Method for preparing instant grass carp cubes

Abstract

The invention relates to the technical field of food, and particularly provides a method for preparing instant grass carp cubes. The method provided by the invention comprises the following steps: performing enzymolysis on grass carp blocks, and then performing Maillard reaction to obtain the ready-to-eat grass carp blocks, the enzymolysis is as follows: flavourzyme accounting for 0.8-1.2% of the mass of the grass carp blocks is used for dry-salting the grass carp blocks for 1.5-3 hours. The ready-to-eat grass carp cubes prepared by the preparation method disclosed by the invention are subjected to enzymolysis treatment by utilizing biological enzyme, so that the use of a large number of chemical fishy smell removing agents and preservatives is avoided. The pollution of chemical substances to the environment is reduced, and the risk of chemical substance residues to human health is also reduced. Meanwhile, the instant grass carp blocks generate flavor substances under natural conditions through the Maillard reaction, artificial spices and flavoring agents do not need to be additionally added, and the product is more natural and healthy.

Description

Technical Field

[0001] The invention relates to the technical field of food, and specifically provides a method for preparing instant grass carp fish chunks. Background Art

[0002] Grass carp is a common freshwater fish widely distributed in lakes and rivers in Asia. It is deeply loved by consumers for its delicious meat and rich nutrition. However, grass carp is currently mainly consumed fresh, with a low processing rate. Due to the high moisture content and high enzyme activity of grass carp, it is easily contaminated by microorganisms during handling, transportation and storage after being caught, and it is very easy to deteriorate, resulting in a large amount of resource waste. Therefore, the development of grass carp processing industry is an important way to solve the key links of the grass carp industry chain.

[0003] However, freshwater fish products often have a strong fishy smell due to factors such as high water content and active tissue enzymes in the body, which to some extent hinders the rapid development of the freshwater fish snack food industry. Therefore, how to effectively cover up the fishy smell of freshwater fish food through scientific methods and technical means, while enhancing its freshness and aroma, and improving the flavor quality of freshwater fish food to meet consumers' demand for deliciousness and health has become the focus of the development of the freshwater fish snack food industry.

[0004] At present, the flavor research on ready-to-eat leisure freshwater fish products mainly focuses on the ingredients. Leisure freshwater fish nugget products generally use overly salty and spicy condiments to cover up the fishy smell of the raw materials, which affects the taste of the product to a certain extent. In addition, some products do not perform well in covering up the fishy smell. Even if heavier condiments are used, consumers can still feel the presence of the fishy smell. In the context of the food health market, products are gradually unable to meet consumers' demand for the health and convenience of leisure foods, resulting in insufficient competitiveness and affecting product sales.

[0005] Patent CN 112401168 A discloses a method for preparing instant fish nuggets. The method comprises the steps of processing fresh fish, rinsing, coating with starch and flour, frying, pickling and seasoning, and sterilizing after sealing and packaging to obtain the finished product. Although a nutritious and local-featured instant food is provided, the frying and pickling steps in the prior art not only make the taste greasy, but also produce nitrite during the pickling process. In addition, during the frying process, surface proteins, amino acids, etc. react with oxides, namely carbonyl compounds, in the frying oil at high temperatures to produce harmful substances, thereby affecting the quality and safety of the product.

[0006] In summary, preparing delicious and colorful instant grass carp fish chunks is a problem that needs to be solved urgently. Summary of the invention

[0007] In order to solve the defects of the prior art, the present invention proposes to use enzymatic hydrolysis combined with Maillard reaction to generate coloring and flavoring substances to enhance the flavor and taste of the product, thereby providing consumers with more delicious and safe ready-to-eat grass carp fish chunks.

[0008] In a first aspect, the present invention provides a method for preparing ready-to-eat grass carp fish chunks, comprising: enzymatically hydrolyzing the grass carp fish chunks and then subjecting them to a Maillard reaction to obtain the ready-to-eat grass carp fish chunks; the enzymatic hydrolysis comprises: dry-salting the grass carp fish chunks for 1.5-3 hours using a flavor protease accounting for 0.8-1.2% of the mass of the grass carp fish chunks.

