1. An image method for identifying adulteration of mushroom powder is characterized by comprising the following steps:

(1) preparing a microscope specimen from to-be-detected mushroom powder by using a chloral hydrate solution; observing by using a microscope to obtain a microscopic image;

(2) preparing a microscope specimen from the mushroom powder to be detected by using a phloroglucinol solution; observing by using a microscope to obtain a microscopic image;

(3) observing whether the microscopic image obtained in the step (1) contains characteristic structures belonging to wood chips, wheat bran, straws, cottonseed hulls and corn flour and whether the microscopic image obtained in the step (2) has a dyeing structure of the wood chips, the wheat bran, the straws, the cottonseed hulls and the corn flour; comprehensively identifying whether the mushroom powder contains wood chips, wheat bran, straws, cottonseed hulls and corn flour;

(4) and obtaining the content of the wood chips, the wheat bran, the straws, the cottonseed hulls and the corn flour in the mushroom powder to be detected according to the semi-quantitative relation between the mushroom powder and the wood chips, the wheat bran, the straws, the cottonseed hulls or the corn flour.

2. The method as claimed in claim 1, wherein the mushroom powder to be tested in step (1) is obtained by sieving with a 100-mesh sieve.

3. The method according to claim 1 or 2, characterized in that the preparation of the microscopic sample in step (2) is in particular: adding 1-2 drops of phloroglucinol solution, slightly standing, and adding 1 drop of hydrochloric acid.

4. The method according to any one of claims 1 to 3, wherein the structural characteristics of the wood chips, wheat bran, straw, cottonseed hulls, corn flour and mushroom flour in step (3) are obtained by microscopic observation, and the specific operations are as follows:

placing sawdust, wheat bran, straw, cottonseed hull, corn or mushroom powder in the center of a glass slide, adding 1 drop of chloral hydrate solution, stirring, and covering a cover glass after chloral hydrate solution permeates into the powder; observing with microscope at 50-300 times to obtain the structural characteristics of sawdust, testa Tritici, caulis et folium oryzae, cottonseed hull, semen Maydis powder, and Lentinus Edodes powder.

5. The method according to any one of claims 1 to 4, wherein the stained structure of the wood chips, wheat bran, straw, cotton seed hulls, corn flour and mushroom powder in the step (3) is obtained by microscopic observation, and the specific operation is as follows:

placing sawdust, testa Tritici, caulis et folium oryzae, cottonseed hull, semen Maydis powder or Lentinus Edodes powder in the center of glass slide, adding phloroglucinol test solution 1-2 drops, stirring, slightly standing, adding hydrochloric acid 1 drop, and covering with cover glass; observing with microscope at 50-300 times to obtain the dyeing structure of sawdust, testa Tritici, caulis et folium oryzae, cottonseed hull, semen Maydis powder, and Lentinus Edodes powder.

6. The method according to any one of claims 1 to 5, wherein the chloral hydrate solution of step (1) is prepared by dissolving 50g of chloral hydrate in 15mL of water and 10mL of glycerin.

7. The method according to any one of claims 1 to 6, wherein the phloroglucinol solution in step (2) is prepared by weighing 0.5g of phloroglucinol, adding ethanol to a volume of 25mL, and storing in a glass bottle in a dark place.

8. The method according to any one of claims 1 to 7, wherein the semi-quantitative relationship between the mushroom powder and the wood chips, wheat bran, straw, cottonseed hulls or corn flour in step (4) is specifically constructed by:

preparing mushroom powder containing wood chips, wheat bran, straws, cottonseed hulls or corn flour in different proportions, then placing the mushroom powder in the center of a glass slide, adding 1 drop of a chloral hydrate solution, and covering the glass slide after chloral hydrate solution permeates into the powder; observing under microscope with 50-300 times; and constructing a semi-quantitative relation between the mushroom powder and the wood chips, the wheat bran, the straws, the cottonseed hulls or the corn flour according to the relation between the proportion of the wood chips, the wheat bran, the straws, the cottonseed hulls or the corn flour and the area which does not belong to the characteristic structure of the mushroom powder.

9. The method of claim 8, wherein the different proportions are a ratio of wood chips, wheat bran, straw, cottonseed hulls or corn flour to lentinus edodes flour of 10: 90. 30: 70. 50: 50. 70: 30. 100, and (2) a step of: 0.

10. use of the method according to any one of claims 1 to 9 in the food field.

