Method for rapidly identifying phyteral adulterated fish meal

Abstract

The invention discloses a method for rapidly identifying phyteral adulterated fish meal, which comprises the following steps: S1, dividing fish meal to be detected into a sample A and a sample B, adding the sample A into an EP tube, and adding the sample B into a glass tube with a cover; s2, adding water into the EP pipe, uniformly mixing, sealing the EP pipe, putting the sealed EP pipe into water bath equipment, heating, and preserving heat; s3, taking out the EP tube, adding an iodine-potassium iodide solution, immediately observing the color of the mixed solution, and entering a step S7; s4, adding diluted hydrochloric acid and phloroglucinol indicators into the glass tube filled with the sample B, and covering the glass tube with a cover; s5, inclining and rotating the glass tube to enable the reacted mixed solution to be hung on the wall, and entering step S6; s6, observing the wall hanging liquid condition on the tube wall of the glass tube by adopting an intense light source, and entering the step S7; and S7, obtaining whether the to-be-detected fish meal is doped with the phytones and the types of the phytones. Equipment adopted by the method is convenient to carry and use, rapid identification can be achieved, and the identification result is accurate and reliable.

Description

Technical Field

[0001] The invention belongs to the field of detection technology, in particular to a method for rapidly identifying fish meal adulterated with plant matter. Background Art

[0002] With the rapid development of my country's feed industry, especially the aquatic feed industry, fishmeal demand is high, currently around 2 million tons annually. Fishmeal is high in protein, easily digestible, and palatable, and its quality directly impacts animal health and aquaculture profitability. However, significant discrepancies between actual fishmeal delivery specifications and packaging specifications are common in the market, particularly with imported fishmeal often being re-sealed or re-sealed. Surveys show that over 60% of fishmeal is adulterated with plant-based substances, particularly starchy (lignin-based) plant-based substances. These substances, due to their low price, can mask the appearance defects of lower-quality fishmeal and are often found as adulterants. This practice, especially when adulterated repeatedly, can seriously impact feed protein quality and animal health. During fishmeal adulteration detection, procurement and regulatory authorities are increasingly concerned with determining whether fishmeal is adulterated, the portability of detection equipment, and the speed and effectiveness of detection protocols. Therefore, developing a portable and efficient method for identifying starchy (lignin-based) plant-based substances is crucial for improving fishmeal quality, ensuring animal health, maintaining market order, and advancing detection technology. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for quickly identifying fish meal adulterated with plant matter, which is portable and can solve the problems existing in the prior art.

[0004] The purpose of the present invention is to be solved by the following technical solutions: A method for rapidly identifying fish meal adulterated with plant matter, characterized in that the method comprises the following steps: S1, the fish meal to be tested is divided into sample A and sample B, sample A is added to an EP tube and proceeds to step S2, sample B is added to a glass tube with a cover and proceeds to step S4; S2. Add water to the EP tube and mix it with sample A. Seal the EP tube and place it in a water bath for heating. Heat the water bath to 80-85°C and keep it warm for 3-5 minutes before proceeding to step S3. S3. Remove the EP tube from the water bath and add 0.15ml to 0.2ml of iodine-potassium iodide solution. Immediately observe the color of the mixed solution in the EP tube and proceed to step S7. S4. Add 0.3 ml to 0.7 ml of dilute hydrochloric acid and then add 2 to 3 drops of phloroglucinol indicator to the glass tube containing sample B, or add 0.4 ml to 0.85 ml of dilute hydrochloric acid mixed with 2 to 3 drops of phloroglucinol indicator to the glass tube containing sample B, cover the lid and proceed to step S5; S5, tilt and rotate the glass tube to allow the mixed solution in the glass tube to react for 3 minutes to 5 minutes, and allow the reacted mixed solution to adhere to the wall, and then proceed to step S6; S6, using a strong light source to observe the wall liquid on the glass tube wall and proceeding to step S7; S7. Determine whether the fish meal to be tested contains plant matter and the type of the plant matter.

