Anchovy snack with high DHA (docosahexaenoic acid) retention and preparation method of anchovy snack

Abstract

The invention provides a high DHA (docosahexaenoic acid) reserved anchovy snack and a preparation method thereof, fresh anchovies are treated in a mode of frying in air and then marinating, and then mixing materials and red oil are added to further enrich the flavor of the anchovy snack. By optimizing the conditions of immobilization time, air frying time, marinating time and the like, the fish larvae with higher DHA content are prepared. The anchovy snack produced by the invention takes the fresh anchovy as a raw material, and compared with dried fish, the anchovy snack is moderate in hardness and good in palatability, and can meet the taste requirements of consumers on taking the anchovy as snacks.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic product processing, and particularly relates to a fry anchovy snack with high DHA retention and a preparation method thereof. Background Art

[0002] DHA is an unsaturated fatty acid that is very important to the human body. It is essential in forming human tissues and maintaining normal physiological functions. It is mainly present in the position of cell membrane phospholipid sn-2 and is an integral part of the cell membrane structure. DHA plays an important role in neuroprotection, promoting the formation and development of the retina, lowering blood pressure and lowering blood lipids. At present, the international standard recommends a daily DHA intake of 250 mg per person, but in 2019, the average intake of Chinese people was less than 30 mg per day. From a global perspective, the intake of inland continental countries is generally lower than that of coastal developed countries, so DHA snack products have a potential market.

[0003] DHA is mainly found in various fish oils, especially in the fat of deep-sea fish. Anchovies are a species of fish in the order Herringiformes, and are one of the world's most productive fish species. Anchovies are widely distributed, mainly in Peru, Argentina, the Atlantic Ocean, the North Pacific Ocean and the coast of China. They are one of the most abundant fish species in the world, and their annual production has reached more than 20% of the total production of marine fish. They have played an important role in the development of the world's fishery economy and are currently one of the top ten marine fish species in terms of annual catch. Anchovies are high in protein, fat, and DHA, and also contain vitamin D and minerals such as phosphorus and iron. Therefore, anchovies have the edible functions and health value of strengthening bones and muscles, promoting brain development, enhancing liver function and preventing anemia.

[0004] At present, most anchovy snacks are made from boiled and dried anchovies in salt and then fried. They not only taste woody and stale, but also have a high loss of nutrients. Therefore, how to use anchovies as raw materials and fully retain the DHA content in anchovies has become a research hotspot in the field of anchovy processing. Summary of the invention

[0005] The invention provides an anchovy snack with high DHA retention and a preparation method thereof. The prepared anchovy snack is rich in DHA, thereby making up for the defects of existing anchovy processing.

[0006] The preparation method of the anchovy snack provided by the present invention comprises the following steps:

[0007] 1) Soaking the frozen anchovies in salt water and thawing them with the assistance of ultrasound;

[0008] The ultrasound is performed for 60-90 seconds every 30 minutes, with an ultrasound power of 60-72W and a temperature maintained at 0-4°C;

[0009] 2) After cleaning the thawed anchovies, the fish bodies are subjected to an electric hot air drying and fixation treatment in an electric hot air drying oven;

[0010] The gas surface velocity of the electric blast drying is 0.8-1m / s, the fixed temperature is set at 55-65°C, and the time is 45-50min.

[0011] 3) Preheat the air fryer to 190-210° C., put the immobilized anchovies in, and apply edible blended oil containing 50-59% linoleic acid, and set the temperature to 190-210° C. for air frying;

[0012] The hot gas flow rate is 2.5-4.0m / s, the time is 12-13min, and the heat transfer medium is purified air or nitrogen;

[0013] 4) Add the air-fried anchovies to the marinade and heat to boiling; when the temperature reaches the boiling point of 100°C, immediately adjust the power to 500W constant temperature mode and maintain the marinade at a slightly boiling state of 85-90°C for marinating;

[0014] 5) Stir the marinated anchovies with the chili sauce for 10-15 minutes;

[0015] 6) Add the cooked red oil to the mixed anchovies, vacuum pack them, and sterilize them to complete the preparation.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The anchovy snack produced by the present invention uses fresh anchovies as raw materials. Compared with dried fish, it has moderate hardness and softness, good palatability, and can meet the taste requirements of consumers for taking it as a snack.

