Fried fish block and preparation method thereof

Abstract

The invention provides a fried fish block and a preparation method thereof. According to the preparation method of the fried fish blocks, the antioxidant capacity of a sample is remarkably enhanced by the spice extract; the peroxide value and the thiobarbituric acid value of the clove extract group are reduced to the maximum extent and are 63.55% and 86.67% respectively; the iodine value of the rosemary extract group is the highest and is 29.22 g / 100g; and the clove extract and the rosemary extract have obvious inhibition effects on lipid oxidation of the fried fish blocks. The content of olefin and heterocyclic compounds is increased by the spice extract, and the content of saturated aldehyde and acid compounds contributing to generation of bad flavor is remarkably reduced; wherein the clove extract endows the fried fish blocks with more faint scent and baking fragrance, and the total sensory acceptance is relatively high. The deep-fried fish blocks added with the 1% clove extract have the best sensory score, and the deep-fried fish blocks and the spices are relatively harmonious in flavor. The invention provides a theoretical basis for the application of the spice extract in grease hot-processed aquatic products.

Description

Technical Field

[0001] The invention relates to the technical field of food engineering, and in particular to a fried fish nugget and a preparation method thereof. Background Art

[0002] In order to slow down the oxidation and deterioration of oil in fried aquatic products and extend their shelf life, antioxidants are usually used to control the oxidation reaction process during the production process. In the food industry, synthetic antioxidants are often used to inhibit oil oxidation, thereby delaying the decline in food quality. However, due to the potential threat of synthetic antioxidants to human health, their use is restricted. Therefore, seeking efficient, stable and safe natural antioxidants to solve the decline in the quality of fried foods during frying has become a research hotspot in related fields. The research and development of natural antioxidants is extremely important. Spice extracts, as a new type of natural antioxidant with a wide source and high antioxidant content, can not only significantly improve the oxidation status of aquatic products, extend their shelf life, but also give aquatic products a special flavor. Therefore, they are increasingly valued by many scholars at home and abroad.

[0003] Many studies have shown that the antioxidant mechanism of natural spices is closely related to its antioxidant components such as phenols and flavonoids. The molecular structure of these substances contains active hydrogen, which can combine with active peroxy radicals, remove free radicals, and transform themselves into phenol oxygen radicals with stable semiquinone structure, chelate metal ions, slow down the transmission speed of auto-oxidation chain reaction, and block chain reaction. At present, the research on the application of spice extracts in aquatic products at home and abroad mainly focuses on the antioxidant and antibacterial effects of fresh aquatic products, conditioned aquatic products and air-dried aquatic products. For example, the prior art discloses the effect of citric acid and rosemary extract compound on the quality of refrigerated white shrimp. The results show that the compound of citric acid and rosemary extract plays a role in delaying fat oxidation and protein oxidation, enhancing the preservation effect of shrimp, improving the storage quality of white shrimp and extending its storage period. The prior art discloses the effect of rosemary extract on the preservation of red shrimp during frozen storage. The results show that rosemary extract significantly reduces the mass loss during frozen storage and delays protein and lipid oxidation. The prior art discloses the effects of alcohol extracts of three spices (cinnamon, aniseed, and cloves) on the color and antioxidant stability of salmon balls during frozen storage. The results show that all three spices can significantly reduce the POV value and AV value of salmon balls during frozen storage.

[0004] However, there are few reports on the inhibitory effect of spice extracts on lipid oxidation and the impact on flavor during the processing of fried aquatic products. Summary of the invention

[0005] In view of this, the present invention provides a method for preparing fried fish chunks and the like. The present invention compares the ability of 6 spice extracts to alleviate oxidized lipid oxidation in fried oval pomfret chunks, and analyzes the flavor improvement effects of different spice extracts on fried oval pomfret chunks, providing new ideas and directions for lipid oxidation and flavor regulation of pre-processed aquatic products.

[0006] The present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing fried fish nuggets, comprising the following steps:

[0008] Add the fish pieces to the marinade, then add the spice extract and marinate;

[0009] After drying the pickled fish pieces, frying them in edible oil to obtain fried fish pieces;

[0010] The spice extract comprises at least one of clove extract, galangal extract, cinnamon extract, prickly ash extract, rosemary extract and citronella extract.

[0011] Preferably, the eugenol content in the clove extract is 1.46-1.48 mg / g, the total flavonoids content is 51.7-56.36 mg / g, and the total phenol content is 35.59-37.99 mg / g;

[0012] The galangin mass content of the galangal extract is 2.79-3.01 mg / g, the total flavonoid mass content is 13.46-15.04 mg / g, and the total phenol mass content is 11.49-16.19 mg / g;

[0013] The cinnamaldehyde content of the cinnamon extract is 0.16-0.17 mg / g, the total flavonoids content is 22.01-24.47 mg / g, and the total phenols content is 18.02-22.04 mg / g.

[0014] The alkaloid mass content of the Zanthoxylum bungeanum extract is 0.64-0.65 mg / g, the total flavonoid mass content is 34.38-36.92 mg / g, and the total phenol mass content is 49.51-53.79 mg / g;

[0015] The rosemary extract has a carnosic acid content of 9.77-9.83 mg / g, a rosmarinic acid content of 22.95-23.01 mg / g, a total flavonoid content of 11.10-11.26 mg / g, and a total phenol content of 3.73-7.85 mg / g;

[0016] The citronellal mass content in the citronella extract is 0.01-0.02 mg / g, the total flavonoid mass content is 21.78-22.72 mg / g, and the total phenol mass content is 21.08-23.52 mg / g.

[0017] Preferably, the fish pieces are added to the marinade, and then the spice extract is added. During the marinating step, the mass of the spice extract is 1 to 3% of the mass of the fish pieces.

[0018] Preferably, the marinade includes salt, onion, ginger and garlic powder, cooking wine and white pepper powder, the mass of the salt is 2-2.5% of the mass of the fish block, the mass of the onion, ginger and garlic powder is 1.5-2% of the mass of the fish block, the mass of the cooking wine is 2-2.5% of the mass of the fish block, and the mass of the white pepper powder is 1-1.5% of the mass of the fish block.

[0019] Preferably, the fish pieces are added to the marinade, and then the spice extract is added, and the marinating is carried out at 2 to 4° C. for 1 to 1.5 hours.

[0020] Preferably, the marinated fish pieces are dried and then fried in edible oil at a temperature of 145 to 155° C. for 3.5 to 4 minutes to obtain fried fish pieces.

[0021] Preferably, in the step of drying the pickled fish pieces, the drying temperature is 50-55° C. and the drying time is 1-1.5 h.

[0022] Preferably, the spice extract is clove extract, and the mass of the clove extract is 1% of the mass of the fish block.

[0023] Preferably, the spice extract is rosemary extract, and the mass of the rosemary extract is 1.85% of the mass of the fish block;

[0024] And / or, the fish chunks include at least one of salmon chunks, golden pomfret chunks, tuna chunks, and grouper chunks.

[0025] In a second aspect, the present invention further provides a fried fish nugget prepared by the preparation method.