[0005] If the color of the mixed solution in the EP tube in step S7 turns blue or blue-purple and the hanging liquid in the glass tube contains rose-red or purple-red particles, it means that the fish meal to be tested contains both starch-based plant adulterants and lignin-based plant adulterants; If the color of the mixed solution in the EP tube in step S7 does not change and the hanging liquid in the glass tube contains rose-red or purple-red particles, it means that the fish meal to be tested does not contain starch-based plant adulterants but contains lignin-based plant adulterants; If the color of the mixed solution in the EP tube in step S7 turns blue or blue-purple and the hanging liquid in the glass tube does not contain rose-red or purple-red particles, it means that the fish meal to be tested contains starch-based plant adulterants but does not contain lignin-based plant adulterants; If the color of the mixed liquid in the EP tube in step S7 does not change and the hanging liquid in the glass tube does not contain rose-red or purple-red particles, it means that the fish meal to be tested contains neither starch-based plant adulterants nor lignin-based plant adulterants.

[0006] The mass of sample A in step S1 is 0.2 g to 0.3 g, and the mass of sample B in step S1 is 0.2 g to 0.3 g. Samples A and B are sampled using a sampling spoon.

[0007] The mass ratio of sample A to water in the EP tube in step S2 is 1:4-5; the water in step S2 is distilled water. In order to facilitate carrying, save reagents and improve efficiency, distilled water can also be pre-installed in the EP tube.

[0008] The water bath equipment in step S2 is a portable constant temperature heating cup. The EP tube is sealed and embedded in the floating board. The floating board and the EP tube are placed in the portable constant temperature heating cup for water bath heating and heat preservation.

[0009] In step S3, the EP tube is taken out with tweezers and the moisture on the outer wall of the EP tube is wiped off.

[0010] The iodine-potassium iodide solution in step S3 is prepared by dissolving 13 g of iodine and 35 g of potassium iodide in 100 mL of distilled water, diluting the solution to 1000 mL, shaking the solution, and storing the solution in a brown bottle. The solution can be dispensed into disposable capillaries or EP tubes according to the amount used each time to prepare a disposable reagent.

[0011] In order to extend the shelf life of the iodine-potassium iodide solution, the iodine-potassium iodide solution in step S3 is packaged in independent light-proof small doses, and the iodine-potassium iodide solution in each small dose package is for single use only and is disposable.

[0012] The concentration of the dilute hydrochloric acid in step S4 is 3 mol / L to 5 mol / L; the phloroglucinol indicator in step S4 is a phloroglucinol ethanol solution with a mass concentration of 5% to 10%.

[0013] The dilute hydrochloric acid and phloroglucinol indicator in step S4 are pre-packed in a glass tube with a cover and are for single use only.

[0014] The amount of the phloroglucinol indicator in step S4 is 0.04 ml / drop to 0.05 ml / drop.

[0015] The illumination intensity of the strong light source in step S6 is not less than 1000 lumens.

[0016] The EP tube is a micro centrifuge tube, and the volume of the EP tube is 1.5ml to 2ml.

[0017] The present invention provides a method for rapidly identifying plant-based adulterated fish meal. The required equipment and reagents include: a portable constant-temperature heating cup for rapid heating and water bathing, a sampling spoon for sampling into an EP tube or a glass tube with a cover, a floating plate for heating the EP tube in a constant-temperature water bath, a dropper for adding distilled water or other reagents, tweezers for clamping the floating plate, distilled water, an EP tube with a cover, a glass tube with a cover, a strong flashlight capable of providing a light intensity of more than 1000 lumens, and 0.15 ml to 0.01 ml of liquid stored away from light for color change reaction. 0.2ml of iodine-potassium iodide solution (pre-packed single-use solution is acceptable), separately packaged dilute hydrochloric acid with a molar concentration of 3mol / L to 5mol / L, separately packaged phloroglucinol indicator (phloroglucinol ethanol solution with a mass concentration of 5% to 10%), or a mixture of pre-packed dilute hydrochloric acid with a molar concentration of 3mol / L to 5mol / L and phloroglucinol indicator (single-use solution is acceptable). The above equipment and reagents can be easily loaded into a small portable test box and can be carried to the place where identification is needed at any time.

