL. Compared with the cooking
wastewater after pre-treatment, the cooking wastewater is
concentrated by around 6 times. The treated permeate solution can
be discharged directly and reused.
Example 7
[0090] 1) Cooling and removal of suspended substances: 2000 L of
cooking wastewater from clove fish in Example 4 are cooled down to
25.degree. C., and then filtrated by a cloth bag.
[0091] 2) Flocculation and precipitation: The pH of the filtrated
cooking wastewater is adjusted by acetic acid to 4.0. Then 800 g of
flocculant (diatomite, produced by Kunming Shuixiao Sci-tech Co.
Ltd.) are added. The wastewater is stirred for 8 min and standing
for 10 min until floccule appears.
[0092] 3) Centrifugation and separation: The precipitate is
obtained by centrifugation separation with a centrifuge (DBSDH5,
Yixing Haide Separation Machinery Co. Ltd.). The supernatant is
cooking wastewater after pre-treatment, with the salt content of
3.8 g/100 mL, the amino acid nitrogen content of 41.25 mg/100 mL,
and the soluble protein content of 3.4 mg/100 mL.
[0093] 4) Microfiltration separation: The ceramic membrane with
aperture of 0.22 .mu.m is used for microfiltration. 1800 L of the
cooking wastewater after pre-treatment are subjected to
microfiltration with the running pressure and temperature of 0.2
MPa and 25.about.30.degree. C., respectively. The permeate solution
after microfiltration treatment flows into the ultrafiltration
device.
[0094] 5) Ultrafiltration separation: The ultrafiltration membrane
with aperture of 50000 Da is used, and the running pressure and
temperature are 0.6 MPa and 25.about.30.degree. C., respectively.
The permeate solution after ultrafiltration has the salt content of
3.8 g/100 mL, the amino acid nitrogen content of 40.6 mg/100 mL,
and the soluble protein content of 3.1 mg/100 mL.
[0095] 6) The permeate solution after ultrafiltration is subjected
to a combined technology of electrodialysis and reverse osmosis
treatment. The permeate solution after ultrafiltration treatment
flows into the electrodialysis device. The parameters for
electrodialysis treatment are as follows: temperature 20.degree.
C., current 3 A, flow rate 300 L/h. According to the prediction
model for the desalting ratio, the desalting ratio is 86.2%. In
practical desalted solution after electrodialysis treatment, its
salt content is 0.54 g/100 mL, and the desalting ratio is
85.7%.
[0096] The desalted solution flows into a reverse osmosis device,
which adopts cellulose triacetate (CTA) membrane (produced by
Japanese Toyobo Co. Ltd.) with aperture of 5.about.10 nm, and the
running pressure and temperature of 2.5 MPa and 20.degree. C.,
respectively. The permeate and retention solutions are obtained.
The retention solution has the salt content of 3.6 g/100 mL, the
amino acid nitrogen content of 276.8 mg/100 mL, and the soluble
protein content of 21.56 mg/100 mL. Compared with the cooking
wastewater after pre-treatment, the cooking wastewater is
concentrated by around 6.6 times. The treated permeate solution can
be discharged directly.
* * * * *