CN104689793A - Special aflatoxin efficient adsorbent for peanut oil and preparation method thereof - Google Patents

Abstract

The invention relates to a high-efficiency aflatoxin adsorbent for peanut oil and a preparation method thereof. The raw material is montmorillonite, which is firstly modified inorganically by inorganic salts, and then organically modified by organic alkyl quaternary ammonium salts. Finally, it is obtained by filtering and drying. The weight ratio of each component is: 75-85% of montmorillonite, 2-5% of inorganic modifier, and 10-20% of organic modifier. The aflatoxin adsorbent prepared by the invention can specifically and efficiently adsorb the aflatoxin contaminated in peanut oil, and has the advantages of low production cost, high adsorption efficiency, less loss of nutrients, low fuel consumption, and the like.

Description

A special aflatoxin high-efficiency adsorbent for peanut oil and its preparation method

(1) Technical field

The invention relates to a special aflatoxin high-efficiency adsorbent for peanut oil and a preparation method thereof, belonging to the field of food processing and safety control.

(2) Background technology

Aflatoxins are secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus, which are highly toxic and carcinogenic to humans and animals, especially aflatoxin B ₁ , whose acute toxicity is 10 times that of potassium cyanide, and arsenic 68 times, is the strongest chemical carcinogen found so far. Peanut is one of the most susceptible grain and oil crops to be contaminated by aflatoxins, and the contamination of aflatoxin in peanut oil, its product, has always attracted people's attention. In recent years, the number of liver cancer patients and deaths caused by eating aflatoxin-contaminated grain and oil products at home and abroad has increased year by year, causing huge economic losses and seriously hindering the import and export of grain, oil and food. Therefore, it is very necessary to research and develop technologies and products for the prevention and control of aflatoxins in peanut oil.

At present, the most effective, feasible and low-cost method to reduce aflatoxins is to use toxin adsorbents. Adsorbents are added to food to absorb toxins, and then the adsorbents are removed by filtration or centrifugation. At present, the use of adsorbents to remove aflatoxin from feed contamination has been widely studied and applied, but it is rarely used in edible oil.

However, there are few high-efficiency adsorbents dedicated to the research and development of aflatoxin in peanut oil, and the existing adsorbents have low adsorption performance, few adsorption types, and large nutritional and weight loss of peanut oil after adsorption. Using montmorillonite as the main raw material, after inorganic and organic mixed modification, can significantly improve the adsorption performance of montmorillonite to aflatoxin, reduce the loss of trace elements and vitamins in peanut oil, and reduce the loss of oil.

(3) Contents of the invention

The invention provides a special aflatoxin high-efficiency adsorbent for peanut oil and a preparation method thereof. The aflatoxin adsorbent prepared by the invention can specifically and efficiently adsorb the aflatoxin polluted in peanut oil, and has the advantages of low production cost, high adsorption efficiency, less loss of nutrients, low fuel consumption, and the like.

A special aflatoxin high-efficiency adsorbent for peanut oil, the weight ratio of each component is: montmorillonite 75-85%, inorganic modifier 2-5%, organic modifier 10-20%, the weight percentage of each component The sum is 100%.

The inorganic modifier is NaCl, Na ₂ CO ₃ or AlCl ₃ .

The organic modifier is organic alkyl quaternary ammonium salt, including C ₁₂ -C ₂₀ aliphatic quaternary ammonium salt, namely dodecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium chloride, Alkyl quaternary ammonium salts such as cetyltrimethylammonium chloride or octadecyltrimethylammonium chloride.

The main component of the montmorillonite is montmorillonite, which is a layered silicate clay mineral with a 2:1 three-layer structure, and its unit cell is composed of two layers of silicon-oxygen tetrahedron sandwiching a layer of aluminum-oxygen octahedron. The tetrahedron and octahedron are connected by sharing oxygen atoms, and the unit cells are stacked in parallel. Al ³⁺ and Si ⁴⁺ ions in the lattice are easily replaced by other low-valent cations, resulting in isomorphic replacement.