[0026] The present invention has the following beneficial effects compared with the prior art:

[0027] The method for preparing fried fish nuggets of the present invention comprises the following steps: adding fish nuggets to a pickling material, then adding a spice extract, and pickling; drying the pickled fish nuggets, and then frying them in edible oil to obtain fried fish nuggets; the spice extract comprises at least one of a clove extract, an galangal extract, a cinnamon extract, a prickly ash extract, a rosemary extract, and a citronella extract; and research results show that the spice extract significantly enhances the antioxidant capacity of the sample; wherein, the peroxide value (POV) and the thiobarbituric acid value (TBA) of the clove extract group are reduced to the greatest extent, which are 63.55% and 86.67% respectively; the iodine value (IV) of the rosemary extract group is the highest, which is 29.22 g / 100 g; and the clove extract group and the rosemary extract group have significant inhibitory effects on lipid oxidation of fried fish nuggets (P<0.05). The spice extract increased the content of olefins and heterocyclic compounds, and significantly reduced the content of saturated aldehydes and acid compounds that contribute to the generation of bad flavors (P<0.05). Among them, clove extract gave fried fish nuggets more fragrance and baking aroma, and the overall sensory acceptance was high. The fried fish nuggets with 1% clove extract had the best sensory score, and the fried fish nuggets and spice flavor were more coordinated. The present invention provides a theoretical basis for the application of spice extracts in oil thermal processing of aquatic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 The peroxide value (POV) of lipids extracted from fried fish nuggets prepared by the methods in Examples 1 to 6 and Comparative Example 1;

[0030] Figure 2 The TBA value of lipids extracted from fried fish nuggets prepared by the methods of Examples 1 to 6 and Comparative Example 1;

[0031] Figure 3 Iodine value (IV) of lipids extracted from fried fish nuggets prepared by the methods of Examples 1 to 6 and Comparative Example 1;

[0032] Figure 4 A bar graph showing the sensory scores of fried fish nuggets prepared by the methods of Examples 1 to 6 and Comparative Example 1;

[0033] Figure 5 A sensory scoring radar chart of fried fish nuggets prepared by the methods in Examples 1 to 6 and Comparative Example 1;

[0034] Figure 6 The peroxide value (POV) of lipids extracted from fried fish nuggets prepared by the methods in Example 1, Examples 7 to 10 and Comparative Example 1;

[0035] Figure 7 The TBA value of lipids extracted from fried fish nuggets prepared by the methods of Example 1, Examples 7 to 10 and Comparative Example 1;

[0036] Figure 8 The iodine value (IV) of lipids extracted from fried fish nuggets prepared by the methods in Example 1, Examples 7 to 10 and Comparative Example 1;

[0037] Fig. 9 A bar graph of sensory scores of fried fish nuggets prepared by the methods of Example 1, Examples 7 to 10 and Comparative Example 1;

[0038] Fig.10 The sensory score radar chart of fried fish nuggets was prepared by the methods in Example 1, Examples 7 to 10 and Comparative Example 1. DETAILED DESCRIPTION

[0039] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0040] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. In addition, in the description of the present application, the term "including" means "including but not limited to". Various embodiments of the present invention may be in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values ​​within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated in this article, it is meant to include any quoted numbers (fractions or integers) within the indicated range.

[0041] The present invention provides a method for preparing fried fish nuggets, comprising the following steps:

[0042] S1. Add the fish pieces to the marinade, then add the spice extract and marinate;

[0043] S2, drying the marinated fish pieces, and frying them in edible oil to obtain fried fish pieces;

[0044] The spice extract includes at least one of clove extract, galangal extract, cinnamon extract, prickly ash extract, rosemary extract and citronella extract.

[0045] In some embodiments, the mass content of eugenol in the clove extract is 1.46-1.48 mg / g (i.e., each gram of clove extract contains 1.46-1.48 mg of eugenol), the mass content of total flavonoids is 51.7-56.36 mg / g, and the mass content of total phenols is 35.59-37.99 mg / g.

[0046] Specifically, eugenol is an organic compound with the chemical name of 4-allyl-2-methoxyphenol. Clove extract is a commercially available product, such as Shaanxi Haiyis Biotechnology Co., Ltd., Shaanxi Xintianyu Biotechnology Co., Ltd., Shaanxi Xinyanghe Biotechnology Co., Ltd., etc.

[0047] In some embodiments, the mass content of galangin in the galangal extract is 2.79-3.01 mg / g, the mass content of total flavonoids is 13.46-15.04 mg / g, and the mass content of total phenols is 11.49-16.19 mg / g.

[0048] Specifically, galangin is a flavonoid compound with the chemical name 3,5,7-trihydroxyflavone. Galangin extract is a commercially available product, such as that available from Shaanxi Haiyis Biotechnology Co., Ltd., Shaanxi Xintianyu Biotechnology Co., Ltd., Chengdu Pusi Biotechnology Co., Ltd., Shaanxi Xinyanghe Biotechnology Co., Ltd., etc.

[0049] In some embodiments, the mass content of cinnamaldehyde in the cinnamon extract is 0.16-0.17 mg / g, the mass content of total flavonoids is 22.01-24.47 mg / g, and the mass content of total phenols is 18.02-22.04 mg / g.

[0050] Cinnamaldehyde is cinnamaldehyde, and its molecular formula is C9H8O. Cinnamon extract is a commercially available product, such as Shaanxi Haiyis Biotechnology Co., Ltd., Shaanxi Xintianyu Biotechnology Co., Ltd., Chengdu Pusi Biotechnology Co., Ltd., Shaanxi Xinyanghe Biotechnology Co., Ltd., etc.

[0051] In some embodiments, the alkaloid content in the Zanthoxylum bungeanum extract is 0.64-0.65 mg / g, the total flavonoids content is 34.38-36.92 mg / g, and the total phenols content is 49.51-53.79 mg / g.

[0052] Zanthoxylum bungeanum contains a variety of alkaloids, mainly including skimmianine, schinifoline, etc. Zanthoxylum bungeanum extract is a commercially available product, such as Shaanxi Haiyisi Biotechnology Co., Ltd., Shaanxi Xintianyu Biotechnology Co., Ltd., Chengdu Pusi Biotechnology Co., Ltd., etc.

[0053] In some embodiments, the rosemary extract has a carnosic acid content of 9.77-9.83 mg / g, a rosmarinic acid content of 22.95-23.01 mg / g, a total flavonoid content of 11.10-11.26 mg / g, and a total phenol content of 3.73-7.85 mg / g.

[0054] Specifically, carnosic acid, the molecular formula is C 20 H 28 O4; the molecular formula of rosmarinic acid is C 18 H 16 O8; Rosemary extract is a commercially available product, such as that available from Shaanxi Haiyis Biotechnology Co., Ltd., Shaanxi Xintianyu Biotechnology Co., Ltd., Chengdu Pusi Biotechnology Co., Ltd., etc.

[0055] In some embodiments, the mass content of citronellal in the citronella extract is 0.01-0.02 mg / g, the mass content of total flavonoids is 21.78-22.72 mg / g, and the mass content of total phenols is 21.08-23.52 mg / g.

