CN112881549A - Detection and evaluation method for flavor of dried scallop - Google Patents

Abstract

The invention discloses a method for detecting and evaluating flavor of dried scallop, belonging to the technical field of food detection, which takes the dried scallop as an object, obtains the rehydrated dried scallop after rehydration, adopts a moisture determination method in food to determine the moisture content and rehydration rate of the rehydrated dried scallop, adopts a colorimeter to determine the muscle color difference of the rehydrated dried scallop, adopts a scanning electron microscope to observe the cross section and the vertical section of the rehydrated scallop, adopts High Performance Liquid Chromatography (HPLC) to determine the amino acid content of the rehydrated dried scallop, adopts a water extraction method to extract betaine, adopts a colorimetric method to determine the betaine content, adopts a TAV value to evaluate the taste of the betaine, adopts the high performance liquid chromatography to determine an ATP related compound, adopts GC-MS to analyze volatile components, can comprehensively know the nutrient components and the flavor characteristics of the dried scallop, can objectively and quantitatively evaluate the flavor of the dried scallop without depending on the subjective evaluation of experts, thereby providing an effective technical means for the research of the flavor substances of the dried scallop.

Description

Detection and evaluation method for flavor of dried scallop

Technical Field

The invention relates to the technical field of food detection, in particular to a detection and evaluation method for flavor of dried scallop.

Background

Scallop, also called Yubei, Yu and scallop, is a seafood raw material prepared from the posterior adductor muscle of shellfish of the families scallopaceae and atrina of the order Heterocyliales of the order of the gills by sun-curing. Dried scallop, bird's nest, sea cucumber shark's fin, abalone, fish maw, fish lip and roe are called eight delicacies in sea. The dried scallop has high protein content and is rich in various mineral substances and fatty acids, has the effects of nourishing yin, tonifying kidney, regulating middle warmer and descending qi, promoting growth and development and the like, is beneficial to reducing blood pressure and cholesterol after being eaten frequently, and has a certain function of regulating blood fat. Scallops for manufacturing dried scallop are distributed in yellow sea, Bohai sea and southeast coastal sea in China, and mostly live in sandy seabed and intertidal zone in shallow sea with the water depth of 2-4 m. The scallops are generally harvested and processed after 3-4 years of culture period until the individual grows to be more than about 7 cm. At present, the dried scallop is mainly produced in the north, the annual output is greatly improved along with the maturity of the breeding technology, so as to meet the increasingly high consumption demand of the people.

At present, domestic and foreign reports on dried scallop are mainly focused on the aspects of drying process, edible value, cooking method, cultivation technology and the like. The Shenshuqi et al keep alive the Argopecten irradians purchased from the water product market in Qinhuang island without water, and measure the changes of the water content, coarse ash content, coarse fat, coarse protein, glycogen, lactic acid and other nutrient components. However, in the research on the volatile components of dried scallop, Hau Yin Chunga adopts a Simultaneous Distillation Extraction (SDE) method to extract frozen and dried scallop, and utilizes a gas chromatography-mass spectrometry (GC-MS) technology to analyze and compare the volatile components of two scallops. The comprehensive analysis of nutrient components and flavor detection of the dried scallop are not reported.

Disclosure of Invention

The invention aims to provide a method for detecting and evaluating the flavor of dried scallop, which is used for solving the problems in the prior art, analyzing the comprehensive nutritional ingredients of the dried scallop, detecting and evaluating the flavor of the dried scallop and comprehensively knowing the nutritional ingredients and the flavor characteristics of the dried scallop.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a detection and evaluation method of dried scallop flavor, which comprises the following steps: the method comprises the steps of obtaining rehydrated dried scallop after rehydration by taking the dried scallop as an object, measuring the moisture content and rehydration rate of the rehydrated dried scallop by a moisture measuring method in food, measuring the muscle color difference of the rehydrated dried scallop by a colorimeter, observing the cross section and the vertical section of the rehydrated scallop by a scanning electron microscope, measuring the amino acid content of the rehydrated dried scallop by a High Performance Liquid Chromatography (HPLC), extracting betaine by a water extraction method, measuring the content of the betaine by a colorimetry, evaluating the taste of the betaine by a TAV value, measuring an ATP related compound by the high performance liquid chromatography, and analyzing volatile components by GC-MS.