Background

The mushroom is edible mushroom which is second to the second most widely planted in the world of oyster mushroom, and China is the first most country in the world for mushroom production. The mushroom is also one of the common edible mushrooms eaten in China, has fleshy, crisp and tender meat and rich nutritional value, and belongs to a healthy food which is high in protein, low in fat and rich in dietary fiber and essential mineral elements of a human body. The fresh mushroom has high water content, is not beneficial to storage, and the dry mushroom is more suitable for being circulated in the market.

The mushroom contains more flavor amino acids and nucleotides, the flavor of the mushroom is at the head of edible mushrooms, meanwhile, the mushroom can generate fragrant substances in the drying process and is a cyclic sulfur-containing compound, rich free amino acids contained in the mushroom can generate Maillard reaction in the drying process, and the variety and the content of flavor substances are greatly increased, so that the dried mushroom contains more flavor substances and has better flavor. Therefore, the dried mushroom can also be made into powder to be used as a seasoning to replace monosodium glutamate, chicken essence and other seasonings, and the mushroom powder is healthier.

The mushroom planting method mainly comprises three planting modes, including wild, basswood and mushroom sticks, and the mushroom sticks are the preferred mode for planting mushrooms due to the advantages of low cost of strain dosage, short mushroom culture time, shortened growth cycle of mushrooms and the like. Due to economic interests, some merchants directly pulverize mushroom sticks produced with mushrooms into powder in the process of producing mushroom powder, and sawdust, wheat bran, straw, cottonseed hulls and corn flour are the most commonly used materials for making the mushroom sticks.

Therefore, how to identify whether the shiitake contains wood chips, wheat bran, straw, cottonseed hulls and corn flour is a technical problem which needs to be solved urgently at present.

Disclosure of Invention

[ problem ] to

At present, no document discloses how to identify whether the mushroom powder contains wood chips, wheat bran, straws, cottonseed hulls and corn flour.

[ solution ]

In order to solve at least one problem, the method comprises the steps of preparing a lentinus edodes powder sample to be detected into a microscope specimen by using chloral hydrate and phloroglucinol solution respectively, observing characteristic structures of sawdust, wheat bran, straw, cottonseed hulls and corn flour under a microscope, and judging whether the lentinus edodes powder sample is doped with the sawdust, the wheat bran, the straw, the cottonseed hulls and the corn flour. Observing different adulteration proportions of the mushroom powder and the wood chips, the wheat bran, the straws, the cottonseed hulls and the corn flour, semi-quantitatively detecting the adulteration of the wood chips, the wheat bran, the straws, the cottonseed hulls and the corn flour in the mushroom powder and establishing a detection limit.

The invention aims to provide an image method for identifying adulteration of mushroom powder, which comprises the following steps:

(1) preparing a microscope specimen from to-be-detected mushroom powder by using a chloral hydrate solution; observing by using a microscope to obtain a microscopic image;

(2) preparing a microscope specimen from the mushroom powder to be detected by using a phloroglucinol solution; observing by using a microscope to obtain a microscopic image;

(3) observing whether the microscopic image obtained in the step (1) contains characteristic structures belonging to wood chips, wheat bran, straws, cottonseed hulls and corn flour and whether the microscopic image obtained in the step (2) has a dyeing structure of the wood chips, the wheat bran, the straws, the cottonseed hulls and the corn flour; comprehensively identifying whether the mushroom powder contains wood chips, wheat bran, straws, cottonseed hulls and corn flour;

(4) and obtaining the content of the wood chips, the wheat bran, the straws, the cottonseed hulls and the corn flour in the mushroom powder to be detected according to the semi-quantitative relation between the mushroom powder and the wood chips, the wheat bran, the straws, the cottonseed hulls or the corn flour.

In one embodiment of the present invention, the chloral hydrate solution in step (1) is prepared by dissolving 50g of chloral hydrate, 15mL of water and 10mL of glycerin.

In one embodiment of the invention, the mushroom powder to be tested in the step (1) is obtained by sieving with a 100-mesh sieve.

In one embodiment of the present invention, the operation of preparing the microscopic sample in step (2) is specifically: adding 1-2 drops of phloroglucinol solution, slightly standing, and adding 1 drop of hydrochloric acid.

In one embodiment of the present invention, the hydrochloric acid in step (2) is concentrated hydrochloric acid, and the mass fraction is 37.5%.

In one embodiment of the present invention, 0.5g of phloroglucinol is weighed in the phloroglucinol solution in step (2), and then ethanol is added to the weighed solution to a volume of 25mL, and the weighed solution is stored in a glass bottle in a dark place.