[0018] The principles of the method for rapidly identifying plant-based adulterated fish meal provided by the present invention include two parts: The first is the starch color change principle. This occurs when starch reacts with iodine to form a starch-iodine complex, resulting in a change in absorbance and a blue or bluish-purple coloration (generally, low starch content results in blue, while high starch content results in bluish-purple). Starch is insoluble in water at room temperature, especially when the amount of starchy plant matter adulteration in fish meal is relatively low. When the water bath temperature rises to 60°C, starch begins to gradually dissolve. At 80°C, starch dissolves substantially. However, at high temperatures (e.g., 100°C), molecular motion accelerates, hindering complex formation. Adding iodine solution at this temperature results in no color change. Therefore, to improve identification accuracy, a portable constant-temperature heating cup is used to maintain the water bath temperature at 80°C to 85°C for 3-5 minutes to observe the color reaction.

[0019] The second principle is the color change of lignin. This is due to the condensation of the hydroxyl groups of the phloroglucinol indicator with the coniferaldehyde groups of lignin in an acidic environment, forming a rose-red or purple-red compound with a conjugated structure. To improve identification accuracy, use a strong flashlight with an intensity of 1000 lumens or more to observe the color of the particles in the hanging solution. If the lignin color reaction is not obvious, extend the reaction time in the glass tube to up to 10 minutes and observe again, or observe under a microscope to improve the reliability of the test results.

[0020] Compared with the prior art, the present invention has the following advantages: The device used in the method for rapidly identifying fish meal adulterated with plant matter provided by the present invention is easy to carry and easy to use, can rapidly identify whether fish meal contains plant matter and can determine the type of the plant matter contained, and the identification result is accurate and reliable, so the method is suitable for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attachment Figure 1 A comparison chart of the identification results of whether the fish meal to be tested contains starch-based plant adulterants provided in Example 1 of the present invention and Comparative Example 1; Attachment Figure 2 This is a diagram showing the identification result of the fish meal to be tested not containing lignin-based plant material adulteration provided in Example 1 of the present invention; Attachment Figure 3 This is a diagram showing the identification results of lignin-based plant material adulteration in the fish meal to be tested provided in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0022] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent like or similar structures, and thus their detailed description will be omitted.

[0023] The terms "a", "an", "the", and "said" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.

[0024] A method for rapidly identifying fish meal adulterated with plant matter, characterized in that the method comprises the following steps: S1, using a sampling spoon to take 0.2g ~ 0.3g of the fish meal to be tested as sample A, take 0.2g ~ 0.3g of the fish meal to be tested as sample B, add sample A to an EP tube and proceed to step S2, add sample B to a glass tube with a lid and proceed to step S4; S2. Add 4-5 times the mass of sample A in distilled water to the EP tube and mix thoroughly. Seal the EP tube and insert it into the floating plate. Place the floating plate and the EP tube in a portable constant-temperature heating cup for heating in a water bath. Heat the portable constant-temperature heating cup to 80-85°C and keep warm for 3-5 minutes before proceeding to step S3. S3. Use tweezers to remove the EP tube from the water bath and wipe off the moisture on the outer wall of the EP tube. Open the tube cap and add 0.15ml-0.2ml of iodine-potassium iodide solution (the iodine-potassium iodide solution is prepared by dissolving 13g of iodine and 35g of potassium iodide in 100ml of distilled water, then diluting the volume to 1000ml, shaking well, and storing in a brown bottle. The solution can be dispensed into disposable caplets or EP tubes). Immediately observe the color of the mixed solution in the EP tube and proceed to step S7. S4. Add 0.3 ml to 0.7 ml of dilute hydrochloric acid to the glass tube containing sample B, and then add 2 to 3 drops of phloroglucinol indicator, or add 0.4 ml to 0.85 ml of dilute hydrochloric acid mixed with 2 to 3 drops of phloroglucinol indicator to the glass tube containing sample B, cover the lid and proceed to step S5; the concentration of the dilute hydrochloric acid is 3 mol / L to 5 mol / L, and the phloroglucinol indicator is a phloroglucinol ethanol solution with a mass concentration of 5% to 10%; S5, tilt and rotate the glass tube to allow the mixed solution in the glass tube to react for 3 minutes to 5 minutes, and allow the reacted mixed solution to adhere to the wall, and then proceed to step S6; S6. Use a strong light source with a light intensity of not less than 1000 lumens to observe the wall liquid on the wall of the glass tube and proceed to step S7; S7. If the color of the mixed liquid in the EP tube turns blue or blue-purple and the hanging liquid in the glass tube contains rose-red or purple-red particles, it means that the fish meal to be tested contains both starch-based plant adulterators and lignin-based plant adulterators; if the color of the mixed liquid in the EP tube does not change and the hanging liquid in the glass tube contains rose-red or purple-red particles, it means that the fish meal to be tested does not contain starch-based plant adulterators but contains lignin-based plant adulterators; if the color of the mixed liquid in the EP tube turns blue or blue-purple and the hanging liquid in the glass tube does not contain rose-red or purple-red particles, it means that the fish meal to be tested contains starch-based plant adulterators but does not contain lignin-based plant adulterators; if the color of the mixed liquid in the EP tube does not change and the hanging liquid in the glass tube does not contain rose-red or purple-red particles, it means that the fish meal to be tested contains neither starch-based plant adulterators nor lignin-based plant adulterators. Example