Preferably, the moisture content is determined according to the moisture assay method in GB5009.3-2016 food products, and the rehydration rate is calculated according to formula (1):

wherein RR: rehydration rate, Wr: sample mass after rehydration, Wd: the quality of the dried scallop before being dried is the quality of the fresh scallop.

Preferably, the method for measuring the color difference of the rehydrated scallop muscle by using the colorimeter comprises the following steps of: measured in natural light by a colorimeter, brightness, redness, greenness, yellowness and blueness are represented by L, a, b, respectively, and the total difference in color is evaluated by Δ E, Δ E ═ Δ L²+(Δa*)²+(Δb*)²]^1/2。

Preferably, the chromatographic conditions for determining the amino acid content of the rehydrated scallop by adopting the high performance liquid chromatography are as follows: KromatC18 column (250 mm. times.4.6 mm. times.5 μm), column temperature: 40 ℃, mobile phase a: acetonitrile, mobile phase B: 0.03mol/L acetate buffer (pH 5.2), detection wavelength: 360nm, flow rate: 1m L/min, injection volume: 10 μ L.

Preferably, the extraction of betaine by water extraction comprises the following steps: decocting scallop with water for 3 times, the water amount is 6 times, 5 times and 4 times of scallop, boiling for 1 hr, 1 hr and 0.5 hr, cooling, mixing filtrates, filtering, and concentrating the filtrate under reduced pressure to obtain betaine.

Preferably, the colorimetric determination of betaine content comprises the following steps: the betaine was dissolved in 70% acetone by mass, the absorbance was measured at 525m, and the content was then looked up on a betaine standard solution.

Preferably, the analysis of the chromatographic column in the volatile components by GC-MS in the determination of ATP related compounds by high performance liquid chromatography: COSMOSIL 5C₁₈MS-II (4.6 mm. times.250 mm. times.5 μm); mobile phase: 0.05mol/L KH₂PO₄-K₂HPO₄Buffer (2% methanol, pH 6.5); flow rate: 0.6mL/min, equal elution amount; column temperature: 25 ℃; detection wavelength: 254 nm; sample introduction amount: 20 μ L.

Preferably, the analysis of volatile components by GC-MS is:

SPME conditions: inserting the aged extraction head into a sample bottle, extracting at 60 deg.C for 30min, transferring into GC-MS joint sampler, and desorbing at 250 deg.C for 3 min;

gas chromatography conditions: rtx-5MS elastic capillary column (30 mm. times.0.25 μm); temperature programming: the initial column temperature was 50 ℃ and held for 5 min; setting a temperature rise speed of 5 ℃/min to 160 ℃, and keeping for 5 min; setting a heating rate of 10 ℃/min to heat to 250 ℃, and keeping for 2 min; inlet temperature: 250 ℃; air bearing capacity (He) flow rate: 1.0 mL/min;

mass spectrum conditions: electron energy 70 eV; the interface temperature is 250 ℃; the ion source temperature is 230 ℃; the mass scanning range is 40-400 um.

The invention discloses the following technical effects:

the invention takes dried scallop as an object, obtains the rehydrated dried scallop after rehydration, measures the moisture content and rehydration rate of the rehydrated dried scallop by a moisture measuring method in food, measures the muscle color difference of the rehydrated dried scallop by a colorimeter, observes the cross section and the vertical section of the rehydrated scallop by a scanning electron microscope, measures the amino acid content of the rehydrated dried scallop by a High Performance Liquid Chromatography (HPLC), extracts betaine by a water extraction method, measures the betaine content by a colorimetry, evaluates the ATP (adenosine triphosphate) taste of the betaine by a TAV (total adenosine triphosphate) value, measures related compounds by a high performance liquid chromatography, analyzes volatile components by a GC-MS (gas chromatography-mass spectrometry), can comprehensively know the nutrient components and the flavor characteristics of the dried scallop, can objectively and quantitatively evaluate the flavor of the dried scallop without depending on the subjective evaluation of experts, thereby providing an effective technical means for the research of flavor substances of the dried scallop.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a 2000 XSEM (10 μm) image of dried scallop prepared from KGM group;

FIG. 2 is a 2000 XSEM image (10 μm) of dried scallop prepared in the control group.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

The scallop of the embodiment of the invention is a fresh bay scallop, which is purchased from the local market in Zhoushan of Zhejiang. KGM (purity > 95%) was purchased from West Anzel silicon technology, Inc., China, CA (purity > 99%) and SA (purity > 99%) were purchased from Jiangsu white drug biotechnology, Inc., China, and the oven was purchased from Shanghai-Hengshi technology, Inc.