[0018] (2) The present invention uses air frying to process anchovies, and only a small amount of oil or even no oil is needed during the processing to provide a relatively crispy fried food.

[0019] (3) The fish snack produced by air frying using purified air or nitrogen as a medium has a DHA content greater than 220 mg / 100 g and has broad economic value.

[0020] (4) The present invention enriches the types of existing anchovy snack products and provides a new type of anchovy snack that is easy to produce and has high DHA retention, and a preparation method thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 These are sensory evaluation charts under different fixation times, air frying times, and marinating times.

[0022] Figure 2This is the texture map of the finished fish fry after air frying and the electronic tongue analysis radar map of the finished fish during the processing.

[0023] Figure 3 Cluster heat map of the different flavor compounds in finished fish during processing.

[0024] Figure 4 It is the odor fingerprint of the finished fish during the processing. DETAILED DESCRIPTION

[0025] The present invention uses a method of first air frying and then braising to process fresh anchovies, and then adds seasoning and red oil to further enrich the flavor of anchovy snacks. By optimizing the conditions such as the immobilization time, air frying time, and braising time, anchovies with a higher DHA content are prepared compared to the traditional frying method, and the finished fish and its preparation process are evaluated.

[0026] The present invention is described in detail below in conjunction with specific embodiments and drawings.

[0027] Embodiment 1:

[0028] Design of a single factor experiment:

[0029] 1) The frozen anchovies are soaked in dilute salt water and thawed with ultrasound assistance, with ultrasound applied for 60-90 seconds every 30 minutes, an ultrasound power of 60-72W, and a temperature maintained at 0-4°C. Incomplete fish and debris are removed from the thawed anchovies, and the anchovies are washed three times in water, and then the heads and internal organs of the anchovies are removed. The pretreated anchovies are placed on a stainless steel tray, and the tray is placed in an electric hot air drying oven to fix the fish, with a gas surface velocity of 0.8-1m / s to ensure uniform tiling, and the fixation temperature is set at 55-65°C for 20, 40, 60, 80, and 100 minutes.

[0030] 2) Place tin foil in an air fryer, preheat to 190-210° C., put the pre-treated anchovies in a matrix single layer arrangement (spacing ≥ 5 mm), coat with edible blended oil containing 50-59% linoleic acid (0.1-0.2 ml / piece), set the temperature to 190-210° C. for air frying, the hot gas flow rate to 2.5-4.0 m / s, the time to 14 min, and the heat transfer medium to purified air or nitrogen.

[0031] 3) Pour 9kg of pure water into the stainless steel brine bucket, and add the pre-proportioned compound brine bag (30g of pepper, 50g of star anise, 5g of costus root, 10g of roukou, 10g of cinnamon, 15g of tsaoko, 6g of sannai, 6g of amomum, 8g of bay leaf, 8g of fragrant sand, 10g of pepper, 20g of fennel, 15g of ginger, 3g of cloves, 10g of ginger slices), making sure that the bag is completely immersed. Enable 2000W power to heat quickly to boiling (takes 20-25 minutes), and use a colander to continuously skim off the foam during this period. When the temperature reaches the boiling point of 100℃, immediately adjust the power to 500W constant temperature mode, maintain the brine at a slightly boiling state of 85-90℃, and marinate for 90 minutes.

[0032] 4) Soak the air-fried anchovies in brine, add 0.4%-0.8% salt, 0.8%-1.2% sugar, 0.4%-0.8% MSG and other ingredients, and stew them in a ratio of 1:10 between fish and brine. In the 500W constant temperature mode, maintain the brine at a slightly boiling state of 85-90℃, and stew for 70 minutes before removing. Stir the stewed anchovies and chili sauce in a rotary drum in a ratio of 6:1 for 10-15 minutes. In the initial stage (0-5min): low-speed mixing (15rpm); in the middle stage (6-10min): medium-speed penetration (20rpm).

[0033] 5) Add the cooked red oil to the mixed anchovies at a ratio of 5:1 and vacuum pack, sterilize at 117° C. for 20 min, and cool rapidly in cold water after sterilization.

[0034] Sensory evaluation was used as the evaluation index to screen subsequent response surface conditions.

[0035] Combined with the sensory evaluation chart, it was found that the fish dried for 60 minutes scored higher in appearance, flavor, color, taste and overall acceptance. The meat was palatable, moderately hard and soft, elastic and salty, with a strong unique aroma of fried anchovies and no peculiar smell. Based on the taste and flavor, the fixed time of 40, 60 and 80 minutes was selected for subsequent response surface experiments.

