rus
Issue #3/2022
A. V. Aprelev, V. A. Smirnov, E. V. Davydova
Application of Spectrophotometric Methods for Dye Identification
Application of Spectrophotometric Methods for Dye Identification
DOI: 10.22184/1993-7296.FRos.2022.16.3.246.256
At present, the actual problem is the identification of wine, alcohol-containing drinks, juices and juice-containing drinks in relation to the available synthetic dyes by simple and affordable methods. The article contains a brief description of the research conducted, the device and database of optical density numerical values of synthetic dyes used for the production of wine, juices and juice-containing drinks.
At present, the actual problem is the identification of wine, alcohol-containing drinks, juices and juice-containing drinks in relation to the available synthetic dyes by simple and affordable methods. The article contains a brief description of the research conducted, the device and database of optical density numerical values of synthetic dyes used for the production of wine, juices and juice-containing drinks.
Теги: alcohol-containing drinks food colorants juices and juice-containing drinks synthetic dyes алкогольные напитки пищевые красители синтетические красители соки и сокосодержащие напитки спектрофотометр
Application of Spectrophotometric Methods for Dye Identification
A. V. Aprelev, V. A. Smirnov, E. V. Davydova
VNIIFTRI, Solnechnogorsk, Moscow region, Russia
At present, the actual problem is the identification of wine, alcohol-containing drinks, juices and juice-containing drinks in relation to the available synthetic dyes by simple and affordable methods. The article contains a brief description of the research conducted, the device and database of optical density numerical values of synthetic dyes used for the production of wine, juices and juice-containing drinks.
Key words: synthetic dyes, food colorants, alcohol-containing drinks, juices and juice-containing drinks
Received on: 08.04.2022
Accepted on: 29.04.2022
At present, there are almost no food products that do not contain any dyes. It is well-known that the natural food colorants in most cases are not only harmless, but also capable of increasing the nutritional and biological value of the product being dyed. Anthocyanins are one of the most widespread pigments in nature. They have antioxidant properties, capillary-strengthening properties, the ability to stop pro-inflammatory mediators, prevent neurodegenerative diseases and age-related bone loss. Moreover, they have a favourable effect on the human cardiovascular system condition [1]. The natural dyes are obtained using the roots or stems, bark or leaves, flowers or fruits of the plants, insects. In this case, the dye quality depends on the plant collection time. The brighter and more intense shades can be achieved when colored with the fresh plants than when colored with the dried plants.
The high price of natural dyes, special storage requirements, and low produce-ability prompted a search to replace them with the cheaper and more stable substances. In the 19th century, the first synthetic dyes were produced, including the food colorants. The main application field of food synthetic colorants is to improve the appearance of food products. Since the synthetic dyes do not have any useful properties and at its best are harmless unlike the natural ones, their use is prohibited or limited in many countries. However, to ensure profits, the manufacturers continue to use such dyes. This causes problems for the food importers and exporters, since a particular food colorant may be legal in one country and illegal in another. It is also possible to replace the food colorants with non-food ones. There are several well-known methods for determination of synthetic dyes in the beverages. A significant disadvantage of these methods is complexity and high cost of the analysis due to the need for a preliminary analysis of all possible synthetic dyes. The disadvantages of all other available methods include high cost of the equipment required for the analysis, as well as the analysis duration.
At present, there are issues with the use of synthetic dyes related to the lack of a unified regulatory ethics for the use of dyes in the world. This causes problems for the food importers and exporters, since a particular food colorant may be legal in one country and illegal in another.
It is also possible to replace the food colorants with non-food ones. There are several well-known methods for determination of synthetic dyes in the beverages. A significant disadvantage of these methods is complexity and high cost of the analysis due to the need for a preliminary analysis of all possible synthetic dyes. The disadvantages of all other available methods include high cost of the equipment required for the analysis, as well as the analysis duration. Currently, the identification of wine and fruit juices entering the consumer market is also a pressing challenge. The insufficiency of food control methods does not allow timely registration of deviations from the standard and identification of the low-quality products. The quality improvement strategy for the food products in the Russian Federation until 2030 and current market trends require the establishment of additional food quality criteria, including their identification attributes that should be preceded by serious scientific work. Only after implementation of such activities, it will be possible to develop the measurement methods and techniques with the participation of specialists from various fields.
Due to this fact, the express methods for determining the dye content are required. However, it is not always possible due to the difficult extraction from the complex matrices.
