AU2021103971A4

AU2021103971A4 - Preparation method of instant fish noodles dried by vacuum microwave

Info

Publication number: AU2021103971A4
Application number: AU2021103971A
Authority: AU
Inventors: Yaqin Hu
Original assignee: Hainan Tropical Ocean University
Current assignee: Hainan Tropical Ocean University
Priority date: 2021-07-08
Filing date: 2021-07-08
Publication date: 2021-09-09
Anticipated expiration: 2029-07-08

Abstract

The invention discloses a preparation method of instant fish noodles dried by vacuum microwave, which comprises the following steps: 1) selecting materials. 2) Grinding 3) Grinding at low temperature: Adding NaCI and ice water into the minced fish obtained in step 2, Grinding at 0-100C, and then adding monosodium and starch to continue grinding at 0-100C to obtain colloidal minced fish. 4) Making colloidal minced fish into thin strips with the thickness of 1.2-1.8mm to obtain thin strips of minced fish, 5) Curing, 6) Sectioning, 7) Vacuum microwave drying, 8) The fish noodles obtained by vacuum microwave drying are vacuum packed at normal temperature or packed with nitrogen to obtain instant fish noodles. The fish noodles prepared by the method not only have low energy consumption, but also can improve the drying quality of the fish noodles.

Description

Preparation method of instant fish noodles dried by vacuum microwave

TECHNICAL FIELD The invention belongs to the field of rapid food drying, and particularly relates to preparation method of instant fish noodles dried by vacuum microwave.

BACKGROUND Microwave refers to electromagnetic wave with frequency ranging from 300 MHz to 300 GHz and wavelength ranging from 1 mm to 1 m. Microwave has many characteristics of electromagnetic wave, such as reflection, transmission, interference, diffraction, polarization, and energy transmission along with electromagnetic wave. In 1945, American researchers first discovered the thermal effect of microwave on dielectric. After that, the food industry began to do a lot of experimental research on microwave heating. Since microwave is widely used in industrial, military, medical and scientific research fields, in order to avoid mutual interference, it is stipulated that 915±25MHz and 2450±50MHz can be used in industrial fields, and the wavelengths of these two frequencies are 0.328m and 0.122m respectively. At present, microwave sterilization and drying technology has been widely used in food industry. The thermal and non-thermal effects of microwaves, especially the electromagnetic waves used by microwaves, have a strong killing effect on microorganisms in food, and can achieve sterilization effect while heating by microwaves. Compared with thermal sterilization, microwave sterilization has the characteristics of short heating time, fast heating speed, uniform sterilization, less damage and loss of food nutrients and flavor substances, etc. Compared with chemical sterilization, microwave sterilization has no chemical residue. Compared with radiation sterilization, there is no pollution and residue of radioactive substances. Conventional thermal sterilization is to transfer heat from the surface of food into the interior through heat conduction, convection, radiation, etc., which often takes a long time for the interior of food to reach the sterilization temperature, while microwave uses its transmission effect to work together with thermal effect and non-thermal effect, so that the inside and outside of food can be heated evenly and quickly to kill bacteria, thus greatly shortening the treatment; Under high power intensity, the sterilization effect can be achieved even in a few seconds to tens of seconds. The unique processing method of microwave can retain more nutrients and keep the original color, fragrance, taste and shape. If conventional thermal treatment is adopted, the vitamin C retained by vegetables is 46% ~ 50%; However, the retention of vitamin C by microwave treatment can reach 60%- 90%; The vitamin A of pig liver heated by conventional method is kept at 58%, while that heated by microwave is kept at 84%. Conventional thermal sterilization starts from the surface of the material, and gradually heats from the surface to the inside through heat conduction. There is a temperature difference gradient between the inside and outside, resulting in inconsistent sterilization effects between the inside and outside, and the thicker the material, the more prominent the problem; In order to keep the flavor of food and shorten the processing time, it is necessary to increase the processing temperature, but this will reduce the quality of food surface such as color, aroma, taste and shape. The penetrability of microwave makes the surface and interior heated at the same time, ensuring uniform sterilization inside and outside; Food ingredients have selective absorption to microwave, and some ingredients in materials can absorb microwave very easily, while others are not easy to absorb microwave, which is beneficial to the control of product quality. For example, when the grain is dried by microwave, the absorption rate of the main components of the grain, such as starch and protein, is relatively small, so the temperature of the grain itself rises slowly. However, pests and microorganisms in grain generally contain more water, have larger medium loss factor, and easily absorb microwave energy, which can kill pests and microorganisms due to the rapid rise of internal temperature, thus achieving the effects of sterilization and insect killing and maintaining grain characteristics. Microwave directly heats food materials, without heat radiation and other heat energy loss, and only consumes a small amount of energy in the power supply part and electronic tube, and the microwave heater itself will not be heated, so there is no extra heat power consumption, which can save energy by 30% ~ 50%. Microwave is easy to control instantaneously and easy to operate. Power on can heat and raise the temperature immediately, and power off can stop heating, which is easy to control. In addition, the microwave sterilization process is simple and easy to operate, and the equipment can be made into tunnel type and the production process can be automated, thus reducing the labor intensity and being beneficial to standardized production. Microwave vacuum drying is a combination of microwave and vacuum technology. When the pressure is low, the partial pressure of water vapor in the gas phase can be reduced, and the boiling point temperature of the material can be lowered, so that the material can be dehydrated at a low temperature, and the moisture diffusion rate can be accelerated. Microwave provides a heat source for vacuum drying and directly heats the material, which can overcome the disadvantage of slow heat conduction rate of conventional convection mode in vacuum state. It not only reduces the drying temperature, but also accelerates the drying speed, so it can better retain the original color, flavor and other effective components of the dried material. At present, domestic fish noodles, such as traditional "Yunmeng fish noodles", are mainly made of flour with 5-50% fish meat or minced fish added, and the processing technology is similar to that of ordinary noodles. That is, kneading dough, adding fish meat, kneading dough (proofing), calendering, and slicing. After the noodles are made, they need to be sold fresh or in frozen storage. The noodles can be sold as dried fish noodles after being dried by hot air. The dried fish noodles can only be eaten after being cooked, and the dried fish noodles have short shelf life and need to be refrigerated before being stored. At present, there is a disclosed preparation method of instant fish noodles, which is made of 100 parts of fish meat, 20-100 parts of edible powder and 30-80 parts of meat, cooked and dried. The proportion of edible powder is high, and it also contains meat, so people with hyperglycemia, hyperlipemia and hypertension may have some psychological conflicts. There is no report on instant fish noodles which can be eaten in open bags, brewed in hot water and boiled with minced fish as the main raw material (minced fish accounts for more than 80%).