The present invention also relates to a preparation method of a special aflatoxin high-efficiency adsorbent for peanut oil, which uses montmorillonite as the raw material, first carries out inorganic modification with inorganic salt, then uses organic alkyl quaternary ammonium salt for organic modification, and finally filters the , obtained by drying. The weight ratio of each component is: 75-85% of montmorillonite, 2-5% of inorganic modifier, 10-20% of organic modifier, and the sum of the weight percentages of each component is 100%; specifically, the following steps are included:

1. Inorganic modification: heat up the deionized water to 60°C, slowly add the montmorillonite to the deionized water according to the ratio of montmorillonite: deionized water = 1:5 (W/V), and stir evenly at a speed of 300r/min. A montmorillonite suspension is formed. Dissolve the inorganic modifier with a weight ratio of 2-5% of the montmorillonite using 60°C deionized water (not exceeding 1/10 of the volume ratio of the deionized water described above in this step, as long as the inorganic modifier can be dissolved) , and slowly and evenly added to the montmorillonite suspension, kept for 2 hours, the ion-exchanged mixture was centrifuged at 3000r/min for 10 minutes, the supernatant was discarded, the precipitate was washed with deionized water and centrifuged to remove excess inorganic salt to obtain inorganic modified montmorillonite; the inorganic modifier is NaCl, Na ₂ CO ₃ or AlCl ₃ .

2. Organic modification: add the inorganic modified montmorillonite obtained in step 1 to deionized water according to the ratio of inorganic modified montmorillonite: deionized water=1:5 (W/V), and adjust the temperature to 60°C , the stirring speed is 300r/min, and a uniform inorganic modified montmorillonite suspension is prepared. Then use 60 DEG C of deionized water (not more than 1/10 of the volume ratio of deionized water described earlier in this step to dissolve the organic modifier with the weight ratio of inorganic modified montmorillonite 5-15%) can be) dissolved, then slowly added to the inorganic modified montmorillonite suspension and reacted for 2h to carry out ion exchange, the mixed solution after ion exchange was centrifuged at 3000r/min for 10min, the supernatant was discarded, the precipitate was washed with deionized water and The excess organic modifier is removed by centrifugation to obtain inorganic-organic modified montmorillonite; the organic modifier is an organic alkyl quaternary ammonium salt, including C ₁₂ -C ₂₀ aliphatic quaternary ammonium salt, i.e. dodecane Alkyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium chloride, cetyl trimethyl ammonium chloride or octadecyl trimethyl ammonium chloride and other alkyl quaternary ammonium salts.

3. Filtration and drying: Dry the inorganic-organic mixed modified montmorillonite obtained in step 2) at 60°C until the color changes from gray to pure white, and pass through a 200-mesh sieve to obtain a high-efficiency aflatoxin adsorbent for peanut oil .

The present invention has the following advantages:

1. The montmorillonite used in the present invention is natural aluminosilicate, which has abundant sources of raw materials and low production cost.

2. The special aflatoxin high-efficiency adsorbent for peanut oil prepared by the present invention has the advantages of small investment, simple preparation, low pollution, high production efficiency, and reusability.

3. The special-purpose aflatoxin high-efficiency adsorbent for peanut oil prepared by the present invention has the advantages of high adsorption performance, strong specificity, less nutrient loss, and low fuel consumption.

(4) Description of drawings

Fig. 1 is common adsorbent and the modified montmorillonite prepared by the present invention compares the adsorption effect of AFB ₁

The test results in Fig. 1 show that commonly used adsorbents (clay, montmorillonite, bentonite and attapulgite) can effectively remove aflatoxin in peanut oil, but still fall short of the national limit requirements for aflatoxin residues in peanut oil ( 20ug/kg); and the modified montmorillonite prepared by the present invention can reduce aflatoxin to below 20ug/kg.