Based on the results of scientific research devoted to the quality assessment of the colored low-alcohol and non-alcohol-containing drinks sold in the retail chains, the employees of the Federal State Unitary Enterprise “All-Russian Scientific Research Institute for Physical-Engineering and Radiotechnical Metrology” have developed an identification method for synthetic dyes by their stability when changing the pH value. The method provides for spectrophotometry of the test sample and a comparative analysis of the typical curves obtained during spectrophotometry of a natural sample of cyanidin‑3-O-glucoside, as well as the synthetic dyes that increases the analysis accuracy with due regard to the specific test conditions. The grounds for the method development included the pressing challenge of identifying wine and fruit juices entering the consumer market. Many studies have found that the main source of free radicals and antioxidants in the human body, due to the high content of phenolic compounds, is alcohol-containing drinks (wine), tea, coffee, juices, vegetables and fruits. The insufficiency of food control methods does not allow timely registration of deviations from the standard and identification of the low-quality products [1].
The synthetic dyes are often used for the production of alcohol-containing drinks, juices and juice-containing drinks. The most important quality specification of alcohol-containing drinks and juices assessed by the consumers, is their organoleptic parameters, such as taste, color and aroma. Moreover, color is the very first quality indicator that the consumer pays attention to when selecting a product. We often use the product color to get an idea about its quality and even its aroma. However, in many cases, the products lose their natural and attractive color during the production and storage stages, and sometimes they do not initially have such color. The chemical flavors are hidden by the wine sweetness. Therefore, the semi-sweet, sweet, dessert, and potent wines often turn out to be counterfeit. Both natural and artificial substances approved for use in the food products are applied as the food colorants.
Initially, only natural dyes were used to color and give an attractive look. With the expansion of food production, a need occurred for a large number of coloring components.
Synthetic or artificial food colorants are the unnatural organic compounds. Almost all of them have been used in the global food industry for decades. The list of synthetic dyes is very long, and their use often causes concerns. According to the research studies, the use of some food colorants can have a harmful effect on the child behavior and attention. It would be better to make a warning about this on the label of the food product where this colorant is used. For example, such dyes include the synthetic dye Ponceau 4R E124. It is possible that the manufacturers are not even aware of this fact, since in the Russian market Ponceau 4R is often described by the “natural” names such as “carmine”, “carminic”, “cochineal red”.
From a chemical point of view, such colorants can be classified into the azo dyes, riarylmethane, quinolinic, and indigoid dyes [4]. The soluble dyes in the form of sodium salts are commonly used. If an insoluble dye is required, then the aluminum derivatives of these dyes are applied [5].
The colored natural fruits are notable for the presence of anthocyanins that are the compounds that determine their color and have high antioxidant activity. Since the anthocyanins stain the berries and plant leaves in a variety of shades, this property has been used to obtain the natural food colorants. The anthocyanins (E163) obtained from the grape skins, blueberries, blueberries, red cabbage, hibiscus and black carrots are used [1, 6]. The anthocyanins are the colored plant glycosides containing anthocyanides as an aglycone, namely the substituted 2‑phenylchromenes related to the flavanoids. The anthocyanins have several forms of isomers. An experimental study was performed at a pH value of 3–4 in the samples of natural wines and counterfeit wines made intentionally in the laboratory. This value corresponded to the pH value of natural red wine [3]. The general formula of anthocyanidins is shown in Fig.1. Depending on which functional groups are in the active molecule centers, anthocyanidins have various properties and chemical structure.
The color of anthocyanins and anthocyanidins is determined by their sensitivity to pH valie: in an acidic environment (pH<3), anthocyanins (and anthocyanidins) are available as red pyrylium salts. When the pH value is increased to 4–5, the hydroxide ion is added to form a colorless pseudobase; in the case of further increase in pH to 6–7, water is eliminated with generation of the blue quinoid form that, in turn, releases a proton to form purple phenolate at pH value of 7–8. Finally, at a pH value of over 8, the quinoid phenolate is hydrolyzed with chromene cycle disruption and generation of the relevant yellow chalcone.
The studies conducted in recent years in our country and abroad allow to conclude that the anthocyanin profile can be considered as the “fingerprints” of fruits colored with pigments. According to such studies, the main anthocyanin of the coloring fruits is cyanidin‑3-O-glucoside.
