Useful Tips

Measurement of salinity in foods - which is better?

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  1. 1 Use this instrument to accurately measure the salt content of a liquid. Refractometers measure the value of refraction or distortion of light when it enters a liquid. The more salts or other materials dissolved in water, the more resistance light encounters and the more it is refracted.
    • A cheaper but less accurate way is to use a hydrometer.
    • Use a conductivity meter to measure soil salinity.
  2. 2 Choose a refractometer designed for a specific fluid. Different fluids themselves refract light differently, so use a refractometer designed for your specific fluid to accurately measure extra salinity (or the content of other solids). If no specific liquid is indicated on the packaging, then the refractometer is likely to measure the salinity of the water.
    • Note:Salt refractometers used to measure the amount of sodium chloride dissolved in water. Seawater Refractometers used to measure salt mixtures, which are usually found in sea water or in aquariums with sea water. Using an improper device will give an error of about 5%, which may be quite acceptable for non-laboratory purposes.
    • Refractometers are also designed to compensate for the expansion of a particular material due to temperature changes.
  3. 3 Open the plate from the flat end of the refractometer. The hand-held refractometer has a round open end to look through, as well as a flat end. Hold the refractometer so that the flat surface is at the top of the instrument and find a small plate at the end that should be shifted to the side.
    • Note: If you have not used this refractometer, then you should first calibrate it to obtain more accurate values. The calibration process is described at the end of the section, but first, read the following steps to better understand how the instrument works.
  4. 4 Apply a few drops of liquid to an open prism. Take the necessary liquid and use a pipette to draw a few drops. Transfer it to a translucent prism that opens under the shifted plate. Add enough water so that the surface of the prism is completely covered with a thin layer of liquid.
  5. 5 Carefully close the plate. Cover the prism again by carefully sliding the plate into place. The elements of the refractometer are very small and fragile, so do not apply excessive force, even if they are a little stuck. Instead, slide the plate back and forth with your finger until it moves smoothly again.
  6. 6 Look into the appliance to see the salinity value. Look at the round end of the appliance. You should see one scale with digital divisions or several scales. The salinity scale is probably marked as 0/00, which means "parts per thousand," and ranges from 0 at the bottom of the scale to at least 50 at the top. Look at the salinity value along the line of convergence of the white and blue areas.
  7. 7 Wipe the prism with a soft and damp cloth. Having learned the necessary measurements, open the plate again and remove water droplets from the prism with a slightly damp cloth. If you leave water on the prism or lower the refractometer into water, it can damage the instrument.
    • If you don’t have a suitable cloth to wipe off the tiny prism, try using a slightly damp paper towel.
  8. 8 Periodically calibrate the refractometer. Between use, periodically calibrate the instrument with clean distilled water to always get the correct results. Add water to the prism in the same way as any other liquid, and then check that the salinity is "0". If the instrument showed a different value, use a small screwdriver to adjust the calibration screw, which is usually located under the cap at the bottom or top of the device, until the salinity value is “0”.
    • A high-quality new refractometer requires calibration no more than once every few weeks or months. An inexpensive and old refractometer may require calibration before each use.
    • Your refractometer may contain calibration instructions with a specific water temperature. If this is not recommended, use distilled water at room temperature.