[0056] The molecular formula of citronellal is C 10 H 18 O; Lemongrass extract is a commercially available product, such as that available from Shaanxi Haiyis Biotechnology Co., Ltd., Shaanxi Xintianyu Biotechnology Co., Ltd., Chengdu Pusi Biotechnology Co., Ltd., etc.

[0057] In some embodiments, the fish pieces are added to a marinade, and then a spice extract is added. During the marinating step, the mass of the spice extract is 1-3% of the mass of the fish pieces.

[0058] In some embodiments, the marinade includes salt, onion, ginger, garlic powder, cooking wine, and white pepper powder. The mass of the salt is 2-2.5% of the mass of the fish block, the mass of the onion, ginger, garlic powder is 1.5-2% of the mass of the fish block, the mass of the cooking wine is 2-2.5% of the mass of the fish block, and the mass of the white pepper powder is 1-1.5% of the mass of the fish block.

[0059] In some embodiments, the fish pieces are added to the marinade, and then the spice extract is added, and the marinade is carried out at 2-4° C. for 1-1.5 hours.

[0060] In some embodiments, the marinated fish pieces are dried and then fried in edible oil at a temperature of 145-155° C. for 3.5-4 minutes to obtain fried fish pieces.

[0061] In some embodiments, in the step of drying the marinated fish pieces, the drying temperature is 50-55° C. and the drying time is 1-1.5 hours.

[0062] In some embodiments, the spice extract is clove extract, and the mass of the clove extract is 1% of the mass of the fish block.

[0063] In some embodiments, the spice extract is rosemary extract, and the mass of the rosemary extract is 1.85% of the mass of the fish chunks.

[0064] In some embodiments, the fish pieces include at least one of salmon pieces, pomfret pieces, tuna pieces, and grouper pieces.

[0065] The invention discloses a method for preparing fried fish nuggets, and explores the effects of clove extract, galangal extract, cinnamon extract, prickly ash extract, rosemary extract and citronella extract on lipid oxidation, sensory evaluation and volatile flavor substances of fried fish nuggets; the research results show that the spice extracts significantly enhance the antioxidant capacity of the samples; among them, the peroxide value (POV) and thiobarbituric acid value (TBA) of the clove extract group are reduced to the greatest extent, which are 63.55% and 86.67% respectively; the IV (i.e. iodine value, IV value is an important indicator for measuring the content of unsaturated fatty acids in oils or oil-containing foods, the higher the iodine value, the more unsaturated fatty acids in the oils, the higher the unsaturated fatty acid content, and the higher the iodine value, the lower the oxidation rate) value of the rosemary extract group, which is the highest, which is 29.22 g / 100 g; the clove extract group and the rosemary extract group have significant inhibitory effects on lipid oxidation of fried fish nuggets (P<0.05). The spice extract increased the content of olefins and heterocyclic compounds, and significantly reduced the content of saturated aldehydes and acid compounds that contribute to the generation of bad flavors (P<0.05). Among them, clove extract gave fried fish nuggets more fragrance and baking aroma, and the overall sensory acceptance was high. The fried fish nuggets with 1% clove extract had the best sensory score, and the fried fish nuggets and spice flavor were more coordinated. The present invention provides a theoretical basis for the application of spice extracts in oil thermal processing of aquatic products.

[0066] Based on the same inventive concept, the present invention also provides a fried fish nugget, which is prepared by the above-mentioned preparation method.

[0067] The following further describes the method for preparing fried fish nuggets of the present application with specific examples. This section further describes the content of the present invention in conjunction with specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the examples are conventional means known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0068] In the following embodiments, the fish pieces are oval-shaped pomfret (commonly known as golden pomfret) fish pieces, and the edible oil is golden arowana edible vegetable blending oil.

[0069] The spice extracts in the following examples are all commercially available products, and their marker components, total phenols, and total flavonoids contents are measured as shown in Table 1 below.

[0070] Table 1 - Marker components, total phenols and total flavonoids content of spice extracts

[0071]

[0072] Note: Different lowercase letters in Table 1 indicate significant differences between the data (P<0.05). The total content of effective substances is the sum of the content of marker components, total phenols and total flavonoids.

[0073] Example 1

[0074] The present invention provides a method for preparing fried fish nuggets, comprising the following steps:

[0075] S1, thawing the frozen oval pomfret at 4°C for 12h, removing the inedible parts such as viscera, gills, and scales, cleaning and cutting into pieces (size 10cm×5cm×1cm), to obtain oval pomfret pieces;

[0076] Add the oval pomfret pieces to the marinade, then add the spice extract, and marinate at 4°C for 1 hour;

[0077] Wherein, the spice extract is clove extract;

[0078] The mass of the spice extract is 1% of the mass of the oval pomfret fish pieces;

[0079] The marinade includes salt, onion, ginger and garlic powder (commercially available product, purchased from Shanghai Weihaomei Food Co., Ltd.), cooking wine and white pepper powder, the mass of salt is 2% of the mass of the oval pomfret fish block, the mass of onion, ginger and garlic powder is 1.5% of the mass of the oval pomfret fish block, the mass of cooking wine is 2% of the mass of the oval pomfret fish block, and the mass of white pepper powder is 1% of the mass of the oval pomfret fish block;

[0080] S2. The marinated fish pieces were dried at 50°C for 1 hour, and then placed in edible oil and fried at 150°C for 3.5 minutes to obtain fried fish pieces. The fried fish pieces were then placed in a 60°C forced air drying oven for 3 days before subsequent testing.

[0081] Example 2

[0082] The method for preparing fried fish chunks provided in the embodiment of the present application is the same as that in Example 1, except that the spice extract is galangal extract, the mass of the spice extract is 2.98% of the mass of the oval pomfret chunks, and the other process parameters are the same as those in Example 1.

[0083] Example 3

[0084] The method for preparing fried fish chunks provided in the embodiment of the present application is the same as that in Example 1, except that the spice extract is cinnamon extract, the mass of the spice extract is 2.12% of the mass of the oval pomfret chunks, and the other process parameters are the same as those in Example 1.

[0085] Example 4

[0086] The method for preparing fried fish chunks provided in the embodiment of the present application is the same as that in Example 1, except that the spice extract is a Zanthoxylum bungeanum extract, and the mass of the spice extract is 1.06% of the mass of the oval pomfret chunks. The other process parameters are the same as those in Example 1.

[0087] Example 5

[0088] The method for preparing fried fish chunks provided in the embodiment of the present application is the same as that in Example 1, except that the spice extract is rosemary extract, the mass of the spice extract is 1.85% of the mass of the oval pomfret chunks, and the other process parameters are the same as those in Example 1.

[0089] Example 6

[0090] The method for preparing fried fish chunks provided in the embodiment of the present application is the same as that in Example 1, except that the spice extract is lemongrass extract, the mass of the spice extract is 2.07% of the mass of the oval pomfret chunks, and the other process parameters are the same as those in Example 1.

[0091] Example 7

[0092] The method for preparing fried fish chunks provided in the embodiment of the present application is the same as that in Example 1, except that the spice extract is clove extract, the mass of the clove extract is 0.5% of the mass of the oval pomfret chunks, and the other process parameters are the same as those in Example 1.

