Crispness grading method for crisp tilapia mossambica

Abstract

The invention provides a crispness grading method for crisp tilapia, and relates to the technical field of tilapia quality detection. The method for grading the crispness of the crisp tilapia mossambica comprises the following steps: determining the crispness of the raw crisp tilapia mossambica by adopting a texture analyzer, setting a sensory evaluation crispness grade for the cooked crisp tilapia mossambica, simultaneously performing sensory evaluation, and performing correlation analysis on the crispness value of the raw crisp tilapia mossambica and the sensory score of the cooked crisp tilapia mossambica. Therefore, the crispness value of the raw crisp-meat tilapia and the grading contrast condition of the cooked crisp-meat tilapia are set. According to the method, the defects in the prior art are overcome, and the sensory evaluation crispness grade of the cooked crisp tilapia can be predicted according to the meat crispness detection result of the raw crisp tilapia, so that reliable reference is provided for transaction pricing, breeding process crispness control, commodity grading and processing process quality control of the crisp tilapia.

Description

Technical Field

[0001] The invention relates to the technical field of tilapia quality detection, and in particular to a crispness grading method for crispy meat tilapia. Background Art

[0002] Tilapia is known as the "fish of the 21st century". Currently, there are more than 140 countries in the world that farm and produce tilapia. In 2017, experts pointed out at the "China Tilapia Industry Development Report" conference that global tilapia production has been on the rise. In 1990, the world's tilapia production was 1 million tons. By 2017, its production had reached 6.5 million tons. It is expected to reach 10 million tons in the next decade, becoming the world's largest aquaculture species. Maoming City is a major tilapia farming city and is known as the "Tilapia Capital of China". Maoming's tilapia industry has always been the largest in the country. In 2019, the tilapia farming area in Maoming City reached 260,000 mu, and the output reached 224,500 tons, accounting for about 1 / 3 of the total farming output in Guangdong Province and 1 / 8 of the total farming output in the country; the annual export volume was 108,000 tons, and the export value was US$323 million, an increase of 131% and 71% respectively compared with 5 years ago, making it the largest tilapia farming advantage area and export processing base in the country, and it has been listed as a national agricultural product regional public brand. The tilapia industry has become a pillar industry for increasing farmers' income in Maoming and earning foreign exchange through agricultural product exports.

[0003] Tilapia is farmed in my country in huge quantities, but domestic consumers are far less receptive to its taste than foreign consumers, so the main way to sell tilapia is through export. In recent years, affected by the external situation, the resistance to the export of tilapia in my country has increased, and the conversion of export to domestic sales has become a realistic choice for the tilapia industry to break through the difficulties. In addition, the price of tilapia has continued to be sluggish in recent years, which urgently requires the tilapia industry to reposition the market, adjust, optimize and upgrade the industrial structure, and then continue to promote the healthy and sustainable development of my country's tilapia industry. In this market context, the emergence of crispy tilapia has undoubtedly added a new "breakthrough" for tilapia to open up the domestic market. Crisp tilapia has a brand-new taste experience. Its meat is firm and crisp, delicious, and does not rot after long cooking. The meat color is bright and bright, and it is deeply loved by domestic consumers. At the same time, the economic benefits of breeding crispy tilapia are several times higher than those of breeding ordinary tilapia, and the prospects for industrial development are very broad.

[0004] However, during the breeding process of crispy tilapia, uneven crisping often occurs, resulting in unstable quality and affecting sales reputation. The more prominent problem is that there is still a lack of efficient and reliable detection methods for the crispness of crispy tilapia, which means that the breeding industry does not have a practical tilapia crispness evaluation standard for reference, which seriously restricts the standardized scale breeding of crispy tilapia. In addition, according to the feedback from consumers who have tasted crispy tilapia, people have different preferences for the crispness of crispy tilapia. Some consumers like high-crisp flavors, while others like slightly crisp flavors. Therefore, it is an important issue that needs to be urgently solved in this industry to establish a more accurate crispness grading standard for crispy tilapia based on the taste experience of consumers and the crispness evaluation method.