In one embodiment of the present invention, the structural characteristics of the wood chips, wheat bran, straw, cottonseed hull, corn flour and mushroom powder in step (3) are observed by a microscope, and the specific operations are as follows:

placing sawdust, wheat bran, straw, cottonseed hull, corn or mushroom powder in the center of a glass slide, adding 1 drop of chloral hydrate solution, stirring, and covering a cover glass after chloral hydrate solution permeates into the powder; observing with microscope at 50-300 times to obtain the structural characteristics of sawdust, testa Tritici, caulis et folium oryzae, cottonseed hull, semen Maydis powder, and Lentinus Edodes powder.

In one embodiment of the present invention, the dyed structure of the wood chips, wheat bran, straw, cottonseed hulls, corn flour and mushroom powder in step (3) is obtained by microscope observation, and the specific operations are as follows:

placing sawdust, testa Tritici, caulis et folium oryzae, cottonseed hull, semen Maydis powder or Lentinus Edodes powder in the center of glass slide, adding phloroglucinol test solution 1-2 drops, stirring, slightly standing, adding hydrochloric acid 1 drop, and covering with cover glass; observing with microscope at 50-300 times to obtain the dyeing structure of sawdust, testa Tritici, caulis et folium oryzae, cottonseed hull, semen Maydis powder, and Lentinus Edodes powder.

In one embodiment of the invention, the amount of powder on the slide is preferably such that the powder is uniformly spread over the entire coverslip after the sample is prepared.

In one embodiment of the present invention, the authentication criteria in step (3) is:

when a characteristic structure which does not belong to the mushroom powder is observed, the mushroom powder contains adulterants (wood chips, wheat bran, straw, cottonseed hulls or corn flour);

when no characteristic structure of the mushroom powder is observed, the mushroom powder does not contain adulterants (wood chips, wheat bran, straw, cottonseed hulls and corn flour).

In one embodiment of the present invention, the semi-quantitative relationship between the mushroom powder and the wood chips, wheat bran, straw, cottonseed hulls or corn flour in step (4) is specifically constructed as follows:

preparing mushroom powder containing adulterant wood chips, wheat bran, straws, cottonseed hulls or corn flour in different proportions, then placing the mushroom powder in the center of a glass slide, adding 1 drop of a chloral hydrate solution, and covering the glass slide after chloral hydrate solution permeates into the powder; observing under microscope with 50-300 times; and constructing a semi-quantitative relation between the mushroom powder and the wood chips, the wheat bran, the straws, the cottonseed hulls or the corn flour according to the relation between the proportion of the adulteration material wood chips, the wheat bran, the straws, the cottonseed hulls or the corn flour and the area which does not belong to the characteristic structure of the mushroom powder.

In one embodiment of the invention, the different proportions are that the mass ratio of the adulteration material wood chips, wheat bran, straw, cotton seed hulls or corn flour to mushroom powder is 10: 90. 30: 70. 50: 50. 70: 30. 100, and (2) a step of: 0.

a second object of the invention is the use of the method according to the invention in the field of food.

[ advantageous effects ]

The method can quickly, simply and conveniently identify the adulteration of the wood chips, the wheat bran, the straws, the cottonseed hulls and the corn flour in the mushroom powder, and has lower detection limit.

Drawings

FIG. 1 is a microscopic picture of lentinus edodes powder hydrated chloral.

FIG. 2 is a phloroglucinol picture of mushroom powder, wood chips, wheat bran, rice straws, cottonseed hulls and corn flour; wherein (a) is mushroom powder; (b) is wood dust; (c) is testa Tritici; (d) is corn flour; (e) is rice straw; (f) is cottonseed hull.

FIG. 3 is a microscopic photograph of chloral hydrate at different adulteration ratios of wood chips (wood chips: mushroom powder); wherein (a) is 10: 90, respectively; (b) is 30: 70; (c) is 50: 50; (d) is 70: 30, of a nitrogen-containing gas; (e) is 100: 0.

FIG. 4 is a microscopic photograph of chloral hydrate at different wheat bran adulteration ratios (wheat bran: lentinus edodes powder); wherein (a) is 10: 90, respectively; (b) is 30: 70; (c) is 50: 50; (d) is 70: 30, of a nitrogen-containing gas; (e) is 100: 0.

FIG. 5 is a microscopic picture of chloral hydrate at different adulteration ratios of corn flour (corn flour: shiitake powder); wherein (a) is 10: 90, respectively; (b) is 30: 70; (c) is 50: 50; (d) is 70: 30, of a nitrogen-containing gas; (e) is 100: 0.