[0093] Example 8

[0094] The method for preparing fried fish chunks provided in the embodiment of the present application is the same as that in Example 1, except that the spice extract is clove extract, the mass of the clove extract is 1.5% of the mass of the oval pomfret chunks, and the other process parameters are the same as those in Example 1.

[0095] Example 9

[0096] The method for preparing fried fish chunks provided in the embodiment of the present application is the same as that in Example 1, except that the spice extract is clove extract, the mass of the clove extract is 2% of the mass of the oval pomfret chunks, and the other process parameters are the same as those in Example 1.

[0097] Example 10

[0098] The method for preparing fried fish chunks provided in the embodiment of the present application is the same as that in Example 1, except that the spice extract is clove extract, the mass of the clove extract is 2.5% of the mass of the oval pomfret chunks, and the other process parameters are the same as those in Example 1.

[0099] Comparative Example 1

[0100] The preparation method of fried fish nuggets provided in this comparative example is the same as that in Example 1, except that the spice extract is not added, and the other process parameters are the same as those in Example 1.

[0101] Performance Testing

[0102] Fried fish nuggets were prepared according to the methods of Examples 1 to 6 and Comparative Example 1; 50 g of the prepared fried fish nuggets were dispersed and mixed with 100 mL of chloroform and 50 mL of methanol (volume ratio of 2:1), stirred evenly for 2 h, 20% volume (i.e. 30 mL) of deionized water was added, the lower organic phase was collected, and the final lipids were collected after vacuum concentration and placed in a -20°C refrigerator for testing (testing the peroxide value, TBA, and iodine value of the lipids).

[0103] 1.1 Determination of peroxide value (POV)

[0104] The specific method for determining the peroxide value (POV) is as follows: accurately weigh 0.1g of lipid into a 20ml stoppered colorimetric tube, add 5ml of chloroform-glacial acetic acid mixed solvent (the volume ratio of chloroform and glacial acetic acid is 2:3), add 1.00ml of saturated KI solution, shake well, add and react in a dark place for 3min, take out and immediately dilute with 10mL of water, add 1.00mL of 1% starch solution by mass concentration, dilute to the scale with water, shake well, take the upper clear liquid, and measure its absorbance at 570nm with a 1cm colorimetric dish. Use the concentration of the I2 standard solution as the horizontal coordinate and its absorbance as the vertical coordinate to draw a standard curve, and calculate the peroxide value content of the sample by the linear regression equation. The test results are as follows Figure 1 shown.

[0105] Figure 1 wherein CK represents the peroxide value measured on the fried fish nuggets prepared in Comparative Example 1; DX represents the peroxide value measured on the fried fish nuggets prepared in Example 1; GJ represents the peroxide value measured on the fried fish nuggets prepared in Example 2; GP represents the peroxide value measured on the fried fish nuggets prepared in Example 3; HJ represents the peroxide value measured on the fried fish nuggets prepared in Example 4; MD represents the peroxide value measured on the fried fish nuggets prepared in Example 5; and XM represents the peroxide value measured on the fried fish nuggets prepared in Example 6. Figure 1 Different lowercase letters indicate significant differences among the data (P<0.05).

[0106] POV indicates the content of hydroperoxides in the initial stage of lipid oxidation. Peroxides are generally unstable and easily degraded during storage. The higher the POV value, the more the primary products of lipid oxidation accumulate. Effects of different spice extracts on the POV of lipids extracted from fried oval pomfret chunks Figure 1 As shown in the figure, compared with the CK group, the POV values ​​of the spice group were significantly reduced (P < 0.05), which indicates that the addition of spice extracts can inhibit the formation of lipid primary products in fish meat during frying. The difference in the ability to inhibit peroxide value in Examples 1 to 6 may be related to the different antioxidant components and their structures. In addition, the oval pomfret fish pieces contain a large amount of unsaturated fatty acids, which are easily oxidized and decomposed to form malondialdehyde and TBA during frying. Moderate lipid oxidation is conducive to the formation of fish flavor.

[0107] 1.2 Determination of thiobarbituric acid value (TBA)

[0108] Thiobarbituric acid value (TBA) determination method: Determine the TBA of lipids, refer to the national standard GB / T 35252-2017. The test results are as follows Figure 2 shown.

[0109] Figure 2 wherein CK represents TBA measured on the fried fish nuggets prepared in Comparative Example 1; DX represents TBA measured on the fried fish nuggets prepared in Example 1; GJ represents TBA measured on the fried fish nuggets prepared in Example 2; GP represents TBA measured on the fried fish nuggets prepared in Example 3; HJ represents TBA measured on the fried fish nuggets prepared in Example 4; MD represents TBA measured on the fried fish nuggets prepared in Example 5; and XM represents TBA measured on the fried fish nuggets prepared in Example 6. Figure 2 Different lowercase letters indicate significant differences among the data (P<0.05).

[0110] Thiobarbituric acid value (TBA) is widely used to evaluate the degree of fat oxidation and rancidity in fish and meat products, and is an important indicator for judging the degree of fat oxidation in aquatic products. TBA is positively correlated with lipid oxidation, and its value indicates the amount of secondary oxidation products of fat, i.e., the final product. Effects of different spice extracts on TBA of fried oval pomfret fillets Figure 2 As shown in the results, after 3 days of oxidation, the TBA of lipids extracted from fried fish nuggets prepared by adding clove extract (DX), galangal extract (GJ), pepper extract (HJ), rosemary extract (MD), and lemongrass extract (XM) was significantly lower than that of the CK group (P < 0.05), indicating that these substances have a significant inhibitory effect on lipid oxidation, and the degree of inhibition of lipid oxidation is from high to low, respectively, DX, MD, HJ, GJ, and XM. Spices mainly contain a variety of antioxidant components such as polyphenols, flavonoids, organic acids, and alkaloids. They can cut off the dynamic oxidation chain of oils and fats, integrate metal ions, and organic acids have a synergistic effect. The TBA of the cinnamon extract (GP) group was significantly higher than that of the CK group (P < 0.05), which may be that some substances in the cinnamon extract accelerated the lipid oxidation of the GP group. Compared with the CK group and other treatment combinations, the DX group is more conducive to reducing the oxidation of fish lipids during frying, which is related to the characteristics of the antioxidant components. The main active ingredient of DX is eugenol, which is relatively stable under high temperature conditions. However, GJ and XM are unstable under high temperature conditions and are easily decomposed and volatilized.

[0111] 1.3 Determination of iodine value (IV): Weigh 0.25g of edible oil sample, put it in a 100mL volumetric flask, add 50mL of an equal volume mixed solvent of cyclohexane and glacial acetic acid, shake to dissolve and make up to volume to obtain a sample treatment solution. Pipette 10μL of sample treatment solution into a 50mL volumetric flask, add 0.80mL of Wei's solution, plug the bottle stopper, shake well and let stand at room temperature for 60min, add 2.00mL of 100g / L potassium iodide, 2.50mL of starch solution, 5.00mL of 0.1mol / L acetic acid-sodium acetate buffer solution, make up to volume with water, shake well for testing, use water as a reference, and measure the absorbance at a wavelength of 610nm. Use the concentration of Wei's solution as the horizontal coordinate and its absorbance as the vertical coordinate to draw a standard curve, and calculate the iodine value of the sample by the linear regression equation. The test results are as follows Figure 3 shown.