[0005] Patent No. 201410259457.4 discloses a "quality grading method for crispy grass carp based on a texture analyzer". The crispness of fish meat is mainly detected by a texture analyzer. However, the detection method is to use a texture analyzer to detect the crispness of cooked fish meat. Although the crispness of cooked fish meat can best reflect the quality and taste of the fish meat for consumers, the cooking process adds a detection step to the grading of large quantities of tilapia during the purchase and sale process. In addition, the cooked tilapia loses water unevenly and the sample curls, resulting in uneven samples and difficulty in sampling. Therefore, the method of directly detecting the crispness of raw fish meat and predicting the crispness of cooked fish meat can more effectively grade tilapia. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a crispness grading method for crispy tilapia and designs a grading standard, which can predict the sensory evaluation crispness of cooked crispy tilapia through the crispness test results of raw crispy tilapia, thereby providing a reliable reference for the pricing in the purchase and sale process of crispy tilapia and the cooking methods of consumers.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented through the following technical solutions:

[0008] A method for grading the crispness of crispy tilapia, comprising the following steps:

[0009] (1) Take fresh crispy tilapia, knock it unconscious and remove the scales, then remove the meat from the left and right sides of the back, clean it and set aside;

[0010] (2) Use absorbent paper to dry the surface moisture of the fish meat on both sides, and start sampling from the back of the gill cover toward the tail. Take 5 samples from each side of the fish meat in succession, put them in a ziplock bag, and place them on ice;

[0011] (3) using a texture analyzer to measure the hardness of one side of the fish meat sample, and measuring three positions of each sample to obtain the crispness value of raw crispy tilapia;

[0012] (4) Establish a sensory evaluation scoring standard for cooked crispy Nile tilapia, and classify the grades of cooked crispy Nile tilapia according to this standard;

[0013] (5) Steam the fish meat samples on the other side to obtain cooked crispy Nile tilapia. Select experimenters to score the crispness of the steamed cooked crispy Nile tilapia according to sensory evaluation to obtain the sensory evaluation scores;

[0014] (6) Correlate the crispness value of raw crispy Nile tilapia with the sensory evaluation score of cooked crispy Nile tilapia of the same Nile tilapia, determine the sensory evaluation grade of cooked crispy Nile tilapia corresponding to the crispness value of raw crispy Nile tilapia, and establish a grade comparison table according to this method to determine the grades of cooked crispy Nile tilapia corresponding to different ranges of crispness values of raw crispy Nile tilapia;

[0015] (7) According to the above grade comparison table, directly detect the crispness of the meat quality of raw crispy Nile tilapia, and then predict the crispness grade of cooked crispy Nile tilapia according to the detection results.

[0016] Preferably, in the step (1), the specific parts of taking the meat on the left and right sides of the lower back are located above the midline of the fish body, and the sampling starts from behind the fish fin.

[0017] Preferably, in the step (2), the size of the sampled sample is 2 cm × 2 cm × 1 cm in length × width × height.

[0018] Preferably, in the step (3), the test probe selected by the texture analyzer is a TA / 5 cylindrical probe, the measurement mode is the TPA mode, and the specific test parameters are: pre-test speed 1.00 mm / s, test speed 1.00 mm / s, post-test speed 1.00 mm / s, trigger type is force, trigger point value 10.00 gf, test type is down press, target mode is deformation, target value is 40.00%, time 5.00 s.

[0019] Preferably, in the step (3), the specific method for obtaining the crispness value of raw crispy Nile tilapia is to use a texture analyzer to test 3 points for each sample, calculate the average value of the 3 data, respectively obtain the hardness values of 5 samples, and then calculate the average value again after removing the maximum value and the minimum value. This average value is the crispness value of raw crispy Nile tilapia.

[0020] Preferably, in the step (4), the grades of cooked crispy Nile tilapia are divided into high crisp, medium crisp, slightly crisp and non-crisp from top to bottom;

[0021] Preferably, the score range of high crispness is: 8 < high crispness ≤ 10, and the scoring criteria are: firm, refreshing, chewy, difficult to disperse, and difficult to chew; the score range of medium crispness is: 6 < medium crispness ≤ 8, and the scoring criteria are: firm texture, difficult to disperse, obvious chewing feeling, and relatively strong chewiness; the score range of slightly crispness is: 4 < slightly crispness ≤ 6, and the scoring criteria are: delicate texture, relatively easy to disperse, general chewing feeling, and tender with toughness; the score range of non-crispness is: 0 ≤ non-crispness ≤ 4, and the scoring criteria are: easy to disperse texture and no obvious chewing feeling.