Fresh scallops (total weight with shell 15kg, sample number 400 parts) were purchased from the local market in Zhoushan, Zhejiang, after removing shell and internal organs, adductor muscles were taken and washed with distilled water, and adductor muscles (i.e. later appearing scallop muscles) were divided into four groups (100 parts each) with no significant difference in each group. The first group was soaked in 3% NaCl aqueous solution at 4 ℃ for 30min (as control group); soaking the second group in mixed solution of 0.2% konjac glucomannan and 3% NaCl (w/v) at 4 deg.C for 30min (marked as KGM group); soaking the third group in a mixed solution of 2% carrageenan and 3% NaCl (w/v) at 4 deg.C for 30min (as CA group); the fourth group was soaked in a mixed solution of 0.2% sodium alginate and 3% NaCl (w/v) at 4 ℃ for 30min (designated as SA group). The soaked adductor muscle is dried in a drying oven at 80 deg.C for 6 hr to obtain dried scallop, and then vacuum packaging them, and storing at room temperature for 48 hr.

Rehydration: soaking dried scallop in purified water at 25 deg.C for 2 hr for rehydration.

Example 1 determination of moisture content and rehydration

Moisture determination moisture was determined according to the moisture determination method in GB5009.3-2016 food products.

And (3) measuring the rehydration rate, namely respectively putting the four groups of dried scallop samples into 100mL of distilled water for soaking for 2h, taking out the rehydration samples, absorbing excessive water on the surfaces of the samples by using filter paper, and weighing, wherein the rehydration rate is calculated according to the formula (1):

wherein RR: rehydration rate, Wr: sample mass after rehydration, Wd: the quality of the dried scallop before being dried is the quality of the fresh scallop.

The moisture content and rehydration results for the four groups are shown in table 1.

TABLE 1

Note: the values of the different superscripts (a-c) differed significantly (P < 0.05).

As can be seen from Table 1, the moisture contents of the control group, KGM group, CA group and SA group after rehydration of dried scallop were 76.06% + -2.17%, 73.93% + -1.06%, 77.25% + -1.34% and 73.13% + -2.51, respectively, and the rehydration rates were 88.73 + -0.12, 90.83 + -0.15, 85.47 + -0.07 and 89.73 + -0.17, respectively. The water content of KGM group and CA group are lower than that of the control group and have obvious difference (P <0.05), but the rehydration rate (R R) of the KGM group and the CA group is higher than that of the control group and have no obvious difference (P > 0.05). This is probably because the complex gel structure formed by konjac glucomannan and myofibrillar protein has stronger binding force to water, and the retention rate of water in the gel is increased. In addition, sodium alginate has strong hydrophilicity and is an excellent water-retaining agent, and in the SA group, the water content is the highest and the rehydration rate is the lowest (P < 0.05). One of the reasons may be that carrageenan dissolves in water to form a hydrophilic gel, adheres to the surface of scallop muscle and solidifies during drying, and this solidified layer reduces the water absorption capacity of scallop muscle and thus reduces its rehydration rate. The addition of the K-carrageenan can obviously reduce the water loss rate of the meat gel and effectively improve the water retention property of the meat gel.

Example 2 color difference measurement

Color difference value utilizing colorThe measurement was performed under natural light by a photometer (CM-5; Konica Minolta, Tokyo, Japan). The lightness, redness, greenness, yellowness and blueness are denoted by L, + a, -a, + b, -b, respectively. At the same time, the total color difference was evaluated by Δ E ═ Δ L ═ Δ E ═ Δ L-²+(Δa*)²+(Δb*)²]^1/2. Each set of 6 samples, each measured 3 times and averaged. The results are shown in Table 2.

TABLE 2

As can be seen from Table 2, there was no significant difference in the L values for all samples. The a values of the four groups of samples have no significant difference (P > 0.05). However, there was a significant difference in a values between the SA and CA groups (P < 0.05). In the SA group, the a values of the samples decreased and turned green, while the a values of the samples in the CA group increased and turned red. After the carrageenan pretreatment, the b values of the samples were significantly different from those of the control group, the KGM group and the CA group, and were significantly reduced. The yellowness tends to decrease with increasing agar or carrageenan concentration. After the addition of KGM, the a values were higher and L and b values were lower for the gel samples. The reason is that the amino group and the carbonyl group in the muscle protein have Maillard reaction, so that the yellow color of the surface of the scallop muscle is deepened, and the quality of the scallop muscle is improved.