[0025] A method for rapidly identifying fish meal adulterated with plant matter, characterized in that the method comprises the following steps: S1, the selected fish meal to be tested does not contain starch-based plant adulterants and lignin-based plant adulterants, use a sampling spoon to take 0.2g of the fish meal to be tested as sample A, take 0.2g of the fish meal to be tested as sample B, add sample A to a 1.5ml EP tube and proceed to step S2, add sample B to a covered glass tube and proceed to step S4; S2. Add distilled water 5 times the mass of Sample A to the EP tube and mix thoroughly. Seal the EP tube and insert it into the floating plate. Place the floating plate and the EP tube in a portable constant-temperature heating cup for heating in a water bath. Heat the portable constant-temperature heating cup to 80°C and keep warm for 3 minutes. Then proceed to step S3. S3. Use tweezers to remove the EP tube from the water bath and wipe off the moisture on the outer wall of the EP tube. Open the tube cap of the EP tube and add 0.15 ml of sub-iodine-potassium iodide solution. Immediately observe the color of the mixed solution in the EP tube and proceed to step S7. S4. Add 0.5 ml of dilute hydrochloric acid to the glass tube containing sample B, and then add 3 drops of phloroglucinol indicator, or add 0.65 ml of dilute hydrochloric acid mixed with 3 drops of phloroglucinol indicator to the glass tube containing sample B (the dilute hydrochloric acid and phloroglucinol indicator are pre-packed in a covered glass tube and are used once). The concentration of the dilute hydrochloric acid is 3 mol / L, and the phloroglucinol indicator is a 5% phloroglucinol ethanol solution. Cover the lid and proceed to step S5. S5, tilt and rotate the glass tube to allow the mixed solution in the glass tube to react for 4 minutes and allow the reacted mixed solution to adhere to the wall, and then proceed to step S6; S6. Use a strong light source with a light intensity of 1500 lumens to observe the wall liquid on the wall of the glass tube and proceed to step S7; S7. If the color of the mixed solution in the EP tube does not change (e.g. Figure 1 D EP tube in the glass tube) and the hanging liquid in the glass tube does not contain rose-red or purple-red particles (such as Figure 2 As shown in the figure, it was determined that the fish meal tested did not contain starch-based plant adulterants and lignin-based plant adulterants.