[0022] Preferably, in step (5), the steaming method of the fish sample is to steam the fish on boiling water for 4 minutes.

[0023] The present invention provides a crispness grading method for crispy tilapia, and its advantages compared with the prior art are as follows:

[0024] The present invention establishes a grading method for predicting the crispness score of cooked crispy tilapia through the texture detection of raw crispy tilapia. The texture detection of raw crispy tilapia is a method for detecting the crispness of crispy tilapia based on texture analysis and rapid analysis, which can accurately and quickly identify the crispness of raw crispy tilapia. At the same time, a certain sensory evaluation standard is designed to grade the cooked crispy tilapia by sensory evaluation. It can establish a relatively accurate and practical tilapia grading standard by combining the sensory preferences of the consumer group. By comparing the direct crispness detection of raw crispy tilapia with the sensory evaluation of cooked crispy tilapia, the grade of cooked crispy tilapia can be predicted quickly and relatively accurately after obtaining the crispness detection result of raw crispy tilapia, providing a reliable reference for the transaction pricing of crispy tilapia, the crispness control in the breeding process, the commodity grading, and the quality control in the processing process. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the position for selecting the fish meat sample of raw crispy tilapia in the embodiment. Detailed Embodiments

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] Example 1:

[0028] I. Crispness grading method for crispy tilapia

[0029] 1. Sample acquisition: Fresh and crispy Nile tilapia was purchased in multiple batches directly from Guandu Market in Maoming City or Huayushuangdiao Xiaoyucang Maonan Store in Maoming City. Each batch contained 10 fish, with a body weight ranging from 1 kg to 3.5 kg. There were 8 batches in total, amounting to 80 fish (0 to 80 crispy Nile tilapia were numbered, with the numbers set as 1-1, 1-2, 1-4... 8-10). After purchase, the crispy Nile tilapia were quickly transported back to the laboratory for standby in an oxygenated water environment. After stunning the fish, their scales were removed and the blood was rinsed clean with running water.

[0030] Sampling was started separately from the posterior edge of the gill cover towards the tail direction. After removing the fish skin and red muscle on the left and right dorsal muscles, they were cut into five pieces with a specification of 2 cm × 2 cm × 1 cm (length × width × height). Among them, 5 pieces of dorsal muscle samples on the right were immediately put into labeled plastic bags and then subjected to texture measurement; 8 pieces of dorsal muscle samples on the left were steamed in boiling water for 4 min, and texture measurement and sensory evaluation were completed respectively within one hour.

[0031] 2. Hardness detection of raw crispy Nile tilapia:

[0032] (1) Using a texture analyzer to measure the hardness of each sample, data at 3 positions of each piece of sample were measured. During the measurement process, the sample to be measured was placed on ice to maintain the stability of the sample. And the test probe selected during detection was a TA / 5 cylindrical probe, the measurement mode was TPA mode, and the test parameters were: pre-test speed 1.00 mm / s, test speed 1.00 mm / s, post-test speed 1.00 mm / s, trigger type was force, trigger point value 10.00 gf, test type was downward pressure, target mode was deformation, target value was 40.00%, and time was 5.00 s;

[0033] (2) Calculate the average value of the data detected at 3 positions of each sample, and obtain the hardness values of 5 samples of one Nile tilapia respectively. After removing the maximum and minimum values, calculate the average value again as the fish meat hardness value (crispness value) of the raw crispy Nile tilapia, and calculate the standard deviation and deviation degree to monitor the reliability of grading;

[0034] 3. Sensory evaluation detection of cooked crispy Nile tilapia:

[0035] (1) Sensory evaluation method and standard: The evaluation team members received multiple sensory standard trainings in accordance with national standards GB / T14195-1993 and GB / T 16860-1997, formulated specific indicators, methods and evaluation descriptions for evaluation, and finally formulated a sensory evaluation standard table. At the same time, the grade division of cooked crispy Nile tilapia was carried out, as shown in Table 1 below.