Example 3 microstructure

The cross-sections and vertical sections of the four groups of prepared dried scallop were observed with a Scanning Electron Microscope (SEM). The samples were cut to 1mm × 1mm × 3mm, first fixed with 2.5% glutaraldehyde solution, washed with phosphate buffer and dehydrated with ethanol gradients of different concentrations, and then CO₂Critical drying, and finally subjecting the surface of the sample to ion spraying and observing the surface by SEM magnification of 500 times, 2000 times, and 5000 times (Hitachi S-4300SE, Hitachi science systems Co., Ltd., Japan).

Scanning Electron Microscope (SEM) results of the scallops prepared in the KGM group and the control group are shown in fig. 1 and 2, respectively. The control, KGM and SA groups all curled to different degrees when viewed in vertical section (500 ×), and the CA group was relatively flat. Under a 2000X electron microscope, the KGM group showed more muscle breakage and curling, the control group showed slight breakage, the CA group showed the best effect, and the muscle was almost not broken. Wrinkles with different degrees can be clearly seen in four groups of fractures under a 5000X electron microscope, and the curling degrees of the four groups of fractures are KGM group > SA group > CA group. The breakage is closely related to the scallop drying process. The temperature difference exists between the inside and the outside of the scallop muscle in the drying process, so that the uneven internal and external water loss is easily caused, and larger internal stress is generated to further cause the fracture in different degrees. In addition, Maillard reactions during drying also tend to cause protein aggregation and fragmentation. In addition, the high-quality gel structure formed between KGM and protein may have a certain water loss resistance during heating, resulting in protein breakage, and therefore in the SA group, the gel film on the surface of scallop blocks the water loss, resulting in a certain degree of breakage.

From the cross-sectional view (500 ×), the control had many cracks at the white boundary. The KGM group broke to a lesser extent. Whereas the SA group had many cracks. Meanwhile, the muscle tissue of the CA group had almost no cracks. Under a 2000 × microscope, dense tissue structures were observed for all four groups of samples. Although a clear white gap boundary was visible in the control group, the gap did not affect the tightness of the tissue structure. In addition, there was a significant curl at the end of the KGM group. At 5000 × magnification, the terminal tissue curling degree of the four groups of samples can be clearly seen as KGM group > SA group > CA group. This is mainly because the proteins and KGM are linked to each other to form a dense network structure that can lock water or other nutrients.

Thus, KGM treated samples have higher degree of breakage and more curling, but also have higher compactability due to protein denaturation during scallop drying. Denaturation of proteins can create protein-protein interactions leading to protein aggregation. The CA group had the highest fiber structural integrity.

Example 4 amino acid determination

Determining the content of amino acid by High Performance Liquid Chromatography (HPLC), wherein the chromatographic conditions are as follows: KromatC18 column (250 mm. times.4.6 mm. times.5 μm), column temperature: 40 ℃, mobile phase a: acetonitrile, mobile phase B: 0.03mol/L acetate buffer (pH 5.2), detection wavelength: 360nm, flow rate: 1m L/min, injection volume: 10 μ L.

Amino acids are the basic units that make up proteins, and their composition and content are often used as a quality indicator for fish and crustacean products. Amino acids are not only a source of seafood umami but also present many complex taste characteristics, such as sweetness and bitterness. Delicious Amino Acids (DAAs) such as asparagine, glycine, alanine, arginine, glutamic acid and proline have been identified as the major free amino acids of live scallop active ingredients and boiled-dried scallops. Glycine is closely related to the palatability of shellfish muscles and is a main amino acid affecting the taste of scallops.

The amino acid content of the four groups of samples is shown in table 3. The total amino acid content of the SA group is higher than that of the control group, and the total amino acid content of the KGM group and the CA group is lower than that of the control group. Amino acids are mainly derived from the breakdown of proteins by endogenous proteolytic enzymes. For carrageenan-treated scallop, Na⁺Can adhere to the surface of the scallop and affect the gel strength of the scallop. In the drying process of the oven, the temperature difference is generated inside and outside the scallop. The activity of the scallop endogenous enzyme is higher than that of a control group, the protein decomposition rate is higher, and the amino acid content is higher than that of the control group.