(5) Specific implementation methods

The inorganic modifiers described in the present invention are all analytically pure, and the described montmorillonite is montmorillonite raw soil, which can be purchased commercially.

Example 1: Measure 7.5L of deionized water into the reactor, set and raise the temperature to 60°C, and adjust the rotation speed to 300r/min; slowly add 400g of montmorillonite into the reactor to form a montmorillonite suspension. Dissolve 16g NaCl in 0.5L deionized water at 60°C, and slowly and evenly add it to the reactor. After 2 hours of reaction, centrifuge the ion-exchanged mixture at 3000r/min for 10 minutes, discard the supernatant, and precipitate Rinse with deionized water and centrifuge to remove excess inorganic salts to obtain inorganically modified montmorillonite. Add 7.5L of deionized water at 60°C to the inorganically modified montmorillonite to make a dispersion suspension; dissolve 68g of octadecyltrimethylammonium chloride in deionized water at 60°C, and then The organic modifier solution was slowly added into the reaction kettle, the stirring speed was 300r/min, and the treatment was carried out at 60°C for 2h. The reaction solution was centrifuged and washed until the presence of chloride ions could not be detected with 0.1mol/L AgNO ₃ . Dry the filter cake in an oven at 60°C for 24 hours, pass through a 200-mesh sieve, and store the under-screened material in an airtight container.

Example 2: Measure 7.5L of deionized water into the reactor, set and raise the temperature to 60°C, and adjust the rotation speed to 300r/min; slowly add 250g of montmorillonite into the reactor to form a montmorillonite suspension. Dissolve 12.5g Na ₂ CO ₃ in 0.5L deionized water at 60°C, and slowly and evenly add it to the reaction kettle. After 2 hours of reaction, the ion-exchanged mixture is centrifuged at 3000r/min for 10 minutes, and discarded. The supernatant liquid and the precipitate were washed with deionized water and centrifuged to remove excess inorganic salts to obtain inorganically modified montmorillonite. Add 7.5L of deionized water at 60°C to the inorganically modified montmorillonite to make a dispersion suspension; dissolve 45g of octadecyltrimethylammonium chloride in 0.5L of deionized water at 60°C, Then the organic modifier solution was slowly added into the reaction kettle, the stirring speed was 300r/min, and the mixture was treated at 60°C for 2h. The reaction solution was centrifuged and washed until the presence of chloride ions could not be detected with 0.1mol/L AgNO ₃ . Dry the filter cake in an oven at 60°C for 24 hours, pass through a 200-mesh sieve, and store the under-sieve in an airtight container.

Example 3: 0.5M Na ₂ CO ₃ was slowly added to 1.0M AlCl ₃ solution, and stirred rapidly for 24 hours, and finally made OH ^- /Al ³⁺ =2.4 to obtain Al ₁₃ solution; Alkyltrimethylammonium chloride (1631) was slowly added to the above Al ₁₃ solution, and stirred rapidly for 2 hours to obtain a mixed solution of Al-OH-1631; 30g of montmorillonite was slowly added to the mixed solution of Al-OH-1631 , and stirred rapidly for 24 hours; the reacted solution was filtered, and then washed with deionized water at 60°C until the presence of chloride ions could not be detected with 0.1mol/L AgNO ₃ . Dry the filter cake in an oven at 60°C for 24 hours, pass through a 200-mesh sieve, and store the under-sieve in an airtight container.

Verification example:

In order to better illustrate the advantages and characteristics of the high-efficiency aflatoxin adsorbent for peanut oil (i.e. modified montmorillonite) of the present invention, we compared the adsorption properties of the commonly used adsorbents used by oil companies and the product of the present invention.