[0112] Figure 3 wherein CK represents the iodine value measured for the fried fish nuggets prepared in Comparative Example 1; DX represents the iodine value measured for the fried fish nuggets prepared in Example 1; GJ represents the iodine value measured for the fried fish nuggets prepared in Example 2; GP represents the iodine value measured for the fried fish nuggets prepared in Example 3; HJ represents the iodine value measured for the fried fish nuggets prepared in Example 4; MD represents the iodine value measured for the fried fish nuggets prepared in Example 5; and XM represents the iodine value measured for the fried fish nuggets prepared in Example 6. Figure 3 Different lowercase letters indicate significant differences among the data (P<0.05).

[0113] IV value is an important indicator to measure the content of unsaturated fatty acids in oils or oil-containing foods. The higher the iodine value, the more unsaturated double bonds there are in the oil, and the higher the unsaturated fatty acid content. A higher iodine value indicates a lower oxidation rate. Silver pomfret is rich in unsaturated fatty acids. As fat oxidation proceeds, the content of unsaturated fatty acids decreases. This is mainly because unsaturated fatty acids contain unsaturated double bonds, which are chemically unstable and prone to oxidation, polymerization and addition reactions. These reactions are more likely to occur under heating conditions. Effects of different spice extracts on the IV of silver pomfret Figure 3 As shown in the figure, after 3 days of accelerated oxidation of fish chunks, the iodine values ​​of lipids extracted from fried fish chunks prepared with clove extract (DX), galangal extract (GJ) and rosemary extract (MD) were 21.67±0.80, 14.37±1.00 and 29.22±1.16 g / 100 g, respectively, which were significantly higher than those in the CK group, while the iodine values ​​of oil samples added with other spice extracts were lower than those in the CK group.

[0114] 1.4 Sensory evaluation

[0115] Fried fish nuggets were prepared according to the methods in Examples 1 to 6 and Comparative Example 1, and sensory evaluation was performed on them; specifically, the sensory evaluation method was as follows: the fried fish nuggets prepared in different Examples and Comparative Examples were placed in transparent ziplock bags, the samples were randomly numbered, and distributed to sensory evaluators in a random order. Ten trained sensory evaluators scored each sample. The evaluation indicators included the color, smell, greasy feeling, texture, and appearance of the fish nuggets, and the scores were set at 0 to 10 points. The specific sensory evaluation criteria are shown in Table 2.

[0116] Table 2 - Sensory evaluation criteria

[0117]

[0118]

[0119] The sensory evaluation results are as follows Figures 4-5 As shown, Figure 4 It is a bar graph of sensory scores (different lowercase letters indicate significant differences between the data (P<0.05)); Figure 5 Radar chart for sensory ratings.

[0120] Figures 4-5wherein CK represents the sensory evaluation results of the fried fish nuggets prepared in Comparative Example 1; DX represents the sensory evaluation results of the fried fish nuggets prepared in Example 1; GJ represents the sensory evaluation results of the fried fish nuggets prepared in Example 2; GP represents the sensory evaluation results of the fried fish nuggets prepared in Example 3; HJ represents the sensory evaluation results of the fried fish nuggets prepared in Example 4; MD represents the sensory evaluation results of the fried fish nuggets prepared in Example 5; and XM represents the sensory evaluation results of the fried fish nuggets prepared in Example 6.

[0121] from Figures 4-5 It can be seen that compared with the CK group, the sensory scores of the DX, MD, and HJ groups after 3 days of oxidation of the fish nuggets were higher, which were 36.7, 36.1, and 34.1 points, respectively; there was no significant difference between the GP and XM groups and the CK group (P<0.05). Compared with the group with added spice extracts, the CK group had stronger fishy and rancid smells. The addition of DX, MD, and HJ significantly weakened the rancid smell of the fish nuggets, and the aroma of fish meat and the aroma of spices were more coordinated. Although the addition of GP reduced the fishy smell of the fish nuggets to a certain extent, its rancid smell was still prominent, resulting in a low overall acceptability of the product. In summary, the six spice extracts selected in this study optimized the flavor of the product to varying degrees when applied to fried egg-shaped pomfret fish nuggets, and effectively reduced the rancid smell and fishy smell of the fish nuggets. Among them, the addition of DX extract made the product perform best in terms of overall acceptability.

[0122] 1.5 Determination of volatile flavor compounds in fried fish nuggets

[0123] According to the methods in Examples 1 to 6 and Comparative Example 1, fried fish nuggets were prepared respectively, and the volatile flavor substances in the fried fish nuggets were determined by HS-SPME-GC-MS analysis, specifically: 3.0 g of fried egg-shaped pomfret fish nuggets prepared in different embodiments and comparative examples were accurately weighed, respectively placed in 20 mL headspace bottles, 2 mL / g of saturated salt water of the sample was added, and after sealing, it was placed in a 50°C water bath with a magnetic stirrer, heated for 10 min, the extraction head was aged at 250°C for 0.5 h, and inserted into the sample for adsorption for 0.5 h, and then the extraction head was quickly inserted into GC-MS, and taken out after 5 min of analysis, and the sample was repeated twice. Chromatographic conditions: chromatographic column model HP-Innowax capillary column (60m×250μm×0.25μm), the front inlet temperature was 250°C, the sample injection volume was 1.0μL, the carrier gas was high-purity He, and the flow rate was 1.0mL / min. Program temperature rise: the initial temperature of the column box is 40℃ and maintained for 5min, then it is increased to 80℃ at 3℃ / min and maintained for 7min, and then it is increased to 200℃ at 7℃ / min. Mass spectrometry conditions: EI source, electron energy is 70eV, ion source temperature is 230℃, transmission line temperature is 250℃, quadrupole temperature is 150℃, and the scanning range is m / z 35~500. The test results are shown in Table 3.

[0124] Table 3 - Volatile flavor content of fried fish nuggets prepared in different embodiments and comparative examples (μg / kg)

[0125]

[0126]

[0127]

[0128] In Table 3, RI indicates that the linear retention index of the sample is consistent with the literature published in the NIST Chemistry WebBook database, MS indicates that the mass spectrometry results are consistent with the reference data in the NIST mass spectrometry database, and "-" means that the substance was not detected, and the internal standard is 2 μg / mL o-dichlorobenzene. Different lowercase letters in Table 3 indicate significant differences between the data (P<0.05). The same applies to Table 4 below.

[0129] In Table 3, CK represents the fried fish nuggets prepared in Comparative Example 1; DX represents the fried fish nuggets prepared in Example 1; GJ represents the fried fish nuggets prepared in Example 2; GP represents the fried fish nuggets prepared in Example 3; HJ represents the fried fish nuggets prepared in Example 4; MD represents the fried fish nuggets prepared in Example 5; and XM represents the fried fish nuggets prepared in Example 6.

[0130] In order to explore the difference in the smell of fried oval pomfret by different spice extracts, the volatile compounds in the oval pomfret were detected. The GC-MS test results showed that a total of 43 volatile compounds were detected in the 7 groups of fried fish samples prepared in Examples 1 to 6 and Comparative Example 1, including 11 aldehydes, 4 ketones, 6 alcohols, 3 aromatics, 11 heterocyclics, 4 olefins, 2 acids, and 2 esters.