TABLE 3

EXAMPLE 5 betaine assay

Extracting betaine by water extraction method, determining its content by colorimetric method, and evaluating betaine taste by TAV value. The water extraction method for extracting the betaine comprises the following steps: decocting scallop with water for 3 times, the water amount is 6 times, 5 times and 4 times of scallop, boiling for 1 hr, 1 hr and 0.5 hr, cooling, mixing filtrates, filtering, and concentrating the filtrate under reduced pressure to obtain betaine. The colorimetric method for determining the content of the betaine specifically comprises the following steps: betaine can generate red precipitate with Raynaud's salt at pH 1, dissolving betaine in acetone with a mass concentration of 70%, measuring absorbance at 525m, and searching content on betaine standard solution. The analytical results are shown in Table 4.

TABLE 4

Betaine is contained in crustaceans, mollusks, aquatic animals and fishes in high content, can effectively increase sweet taste, and is one of main flavor substances of aquatic products. It can be seen from table 4 that the TAV values of the four groups of samples were greater than 1, the TAV value of KGM group was the largest (35.82), and the CA group, SA group and control group were 30.67, 25.34 and 20.72, respectively. This indicates that KGM, CA and SA pretreatment of the samples can effectively affect scallop flavor, and that KGM has the greatest effect. The reason for this is probably that betaine has stable physicochemical properties and high temperature resistance, and the high temperature treatment destroys the structure of scallop during processing, and fully releases betaine.

EXAMPLE 6 determination of ATP-related Compounds

Analysis by HPLC, column: COSMOSIL 5C₁₈MS-II (4.6 mm. times.250 mm. times.5 μm); mobile phase: 0.05mol/L KH₂PO₄-K₂HPO₄Buffer (2% methanol, pH 6.5); flow rate: 0.6mL/min, equal elution amount; column temperature: 25 ℃; detection wavelength: 254 nm; sample introduction amount: 20 μ L. The results are shown in Table 5.

TABLE 5

Besides amino acids, part of the nucleotides can also enhance the overall taste of seafood. Table 5 shows that the ATP content in the SA group was the highest among the four groups96.8mg/kg, whereas ATP was not detected in KGM group. The control group had an AMP content of 429.3mg/kg, followed by the CA, SA and KGM groups (251.1 mg/kg, 203.2mg/kg and 124.1mg/kg, respectively). The highest IMP content in the SA group was 880.8mg/kg, followed by the control, KGM and CA groups (717.4 mg/kg, 593.6mg/kg and 507.7mg/kg, respectively), and all were above the threshold, indicating that they contribute to the taste of scallops. In general, the breakdown pathway of ATP of shellfish after death is ATP → ADP → AMP → IMP → H_XR→H_X. Wherein AMP is a good flavoring agent in shellfish meat; IMP is a glutamic acid-fortified umami substance that imparts sweetness to meat and can exhibit an intense umami taste, while it exhibits an unpleasant bitter taste when converted to HxR and Hx. The sum of HxR and Hx content for the SA group was 230.0mg/kg, which is significantly higher than that for the other groups. However, the addition of the carrageenan can increase the richness of the flavor of the scallop, improve the umami taste of the scallop, and reduce the generation of bitter taste to a certain extent.

EXAMPLE 7 volatile component analysis

Analysis by GC-MS:

SPME conditions: inserting the aged extraction head into a sample bottle, extracting at 60 deg.C for 30min, transferring into GC-MS joint sampler, and desorbing at 250 deg.C for 3 min.

Gas chromatography conditions: rtx-5MS elastic capillary column (30 mm. times.0.25 μm); temperature programming: the initial column temperature was 50 ℃ and held for 5 min; setting a temperature rise speed of 5 ℃/min to 160 ℃, and keeping for 5 min; setting a heating rate of 10 ℃/min to heat to 250 ℃, and keeping for 2 min; inlet temperature: 250 ℃; air bearing capacity (He) flow rate: 1.0 mL/min.

Mass spectrum conditions: electron energy 70 eV; the interface temperature is 250 ℃; the ion source temperature is 230 ℃; the mass scan range is 40-400 um. The results are shown in Table 6.

TABLE 6

Table 6 shows the results of the muscle volatile component analysis of the control group, KGM group, SA group and CA group scallop. A total of 78 compounds were identified. The number of esters (15) is the largest, and other compound classes include amines (7), acids (10), ketones (6), alkanes (10), aldehydes (6), arenes (6), phenolic compounds (6), alcohols (5), bases (3), furans (3), naphthalenes (2), pyrazines (1) and pyridines (1).