SUMMARY This invention provides a preparation method of instant fish noodles dried by vacuum microwave, which has low energy consumption and can improve the drying quality of fish noodles In order to solve the technical problems described above, this invention provides a preparation method of instant fish noodles dried by vacuum microwave that comprises the following steps: 1) Selecting material: Choose any of the following: A, Selecting fresh minced fish with white color and good elasticity, and directly performing air beating in step 2; B, Selecting frozen minced fish with white color and good elasticity, thawing, and performing air beating in step 2 2) Solely Grinding Grinding the minced fish obtained in step 1 for 5-15min 3) Low temperature grinding: Adding NaCI that accounts for 2,0-3.5% and ice water that accounts for 10-30% of the weight of the minced fish into the processed minced fish in the previous step, grinding it at 0-10 0 C for 20 ~ 30 min, then adding monosodium that accounts for 2-2.5% and Starch that accounts for 2.5-15% of the weight of the minced fish for continuously grinding for 10-15min at 0-10°C to obtain colloidal minced fish. 4) Making colloidal minced fish into thin strips with the thickness of 1.2-1.8mm to obtain thin strips of minced fish 5) Curing: Heating the thin strip-shaped minced fish in a steam box at the temperature of 120-150 0C for 20-30 seconds to obtain cured thin strip-shaped minced fish 6) Sectioning: Naturally cooling that cured thin strip-shaped surimi to 35-400 C, and then cutting it into fish noodles with a width of 0.8-1.2mm; 7) Vacuum microwave drying: Placing 50-150 g of fish noodles in microwave oven under microwave power of 900-1300 W and vacuum degree of -70-9kPa. Performing vacuum microwave drying for 20-40min;