[0009] In the method provided by the present invention, the Maillard reaction is carried out at 180-210° C. and the baking time is 15-25 min.

[0010] In the method provided by the present invention, the grass carp fish pieces are dry-cured for 1.5-3 hours using 0.8-1.2% of flavor protease by weight, 0.8-1% of glucose by weight and 0.8-1% of salt by weight.

[0011] As a specific embodiment of the present invention, the method for preparing ready-to-eat grass carp fish chunks provided by the present invention comprises: The grass carp is cut into pieces to obtain grass carp pieces, flavor protease accounting for 0.8-1.2% of the mass of the grass carp pieces, glucose accounting for 0.8-1% of the mass of the grass carp pieces, and salt accounting for 0.8-1% of the mass of the grass carp pieces are mixed, and then added to the grass carp pieces, and after being marinated at room temperature for 1.5-3 hours, Maillard reaction is performed to obtain ready-to-eat grass carp pieces.

[0012] Preferably, dry curing is carried out at 25°C.

[0013] The present invention uses flavor protease to perform mild enzymolysis on grass carp fish pieces, decomposes macromolecular proteins in fish meat, and reduces the generation of fishy smell substances. The amino acids and small molecule peptides generated in the enzymolysis process of the present invention are key precursors of the Maillard reaction. These precursors will generate more flavor compounds in the subsequent Maillard reaction, further enhancing the flavor of the fish meat. The Maillard reaction will produce brown pigments, which can give the fish meat an attractive golden or brown appearance, thereby enhancing the visual appeal of the product.

[0014] In a second aspect, the present invention provides the use of the method for preparing instant grass carp fish chunks in promoting the formation of brown pigment with a red hue in instant grass carp fish chunks.

[0015] More specifically, the color-enhancing effect on the ready-to-eat grass carp fillets is most obvious when 1.2% of the weight of the flavor protease is used for enzymatic hydrolysis for 1.5 hours, or 0.8% of the weight of the flavor protease is used for enzymatic hydrolysis for 3 hours.

[0016] In a third aspect, the present invention provides an application of the method for preparing ready-to-eat grass carp fish chunks in increasing the types of volatile flavor substances in ready-to-eat grass carp fish chunks.

[0017] The instant grass carp chunks were enzymatically hydrolyzed for 3 h with 1% flavor protease by weight, and the types of volatile flavor substances in the chunks were the largest.

[0018] More specifically, in the application provided by the present invention, the sulfide content of the instant grass carp fish nuggets prepared by the above method is increased.

[0019] In the above application, the content of furan and pyrazine compounds in the instant grass carp fish nuggets prepared by the above method is increased.

[0020] In a fourth aspect, the present invention provides a ready-to-eat product prepared by the above method, wherein the ready-to-eat product is a ready-to-eat grass carp fish block of (3-4) cm×(3-4) cm.

[0021] The beneficial effects of the present invention are: (1) The comprehensive deodorization effect is significant: the flavor protease decomposes the protein in the fish meat, reducing the content of fishy substances. The Maillard reaction further reacts the small molecule peptides and amino acids produced during the enzymatic hydrolysis with reducing sugars to generate attractive aroma and flavor compounds, thereby masking the residual fishy smell.

[0022] (2) Enhanced flavor: The Maillard reaction generates various flavor compounds such as aldehydes, ketones, and pyrazines, which give the fish a rich aroma and unique flavor. Amino acids such as glutamic acid generated during the enzymatic hydrolysis process are further transformed in the Maillard reaction, enhancing the umami taste and overall sensory experience of the fish.

[0023] (3) Improved color: The brown pigment produced during the Maillard reaction gives the fish pieces a golden or brown appearance, improving the visual appeal of the product and increasing consumers' desire to buy.