15 esters were detected in all four groups of samples, with methyl palmitate accounting for 12.96% of the KGM group, followed by 12.83%, 8.57% and 7.17% of the CA, SA and control groups, respectively. Methyl palmitate is one of the main aroma components of Anji white tea, and is prepared by dehydrating and condensing higher fatty acid and lower alcohol. Butyl butyrate and diethylmethylcarbamoyl disulfide were also detected in the control, KGM and SA groups. Carbazolyl-3, 6-thiocyanate was detected in three groups other than the SA group at a ratio of up to 3.26% in the KGM group and 2.67% and 1.93% in the control and CA groups, respectively. Butyl butyrate is a low fatty acid ester that is commonly used as a flavor additive because it exhibits some fruity flavor. Residual esters were unique in each set of samples. For example, dodecyl methyl ester is characteristic of the control group and accounts for 5.65%. Triglycerides are characteristic of the SA group and account for 3.80%. Phenylacetic acid, 4- (1, 1-dimethylethyl) -methyl ester, was unique in the CA group and accounted for 2.21%. Wherein methyl dodecanoate and glycerol trioctylate are important components of mushroom flavor.

A total of 6 ketones were detected for the four groups of samples. Acetophenone was detected in KGM, SA and CA groups, accounting for 0.44%, 0.39% and 0.49%, respectively. The only ketones detected in the control group were 2-propanon-1-one, 1- (4-aminophenyl) -3-phenyl, accounting for 3.18%, and characteristic of the control group. Other ketones detected in the SA group were 3-methyl-3-cyclohexen-1-one (0.84%) and 7-methoxy-2, 3-diphenyl-4H-Chromen-4-one (0.43%). Generally, ketones are derived from lipid oxidation and degradation and maillard reactions.

Four groups of samples were tested for 10 acidic substances, of which tetracaprylic acid and palmitic acid were detected in the control group, KGM group and CA group. Three groups of palmitic acid were 11.16%, 9.46% and 12.01%, respectively. The tetra-decanoic acid accounted for 3.16%, 1.76%, and 2.34% in three groups, respectively. In addition, valeric acid (0.62%) and n-octadecanoic acid (0.66%) were detected, respectively, for the control group. Decanoic acid was detected separately in KGM group (1.36%). In the SA group, octanoic acid (1.07%) and benzene nitric acid (0.62%) were detected, respectively. Fumaric acid (0.44%), folic acid (2.28%) and 16-hydroxy-hexadecanoic acid (0.99%) were detected in the CA group, respectively.

Four sets of samples tested 6 aldehydes in total. Benzaldehyde was the aldehyde detected in all four groups, with the highest proportion of total volatile components in the SA group (5.09%), followed by the control, KGM and CA groups, accounting for 1.36%, 1.15% and 0.42%, respectively. Benzaldehyde has pleasant almond, nut and fruit aroma and is an important flavor component of crab meat and wild silurus meridionalis. 3-methylbutyraldehyde (1.47%) and (E) -2-heptanal (1.15%) were detected in the KGM group, respectively. In the SA group, 4-isopropylbenzaldehyde (1.03%) and acetaldehyde (0.53%) were detected, respectively. Different aldehydes have different odors, and C3C4 aldehydes have strong odors. The C5C9 aldehyde has green fragrance, oil wax fragrance, and oil putty fragrance. The C10C12 aldehyde has an orange peel and lemon flavor. These aldehydes are typically produced by lipid degradation oxidation.

A total of 5 alcohols were detected for the four groups of samples. Heptanol was detected in both control and CA groups (0.92% and 1.14%, respectively). 1-tetrasaccharide (0.73%) was isolated from the KGM group. In the SA group, 5-nonanol (3.95%) and menthol (1.11%), respectively, only 11-Heneicosanol (0.37%) was detected in the CA group. Alcohol is derived from lipid oxidation and degradation.