[0036] Embodiment 2:

[0037] A single factor experiment was designed, and the specific steps were the same as in Example 1, except that the immobilization time was 60 min, and the single factor condition was air frying time of 12, 13, 14, 15, and 16 min. The sensory evaluation was used as the evaluation index to screen the subsequent response surface conditions.

[0038] Combined with the sensory evaluation chart, compared with other groups, the fish fried for 13 minutes in air performed best in flavor and taste, with a moderate taste and a strong unique aroma of fried anchovies. Based on the taste and flavor, air frying times of 12, 13, and 14 minutes were selected for subsequent response surface experiments.

[0039] Embodiment 3:

[0040] A single factor experiment was designed, and the specific steps were the same as in Example 1, except that the immobilization time was 60 min, and the single factor conditions were the marinating time of 30, 50, 70, 90, and 110 min. The sensory evaluation was used as the evaluation index to screen the subsequent response surface conditions.

[0041] From the sensory evaluation chart, it can be found that the flavor, appearance, and color of the 70-min marinating group are better than those of the other groups, but the taste score is not high. Based on the taste and flavor, the marinating time of 50, 70, and 90 minutes was selected for subsequent response surface experiments.

[0042] Embodiment 4:

[0043] In this example, the processing conditions of fry were optimized. Based on the previous single-factor experiment, the immobilization time (A), air frying time (B), and marinating time (C) were selected. The sensory evaluation was used as the response value, and the Box-Behnken central composite design experimental model was used to fit the quadratic polynomial equation to obtain the optimal preparation method. The results of the response surface test with 3 factors and 3 levels are shown in Table 1.

[0044] Table 1: Box-Behnken central composite design experimental model

[0045]

[0046]

[0047] By fitting the Box-Behnken central composite design test model data using Design-Expert 12 software, the quadratic polynomial regression equation can be obtained:

[0048] Y=-0.1912A-0.3412B+0.1225C-0.67AB+0.0125AC+0.1325BC-0.753A 2 -0.478B 2 -0.5205C 2 +8.17.

[0049] Table 2: ANOVA table of regression model

[0050]

[0051]

[0052] From the variance analysis in Table 2, we can see that the F value of the regression model is 13.13, and the P value is 0.0013 (P < 0.01), indicating that the regression model is significant; the F value of the lack of fit term is 4.62, and the P value is 0.0868 (P > 0.05), indicating that the lack of fit term is not significant. The above results show that the model is accurate in simulating the real situation, and also show that this prediction model can be used to optimize the preparation process of air fried fish. In addition, the regression coefficient R 2 =0.9441, indicating that the model can explain 94.41% of the response value changes, and the fitting degree is good. In summary, it can be predicted by this model to obtain the optimal process for preparing air-fried fish.

[0053] The parameters were optimized and analyzed through Design-Expert 12 software. Combined with production practice, the fixed temperature was set at 55-65℃ and the time was 45-50min. The air frying temperature was set at 190-210℃ and the time was 12-13min. For the marinating conditions, the marinade was maintained at 85-90℃ and slightly boiling for 70min. After mixing and sterilization, the best process for anchovy snacks was obtained with a comprehensive sensory evaluation score of 8.134, with a moderate hardness and a salty, spicy taste.

[0054] Embodiment 5:

[0055] The prepared anchovy snacks are tested, including the following testing indicators and methods.

[0056] (1) Nutrient component determination: Routine nutrient component testing includes moisture, crude protein, crude fat and ash, and is determined using the methods specified in the national food safety standards.

[0057] (2) Determination of DHA content: The fat sample obtained by the chloroform-methanol extraction method was methyl esterified on a metal bath, and the DHA content was determined by gas phase.

[0058] (3) TPA determination: The hardness of the fish fry was measured by TMS-Touch texture analyzer using a cylindrical probe with a deformation of 30% and a downward speed of 60 mm / min.

[0059] (4) Electronic tongue analysis: The sample was homogenized with distilled water at a ratio of 1:5 (w / v) and centrifuged. The supernatant was collected and filtered through a membrane. The supernatant was then poured into a small beaker for electronic tongue analysis.