[0036] Table 1: Sensory evaluation standard

[0037]

[0038] Due to the different taste biases of different evaluators, in order to avoid the biases of evaluators towards products caused by factors such as their respective preferences, the sample number sequence was shuffled in this experiment. The samples for sensory evaluation were steamed in boiling water for 4 minutes before being presented to the evaluators. After being steamed, they were tasted immediately, and scores were given according to the evaluation criteria. There were 4 boys and 4 girls in each batch, and a total of 8 people participated in the sensory evaluation. Each evaluator tasted independently and gave scores without communicating with each other. The evaluators rinsed their mouths with water between tasting each sample to eliminate the error influence of the previous sample on the next sample.

[0039] The control results of the crispness detection of raw crispy tilapia and the crispness scoring of sensory evaluation of cooked crispy tilapia for the same tilapia are shown in Table 2 below:

[0040] Table 2: Results of TPA determination and sensory evaluation of crispness of crispy tilapia

[0041]

[0042]

[0043] Bivariate correlation test analysis was carried out on the texture determination and sensory evaluation crispness of 80 crispy tilapia (using bivariate correlation analysis in SPSS 26.0 software), and the results are as follows:

[0044] TPA determination was carried out on the dorsal muscles of 80 crispy tilapia and sensory evaluation was conducted. It can be seen that there is a significant correlation (P<0.01) between the crispness determined by TPA and the crispness evaluated by sensory evaluation of crispy tilapia. The Pearson correlation coefficient is r = 0.884, indicating a positive correlation between the crispness determined by TPA and the crispness evaluated by sensory evaluation of crispy tilapia.

[0045] 4. According to the above method, the sample size was expanded, and finally the control relationship between the texture detection values of raw crispy tilapia and the sensory evaluation grades of cooked crispy tilapia was determined, as shown in Table 3 below:

[0046] Table 3 Control of the crispness of raw crispy tilapia and the sensory evaluation grades of cooked crispy tilapia

[0047] Grade Texture measurement of crispy raw Nile tilapia - crispness Sensory evaluation score of cooked crispy Nile tilapia High crispness ＞800 8 - 10 points Medium crispness 650 - 800 (excluding 800) 6 - 8 points (excluding 8 points) Slight crispness 550 - 600 (excluding 600) 4 - 6 points (excluding 6 points) Not crispy ＜550 0 - 4 points (excluding 4 points)

[0048] According to Table 3 above, the crispness determined by the texture measurement of raw crispy tilapia can be directly obtained, and then the crispness grade of cooked crispy tilapia can be deduced.

[0049] II. Comparative analysis of texture determination and sensory evaluation crispness between crispy tilapia and common tilapia

[0050] 1. Twenty samples of crispy tilapia and twenty samples of common tilapia were taken (the sources and treatment methods were the same as above). The crispness of the samples was measured using texture measurement and sensory evaluation according to the above detection methods. The data were analyzed by bivariate correlation test (using one-way ANOVA in SPSS 26.0 software), and the data results were expressed in the form of Mean±SD. The results are shown in Tables 4 and 5 below.

[0051] Table 4 Texture measurement crispness of crispy tilapia and common tilapia

[0052] Sample Mean±SD t - value Significance Crispy Nile tilapia 685.377±61.850 3.495 0.001 Common Nile tilapia 592.706±101.179

[0053] Table 5 Sensory evaluation results of crispy tilapia and common tilapia

[0054] Sample Mean±SD t - value Significance Crispy Nile tilapia 6.294±0.644 28.7 0.000 Common Nile tilapia 1.438±0.396