[0024] (4) Flexible process combination: Enzymatic hydrolysis and Maillard reaction can be adjusted and optimized according to specific needs to adapt to different types of fish and product positioning.

[0025] (5) Clean label: Enzymatic treatment with biological enzymes can avoid the use of large amounts of chemical deodorants and preservatives. This not only reduces the pollution of chemicals to the environment, but also reduces the risk of these chemical residues to human health. The Maillard reaction generates flavor substances under natural conditions, without the need to add artificial flavors and seasonings, making the product more natural and healthy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is the state of the fish block after the enzymatic hydrolysis conditions of the present invention are combined with the Maillard reaction treatment.

[0028] Figure 2 The sensory evaluation of fish chunks under different treatment conditions of the present invention is shown in Figure 1, wherein A: sensory evaluation of fish chunks after 1.5 h of enzymolysis; B: sensory evaluation of fish chunks after 3.0 h of enzymolysis.

[0029] Figure 3 This is the electronic nose analysis of fish pieces after enzymatic hydrolysis with different enzyme concentrations combined with Maillard reaction of the present invention. Wherein, A: principal component analysis diagram; B: odor radar diagram.

[0030] Figure 4 The invention relates to the effect of the enzymatic hydrolysis conditions combined with the Maillard reaction on the types of volatile flavor substances (A) and the proportions of (B) in fish chunks.

[0031] Figure 5 It is the sensory score of the fish pieces under different Maillard reaction conditions of the present invention.

[0032] Figure 6 It is the sensory score of fish chunks at different dosages of flavor protease.

[0033] Figure 7 It is the sensory score of fish chunks at different enzymatic hydrolysis temperatures.

[0034] Figure 8 These are the sensory scores of fish chunks at different enzymatic hydrolysis times. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The flavor protease used in the present invention is sourced from Novozymes (China) Biotechnology Co., Ltd.

[0037] Example 1 Preparation of instant grass carp fish nuggets

[0038] This embodiment provides a preparation process of grass carp fish fillets, which is as follows: knock the head of a fresh grass carp to stun it, remove the scales, remove the internal organs and clean it, then cut off the fish head with a knife and cut the fish body into two pieces, and remove the black film and mucus with running water, cut the fish fillets into fish pieces of about 4 cm×3 cm after shaping, and place them in ice for later use. The fish pieces are lightly enzymatically cured by a dry-curing method.

[0039] The specific steps are as follows: add flavor protease (0.8%, 1.0%, 1.2%), 0.8% glucose and 0.8% salt to the fish pieces (based on the weight of the fish pieces). Marinate or enzymolyze at 25°C for 1.5 h and 3.0 h respectively. The fish pieces without flavor protease are used as the control group. After marinating, put them in the oven at 210°C for 20 min to perform Maillard reaction. After cooling, ready-to-eat grass carp fish pieces are obtained, such as Figure 1 shown.

[0040] Example 2 Sensory Evaluation of Fish Chunks

[0041] This embodiment provides a sensory evaluation panel consisting of 10 people to conduct sensory evaluation on fish block products with different treatments from five aspects: appearance, color, taste, flavor and smell. Specific indicators and methods are shown in Table 1.

[0042] Table 1

[0043] (2) Organize sensory panel members to conduct sensory evaluation on the fish block samples prepared in Example 1 according to the above-mentioned standards.

[0044] Figure 2 As shown in the figure, with the gradual increase of enzyme concentration, the total sensory score of fish chunks showed a significant upward trend. This shows that enzymatic hydrolysis has a significant improvement effect on the sensory quality of fish chunks. Enzymatic hydrolysis breaks down proteins and fats to generate small peptides, amino acids and short-chain fatty acids, reduces the accumulation of fat oxidation products, promotes a moderate Maillard reaction, and removes undesirable pigments, thereby significantly improving the color of fish chunks, making them more vivid and attractive. In addition, enzymatic hydrolysis can effectively remove the fishy smell in fish chunks, increase the aroma of fish chunks, and make their flavor more intense.