Four groups of samples tested 6 phenolic compounds. Yujinuo is the highest proportion of compounds in the four sample groups. The control, KGM, SA and CA groups accounted for 42.54%, 31.28%, 36.30% and 40.17%, respectively. Clove oil has a particularly strong spicy, bacon-like aroma. Phenol was detected simultaneously in the control group (0.87%), the KGM group (0.69%), the SA group (1.10%) and the CA group (0.76%). The phenolic compounds have a sweet taste. 2, 4-phenol was detected in the KGM group at 0.44%. Isopentenol (0.51%) and 3, 5-di-tert-butylphenol (6.42%) were detected in the SA group. Phenolic compounds are generally synthesized from the esters of alcohols and free fatty acids produced by the oxidation of fats, giving meat products a fruity taste. The phenolic compounds may also be derived from intestinal microbial fermentation of food or scallops.

Four groups of samples detected 8 hydrocarbons. Tetradecane (0.41%), nonane (0.64%), octadiene (0.64%) were detected in the control group. Octadecane (0.44%) and cyclooctane (0.58%) were detected in the KGM group, respectively. In the CA group, 1-methyl-2-methylenecyclohexane (0.53%) and hexadecane (0.43%) were detected, respectively. Most hydrocarbons have sweet and aromatic notes but generally have a high threshold and therefore do not contribute much to the note. Hydrocarbons are generally derived from lipid degradation. In addition, 6 aromatic hydrocarbon control groups, SA group and CA group were detected in combination to detect benzothiazole, accounting for 0.40%, 0.74% and 1.86%, respectively. 3, 3 ', 4, 4' -tetramethylbiphenyl was unique to example 1 and accounted for 1.48%. Naphthalene was detected in all four groups, with KGM, CA and CA groups accounting for 1.41%, 2.22%, 1.02% and 2.12, respectively. Biphenyl, naphthalene and phthalate are considered environmental pollutants. There was a different degree of detection in all four groups. 1, 1-Biphenyl has a pleasant, spicy, mild, geranium and strange complex odor. Naphthalene can be a product of microbial degradation of plant material or environmental pollutants. The olefins are believed to be oxidation products of fatty acids, or derived from N-6 PufAs.

Heterocyclic compounds including furan, pyridine and thiazole were detected in four samples. Furans are mainly produced by the thermal decomposition of amino acids, fat oxidation and maillard reactions, and tend to have a meaty taste. The control, KGM, SA and CA groups accounted for 2.65%, 3.09%, 1.77% and 3.14%, respectively. Wherein 3-methylindole is specific to the SA group and accounts for 11.05 percent. The presence of indole indicates that the microorganism contributes to the flavour of the product. Amines were also detected, 4 in the control group, 2 in the KGM group and 2 in the CA group. Amines generally have a decaying fishy odor. This also indicates that the pre-treatment combination produced a somewhat better mouthfeel than the control. Other compounds such as guanidines are detected, mostly from protein degradation, which may be related to added sugars and processing.

After the scallop muscle is soaked and pretreated in different modes, after the dried product is rehydrated, the water content of the CA group sample is the highest, and the rehydration rate of the KGM group sample is the highest. There was no significant difference in L and Δ E values for each set of samples in terms of color difference. The scallops pretreated with CA had a significant reduction in b, i.e. the yellowness of the scallops in the CA group was significantly reduced compared to the other groups. From SEM observation, it was found that the protein and KGM formed a three-dimensional network structure which helped lock the water, but also easily caused denaturation and aggregation of the protein during drying, so that the KGM group had a high degree of muscle fiber breakage and curling. In conclusion, KGM has excellent water retention, the CA group has a higher water content, and the yellowness is reduced.

The amino acid detection shows that the total content of CA group amino acid is the highest, and the content of flavor amino acid is the highest. The ATP-associated compound detection shows that the IMP content of the four groups of samples is greater than a threshold value, which is beneficial to the taste development of the scallops, and the IMP content of the CA group is the highest. The KGM group had the highest betaine content. In volatile component analysis, a total of 78 compounds were detected, most of which were ester compounds. Yujinnuo has the aroma of smoked meat and is the highest in the four groups of samples. Palmitic acid, methyl palmitate, myristic acid, biphenyl and heterocyclic compounds. Aldehydes which greatly contribute to the flavor of the samples, such as benzaldehyde, were also detected in the four groups of samples, and the proportion of benzaldehyde in the CA group was the highest. At the same time, some environmental contaminants, such as naphthalene and diphthalate, are detected in the sample, which complicates the taste of scallop muscle. Comparison and analysis show that the CA group has the highest total amino acid content, the highest flavor amino acid content, the highest ATP-related compound content and the highest IMP compound (such as benzaldehyde) content for enhancing the flavor of the scallop.