8) Packaging: The fish noodles obtained by vacuum microwave drying are vacuum packed at normal temperature or packed with nitrogen. As improvement of preparation method of instant fish noodles dried by vacuum microwave, the width of the fish noodles obtained in step 4 is 110cm-130cm. As improvement of preparation method of instant fish noodles dried by vacuum microwave, the length of the fish noodles obtained in step 6 is 15-30cm. As improvement of preparation method of instant fish noodles dried by vacuum microwave, the rotating speed of the turntable in the step 7 is 25-35r/min. As improvement of preparation method of instant fish noodles dried by vacuum microwave, the step 7 is executed as following: Putting 100g of fish noodles on a turntable to be vacuum microwave dried at a microwave power of 900w and a vacuum degree of -80kPa, the time of vacuum microwave drying is 30min, and the rotating speed of the turntable is 30r/min. In the preparation method of instant fish noodles of the present invention: The minced fish is prepared by conventional process, meaning minced fish (fresh minced fish) used immediately after the fish is rinsed to remove some pigments, fats and soluble substances which easily lead to the deterioration of the quality of minced fish, or minced fish (frozen minced fish) preserved by freezing. The significance of low-temperature grinding in step 3 is to destroy the fish tissue structure, so that the salt-soluble protein can be fully dissolved under the condition of adding salt, and creating suitable conditions for the formation of network structure. Because the solubility of myogenic fibrous protein is closely related to the type, concentration and pH of salt. Therefore, 2.5-3.5% (by weight) NaCI was added to minced fish for low-temperature beating. In this way, the minced fish obtained after crushing at low temperature can meet the requirements in terms of food feeling and elasticity. The whole crushing time at low temperature takes 30-45 min. In step 4, coating process can be adopted to obtain thin strip-shaped minced fish. Specifically, the colloidal minced fish obtained in the low-temperature grinding step is coated by a coating machine to obtain thin strip-shaped minced fish with a thickness of 1.2-1.8mm.

In step 5, the minced fish can be coagulated and further gelatinized by heating in a steam box, thus forming an elastic minced fish product. The sectioning of step 6 can be carried out in a roller with stripes (thread comb). The prepared fish noodles must be immediately dried by vacuum microwave in the following steps: Or frozen and stored at -80 - -18 0C for later use. The purpose of controlling the vacuum degree in step 7 is to prevent arcing discharge, so as to avoid damaging the magnetron in the vacuum microwave equipment and other electronic components in the drying chamber. Because the fish content in the invention is as high as 80% or more, the starch content is below 15%, and no flour is added. However, the extensibility of fish protein fiber is very low, and noodles can not be produced by the disclosed preparation method of instant fish noodles. Only by adopting the method of the present invention can the fish noodles be successfully made, and after being dried by microwave, the fish noodles can become real fish noodles. The instant fish noodles prepared by the method of the invention can be stored at room temperature or low temperature, and the shelf life can reach 6 months at normal temperature (15-300 C), 12 months at low temperature (4-10°C) and 18-24 months at frozen storage (-18- -800 C). The preparation method of instant fish noodles in the invention has the following advantages. 1) The fish noodles prepared by the method of the present invention are mainly minced fish, i.e., rinsed fish meat, which is recognized as a high-protein and low-fat product and is suitable for a wide range of people. Fish is rich in a variety of bio-active substances, especially highly unsaturated fatty acids such as DHA and EPA, which are beneficial to intelligence and brain, and it is convenient to eat without fish bone. 2) Using vacuum microwave technology, the instant fish noodle with minced fish as main material which can be preserved at normal temperature is prepared. Like instant noodles, it can be eaten in bags, brewed in hot water and boiled in water, or added with appropriate amount of vegetables to make fish noodle soup, which can be used as high quality animal protein food. 3) The drying efficiency of fish noodles is effectively improved, and the drying quality of fish noodles is improved. Traditional fish noodles are mainly made of noodles and supplemented with fish meat, so they are dried by hot air and the temperature is higher. However, the fish noodles of the present invention are mainly fish meat (minced fish), and the protein of the fish meat is highly unstable, and high-temperature drying can easily lead to browning of the fish noodles and affect the color of the products. Therefore, the invention adopts microwave vacuum drying, which not only shortens the drying time, but also improves the drying efficiency, and at the same time greatly improves the drying quality of fish noodles, and has little influence on color and luster. 4) The shelf life of products is greatly prolonged due to the sterilization effect of microwave and low water content of products. Microwave has sterilization effect, and the product does not need strong secondary sterilization. The obtained product has low water content and low water activity, which is beneficial to the storage and transportation of the product. 5) The process parameters are easy to control, the production is environment friendly, and the real continuous, automatic and clean production can be realized. The key parameters of vacuum micro-wave technology, such as vacuum degree, microwave power, drying time, etc., are easy to control, have no pollution and can be produced continuously. 6) Fish noodles are white or slightly yellowish in color, with good rehydration and low moisture content. According to the protein content determination method (Kjeldahl nitrogen determination) specified by the national standard, the protein content is higher than that of commercially available fish noodles. To sum up, the invention uses minced fish as the main material, and the shelf life of the obtained instant fish noodles is greatly prolonged compared with that of fresh fish noodles sold in the market. The obtained instant fish noodles can be eaten in bags like instant noodles, or treated with hot water and boiled water. It does not undergo high temperature oil frying, and will not cause the harm caused by high-temperature frying of ordinary instant noodles. Fish is rich in nutrition and belongs to the internationally recognized typical white meat, which is a kind of food with high protein and low fat. Not only is the content of protein high, but more importantly, the amino acid composition of fish protein is relatively balanced, which is rich in amino acids lacking in staple foods such as lysine, methionine and cystine, and is matched with cereals to achieve the best amino acid composition; Compared with vegetable proteins such as bean products, fish protein has good homology with human beings and is easy to digest and absorb. The invention is an animal protein food for both young and old age consumers.