FIG. 6 is a photograph of chloral hydrate of different adulteration ratios of straw (straw: mushroom powder); wherein (a) is 10: 90, respectively; (b) is 30: 70; (c) is 50: 50; (d) is 70: 30, of a nitrogen-containing gas; (e) is 100: 0.

FIG. 7 is a photograph showing chloral hydrate in different adulteration ratios of cotton seed hulls (cotton seed hulls: shiitake powder); wherein (a) is 10: 90, respectively; (b) is 30: 70; (c) is 50: 50; (d) is 70: 30, of a nitrogen-containing gas; (e) is 100: 0.

FIG. 8 is a photograph showing the limit of chloral hydrate detection for the adulteration of wood dust, wheat bran, rice straw, cottonseed hull and corn flour of the mushroom powder; wherein the doping amount of the wood chips in the step (a) is 5 percent; (b) the doping amount of the middling wheat bran is 2%; (c) the doping amount of the medium corn flour is 2 percent; (d) the doping amount of the medium straw is 2 percent; (e) the doping amount of the medium cotton seed hulls is 2 percent.

FIG. 9 is a photograph showing the phloroglucinol detection limit of the adulterated wood dust, wheat bran, rice straw, cottonseed hull and corn flour of the mushroom powder; wherein the doping amount of the wood chips in the step (a) is 2 percent; (b) the doping amount of the middling wheat bran is 5 percent; (c) the doping amount of the medium corn flour is 15 percent; (d) the doping amount of the medium straw is 2 percent; (e) the doping amount of the medium cotton seed hulls is 2 percent.

FIG. 10 shows the results of the identification in example 4; wherein (a) is chloral hydrate treatment; (b) the phloroglucinol treatment is carried out.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of better illustrating the invention and is not intended to limit the invention thereto.

Example 1

An image method for identifying adulteration of mushroom powder comprises the following steps:

(1) obtaining the structural characteristics of single mushroom powder, wood dust, wheat bran, straw, cottonseed hull and corn flour

Placing single mushroom powder, sawdust, wheat bran, straw, cottonseed hull or corn powder in the center of a glass slide, adding 1 drop of hydrated chloral solution (dissolving 50g of hydrated chloral in 15mL of water and 10mL of glycerin to obtain the hydrated chloral solution), uniformly stirring with tweezers, after the hydrated chloral solution permeates into the powder, clamping the edge of the glass slide by using a left index finger and a thumb cover to enable the left side of the powder to be in contact with the left side of the hydrated chloral solution, holding the right side of the glass slide by using a right hand and using a small tweezers, slowly putting down, and enabling the hydrated chloral solution to gradually spread and fill the lower side of the glass slide; if the liquid is not filled in the cover glass, dripping chloral hydrate solution from the opposite edge of the gap to prevent bubbles from being generated, and if the liquid is too much, sucking the overflowed liquid by using a filter paper sheet; then observing by using 50-300 times under a microscope to obtain the structural characteristics of single mushroom powder, wood dust, wheat bran, straw, cottonseed hulls and corn flour; the microscopic picture of the mushroom powder is shown in figure 1;

(2) obtain the dyeing characteristics of single mushroom powder, wood dust, wheat bran, straw, cottonseed hull and corn flour

Clamping single mushroom powder, sawdust, wheat bran, straw, cottonseed hull or corn powder by using tweezers, placing the single mushroom powder, the sawdust, the wheat bran, the straw, the cottonseed hull or the corn powder in the center of a glass slide, adding 1-2 drops of phloroglucinol solution (weighing 0.5g of phloroglucinol, adding ethanol to a constant volume of 25mL, storing the solution in a dark place in a glass bottle to obtain the phloroglucinol solution), uniformly stirring by using the tweezers, slightly placing the solution, adding 1 drop of hydrochloric acid, clamping the edge of the glass slide by using a left index finger and a thumb cover to enable the left side of the glass slide to be in contact with the left side of the phloroglucinol solution, using a right hand-held small tweezers to support the right side of the glass slide, slowly placing the glass slide, enabling the liquid to gradually spread to fill the lower side of the glass slide, and observing the dyeing characteristics of the single mushroom powder, the sawdust, the wheat bran, the corn meal, the straw, the corn meal, the cottonseed hull and the corn powder under a microscope by using 50-300 times; as shown in fig. 2;

(3) preparing a microscope specimen by using a chloral hydrate solution for the lentinus edodes powder to be detected, and specifically operating the same as the step (1); observing by using a microscope to obtain a microscopic image;

(4) preparing a microscope specimen from the mushroom powder to be detected by using a phloroglucinol solution, and specifically operating the same as the step (2); observing by using a microscope to obtain a microscopic image;

(5) observing whether the microscopic image obtained in the step (3) contains characteristic structures belonging to wood chips, wheat bran, straws, cottonseed hulls and corn flour and whether the microscopic image obtained in the step (4) has a dyeing structure of the wood chips, the wheat bran, the straws, the cottonseed hulls and the corn flour; so as to comprehensively identify whether the mushroom powder contains wood chips, wheat bran, straws, cottonseed hulls and corn flour.