[0045] Example 3 Fish Block Color

[0046] By measuring the brightness value using a colorimeter , red and green values Yellow and blue value To evaluate the color of fish pieces, see Table 2.

[0047] As shown in Table 2, the group treated with flavor protease The value was significantly higher than that of the control group (P < 0.05); this indicates that the enzymatic hydrolysis process has a significant effect on enhancing the redness of the fish nuggets. The small molecules produced by enzymatic hydrolysis react with the sugars in the fish meat to form brown pigments with a red hue. These pigments not only increase the redness of the fish nuggets, but also improve the overall color uniformity and visual appeal.

[0048] Table 2 Effects of enzymatic hydrolysis combined with Maillard reaction on the color of fish fillets

[0049] Note: Different letters in the same column indicate significant differences (P<0.05), the same below.

[0050] Example 4 Fish Nugget Flavor

[0051] (1) Electronic nose analysis

[0052] The sensor array of the electronic nose is shown in Table 3, which consists of 10 metal oxide semiconductor chemical sensors. 2 g of fish block sample was placed in a 20 mL sealed glass bottle and incubated in a 55 °C water bath for 30 min before measurement. The test parameters were set as follows: headspace generation time 120 s, headspace temperature 50 °C, oscillation speed 500 r / min, headspace injection volume 2.5 mL, injection speed 1.5 mL / s, injection needle temperature 60 °C, test acquisition time 120 s, delay time 300 s, carrier gas was synthetic dry air, flow rate 150 mL / min.

[0053] Table 3

[0054] (2) GC-MS analysis

[0055] 5 g of fish block sample was weighed and placed in a headspace bottle for testing. After the SPME solid phase microextraction head extracted the sample volatiles at 50 °C for 40 min, thermal desorption was performed at the gas chromatograph injection port for 5 min. The desorbed volatile substances were separated by a capillary column. The heating program was as follows: the initial temperature was maintained at 40 °C for 1 min, increased to 160 °C at 6 °C / min, and immediately increased to 250 °C at 10 °C / min and maintained for 3 min; the carrier gas (He) flow rate was 1.0 mL / min; no splitting.

[0056] Figure 3 A showed that at lower enzyme concentrations and shorter enzymatic hydrolysis times, the fish chunks obtained by enzymatic hydrolysis combined with Maillard reaction showed higher similarity in flavor characteristics, mainly composed of aromatic compounds. Figure 3Figure B shows that the response value of the W1W sensor to fish chunks is larger, and compared with the control group (CK), the response values ​​of the W1W sensor in different enzyme treatment groups are significantly increased, indicating that a certain degree of enzyme treatment can increase the sulfur compounds in fish chunks and enhance the meaty and roasted aroma of fish chunks.

[0057] Figure 4 The results showed that compared with the control group (CK), the types of volatile flavor substances in different enzyme treatment groups increased. The fish blocks obtained after 3.0 h of enzymatic hydrolysis at 1.0% enzyme concentration had the largest number of volatile flavor substances, with 27 species. In general, the number of volatile flavor substances increased with the increase of enzyme concentration and the extension of enzymatic hydrolysis time. Aldehydes were the type of volatile flavor substances with the highest relative content in fish blocks, with a content of between 35.8% and 60.7%. The content of aldehydes and sulfur-containing compounds in the group with flavor protease added increased compared with the control group.

[0058] In addition, flavor substances such as furan and pyrazine were detected in the fish nuggets added with flavor protease, which were not detected in the control group. As the enzyme concentration gradually increased, the content of furan and pyrazine compounds also showed an increasing trend, thus giving the fish nuggets a rich aroma and forming a unique flavor.