In conclusion, the method can comprehensively analyze and evaluate the nutrient components and the flavor of the dried scallop.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims (8)

1. The detection and evaluation method for the flavor of the dried scallop is characterized by comprising the following steps of: the method comprises the steps of obtaining rehydrated dried scallop after rehydration by taking the dried scallop as an object, measuring the moisture content and rehydration rate of the rehydrated dried scallop by a moisture measuring method in food, measuring the muscle color difference of the rehydrated dried scallop by a colorimeter, observing the cross section and the vertical section of the rehydrated scallop by a scanning electron microscope, measuring the amino acid content of the rehydrated dried scallop by a high performance liquid chromatography, extracting betaine by a water extraction method, measuring the betaine content by a colorimetry, evaluating the taste of the betaine by a TAV value, measuring an ATP related compound by the high performance liquid chromatography, and analyzing volatile components by GC-MS.

2. The method for detecting and evaluating the flavor of the dried scallop as claimed in claim 1, wherein the moisture content is measured according to a moisture measuring method in GB5009.3-2016 food, and the rehydration rate is calculated according to formula (1):

wherein RR: rehydration rate, Wr: sample mass after rehydration, Wd: the quality of the dried scallop before being dried is the quality of the fresh scallop.

3. The method for detecting and evaluating flavor of dried scallop as claimed in claim 1, wherein the method comprises the step ofThe method for measuring the muscle color difference of the rehydrated scallop by the colorimeter comprises the following steps: measured in natural light by a colorimeter, brightness, redness, greenness, yellowness and blueness are represented by L, a, b, respectively, and the total difference in color is evaluated by Δ E, Δ E ═ Δ L²+(Δa*)²+(Δb*)²]^1/2。

4. The detection and evaluation method for flavor of dried scallop meat as claimed in claim 1, wherein the chromatographic conditions for determining the amino acid content of the rehydrated dried scallop meat by high performance liquid chromatography are as follows: KromatC18 column, column temperature: 40 ℃, mobile phase a: acetonitrile, mobile phase B: 0.03mol/L acetate buffer, detection wavelength: 360nm, flow rate: 1m L/min, injection volume: 10 μ L.

5. The method for detecting and evaluating flavor of dried scallop as claimed in claim 1, wherein the extraction of betaine by water extraction comprises the following steps: decocting scallop with water for 3 times, the water amount is 6 times, 5 times and 4 times of scallop, boiling for 1 hr, 1 hr and 0.5 hr, cooling, mixing filtrates, filtering, and concentrating the filtrate under reduced pressure to obtain betaine.

6. The method for detecting and evaluating flavor of dried scallop as claimed in claim 1, wherein the colorimetric determination of betaine content comprises the following steps: the betaine was dissolved in 70% acetone by mass, the absorbance was measured at 525m, and the content was then looked up on a betaine standard solution.

7. The method for detecting and evaluating flavor of dried scallop as claimed in claim 1, wherein the step of analyzing the chromatographic column in volatile components by GC-MS in the determination of ATP-related compounds by high performance liquid chromatography is as follows: COSMOSIL 5C₁₈-MS-II; mobile phase: 0.05mol/L KH₂PO₄-K₂HPO₄A buffer solution; flow rate: 0.6mL/min, equal elution amount; column temperature: 25 ℃; detection wavelength: 254 nm; sample introduction amount: 20 μ L.

8. The detection and evaluation method for flavor of dried scallop as claimed in claim 1, wherein the GC-MS is used for analyzing volatile components, wherein the volatile components comprise:

SPME conditions: inserting the extraction head into a sample bottle, extracting at 60 deg.C for 30min, transferring into GC-MS joint sampler, and desorbing at 250 deg.C for 3 min;

gas chromatography conditions: rtx-5MS elastic capillary column; temperature programming: the initial column temperature was 50 ℃ and held for 5 min; setting a temperature rise speed of 5 ℃/min to 160 ℃, and keeping for 5 min; setting a heating rate of 10 ℃/min to heat to 250 ℃, and keeping for 2 min; inlet temperature: 250 ℃; air bearing capacity flow rate: 1.0 mL/min;

mass spectrum conditions: electron energy 70 eV; the interface temperature is 250 ℃; the ion source temperature is 230 ℃; the mass scanning range is 40-400 um.

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