The method of detecting sulfur dioxide in wolfberry, how to remove sulfur dioxide in wolfberry

Detection of sulfur dioxide.

The color reaction is extremely sensitive to temperature and time, the color temperature and time should be selected in strict accordance with the standard, and the color reaction should be carried out in a constant temperature water bath, and preparations should be made in advance.

Sodium sulfame and sodium hydroxide are tested.

It should be sealed and stored to avoid absorbing sulfur dioxide in the air, which will affect the test results, and the sodium sulfame solution has a short validity period, and it should be reconfigured beyond the expiration date; Sodium hydroxide should be decarbonized.

distilled water, PRAS solution should be preferentially selected for commercial reagents with high purity.

Formaldehyde method for the determination of sulfur dioxide on sampling has high detection requirements. It is susceptible to the conditions of sampling light, temperature, time, detection color rendering temperature, and time, and every small operation may have an impact on the results, so the operating conditions must be strictly grasped in the process of sampling and detection to ensure the accuracy of the measurement.

So it's good to use a sulfur dioxide detection tube to test, but the buyer doesn't operate well, and it's easy to shoot yourself in the foot.

Alkali is used to speed up drying, edible alkali.

Industrial alkalis are almost the same. The alkali itself does not stay on the goji berries, and it doesn't matter with alkali.

This is not the case with sulfur.

Sulfur is a decolorizing agent, and wolfberries smoked with sulfur must be recolored, otherwise they cannot be sold.

Therefore, the biggest problem with goji berries is the harm caused by dyes.

The inspection is also simple: buy wolfberries, don't pick a particularly uniform color, natural wolfberries are not so neat, if it is a bulk shipment, grab a few and put them in your hands, pour a little water to soak them, and then see if there is color in the water or on your hands.

There are three simple and effective ways to identify wolfberries smoked with sulfur: one look, two touches, and three tastes.

Sulfur dioxide detector.

At first glance, the color is particularly bright red, and the bright one may be "poisonous wolfberry"; The color is slightly dark, and the slightly earthy color is natural goji berries.

Second, touching the "poisonous wolfberry" with your hands has a sticky feeling, while the natural wolfberry is relatively dry.

Three tastes Take one and chew it in your mouth, the natural wolfberry is sweet and sour, and the "poisonous wolfberry" has a strong sour and bitter taste.

Sulfur Dioxide DetectorCSY-SE8 Sulfur Dioxide Detector can quickly detect sulfur dioxide content in food (bamboo shoots, candied fruits, biscuits, vermicelli, sugar, starch, daylily, preserved fruits, chocolate, wine, beer and malt beverages, etc.).

The sulfur dioxide detector is composed of a light source, a color cell, a high-sensitivity integrated photocell, a microprocessor, a large-screen LCD screen in all Chinese characters, an embedded miniature thermal printer, a wireless transmission module and an integrated chip, which can directly display the content of relevant indicators in the measured sample on the large-screen LCD screen, and print out the analysis results, and can also transmit the data to the terminal database of the "food safety information system" through the computer interface for analysis. This method has a low cost of single detection, simple and fast operation, and is convenient for on-site and vehicle-mounted use by law enforcement personnel or production quality control personnel.

Instrument principle: the relevant index components in the tested sample and the chromogenic agent react specifically under certain conditions, which can generate products with different color depths, which will selectively absorb visible light of different wavelengths, and the depth of the color, that is, the absorbance, is correlated with the concentration of the index components in the sample, and obeys the Lambert-Beale law in the appropriate concentration range. Therefore, the detected absorbance value is automatically calculated by the built-in standard curve software of the instrument, and the accurate concentration of the index component in the sample and whether it exceeds the standard can be obtained.

There are the following methods to remove sulfur dioxide from wolfberry: edible salt soaking method, water soaking method, vinegar water soaking method.

1. Edible salt soaking method.

Soaking goji berries in edible brine can effectively remove sulfur dioxide from goji berries.

2. Water immersion method.

It can be lightly removed with clean water, and most of the sulphur dioxide can be removed by soaking. However, wolfberry contains water-soluble goji polysaccharides, and high temperature is conducive to the dissolution of polysaccharides. In order to reduce the loss of polysaccharides and other nutrients, it is necessary to minimize the soaking time and reduce the temperature of the water.

If you use room temperature water, you can soak for 1 minute, and if you use hot water, you can choose to soak for 30 seconds.