In the oil refining process, oil companies often use white clay, montmorillonite, bentonite, and attapulgite as pigment adsorbents. These adsorbents can also remove part of aflatoxin while adsorbing pigments in oil. The adsorption effects of common adsorbents and modified montmorillonite on AFB ₁ in peanut oil are shown in Figure 1 (the addition amount of the above four pigment adsorbents is 2.5% of the weight ratio of peanut oil). AFB ₁ in peanut oil raw material is 389.09ug/kg, after being adsorbed by white clay, the content of AFB ₁ in peanut oil is reduced to 23.30ug/kg; after being adsorbed by montmorillonite, the content of AFB ₁ in peanut oil is reduced to 24.53ppb; , the content of AFB ₁ in peanut oil decreased to 21.60ug/kg; after being adsorbed by attapulgite, the content of AFB ₁ in peanut oil decreased to 36.46ug/kg; after being attached by bentonite, the content of AFB ₁ in peanut oil decreased to 21.60ug/kg and after the adsorption of modified montmorillonite prepared by the present invention, AFB ₁ in peanut oil was reduced to 11.81ug/kg. Result of the test shows that commonly used adsorbents can effectively remove the aflatoxin in peanut oil, but still fall short of the country's limit requirement (20ug/kg) to aflatoxin residues in peanut oil; and through the modified montmorillonite prepared by the present invention Can reduce aflatoxin to below 20ug/kg. This shows that the modified montmorillonite can more effectively remove aflatoxin from peanut oil and meet the requirements of food safety.

Claims (2)

1. A special aflatoxin high-efficiency adsorbent for peanut oil, characterized in that, using montmorillonite as raw material, first carry out inorganic modification by inorganic modifier, then use organic modifier to carry out organic modification, and finally filter and dry Prepared; the weight ratio of each component is: 75-85% of montmorillonite, 2-5% of inorganic modifier, 10-20% of organic modifier, and the sum of the weight percentages of each component is 100%; The inorganic modifier is NaCl, Na ₂ CO ₃ or AlCl ₃ ; the organic modifier is dodecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium chloride, hexadecyl Trimethylammonium Chloride or Octadecyltrimethylammonium Chloride. 2. a preparation method of a special aflatoxin high-efficiency adsorbent for peanut oil, characterized in that it may further comprise the steps: 1) Inorganic modification: heat up deionized water to 60°C, slowly add montmorillonite to deionized water according to the ratio of montmorillonite: deionized water W/V=1:5, stir at a speed of 300r/min to form a montmorillonite Desoil suspension: Take the inorganic modifier with a weight ratio of 2-5% of montmorillonite and dissolve it in 60°C deionized water, slowly and evenly add it to the montmorillonite suspension, keep it warm for 2 hours, and the mixed solution after ion exchange Centrifuge at 3000r/min for 10min, discard the supernatant, wash the precipitate with deionized water and centrifuge to remove excess inorganic salts to obtain inorganic modified montmorillonite; the inorganic modifier is NaCl, Na ₂ CO ₃ or AlCl ₃ ; 2) Organic modification: add the inorganic modified montmorillonite obtained in step 1) to deionized water according to the ratio of inorganic modified montmorillonite: deionized water W/V=1:5, adjust the temperature to 60°C, The stirring speed is 300r/min, and a uniform inorganic modified montmorillonite suspension is made; then the organic modifier with a weight ratio of 10-20% of the inorganic modified montmorillonite is dissolved in 60°C deionized water and slowly added to the Inorganic modified montmorillonite suspension was reacted for 2h for ion exchange, the mixed solution after ion exchange was centrifuged at 3000r/min for 10min, the supernatant was discarded, the precipitate was washed with deionized water and centrifuged to remove excess organic modifier, Obtain inorganic-organic modified montmorillonite; described organic modifier is dodecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride or octadecyltrimethylammonium chloride; 3) Filtration and drying: drying the inorganic-organic mixed modified montmorillonite obtained in step 2) at 60°C until the color changes from gray to pure white, passing through a 200-mesh sieve to obtain a high-efficiency aflatoxin adsorbent for peanut oil; The montmorillonite, inorganic modifier and organic modifier are in weight ratio: 75-85% of montmorillonite, 2-5% of inorganic modifier, 10-20% of organic modifier, each component weight The sum of the percentages is 100%.