[0059] Example 5 Sensory evaluation of fish chunks under different Maillard reaction conditions

[0060] The enzymatic hydrolysis step of this example is the same as that of Example 1. The Maillard reaction conditions used are respectively baked at 180°C, 190°C, 200°C, 210°C, and 220°C for 20 min. The effect of Maillard reaction on the sensory score of fish pieces is shown in Figure 5 .

[0061] Comparative Example 1 Different dosages of flavor protease

[0062] The difference between this comparative example and Example 1 is that this comparative example uses 0.0%, 0.6%, 0.8%, 1.0%, 1.2%, and 1.4% of the fish block weight, and enzymolysis is carried out at 25°C for 1.5 h. Under different dosages of flavor protease, the sensory score of the fish block shows a trend of first increasing and then decreasing, as shown in FIG. Figure 6 .

[0063] Comparative Example 2 Different enzymatic hydrolysis temperatures

[0064] The difference between this comparative example and Example 1 is that this comparative example uses 1% of the weight of the fish block flavor protease, and enzymolysis is carried out at 15°C, 20°C, 25°C, 30°C or 35°C for 1.5 h. At different enzymolysis temperatures of the flavor protease, the sensory score of the fish block shows a trend of first increasing and then decreasing, as shown in FIG. Figure 7 .

[0065] Comparative Example 3 Different enzymolysis time

[0066] The difference between this comparative example and Example 1 is that this comparative example uses 1% of the weight of the fish block flavor protease, and enzymolysis is performed at 25°C for 0 h, 0.5 h, 1.5 h, 3.0 h or 4.5 h. At different enzymolysis temperatures of the flavor protease, the sensory score of the fish block shows a trend of first increasing and then decreasing, as shown in FIG. Figure 8 .

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing ready-to-eat grass carp fish nuggets, characterized in that: include: The grass carp fish pieces are enzymatically hydrolyzed and then subjected to Maillard reaction to obtain the instant grass carp fish pieces; the enzymatic hydrolysis comprises: dry-curing the grass carp fish pieces for 1.5-3 hours using flavor protease accounting for 0.8-1.2% of the mass of the grass carp fish pieces.

2. The method according to claim 1, characterized in that: The Maillard reaction is carried out at 190-220° C. and the baking time is 15-25 minutes.

3. The method according to claim 1, characterized in that The grass carp fish pieces are dry-cured for 1.5-3 hours using 0.8-1.2% of flavor protease accounting for the mass of the grass carp fish pieces, 0.8-1% of glucose accounting for the mass of the grass carp fish pieces, and 0.8-1% of salt accounting for the mass of the grass carp fish pieces.

4. The method according to any one of claims 1 to 3, characterized in that: include: The grass carp is cut into pieces to obtain grass carp pieces, flavor protease accounting for 0.8-1.2% of the mass of the grass carp pieces, glucose accounting for 0.8-1% of the mass of the grass carp pieces, and salt accounting for 0.8-1% of the mass of the grass carp pieces are mixed, and then added to the grass carp pieces, and after being marinated at room temperature for 1.5-3 hours, Maillard reaction is performed to obtain ready-to-eat grass carp pieces.

5. Use of the method according to any one of claims 1 to 4 in promoting the formation of a brown pigment with a red hue in ready-to-eat grass carp fish nuggets.

6. Use of the method according to any one of claims 1 to 4 in increasing the types of volatile flavor substances in ready-to-eat grass carp fish nuggets.

7. The use according to claim 6, characterized in that: The instant grass carp nuggets prepared by the method according to any one of claims 1 to 4 have an increased sulfide content.

8. The use according to claim 6, characterized in that: The instant grass carp fish nuggets prepared by the method according to any one of claims 1 to 4 have increased contents of furan and pyrazine compounds.

9. A ready-to-eat product, characterized in that The instant product is prepared by the method described in any one of claims 1 to 4, and is an instant grass carp fish block of (3-4) cm×(3-4) cm.

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