[0055] From the TPA measurement results of crispy tilapia and common tilapia (Table 4), there were very significant differences in crispness between crispy tilapia and common tilapia (P = 0.001 < 0.05). From the TPA measurement results of crispy tilapia and common tilapia (Table 5), there were very significant differences in crispness between crispy tilapia and common tilapia (P = 0.000 < 0.05). These results confirmed that the TPA measurement results showed significant differences in crispness between crispy tilapia and common tilapia. The texture measurement method could significantly distinguish crispy tilapia from common tilapia. Therefore, this method could be used for instrumental analysis of the special crispness of crispy tilapia muscle. In sensory analysis, there were also significant differences in crispness between crispy tilapia and common tilapia.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for grading the crispness of crispy tilapia, characterized in that, The method for grading the crispness of crispy Nile tilapia includes the following steps: (1) Take fresh crispy Nile tilapia, stun it, scale it, and then cut the meat on both sides of the back, wash it clean, and set aside; (2) Blot the moisture on the surface of the fish meat on both sides with absorbent paper, start sampling from the back edge of the gill cover towards the tail direction, continuously take 5 samples from each side of the fish meat, put them in a self-sealing bag, and place them on ice; (3) Use a texture analyzer to measure the hardness of the fish meat samples on one side, and measure three positions for each sample to obtain the crispness value of raw crispy Nile tilapia; (4) Establish a sensory evaluation scoring standard for cooked crispy Nile tilapia, and divide the grades of cooked crispy Nile tilapia according to this standard; (5) Steam the fish meat samples on the other side to obtain cooked crispy Nile tilapia, select experimenters to score the crispness of the steamed cooked crispy Nile tilapia according to the sensory evaluation to obtain the sensory evaluation score; (6) Correlate the crispness value of raw crispy Nile tilapia with the sensory evaluation score of cooked crispy Nile tilapia of the same tilapia, determine the sensory evaluation grade of cooked crispy Nile tilapia corresponding to the crispness value of raw crispy Nile tilapia, and establish a grade comparison table according to this method to determine the grades of cooked crispy Nile tilapia corresponding to different ranges of crispness values of raw crispy Nile tilapia; (7) According to the above grade comparison table, directly detect the crispness of the meat quality of raw crispy Nile tilapia, and then predict the crispness grade of cooked crispy Nile tilapia according to the detection result.

2. The method for grading the crispness of crispy tilapia according to claim 1, wherein: In the step (1), the specific parts for cutting the meat on both sides of the back are above the midline of the fish body, and sampling starts from behind the fish fin.

3. A method for grading the crispness of crispy tilapia according to claim 1, characterized in that: In the step (2), the size of the sampled sample is 2 cm × 2 cm × 1 cm in length × width × height.

4. A method for grading the crispness of crispy tilapia according to claim 1, characterized in that: In the step (3), the test probe selected by the texture analyzer is a TA / 5 cylindrical probe, the measurement mode is the TPA mode, and the specific test parameters are: pre-test speed 1.00 mm / s, test speed 1.00 mm / s, post-test speed 1.00 mm / s, trigger type is force, trigger point value 10.00 gf, test type is downward pressure, target mode is deformation, target value is 40.00%, and time is 5.00 s.

5. A method for grading the crispness of crispy tilapia according to claim 1, characterized in that: In the step (3), the specific method for obtaining the crispness value of raw crispy Nile tilapia is to use a texture analyzer to test 3 points for each sample, calculate the average value of the 3 data, respectively obtain the hardness values of 5 samples, and then calculate the average value again after removing the maximum and minimum values. This average value is the crispness value of raw crispy Nile tilapia.

6. A method for grading the crispness of crispy tilapia according to claim 1, characterized in that, In the step (4), the grades of cooked crispy Nile tilapia are divided into high crisp, medium crisp, slightly crisp, and non-crisp from top to bottom; Among them, the score range of high crisp is: 8 points < high crisp ≤ 10 points, and the scoring standard is: the meat is firm, refreshing, elastic, difficult to disperse, and difficult to chew; The score range of medium crisp is: 6 points < medium crisp ≤ 8 points, and the scoring standard is: the meat is firm, difficult to disperse, with obvious chewing feeling and strong chewiness; The score range of slightly crisp is: 4 points < medium crisp ≤ 6 points, and the scoring standard is: the meat is delicate, relatively easy to disperse, with general chewing feeling, tender and tough; The score range of non-crisp is: 0 ≤ non-crisp ≤ 4, and the scoring standard is: the meat is easy to disperse and the chewing feeling is not obvious.

7. A method for grading the crispness of crispy tilapia according to claim 1, characterized in that, In the step (5), the steaming method of the fish meat samples is to steam the fish meat on boiling water for 4 minutes.

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