Example 2

An image method for semi-quantitatively identifying adulteration of mushroom powder comprises the following steps:

preparing mushroom powder containing adulterant wood chips, wheat bran, straws, cottonseed hulls or corn flour in different proportions (the mass ratio of the adulterant to the mushroom powder is 10: 90, 30: 70, 50: 50, 70: 30 and 100: 0), then placing the mushroom powder in the center of a glass slide, adding 1 drop of chloral hydrate solution, and covering the glass slide after chloral hydrate solution permeates into the powder; observing under microscope with 50-300 times; constructing a semi-quantitative relation between the mushroom powder and the wood chips, the wheat bran, the straws, the cottonseed hulls or the corn flour according to the relation between the proportion of the adulteration material wood chips, the wheat bran, the straws, the cottonseed hulls or the corn flour and the area which does not belong to the characteristic structure of the mushroom powder;

and (3) comparing the microscopic image obtained in the step (3) in the embodiment 1 with the microscopic image of the semi-quantitative relationship between the mushroom powder and the wood chips, the wheat bran, the straws, the cottonseed hulls or the corn flour to obtain the content of the wood chips, the wheat bran, the straws, the cottonseed hulls and the corn flour in the mushroom powder to be detected.

FIGS. 3, 4, 5, 6 and 7 are micrographs of wood chips, wheat bran, corn, straw and cotton seed hulls (proportion of inclusions and mushroom powder) at different doping ratios.

Example 3 detection Limit

An image method for semi-quantitatively identifying adulteration of mushroom powder comprises the following steps:

(1) preparing mushroom powder containing adulterant wood chips, wheat bran, straws, cottonseed hulls or corn flour in different proportions (the mass ratio of the adulterant to the mushroom powder is 2: 98, 5: 95, 10: 90, 15: 85, 20: 80, 30: 70, 40: 60 and 50: 50), placing the mushroom powder in the center of a glass slide, adding 1 drop of chloral hydrate solution, and covering the glass slide after the chloral hydrate solution permeates into the powder; observing under microscope with 50-300 times; the lowest adulteration ratio of the characteristic structure of the adulterant which can be seen under a microscope is defined as a detection limit, the lowest adulteration ratio of the prepared mushroom powder is 2%, namely if the characteristic structure of the adulterant can be seen under the ratio of 2%, the detection is defined as 2%, and the detection with lower ratio is not carried out any more.

(2) Preparing mushroom powder containing adulterant wood chips, wheat bran, straws, cottonseed hulls or corn flour in different proportions (the mass ratio of the adulterant to the mushroom powder is 2: 98, 5: 95, 10: 90, 15: 85, 20: 80, 30: 70, 40: 60 and 50: 50), then placing the mushroom powder in the center of a glass slide, adding 1-2 drops of phloroglucinol solution, uniformly stirring by using forceps, slightly placing, adding 1 drop of hydrochloric acid, uniformly stirring by using the forceps, and covering the glass slide; observing under microscope with 50-300 times; the lowest adulteration ratio of the characteristic structure of the adulterant which can be seen under a microscope is defined as a detection limit, the lowest adulteration ratio of the prepared mushroom powder is 2%, namely if the characteristic structure of the adulterant can be seen under the ratio of 2%, the detection is defined as 2%, and the detection with lower ratio is not carried out any more.

FIG. 8 and FIG. 9 are the detection limit pictures of chloral hydrate and phloroglucinol of mushroom powder with wood chips, wheat bran, rice straw, cottonseed hull and corn flour.

Example 4

Preparing a mushroom powder, wood chips, wheat bran, straws, cottonseed hulls and corn flour in a mass ratio of 70: 5: 10: 10: 5: 5, the powder mixture was identified by the method of example 1.

The identification results are as follows:

as can be seen from fig. 10: (a) the mushroom powder contains structural characteristics which do not belong to mushroom powder; (b) the mushroom powder has a dyeing characteristic which does not belong to mushroom powder.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.