[0131] Aldehydes generally come from the oxidative decomposition of unsaturated fatty acids such as linoleic acid and oleic acid. They have a low threshold and are the main contributors to fish odor. Saturated aldehydes such as hexanal, heptanal, and nonanal are all products of lipid oxidation. Hexanal is a representative substance of fat oxidation and the only saturated aldehyde produced by linoleic acid oxidation. It has the characteristics of grassy, ​​fishy, ​​and sour smells; heptanal has a green and nutty aroma; nonanal has a fat and grassy smell. After 3 days of storage of fish pieces, the hexanal content in the control group (CK) was 22.22 μg / kg, and the hexanal contents in the DX and MD groups were 11.59 and 13.13 μg / kg, respectively, indicating that DX and MD can inhibit the continued oxidation of linoleic acid to a certain extent, thereby reducing the sour and rancid taste of fish meat. Significantly reduce the lipid oxidation of fried oval pomfret. Compared with the control group, the content of benzaldehyde in DX, MD, and XM samples was higher, adding a sweet aroma to them.

[0132] The effect of alcohols on the flavor of aquatic products is relatively smaller than that of aldehydes. 1-Octene-3-ol is derived from the oxidation of unsaturated fatty acids, has a mushroom aroma, and is considered to be one of the best markers of oil oxidation. After 3 days of storage, the 1-octen-3-ol content in the DX group and the MD group was significantly reduced compared with the CK group. The 1-octen-3-ol content is highly correlated with chemical indicators such as the peroxide value and thiobarbituric acid value related to fat oxidation in fish meat. Therefore, changes in the 1-octen-3-ol content can also reflect the degree of rancidity of fish meat. The content of unsaturated alcohols (2-ethylhexanol) in the control group was 4.10 μg / kg, and its content in the DX group decreased (2.67 μg / kg), indicating that DX can reduce the production of alcohols.

[0133] The increase of volatile acids is highly correlated with the spoilage of aquatic products. The acid in the oval pomfret can be produced by amino acid degradation or lipid oxidation. After 3 days of storage, the acetic acid and caproic acid in the control group of fried oval pomfret pieces were higher (42.50 μg / kg), which was significantly different from the acid content in the sample group with added spice extract. The content in the DX group was significantly reduced, indicating that the addition of spice extract can reduce the production of acidic substances in fried oval pomfret, and the effect of adding DX is better.

[0134] Olefins can enhance the freshness of food flavors and are found in higher concentrations in DX, GJ, GP, MD, and XM samples. Dextrorotatory terpenes have a fresh, herbaceous aroma and were detected in samples containing DX, MD, and XM.

[0135] Ketones are mainly produced by the metabolism of lipids or amino acids by microorganisms and the oxidation of polyunsaturated fatty acids. Their odor threshold is higher than that of aldehydes, and their contribution to the odor of fish products is relatively small. They mainly provide sweet floral flavors. Methylheptenone has a citrus and fruity odor. Its content is higher in the MD and XM groups, but not detected in the CK group.

[0136] Esters are generated by esterification of alcohols and acids. They are the main source of fruity, sweet and floral aromas and have a low odor threshold, so they have a greater impact on the overall odor of fish. Compared with the CK group, the fish with added spice extract had a higher content of methyl butyrate, which provided the fish with a pineapple aroma. Methyl 2-methylbutyrate, which has a fruity aroma, was only detected in the DX group.

[0137] Heterocyclic compounds, mainly including pyrazines and furans, are typical aroma components in fried foods. Pyrazine compounds play a leading role in the roasted caramel flavor, such as 2-methylpyrazine, 2,3,5-trimethylpyrazine and 3-ethyl-2,5-dimethylpyrazine, which can give the sample meaty, nutty and aromatic characteristics. After 3 days of storage, the content of heterocyclic compounds in the group treated with spice extract was higher than that in the control group, indicating that the spice extract promoted the formation and transformation of flavor substances in fish meat during the pickling and frying process, making it have a more unique and rich flavor characteristics. Compared with the control group, the GP, MD, and DX groups had the highest concentrations of heterocyclic substances, reaching 27.50, 24.46, and 22.73 μg / kg. The DX group produced a higher content of melanoidins, indicating that its Maillard reaction was higher. High molecular weight melanoidins generated by the Maillard reaction, as well as low molecular weight pyrroles, furans, and reductones, all have antioxidant activity. This is also one of the reasons why clove extract has a significant inhibitory effect on lipid oxidation.

[0138] In summary, clove extract, galangal extract, cinnamon extract, pepper extract, rosemary extract, and citronella extract can effectively inhibit lipid oxidation in fried oval pomfret chunks, among which clove extract and rosemary extract have more prominent antioxidant effects. The addition of clove extract and rosemary extract can delay lipid oxidation in the fish chunks during processing and storage, reduce the content of saturated aldehydes in the fish chunks, and give the fried oval pomfret chunks a new aroma and baking aroma, making the flavor of the fish chunks more layered and with good sensory acceptance. The volatile flavor substances of the fried oval pomfret chunks with galangal extract and citronella extract are similar to those of the control fried oval pomfret chunks, but the ability to alleviate oxidized lipids in the fried oval pomfret chunks during processing is relatively low, making the fish chunks more prone to deterioration and having low sensory acceptance. Comprehensive comparison shows that among the six spices added to oval pomfret, the addition of clove extract can not only significantly reduce the POV value and TBA value of fish pieces after accelerated oxidation and delay lipid oxidation, but also introduce other good flavors while retaining the original flavor of fried fish pieces, and has good sensory acceptance.

[0139] 1.6 Effect of different amounts of clove extract on the POV of lipids extracted from fried fish nuggets

[0140] Further, fried fish nuggets were prepared according to the methods in Examples 1 and 7 to 10, and the effects of different amounts of clove extract added on the lipid POV extracted from fried fish nuggets were tested according to the method in 1.1 above. The results are as follows: Figure 6 shown.

[0141] Figure 6 CK represents the peroxide value measured by the fried fish nuggets prepared in Comparative Example 1; the abscissa 0.5 represents the peroxide value measured by the fried fish nuggets prepared in Example 7; the abscissa 1 represents the peroxide value measured by the fried fish nuggets prepared in Example 1; the abscissa 1.5 represents the peroxide value measured by the fried fish nuggets prepared in Example 8; the abscissa 2 represents the peroxide value measured by the fried fish nuggets prepared in Example 9; the abscissa 2.5 represents the peroxide value measured by the fried fish nuggets prepared in Example 10; Figure 6 Different lowercase letters indicate significant differences among the data (P<0.05).

[0142] Effect of clove extract addition on POV of fried egg-shaped pomfret fillets Figure 8 As shown in the results, after 3 days of accelerated oxidation of fish pieces, the POV value showed a downward trend with the addition of clove extract. There were significant differences between the CK group (0% clove extract addition) and the treatment groups with different clove extract additions (0.5%, 1%, 1.5%, 2%, 2.5%) (P<0.05), indicating that clove extract has an inhibitory effect on the peroxidation reaction of fish pieces.