[0060] (5) Gas chromatography-mass spectrometry (GC-MS) analysis of volatile flavor compounds: Accurately weigh 3.0 g of the homogenized sample and transfer it to a headspace bottle, add 2,4,6-trimethylpyridine solution. Heat the headspace bottle in a 65°C metal bath and adsorb the headspace at 65°C for 45 minutes. Then desorb at 250°C for 5 minutes.

[0061] (6) Gas chromatography-ion mobility spectrometry (GC-IMS) analysis of volatile flavor compounds: 3.0 g of sample was accurately weighed into a 20 mL headspace vial and sealed with a cap. After incubation at 60°C for 10 min, a syringe (65°C) automatically drew 500 μL of headspace sample and injected it into the heated syringe of the GC-IMS unit.

[0062] By testing the prepared anchovy snacks, it was found that the obtained instant fish snacks are rich in protein, and the DHA content of the existing anchovy snacks is increased by 47.68%, with high nutritional value; the texture was measured to have a hardness of 5.49±0.75N and a chewiness of 4.77±0.66mj, with moderate hardness and a tender and elastic taste.

[0063] from Figure 2 It can be seen that umami is the main taste characteristic of the sample, and the intensity of astringency and bitterness is low and can be basically ignored.

[0064] The preparation method of the present invention enables anchovies to produce a variety of pleasant volatile flavor substances such as 2-ethylfuran and diacetyl, and have a variety of aromas such as caramel aroma and cream aroma. Through the entire process, anchovies produce volatile flavor substances such as β-pinene, 3-carene, citronellal, linalyl butyrate, 2,3,5-trimethylpyrazine, and have a variety of aromas such as pine aroma, citrus aroma, fruit aroma, cocoa aroma, and nut aroma.

[0065] Table 3: Basic nutritional composition analysis

[0066]

[0067] In summary, the method provided by the present invention uses purified air or nitrogen as a medium for air frying, and the DHA content of the anchovy snack obtained after braising, mixing, and sterilization is 324.89±8.83mg / 100g, which is significantly higher than the DHA content of existing anchovy snack products, wherein the protein and fat contents are 22.45±2.17% and 24.60±1.72% respectively, and the nutritional value is high. Texture property research shows that the fish snack prepared by the present invention has strong elasticity and chewiness, moderate hardness, tender and delicious meat, and crispy and refreshing.

Claims

1. A snack of juvenile anchovies, characterized in that: The preparation method of the anchovy snack comprises the following steps: 1) Soaking the frozen anchovies in salt water and thawing them with the assistance of ultrasound; 2) After cleaning the thawed anchovies, the fish bodies are subjected to an electric hot air drying and fixation treatment in an electric hot air drying oven; 3) Preheat the air fryer to 190-210°C, put the immobilized anchovies in, and apply edible blended oil containing 50-59% linoleic acid, and set the temperature to 190-210°C for air frying; 4) Add the air-fried anchovies to the marinade and heat to boiling; when the temperature reaches the boiling point of 100°C, immediately adjust the power to 500W constant temperature mode and maintain the marinade at a slightly boiling state of 85-90°C for marinating; 5) Mix the marinated anchovies with the chili sauce; 6) Add the cooked red oil to the mixed anchovies, vacuum pack them, and sterilize them to complete the preparation.

2. The anchovy snack according to claim 1, characterized in that: The ultrasonic assisted thawing process in 1) is to perform ultrasonication for 60-90 seconds every 30 minutes, with an ultrasonic power of 60-72W and the temperature maintained at 0-4°C.

3. The anchovy snack according to claim 1, characterized in that: The gas surface velocity of the electric hot air drying in 2) is 0.8-1 m / s, the fixed temperature is set at 55-65°C, and the time is 45-50 minutes.

4. The anchovy snack according to claim 1, characterized in that: The hot gas flow rate of the air frying treatment 3) is 2.5-4.0 m / s, and the time is 12-13 min.

5. The anchovy snack according to claim 1, characterized in that: The heat transfer medium of the air frying treatment described in 3) is purified air or nitrogen.

6. The anchovy snack according to claim 1, characterized in that: In the above 5), the marinated anchovies are mixed with the chili sauce, with low-speed mixing in the early stage and high-speed mixing in the later stage.

7. The anchovy snack according to claim 1, characterized in that: Add the cooked red oil to the anchovies mixed with the ingredients in step 6) at a ratio of 5:1.

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