The employees of the Federal State Unitary Enterprise “All-Russian Scientific Research Institute for Physical-Engineering and Radiotechnical Metrology” have developed the method to detect the synthetic dyes in red wines using the optical density value. Advantages of the proposed method are as follows:
The laboratory studies of the optical density of various natural juices were performed by comparing the optical density curves with the optical density curve and the extremum range of natural cyanidin 3-O-glucoside. Natural cyanidin can be found in such fruits as strawberries, cherries, chokeberries, lingonberries, blueberries, cranberries, blackberries, pomegranates, raspberries, plums, black cherries, grapes, black currants, red currants, and honeysuckle. The analytical result is obtained by spectrophotometry of the test sample and a comparative analysis of the typical curves obtained during spectrophotometry of a natural sample of cyanidin‑3-O-glucoside, as well as the synthetic dyes that increases the analysis accuracy with due regard to the specific test conditions. The optical density graphs obtained by spectrophotometry of juices of some of the above fruits are provided.
Our study has confirmed the assertion that the anthocyanin profile can be considered as the “fingerprints” of natural cyanidin‑3–0‑glucoside. Very similar curves were obtained for the juices of various berries containing this anthocyanin, with the values of extrema within the same wavelength range.
The same group of specialists from the VNIIFTRI has conducted a study of changes in the optical density extremes of natural wine at pH values of 1–10 in the samples of natural wines and counterfeit wines. They were using the methods of optical spectroscopy and measuring the shifts of the absorption band maximum (bathochromic shift – shift of the absorption band to the long-wavelength region of the spectrum; hypsochromic shift – shift of the absorption band to the short-wavelength region of the spectrum; hyperchromic and hypochromic shifts – increase and decrease in the intensity of the absorption band maximum, see Fig. 5).
With an increase in polarity of the analyzed wine sample due to the pH value increase of the natural wine solution, the long-wavelength absorption band is subject to a bathochromic shift. The resulting graphs (Fig. 6) of the optical density function of the natural wine samples at various pH values, propagating along the Ox axis, plotted at a fixed time point (t = const) have all types of absorption band shifts.
The dependency diagrams of optical density and the wavelength, as well as the absorption band shift value for all types of shifts are considered as the criteria for the wine naturality determination. Fig. 8 shows the dependency diagrams of optical density and the wavelength of natural wines Cabernet and Isabella and dyes E 122, E 180 and E 124. The extrema of optical density graphs of red wines with the available synthetic dyes at pH 3.0, 3.5 and 4.0 are out of control range.
Based on the red wine counterfeiting methods, the wine samples were prepared in the laboratory by adding the natural and synthetic dyes. Thus, the green plot shows the optical density of wine with the added dye E 163. The dye E163 is included in the list of additives approved for use in the food industry in Russia, Ukraine, Europe and other countries of the world. This additive is used for coloring the confectionery, wine, various sauces and soft drinks.
The orange plot indicates a wine sample based on the synthetic dye carmoisine (E 122). Azorubine, carmoisine is the synthetic azo dye represented by the small water-soluble red, burgundy or maroon granules or powder. Azorubine is a derivative of coal tar that causes hazard to human health. The food additive E122 is recognized as a carcinogen and poses a danger to the body. The light-blue plot corresponds to the wine sample with the addition of E 122. The blue plot demonstrates the natural wine without any additives and dyes. The pink plot is used for a sample of natural wine with the addition of chokeberry.
Thus, it has been established that the natural red wines that are in accordance with the regulatory documents for wine in terms of quality and, in particular, in terms of pH value, have specific spectra and an extremum. All values of the optical density extremum of the test sample that are not within this wavelength range (according to the bathochromic and hypsochromic shifts), confirm the available synthetic dye in the tested wine sample.
A database of the optical density numerical values for synthetic dyes used in the food industry for the production of wine, juices, juice-containing drinks and confectionery has been prepared. The database is a set of optical density spectrograms and extrema of synthetic dyes having an index in the European codification of food additives (E). The set of spectrograms is also presented in the form of a numerical table of the optical density spectrograms for synthetic dyes (at a pitch of 1 nm). The data format provides for the convenient navigation and helps to optimize the database operation process.
The fast, low-demanding and cost-effective method to assess the beverage naturality based on spectrophotometry in comparison with HPLC, mass spectrometry and other expensive analytical methods has been developed together with the Federal State Budgetary Research Institution “Gorbatov Federal Scientific Center for Food Systems” with participation of Panasyuk A. L., a doctor of engineering sciences, professor.