Method 2 Using a Hydrometer

  1. 1 This low-cost instrument will provide fairly accurate measurements. Hydrometer measures specific gravity water or its density compared to pure H2O. Since almost all types of salts are denser than water, the hydrometer will show you the salt content. The value obtained will be accurate enough for most tasks like measuring the salt content in an aquarium, but many hydrometer models are inaccurate or can easily be used incorrectly.
    • This method is not suitable for solids. To measure the salt content in the soil, use the conductivity method.
    • For a more accurate result, use an inexpensive evaporative method or a faster refractometer.
  2. 2 Hydrometer options. Hydrometers, also called hydrometersare sold in several basic variants both online and in aquarium stores. Glass hydrometers floating in water are usually the most accurate, but often do not have a scale for accurate readings (beyond the decimal value). Rotary-handle plastic hydrometers may be cheaper and more reliable, but they will become less accurate over time.
  3. 3 Select a hydrometer with the specified temperature standard. Because different materials expand or contract at different speeds as they heat up or cool down, it's important to know the temperature for which your hydrometer is calibrated to calculate salinity. Choose a hydrometer at the temperature indicated on the device or packaging. The easiest way to calculate salinity is with hydrometers calibrated at 15ºC or 25ºC, as these are the most common standards for measuring water salinity. You can use a hydrometer with a different calibration, if complete with it there is a table for converting salinity readings.
  4. 4 Take a sample of water. Collect a small amount of water, the salinity of which you plan to measure, into a clean, transparent container. It should be wide enough to fit a hydrometer, and the amount of water should be sufficient to immerse most of the instrument. Be sure to check that the container is clean.
  5. 5 Measure the temperature of the water sample. Use a thermometer to measure the temperature of the water. Knowing the water temperature and the temperature standard of your hydrometer, you can calculate the salinity.
    • To obtain a slightly more accurate value, you can heat or cool the water to the standard temperature of the hydrometer. Be careful not to overheat the water, as the specific gravity changes significantly when boiling or forming steam.
  6. 6 Clean the hydrometer if necessary. Rub the hydrometer to remove visible dirt or other solid particles on the surface. After use in salt water, flush the hydrometer with clean water, as salt may accumulate on the surface of the device.
  7. 7 Carefully lower the hydrometer into water. Glass hydrometers are partially immersed in water, after which they themselves float. Hydrometers with a rotary handle do not float and usually come with a small handle that allows you to lower the device into water and not wet your hands.
    • Do not immerse glass hydrometers completely, otherwise you may get erroneous readings.
  8. 8 Gently shake to remove air bubbles. If air bubbles collect on the surface of the hydrometer, then their buoyancy can affect the accuracy of determining density. Shake the hydrometer gently to get rid of them, then let the water calm down.
  9. 9 Read the hydrometer with a rotary knob. Hold such a hydrometer horizontally, without tilting in any direction. The value indicated by the rotary knob is the specific gravity of the water.
  10. 10 Read the readings of the glass hydrometer. The readings of such a device are read at the point of contact of the water surface with a hydrometer. If the surface of the water has a wave character, then ignore the waves and read the readings on the level of the flat surface of the water.
    • Such waves are called meniscus and are caused by surface tension, not salt content.
  11. 11 If necessary, convert the specific gravity measurement to salinity. Many aquarium care guides indicate specific gravity (usually between 0.998 and 1.031), so there is no need to convert this value to salinity (which usually should be between 0 and 40 parts per thousand). But if the reference lists salinity, then you need to perform the conversion yourself. If your hydrometer does not have a special table for this, then try to find a table or calculator for "converting specific gravity to salinity" online or in the aquarium care guide. The table must comply with the temperature standard of the hydrometer, otherwise you will get the wrong result.
    • can be used for a hydrometer calibrated to a standard temperature of 15ºC. Please note that the temperature of the water sample is also indicated in ºC.
    • Intended for hydrometers calibrated at 25ºC. Indicating water sample temperature in ºC.
    • Such tables and calculators vary depending on the liquid, but most of them are used for salt water.

At the same time, ATAGO salinometers have a number of advantages in the circle of "conductometric" salinometers.

  • The first is ease of use: the device was manufactured specifically for food production, so it has an extremely compact size, it can be washed under running water, used at high temperatures and calibrated by air.
  • Secondly it high accuracy: diluted samples can usually be measured with an accuracy of ± 0.05% (g / 100g).
  • Thirdly, it is wide range measurements: it reaches salt concentrations of 5, 10% (50,000, 100,000 ppm, respectively) and allows you to measure salinity in almost any sample!
  • And also a model is available that shows the salt concentration as close as possible to the titration method.

Let's look at cases when saline testers can be used.