[0026] A method for rapidly identifying fish meal adulterated with plant matter, characterized in that the method comprises the following steps: S1, the selected fish meal to be tested contains both starch-based and lignin-based plant-based adulterants, 0.2 g of the fish meal to be tested is taken as sample A using a sampling spoon, and 0.2 g of the fish meal to be tested is taken as sample B. Sample A is added to a 1.5 ml EP tube and the process proceeds to step S2. Sample B is added to a covered glass tube and the process proceeds to step S4; S2. Add distilled water 5 times the mass of Sample A to the EP tube and mix thoroughly. Seal the EP tube and insert it into the floating plate. Place the floating plate and the EP tube in a portable constant-temperature heating cup for heating in a water bath. Heat the portable constant-temperature heating cup to 80°C and keep warm for 3 minutes. Then proceed to step S3. S3. Use tweezers to remove the EP tube from the water bath and wipe off the moisture on the outer wall of the EP tube. Open the tube cap of the EP tube and add 0.15 ml of sub-iodine-potassium iodide solution. Immediately observe the color of the mixed solution in the EP tube and proceed to step S7. S4. Add 0.5 ml of dilute hydrochloric acid to the glass tube containing sample B, and then add 3 drops of phloroglucinol indicator, or add 0.65 ml of dilute hydrochloric acid mixed with 3 drops of phloroglucinol indicator to the glass tube containing sample B (the dilute hydrochloric acid and phloroglucinol indicator are pre-packed in a covered glass tube and are used once). The concentration of the dilute hydrochloric acid is 3 mol / L, and the phloroglucinol indicator is a 5% phloroglucinol ethanol solution. Cover the lid and proceed to step S5. S5, tilt and rotate the glass tube to allow the mixed solution in the glass tube to react for 4 minutes and allow the reacted mixed solution to adhere to the wall, and then proceed to step S6; S6. Use a strong light source with a light intensity of 1500 lumens to observe the wall liquid on the wall of the glass tube and proceed to step S7; S7, the color of the mixed solution in the EP tube turns blue-purple (such as Figure 1 C EP tube in the glass tube) and the hanging liquid in the glass tube contains rose-red or purple-red particles (such as Figure 3 As shown in the figure, it was identified that the fish meal to be tested contained both meal-type plant adulterants and lignin-type plant adulterants.

[0027] The above-described Example 1 and Comparative Example 1 can be performed simultaneously, particularly the portion of the process requiring water bath heating to identify starch-based plant-based adulterants. Comparative Example 1 differs from Example 1 in that the fish meal used for testing contains both starch-based and lignin-based plant-based adulterants, as well as in the identification results. All other steps and methods remain the same, demonstrating the accuracy of the method provided by the present invention for rapidly identifying plant-based adulterated fish meal.

[0028] Figure 1-Figure 3 The label C in the figure represents the identification result of Comparative Example 1, and the label D represents the identification result of Example 1.

[0029] The device used in the method for rapidly identifying fish meal adulterated with plant matter provided by the present invention is easy to carry and easy to use, can rapidly identify whether fish meal contains plant matter and can determine the type of the plant matter contained, and the identification result is accurate and reliable, so the method is suitable for popularization and use.

[0030] In the embodiments of the present invention, the term "plurality" refers to two or more, unless otherwise specified. Terms such as "installed," "connected," and "fixed" should be interpreted broadly. For example, "connected" can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art will understand the specific meanings of these terms in the embodiments of the present invention based on specific circumstances.

[0031] In the description of the embodiments of the present invention, it should be understood that the terms "upper" and "lower" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the embodiments of the present invention.

[0032] Throughout this specification, terms such as "one embodiment" and "a preferred embodiment" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0033] The above embodiments are only for illustrating the technical ideas of the present invention and cannot be used to limit the scope of protection of the present invention. Any changes made on the basis of the technical solutions in accordance with the technical ideas proposed by the present invention fall within the scope of protection of the present invention; any technologies not involved in the present invention can be implemented by existing technologies.