DESCRIPTION OF THE INVENTION Embodiment 1 1) Selecting material: Selecting frozen minced fish with white color and good elasticity as raw materials; The frozen minced fish is cut into granules with a grain size of 2cm, and the granular frozen minced fish is thawed at 50 C for 2 hours 2) Grinding solely Grinding solely the minced fish obtained in step 1 for 10min 3) Low temperature grinding Adding 2.5% NaCI and 20% ice water to the minced fish obtained in step 2, grinding at 0-10°C for 30min, then adding 2% monosodium and 10% starch to the minced fish for further grinding at 0-100 C for 15 min, to obtain colloidal minced fish 4) Coating The colloidal minced fish obtained after crushing is sent into a filling and coating machine, so that the colloidal minced fish is made into thin strip-shaped minced fish with a thickness of 1.5mm and a width of 120 mm. 5) Curing Heating thin strip minced fish in a steam box at 90 0C for 30s, and then heating in a steam box at 1400 C for 1Os, obtaining cured thin strip-shaped minced fish; 6) Sectioning After curing, the thin strip-shaped minced fish starts to cool naturally by running on the conveyor belt, generally, the cooling time is 2 - 3 min, and the temperature after cooling is 35 ~ 40 0C. At this time, the cured thin strip-shaped minced fish after cooling treatment can be sent to a striped roller (spiral comb knife), cutting into fish noodles with a width of about 1mm, and cut off in a length of 15cm. The prepared fish noodles must be immediately dried by vacuum microwave in the following steps: Or frozen at-80 18 0C for later use.