Restaurant and cafe chains

With a large number of restaurants or cafes, it becomes necessary to maintain the same taste in different places: it can be soups, sauces, or other salt-containing dishes. ATAGO salinometers will help to measure salinity both in the central kitchen and in each particular restaurant, allowing to guarantee the quality of the finished product throughout the network. And some demanding customers will appreciate the indication in the menu in addition to calories and salt concentration.

Method 3 Using a conductivity meter

  1. 1 This instrument measures the salinity of soil or water. An electric conductivity meter is the only publicly available instrument that can be used to measure soil salinity. It is also suitable for measuring water salinity, but a high-quality electric conductivity meter can be much more expensive than a refractometer or hydrometer.
    • Some aquarium enthusiasts prefer to use a conductivity meter and one of the above instruments at the same time to check if the values ​​match.
  2. 2 Choosing an electrical conductivity meter. Such probes send electric current through the material and measure the resistance of the material to the passage of current. The more salt is contained in water or soil, the higher the conductivity. To get the correct values ​​for common types of water and soil, choose a conductivity meter that can measure at least 19.99 mS / cm (19.99 dS / m).
  3. 3 To measure soil salinity, mix it with distilled water. Mix one part of the soil into five parts of distilled water and mix thoroughly. Allow the mixture to stand for at least two minutes before continuing. Since there is no salt or electrolyte in distilled water, the measurements obtained will reflect the correct amount of material in the soil.
    • In laboratory conditions, you may need to leave the mixture for half an hour or use the more accurate method of "soil paste saturated with water", which takes about two hours. Such methods are rarely used outside the laboratory, and the above method also provides a fairly accurate result.
  4. 4 Having removed the cap, lower the conductivity meter to the required depth. Remove the protective cap covering the thin end of the conductivity meter. Immerse this end to the depth indicated on the device itself or simply deep enough so that the thin part goes under water (if the depth is not indicated). Most conductometers are water resistant only to a certain point, so do not immerse the entire device in water.
  5. 5 Carefully move the appliance up and down. This movement allows you to get rid of air bubbles that hit the probe. You do not need to shake it strongly so as not to push the water out of the probe.
  6. 6 Correct the temperature according to the conductometer manual. Some conductometers automatically adjust for fluid temperature, which can affect conductivity. Wait 30 seconds for the instrument to make this correction, and if the water is very cold or hot, then you have to wait longer. Other instruments have a scale that can be manually adjusted to correct the temperature.
    • If your conductometer does not have these functions, then it can be equipped with a table for manual correction of the value for water temperature.
  7. 7 Read the display. The display is usually digital and can display values ​​in mS / cm, dS / m or μS / cm. Fortunately, all three units are the same size, so you do not have to perform conversions.
    • These units mean milliSiemens per centimeter, deciSiemens per meter or microSiemens per centimeter. The old Siemens unit designation is Mo (the inverse of Ohm), which is still used in some areas of industry.
  8. 8 Determine if soil salinity is appropriate for your plants. When using the method described here, a conductometer reading of 4 or higher may indicate a hazard. Susceptible plants like mangoes or banana trees can not tolerate even salinity at level 2, while more resistant plants like coconut palm trees can withstand salinity of about 8–10.
    • Note: When studying salinity ranges for specific plants, it is important to know by what method the compilers of the document were guided in the conductivity test. If the soil was diluted into two parts of water, or simply in a sufficient amount of water to form a paste, and not in the ratio of 1: 5 indicated here, then the obtained values ​​can be very different.
  9. 9 Periodically calibrate the conductivity meter. Between uses, calibrate the conductivity meter using the "conductivity calibration solution" that is purchased for this purpose. If the measurement does not correspond to the known conductivity of such a solution, then use a small screwdriver to adjust the calibration screw to the correct value.
    • Some calibration solutions come with a “control solution” for testing after calibration is complete. If the conductivity of the control solution is inaccurate, then your conductivity meter may be malfunctioning.

Where better to install a softener

The installation of such a filter on the highway (inlet, main pipe) will not only improve the drinking properties of water. Hard water with regular oral administration can cause a number of health problems:

  • gout,
  • urolithiasis disease,
  • joint problems.