Claims

1. A method for rapidly identifying fish meal adulterated with plant matter, characterized in that: The steps of this method are as follows: S1, the fish meal to be tested is divided into sample A and sample B, sample A is added to an EP tube and proceeds to step S2, sample B is added to a glass tube with a cover and proceeds to step S4; S2. Add water to the EP tube and mix it with sample A. Seal the EP tube and place it in a water bath for heating. Heat the water bath to 80-85°C and keep it warm for 3-5 minutes before proceeding to step S3. S3. Remove the EP tube from the water bath and add 0.15ml to 0.2ml of iodine-potassium iodide solution. Immediately observe the color of the mixed solution in the EP tube and proceed to step S7. S4. Add 0.3 ml to 0.7 ml of dilute hydrochloric acid and then add 2 to 3 drops of phloroglucinol indicator to the glass tube containing sample B, or add 0.4 ml to 0.85 ml of dilute hydrochloric acid mixed with 2 to 3 drops of phloroglucinol indicator to the glass tube containing sample B, cover the lid and proceed to step S5; S5, tilt and rotate the glass tube to allow the mixed solution in the glass tube to react for 3 minutes to 5 minutes, and allow the reacted mixed solution to adhere to the wall, and then proceed to step S6; S6, using a strong light source to observe the wall liquid on the glass tube wall and proceeding to step S7; S7. Determine whether the fish meal to be tested contains plant matter and the type of the plant matter.

2. The method for rapidly identifying plant-based adulterated fish meal according to claim 1, wherein: If the color of the mixed solution in the EP tube in step S7 turns blue or blue-purple and the hanging liquid in the glass tube contains rose-red or purple-red particles, it means that the fish meal to be tested contains both starch-based plant adulterants and lignin-based plant adulterants; If the color of the mixed solution in the EP tube in step S7 does not change and the hanging liquid in the glass tube contains rose-red or purple-red particles, it means that the fish meal to be tested does not contain starch-based plant adulterants but contains lignin-based plant adulterants; If the color of the mixed solution in the EP tube in step S7 turns blue or blue-purple and the hanging liquid in the glass tube does not contain rose-red or purple-red particles, it means that the fish meal to be tested contains starch-based plant adulterants but does not contain lignin-based plant adulterants; If the color of the mixed liquid in the EP tube in step S7 does not change and the hanging liquid in the glass tube does not contain rose-red or purple-red particles, it means that the fish meal to be tested contains neither starch-based plant adulterants nor lignin-based plant adulterants.

3. The method for rapidly identifying plant-based adulterated fish meal according to claim 1, wherein: The mass of the sample A in the step S1 is 0.2 g to 0.3 g, and the mass of the sample B in the step S1 is 0.2 g to 0.3 g.

4. The method for rapidly identifying plant-based adulterated fish meal according to claim 1 or 3, wherein: The mass ratio of the sample A to the water in the EP tube in step S2 is 1:4-5; the water in step S2 is distilled water.

5. The method for rapidly identifying plant-based adulterated fish meal according to claim 1, wherein: The water bath equipment in step S2 is a portable constant temperature heating cup. The EP tube is sealed and embedded in the floating board. The floating board and the EP tube are placed in the portable constant temperature heating cup for water bath heating and heat preservation.

6. The method for rapidly identifying fish meal adulterated with plant matter according to claim 1 or 5, characterized in that: In step S3, the EP tube is taken out with tweezers and the moisture on the outer wall of the EP tube is wiped off.

7. The method for rapidly identifying fish meal adulterated with plant matter according to claim 1, wherein: The iodine-potassium iodide solution in step S3 is packaged in independent light-proof small doses, and the iodine-potassium iodide solution in each small dose package is for single use only.

8. The method for rapidly identifying fish meal adulterated with plant matter according to claim 1, wherein: The concentration of the dilute hydrochloric acid in step S4 is 3 mol / L to 5 mol / L; the phloroglucinol indicator in step S4 is a phloroglucinol ethanol solution with a mass concentration of 5% to 10%.

9. The method for rapidly identifying fish meal adulterated with plant matter according to claim 1, wherein: The dilute hydrochloric acid and phloroglucinol indicator in step S4 are pre-installed in a glass tube with a cover.

10. The method for rapidly identifying fish meal adulterated with plant matter according to claim 1, wherein: The illumination intensity of the strong light source in step S6 is not less than 1000 lumens.

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