3. Vinegar water immersion method.

Soaking goji berries in dilute vinegar water can also remove sulfur dioxide from goji berries. Depending on the amount and a little white vinegar, the acidic substance also helps to eliminate sulfur dioxide residues.

How to choose goji berries

1. The number of buries is like color: a good wolfberry has a bright color, smooth skin, shiny, and uniform color.

2. Shape: The shape of a good wolfberry is long and thin, uniform in size, and not distorted.

3. Taste: A good wolfberry should have a unique aroma and a sweet taste.

4. Brand: Choose a well-known brand to ensure that the quality is guaranteed.

5. Organized: Good wolfberry is clear, free of impurities, clean and tidy.

6. Quantity: When selecting wolfberries, you can buy different quantities of wolfberries according to the needs of the bend, but be careful not to buy too much, so as not to expire and deteriorate.

Sulfur dioxide is used as a bleaching agent in wolfberries, because the compounds produced by bleaching are unstable, and it can be considered to heat wolfberries to see if they change color.

Goji berries have the effect of nourishing yin and nourishing the kidneys, clearing the liver and brightening the eyes, and can be eaten or used medicinally.

Goji berries are a kind of nourishing food for both medicine and food, which can be used to make soup, soak in water and drink, and of course, can be eaten directly. Dosage is 10 to 2 og per meal.

Summary. Hello dear, glad for your question oh <>

Is the sulfur dioxide in goji berries measured after 5 minutes or 1 hour later? It's the result of 5 minutes. The sulfur dioxide velocity test tube was used for detection, 1g of wolfberry sample was weighed and added to 49ml of distilled water, stirred and allowed to stand for 10min, and then transferred 1ml to the centrifuge tube, and 2D sulfur dioxide detection reagent A and 1D sulfur dioxide detection reagent B were added.

After stirring well, use a centrifuge tube to compare with a colorimetric card after 5 minutes. Found with the presence of sulfur dioxide.

Is the sulfur dioxide in goji berries measured after 5 minutes or 1 hour later?

Hello dear, very respectful or happy for your question oh <>

Is the sulfur dioxide in goji berries measured after 5 minutes or 1 hour later? It's the result of 5 minutes. The sulfur dioxide speed test tube was used for detection, 1g of wolfberry sample was weighed and added to 49ml of distilled water, stirred and left for 10min, and then transferred 1ml to the centrifuge tube, and 2D sulfur dioxide detection reagent A and 1D sulfur dioxide detection reagent B were added.

After stirring well, use a centrifuge tube to compare with a colorimetric card after 5 minutes. Found with the presence of sulfur dioxide.

Quantitative detection of sulfur dioxide jujube in wolfberry: weigh the gram and put it back into a 25ml colorimetric tube stool, add reagent C, add 20ml of distilled water, ultrasonic extraction for 15min, because the upper solution is not clear, add solution A and solution B, then add distilled water to the 25ml scale line, shake well, let stand for 5min, filter, filtrate (i.e., sample liquid) for later use.

Then take a 10ml colorimetric tube, add 1ml of sample solution, add 80 L of C solution, add distilled water to 10ml of the scale line, add D solution, shake well, open the lid and let it stand for 10min, add the F solution of Jianhuimin, quickly turn the lid plug upside down twice, quickly add 1ml of E solution, mix the lid plug, and let it stand for 7min. After processing, it is used as a sample tube. Distilled water was added to the blank tube to replace the sample solution, and the rest of the steps were the same as the sample tube, and then the blank tube was used to calibrate, and then the sulfur dioxide content in the wolfberry branch was detected by Bijian, and the sulfur dioxide content in the wolfberry branch was only mg kg, which exceeded the national standard of China and was a substandard product.

The nationally certified brands of Shina wolfberry dioxide repatriation residual sulfur tester are: Haixingxing (Xiamen, Fujian), Zhiyunda (Beijing), Huilid (Shenyang, Liaoning), Xinfan (Nanjing, Jiangsu) ......Wait.

1 The nationally certified brand of wolfberry sulfur dioxide tester is "Food and Drug Administration EG01 Certified Brand".

2 The nationally certified brand has reliable test results and high accuracy, which can be searched to effectively ensure food safety.

3 Although some other brands may have a certain degree of popularity in the market, without a nationally certified brand number, the accuracy and reliability of their test results cannot be guaranteed.