7) Vacuum microwave drying 100g of fish noodles are placed on a turntable to be vacuum microwave dried at a microwave power of 900w and a vacuum degree of -80kPa, and the vacuum microwave drying time is 30min; Rotating speed of turntable is 30r/min. About 35g of dried fish noodles can be obtained. After detection, the water content of the dried fish noodles is 5.79%, and the protein content is 16.8%. Heinz whiteness value is 80.84; The rehydration ratio of dried fish noodles after absorbing water is 4.2 times. 8) Packaging The fish noodles obtained by vacuum microwave drying are packaged in general sealing, vacuum packaging or nitrogen filling packaging. The quality retention period can reach 6 months at normal temperature, 12 months at low temperature and 24 months in frozen storage Embodiment 2 Preparation method of instant fish noodles dried by vacuum microwave, the curing of step 5) is changed into the following contents: The thin strip minced fish is heated in a steam box at 950 C for 25 seconds, and then heated in a steam box at 1500 C for 5 seconds; Obtain cured thin strip-shaped surimi. The rest is the same as Embodiment 1. By detection, the water content of the dried fish noodles is 5.86%, and the protein content is 16.5%. Heinz whiteness value is 80.24; The rehydration ratio of dried fish noodles after absorbing water is 4.1 times. The shelf life can reach 6 months at normal temperature, 12 months at low temperature and 24 months in frozen storage. Embodiment 3 Preparation method of instant fish noodles dried by vacuum microwave, the curing of step 5 is changed into the following contents: The thin strip-shaped minced fish was heated in a steam box at 1400 C for 25s to obtain the cooked thin strip-shaped minced fish. The rest is the same as Embodiment 1. After detection, the water content of the dried fish noodles is 6.2%, and the protein content is 17.6%. Heinz whiteness value is 80.49.

The rehydration ratio of dried fish noodles after absorbing water is 4.0 times. The shelf life can reach 6 months at normal temperature, 12 months at low temperature and 24 months in frozen storage. Embodiment 4 Preparation method of instant fish noodles dried by vacuum microwave, Selecting fresh minced fish in step 1), and directly performing grinding in step 2); The rest is the same as Embodiment 1. By detection, the water content of the dried fish noodles is 6.5%, and the protein content is 16.9%. Heinz whiteness value is 80.28. The rehydration ratio of dried fish noodles after absorbing water is 3.9 times. The shelf life can reach 6 months at normal temperature, 12 months at low temperature, and 24 months in frozen storage. Finally, it should be noted that the above list is only a few specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and many variations are possible. All the variations that can be directly derived or associated with the disclosure of the present invention by those of ordinary skill in the art should be regarded as the protection scope of the present invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: Preparation method of instant fish noodles dried by vacuum microwave is characterized in 1) Selecting material: Choose any of the following: A, Selecting fresh minced fish with white color and good elasticity, and directly performing air beating in step 2; B, Selecting frozen minced fish with white color and good elasticity, thawing, and performing air beating in step 2 2) Solely Grinding Grinding the minced fish obtained in step 1 for 5-15min 3) Low temperature grinding: Adding NaCI that accounts for 2,0-3.5% and ice water that accounts for 10-30% of the weight of the minced fish into the processed minced fish in the previous step, grinding it at 0-100 C for 20 ~ 30 min, then adding monosodium that accounts for 2-2.5% and Starch that accounts for 2.5-15% of the weight of the minced fish for continuously grinding for 10-15min at 0-10°C to obtain colloidal minced fish. 4) Making colloidal minced fish into thin strips with the thickness of 1.2-1.8mm to obtain thin strips of minced fish 5) Curing: Heating the thin strip-shaped minced fish in a steam box at the temperature of 120-150 0C for 20-30 seconds to obtain cured thin strip-shaped minced fish 6) Sectioning: Naturally cooling that cured thin strip-shaped surimi to 35-400 C, and then cutting it into fish noodles with a width of 0.8-1.2mm; 7) Vacuum microwave drying: Placing 50-150 g of fish noodles in microwave oven under microwave power of 900-1300 W and vacuum degree of -70-9kPa. Performing vacuum microwave drying for 20-40min; 8) Packaging: The fish noodles obtained by vacuum microwave drying are vacuum packed at normal temperature or packed with nitrogen.
2. According to claim 1, Preparation method of instant fish noodles dried by vacuum microwave is characterized in that the width of the fish noodles obtained in step 4 is 11Ocm-130cm.
3. According to claim 2, Preparation method of instant fish noodles dried by vacuum microwave is characterized in that the length of the fish noodles obtained in step 6 is 15 cm.
4. According to claim 3, Preparation method of instant fish noodles dried by vacuum microwave is characterized in that the rotating speed of the turntable in the step 7 is 25 r/min.
5. According to claim 4, Preparation method of instant fish noodles dried by vacuum microwave is characterized in that putting 100g of fish noodles on a turntable to be vacuum microwave dried at a microwave power of 900w and a vacuum degree of kPa, the time of vacuum microwave drying is 30min, and the rotating speed of the turntable is 30r/min.