[0143] 1.7 Effect of different amounts of clove extract on lipid TBA extracted from fried fish nuggets

[0144] Further, fried fish nuggets were prepared according to the methods in Examples 1 and 7 to 10, and the effects of different amounts of clove extract added on lipid TBA extracted from fried fish nuggets were tested according to the method in 1.2 above. The results are as follows: Figure 7 shown.

[0145] Figure 7 CK represents the TBA measured by the fried fish nuggets prepared in Comparative Example 1; the abscissa 0.5 represents the TBA measured by the fried fish nuggets prepared in Example 7; the abscissa 1 represents the TBA measured by the fried fish nuggets prepared in Example 1; the abscissa 1.5 represents the TBA measured by the fried fish nuggets prepared in Example 8; the abscissa 2 represents the TBA measured by the fried fish nuggets prepared in Example 9; the abscissa 2.5 represents the TBA measured by the fried fish nuggets prepared in Example 10; Figure 7 Different lowercase letters indicate significant differences among the data (P<0.05).

[0146] Effect of clove extract addition on TBA of fried egg-shaped pomfret fillets Figure 8 As shown in the figure, after 3 days of accelerated oxidation of fish chunks, the TBA values ​​of the experimental groups with added clove extract were lower than those of the CK group, and showed a decreasing trend with the increase of the added amount. This shows that the addition of clove extract can significantly inhibit the formation of malondialdehyde in fish chunks to a certain extent, and has the effect of alleviating fat oxidation. The TBA values ​​of the CK group and the clove extract added at 0.5% and 1% were significantly different (P<0.05). The difference between the addition amounts of clove extract of 1.5%, 2%, and 2.5% was not significant, indicating that the addition of clove extract after 1% has little effect on the TBA of fish chunks.

[0147] 1.8 Effect of different amounts of clove extract on the iodine value (IV) of fried fish nuggets

[0148] Further, fried fish nuggets were prepared according to the methods in Examples 1 and 7 to 10, and the effects of different amounts of clove extract added on the iodine value (IV) of fried fish nuggets were tested according to the method in 1.3 above. The results are as follows: Figure 8 shown.

[0149] Figure 8CK represents the iodine value (IV) measured by the fried fish nuggets prepared in Comparative Example 1; the abscissa 0.5 represents the iodine value (IV) measured by the fried fish nuggets prepared in Example 7; the abscissa 1 represents the iodine value (IV) measured by the fried fish nuggets prepared in Example 1; the abscissa 1.5 represents the iodine value (IV) measured by the fried fish nuggets prepared in Example 8; the abscissa 2 represents the iodine value (IV) measured by the fried fish nuggets prepared in Example 9; the abscissa 2.5 represents the iodine value (IV) measured by the fried fish nuggets prepared in Example 10; Figure 8 Different lowercase letters indicate significant differences among the data (P<0.05).

[0150] Effect of clove extract addition on the IV of fried egg-shaped pomfret fish pieces Figure 8 As shown in the figure, after 3 days of accelerated oxidation of fish pieces, the IV of the experimental group with added clove extract was higher than that of the CK group, and showed an increasing trend with the increase of the added amount. This shows that the addition of clove extract can significantly reduce the oxidation rate to a certain extent (P<0.05). Among them, the iodine value of adding 2.5% clove extract was higher, reaching 29.32g / 100g. There was no significant difference in the iodine value of adding 1% and 1.5% clove extract (P<0.05).

[0151] 1.9 Effects of different added amounts of clove extract on sensory evaluation of fried fish nuggets.

[0152] Further, fried fish nuggets were prepared according to the methods in Examples 1 and 7 to 10, and the sensory effects of different amounts of clove extract on fried fish nuggets were evaluated according to the method in 1.4 above. The results are as follows: Figures 9-10 shown. Fig. 9 It is a bar graph of sensory scores (different lowercase letters indicate significant differences between the data (P<0.05)); Fig.10 Radar chart for sensory ratings.

[0153] Figures 9-10 CK represents the sensory evaluation results of the fried fish nuggets prepared in Comparative Example 1; 0.5 / 0.5% represents the sensory evaluation results of the fried fish nuggets prepared in Example 7; 1 / 1% represents the sensory evaluation results of the fried fish nuggets prepared in Example 1; 1.5 / 1.5% represents the sensory evaluation results of the fried fish nuggets prepared in Example 8; 2 / 2% represents the sensory evaluation results of the fried fish nuggets prepared in Example 9; 2.5 / 2.5% represents the sensory evaluation results of the fried fish nuggets prepared in Example 10; Fig. 9 Different lowercase letters indicate significant differences among the data (P<0.05).

[0154] Effect of clove extract addition on sensory evaluation of fried oval pomfret fillets Figures 9-10As shown, the scores of the group with 1% DX in each sensory attribute were significantly higher than those of the other groups, and the sensory evaluation score was 36 points. As the amount of clove extract added increased, the color of the fish pieces gradually deepened. If the color of the fish pieces was too dark, the sensory visual effect would be poor. The clove group produced a higher content of melanoidins, indicating that its Maillard reaction degree was higher. When the amount of clove added was 2 and 2.5%, the clove aroma in the fish pieces was stronger and the aroma of the fish pieces was weaker, resulting in the incoordination between the fried fish pieces and the aroma of spices, and the overall acceptability was low. When the amount of clove added was 0.5%, the clove aroma in the fish pieces was weaker. When the amount of clove extract added was 1%, the fried fish pieces were more coordinated with the aroma of spices, the color was golden yellow, and the overall acceptability was high.

[0155] 1.10 Effects of different amounts of clove extract on volatile flavor compounds in fried fish nuggets

[0156] Furthermore, fried fish nuggets were prepared according to the methods in Example 1 and Examples 7 to 10, and the volatile flavor substances in the fried fish nuggets were measured according to the method in 1.5 above to study the effects of different added amounts of clove extract on the volatile flavor substances in the fried fish nuggets; the results are shown in Table 4 below.

[0157] Table 4 - Effect of clove extract addition on the content of volatile flavor substances (μg / kg) in fried oval pomfret

[0158]

[0159]

[0160] In Table 4, 0 represents the fried fish nuggets prepared in Comparative Example 1; 0.5 represents the fried fish nuggets prepared in Example 7; 1 represents the fried fish nuggets prepared in Example 1; 1.5 represents the fried fish nuggets prepared in Example 8; 2 represents the fried fish nuggets prepared in Example 9; and 2.5 represents the fried fish nuggets prepared in Example 10.

[0161] The effect of the amount of clove extract added on the volatile flavor of fried oval pomfret nuggets is shown in Table 4. A total of 42 volatile compounds were detected, including 10 aldehydes, 4 ketones, 5 alcohols, 4 aromatics, 9 heterocyclics, 6 olefins, 2 acids, and 2 esters.