TITANOF offers cation exchange filters with an extended shelf life of up to 12 months. Installation can be carried out both on the highway and under the sink (in case soft water is needed only for drinking).

Hard salt water and scale

Water hardness can also be determined by scale. Increasing a thick layer inside the heating elements of expensive equipment, scale reduces their life. The TITANOF magnetic transducer, a small device mounted on the trunk and protecting household appliances, will help get rid of scale. Magnets act in a special way on water, depriving it of the ability to “grow” scale on pipes.

Determination of water and moisture in the food industry

Analysis of moisture content (or determination of water content) plays an important role in all areas of the food industry: in the control of raw materials, production, inspection of finished products and their storage, as well as in the development of new products. Modern manufacturers are forced to maintain low prices and produce huge volumes of products, so the analysis of moisture content should be very fast, accurate and reliable. In addition, there are many requirements that must be observed. Therefore, all analyzes and their results should be reliably documented.

There are several moisture analysis procedures. Choosing the right one depends on a variety of factors. Основные характеристики, преимущества и риски этих процедур представлены ниже.

1.1. Свободная и связанная влага

Almost all naturally occurring substances contain water. In the simplest case, water is adsorbed from air onto the surface of the particles. It can also be retained in pores of solids or exist in a chemically bound form. In foods and their ingredients, moisture is present in almost all of these forms. In addition to products that are simple in composition, such as regular sugar or alcoholic beverages, there are complex cellular structures, such as dried fruits or meat, in which water is present in the form of sorption and capillary moisture. Water is also found deep in the cells, where its amount is very difficult to measure. For this reason, methods for sample preparation and analysis should be selected based on the properties of the test product.

Salt: from "white gold" to a mass product

Salt has been known for a long time, and its mention can be found in the history of most civilizations. The Babylonians and Sumerians used salt to preserve food. Salt has always been in great demand and in many regions was a rare product. It is salts that owe their wealth and influence to many cities - for example, the Hanseatic city of Luneburg.

Not surprisingly, salt was called "white gold." Interestingly, even the English word salary (salary) once had the meaning of "a soldier’s allowance for salt." Salt was especially expensive in the Middle Ages. It became available in the German regions only when it became possible to mine it from the saline deposits of the Central European workshop basin 100 meters thick and about 250 million years old.

Most often, table salt is used in food, consisting mainly of sodium chloride. Even after the industrial production of ordinary table salt from rock or sea salt, 1-3% of other salts remain in it. Untreated sea salt contains up to 5% water. Salt (or table) salt is refined and refined salt. To improve properties such as flowability and hygroscopicity, a small amount of other substances is added to the salt. By origin, table salt is divided into sea and rock. Each of them is mined in a different way.

Rock salt

Rock salt is often mined underground. The collection is carried out either by the development of mines, or by leaching. To obtain table salt, the brine is purified from other substances by concentration, followed by condensation or evaporation.

Different regions of the world have their own methods of salt extraction. Some South American Indian tribes obtain potassium chloride-rich salt by leaching from vegetable ash. In the area around Lake Chad, salt-containing land is washed, filtered and then evaporated. In the past, salt was extracted from peat in some parts of Northern Germany, which was flooded with sea water.

Sea salt

Mining salt from seawater is probably the oldest method. Sea water is allowed into the swimming pools, where it slowly evaporates. All dissolved ions, depending on their solubility, crystallize sequentially in different layers. Sodium chloride is in the upper layer, which is removed until the water has completely evaporated. With this method of extraction various impurities get into table salt, but often this becomes a marketing feature of the product. Currently, about 20% of table salt in the world is obtained from sea water.

Salt today

Salt is the main ingredient in many foods, and its content, as a rule, needs to be determined as accurately as possible. Although this substance used to be considered “white gold”, today it does not have the best reputation. Too much dose of salt - mainly sodium ion - has an adverse effect on human health. Currently, WHO and FAO are conducting campaigns to limit salt intake, which determine the maximum values ​​for food. This trend will continue and maximum salt values ​​will be introduced. Pressure on food producers to lower salt levels is likely to increase. Many recipes have already changed or will be changed in the near future. This will require a fairly large number of tests, including salt analysis.