[0162] Aldehydes come from the decomposition of unsaturated fatty acids. Among aldehyde compounds, the content of hexanal is relatively high. Hexanal is a representative substance of fat oxidation. Compared with the control group, except for the 2% DX group, the other groups showed a significant downward trend with the increase of clove addition. Nonanal is an oxidation product of oleic acid. Compared with the control group, the content of nonanal decreased significantly with the increase of clove addition. Benzaldehyde is a degradation product of phenylalanine, indicating that amino acid degradation occurred in fish pieces after accelerated oxidation, and the addition of clove extract could not inhibit all oxidation. The generation of hexanal, nonanal and benzaldehyde indicates that lipid oxidation has occurred during processing or storage. With the increase of clove extract, the content of hexanal, nonanal and benzaldehyde decreased, indicating that clove extract can inhibit the decomposition or transformation of such substances to a certain extent.

[0163] Ketone compounds are generally formed by the oxidation and decarboxylation of unsaturated fatty acids. Some ketone substances come from spices and play an important role in the overall flavor of aquatic products. Methyl heptenone was detected in the DX group. This substance has a citrus and fruity smell and can give the product a pleasant aroma.

[0164] Alcohols generally come from the auto-oxidation reaction of unsaturated fatty acids and have a mild plant aroma. Unsaturated alcohols have a low threshold and contribute more to flavor. 1-octen-3-ol has a mushroom and fishy smell and is one of the sources of fishy smell in fish. As the amount of clove extract added increases, the content of 1-octen-3-ol decreases. When the amount of clove extract added is 2.5%, no 1-octen-3-ol is detected. This shows that adding clove extract can effectively reduce the fishy smell. In addition, the addition of clove extract makes the fish pieces produce a rich aroma, which is mainly reflected in the increase of spice substances such as α-pineneol (fresh, aromatic eucalyptus flavor).

[0165] Esters are formed by the esterification of alcohols and acids, and generally have a fruity aroma, contributing greatly to the flavor. Compared with the control group, the ester content increased with the increase in the amount of cloves added. Methyl butyrate and methyl 2-methylbutyrate provide a fruity aroma to the fried egg-shaped pomfret chunks. In addition, olefin compounds such as mentha-1,5-diene, caryophyllene, and curcumin usually exhibit relatively fresh and soft aromas such as herbal and fruity aromas, which can give the product a pleasant aroma. The content and variety of samples in the DX group are relatively rich, all of which come from the addition of spices attached to the meat chunks during marinating.

[0166] The preparation method of fried fish nuggets of the present invention significantly improves the antioxidant capacity of fried fish nuggets after adding spice extracts (clove extract, galangal extract, cinnamon extract, prickly ash extract, rosemary extract and citronella extract), inhibits lipid oxidation reaction, wherein clove extract has the greatest inhibition degree on primary and secondary oxidation of lipids, which are 63.55% and 86.67% respectively; the iodine values ​​of rosemary extract group and clove extract group are relatively high, which are 29.22g / 100g and 21.68g / 100g respectively; clove extract and rosemary extract can significantly inhibit lipid oxidation of fried fish nuggets (P<0.05). Adding spice extracts can increase the flavor substances of fried fish nuggets, and at the same time reduce the content of bad flavor substances in fried fish nuggets, wherein the clove extract group gives fried egg-shaped pomfret scad fish nuggets more fragrance and baking aroma, and the overall sensory acceptance is relatively high. After optimizing the conditions, it was found that the POV and TBA of the fried oval pomfret fish nuggets with 1% clove extract were lower than those of the control group; the IV was higher than that of the control group, and the fried fish nuggets were more coordinated with the spice flavor, and the sensory score reached 36 points, which was better than other groups, indicating that the clove extract can effectively inhibit lipid oxidation and maintain the good flavor of the product. The present invention provides a theoretical basis for the application of spice extracts in oil thermal processing aquatic products, and also opens up new ideas and directions for lipid oxidation and flavor regulation of pre-processed aquatic products.

[0167] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing fried fish nuggets, characterized in that: The following steps are involved: Add the fish pieces to the marinade, then add the spice extract and marinate; After drying the pickled fish pieces, frying them in edible oil to obtain fried fish pieces; The spice extract comprises at least one of clove extract, galangal extract, cinnamon extract, prickly ash extract, rosemary extract and citronella extract.

2. The method for preparing fried fish nuggets according to claim 1, characterized in that: The clove extract has a eugenol content of 1.46-1.48 mg / g, a total flavonoid content of 51.7-56.36 mg / g, and a total phenol content of 35.59-37.99 mg / g; The galangin mass content of the galangal extract is 2.79-3.01 mg / g, the total flavonoid mass content is 13.46-15.04 mg / g, and the total phenol mass content is 11.49-16.19 mg / g; The cinnamaldehyde content of the cinnamon extract is 0.16-0.17 mg / g, the total flavonoids content is 22.01-24.47 mg / g, and the total phenols content is 18.02-22.04 mg / g. The alkaloid mass content of the Zanthoxylum bungeanum extract is 0.64-0.65 mg / g, the total flavonoid mass content is 34.38-36.92 mg / g, and the total phenol mass content is 49.51-53.79 mg / g; The rosemary extract has a carnosic acid content of 9.77-9.83 mg / g, a rosmarinic acid content of 22.95-23.01 mg / g, a total flavonoid content of 11.10-11.26 mg / g, and a total phenol content of 3.73-7.85 mg / g; The citronellal mass content in the citronella extract is 0.01-0.02 mg / g, the total flavonoid mass content is 21.78-22.72 mg / g, and the total phenol mass content is 21.08-23.52 mg / g.

3. The method for preparing fried fish nuggets according to claim 1, characterized in that: The fish pieces are added into the marinade, and then the spice extract is added. In the marinating step, the mass of the spice extract is 1-3% of the mass of the fish pieces.

4. The method for preparing fried fish nuggets according to claim 1, characterized in that: The marinade comprises salt, onion, ginger and garlic powder, cooking wine and white pepper powder, wherein the mass of the salt is 2-2.5% of the mass of the fish block, the mass of the onion, ginger and garlic powder is 1.5-2% of the mass of the fish block, the mass of the cooking wine is 2-2.5% of the mass of the fish block, and the mass of the white pepper powder is 1-1.5% of the mass of the fish block.

5. The method for preparing fried fish nuggets according to claim 1, characterized in that: Add the fish pieces to the marinade, then add the spice extract, and marinate at 2-4°C for 1-1.5 hours.

6. The method for preparing fried fish nuggets according to claim 1, characterized in that: The marinated fish pieces are dried and then fried in edible oil at a temperature of 145 to 155° C. for 3.5 to 4 minutes to obtain fried fish pieces.

7. The method for preparing fried fish nuggets according to claim 1, characterized in that: In the step of drying the pickled fish pieces, the drying temperature is 50 to 55° C. and the drying time is 1 to 1.5 hours.

8. The method for preparing fried fish nuggets according to any one of claims 1 to 7, characterized in that: The spice extract is clove extract, and the mass of the clove extract is 1% of the mass of the fish block.

9. The method for preparing fried fish nuggets according to any one of claims 1 to 7, characterized in that: The spice extract is rosemary extract, and the mass of the rosemary extract is 1.85% of the mass of the fish block; And / or, the fish chunks include at least one of salmon chunks, golden pomfret chunks, tuna chunks, and grouper chunks.

10. A fried fish nugget, characterized in that: The preparation method is as described in any one of claims 1 to 9.

Images