The following sections provide an overview of various methods for determining the salt content: titration, weight loss during drying, etc. Then, the features of determining the salt content in individual foods are described, and finally, some tips and recommendations are given on how to improve analysis methods - to simplify working procedures and more accurate results.

Bakeries

Salt is an important component in the preparation of bread, rolls or other baked goods. And in some cases it is necessary to maintain the salinity of the test at a certain level: for example, 1-2%. And since in appearance it is impossible to determine salinity, it is possible to entrust this task to the salinometer.

Canning factory

Pickles and marinades are ordinary guests at canneries, especially in Russia. Saline testers make it possible to determine the concentration of both the pickles and pickles themselves and the brines. For example, to measure pickled cucumbers, it is enough to chop them finely and dilute them with water to a ratio of 1 to 9. A brine is even easier to measure: dilution with water is not even required!

Food Labs

In many countries, retailers are requesting product testing, including salt testing. Moreover, requests can come from a wide variety of products, therefore reliable devices are needed that are easy to use on the one hand and high metrological characteristics on the other. ATAGO salinometers can replace standard titration systems, which take up a lot of space and require reagents for titration.

At the same time, large retailers can conduct such tests on their own.

What do you need

  • Liquid or soil for measurement

With a hydrometer:

  • Hydrometer
  • Thermometer
  • Net water sample tank

Using a refractometer:

  • Refractometer
  • Pipette
  • Distilled water (for calibration)

Using a conductivity meter:

  • Conductivity meter
  • Distilled water (for measuring soil salinity)
  • Thermometer

Meat processing plants

Sausage, ham, sausages, sausages, smoked meats, pastes, stews and much more - we all know that meat processing plants are one of the largest food enterprises in Russia, and most of the assortment contains salt. ATAGO conductivity testers allow you to take measurements directly to the workshop when every second is important. The compact size and the ability to wash under running water provide additional benefits!

Estimated salt content in some products,% (g / 100g)

Broths, brinesCheeses, butter
Miso soup0,9Butter0,1
Water for cooking vegetables1Mozzarella0,7
Water for cooking pasta1Gouda0,9
Soup broth1,9Emmental1,1
Brine2,9Maribo1,6
Ayran4,9Bree1,8
Gorgonzola3,6
Sauces
Gravy0,8Meat
Bechamel, white sauce0,9Sausages0,8
Demiglas1,1Ham1,1
Pasta sauce1,2Salami1,6
Mayonnaise1,6Bacon1,7
Mashed Tomato1,7Prosciutto3,2
Salad dressing1,7
Taco sauce2A fish
Steak sauce2Sardine1
Ketchup3Tuna1,1
Spicy pancake sauce4,5Pickled Octopus1,3
Barbecue sauce4,8Salmon2,4
Sushi Rice Vinegar5,2Salmon caviar2,8
Soy sauce6,1Taraco salted caviar5,2
Kimchi pasta sauce6,1Anchovy10
Yakitori Sauce6,5
Habanero sauce6,8Pickles and pickles
Bean oil7Pickles1,7
Oyster sauce9,4Sauerkraut2,1
Bean paste11Kimchi2,2
Soy sauce13Olives2,8
Fish sauce21,4Pickled radish3,6
SoupsSnack
Minestrone1,2Chips1,4
Potato soup1,2Crackers2,3
Noodles soup1,4
Tom Yam1,5
Curry soup1,6

Why do the salinity concentration readings not coincide with the concentrations obtained by titration?

ATAGO saline testers use a conductometric method for measuring salinity, which involves the measurement of electrical conductivity and is fundamentally different from the titration method (Mora). However, a correlation can be established between the readings of these two methods. If you need results close to the titration results, you can purchase a special PAL-ES3 salinometer, in which correction factors are already entered.

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