On the basis of researches performed, a FASK photospectrometric analyzer of synthetic dyes has been produced. The analyzer has small dimensions. However, it is able to identify the availability of synthetic components in the beverages in a few seconds. The device is very easy to use and allows express analysis of the beverages for the synthetic dyes. There is a simplest optical circuit, consisting of 385, 430, and 530 nm LEDs, that alternately turns on while transilluminating the sample cuvette. The digital light indicator transmits the obtained values to the microcontroller. The microcontroller displays the measurement result on the screen according to the data processing algorithm.
The continuous product quality improvement and enhanced consumer demands for the product safety lead to an increase in the role of quality control methodology. While solving the problems of maintaining a high level of product quality and safety, the employees of the VNIIFTRI are interested in harmonizing and expanding the capabilities of analyzing the food products, including the beverages.
A. V. Aprelev, V. A. Smirnov, E. V. Davydova
VNIIFTRI, Solnechnogorsk, Moscow region, Russia
At present, the actual problem is the identification of wine, alcohol-containing drinks, juices and juice-containing drinks in relation to the available synthetic dyes by simple and affordable methods. The article contains a brief description of the research conducted, the device and database of optical density numerical values of synthetic dyes used for the production of wine, juices and juice-containing drinks.
Key words: synthetic dyes, food colorants, alcohol-containing drinks, juices and juice-containing drinks
Received on: 08.04.2022
Accepted on: 29.04.2022
At present, there are almost no food products that do not contain any dyes. It is well-known that the natural food colorants in most cases are not only harmless, but also capable of increasing the nutritional and biological value of the product being dyed. Anthocyanins are one of the most widespread pigments in nature. They have antioxidant properties, capillary-strengthening properties, the ability to stop pro-inflammatory mediators, prevent neurodegenerative diseases and age-related bone loss. Moreover, they have a favourable effect on the human cardiovascular system condition [1]. The natural dyes are obtained using the roots or stems, bark or leaves, flowers or fruits of the plants, insects. In this case, the dye quality depends on the plant collection time. The brighter and more intense shades can be achieved when colored with the fresh plants than when colored with the dried plants.
The high price of natural dyes, special storage requirements, and low produce-ability prompted a search to replace them with the cheaper and more stable substances. In the 19th century, the first synthetic dyes were produced, including the food colorants. The main application field of food synthetic colorants is to improve the appearance of food products. Since the synthetic dyes do not have any useful properties and at its best are harmless unlike the natural ones, their use is prohibited or limited in many countries. However, to ensure profits, the manufacturers continue to use such dyes. This causes problems for the food importers and exporters, since a particular food colorant may be legal in one country and illegal in another. It is also possible to replace the food colorants with non-food ones. There are several well-known methods for determination of synthetic dyes in the beverages. A significant disadvantage of these methods is complexity and high cost of the analysis due to the need for a preliminary analysis of all possible synthetic dyes. The disadvantages of all other available methods include high cost of the equipment required for the analysis, as well as the analysis duration.
At present, there are issues with the use of synthetic dyes related to the lack of a unified regulatory ethics for the use of dyes in the world. This causes problems for the food importers and exporters, since a particular food colorant may be legal in one country and illegal in another.
It is also possible to replace the food colorants with non-food ones. There are several well-known methods for determination of synthetic dyes in the beverages. A significant disadvantage of these methods is complexity and high cost of the analysis due to the need for a preliminary analysis of all possible synthetic dyes. The disadvantages of all other available methods include high cost of the equipment required for the analysis, as well as the analysis duration. Currently, the identification of wine and fruit juices entering the consumer market is also a pressing challenge. The insufficiency of food control methods does not allow timely registration of deviations from the standard and identification of the low-quality products. The quality improvement strategy for the food products in the Russian Federation until 2030 and current market trends require the establishment of additional food quality criteria, including their identification attributes that should be preceded by serious scientific work. Only after implementation of such activities, it will be possible to develop the measurement methods and techniques with the participation of specialists from various fields.
Due to this fact, the express methods for determining the dye content are required. However, it is not always possible due to the difficult extraction from the complex matrices.
Based on the results of scientific research devoted to the quality assessment of the colored low-alcohol and non-alcohol-containing drinks sold in the retail chains, the employees of the Federal State Unitary Enterprise “All-Russian Scientific Research Institute for Physical-Engineering and Radiotechnical Metrology” have developed an identification method for synthetic dyes by their stability when changing the pH value. The method provides for spectrophotometry of the test sample and a comparative analysis of the typical curves obtained during spectrophotometry of a natural sample of cyanidin‑3-O-glucoside, as well as the synthetic dyes that increases the analysis accuracy with due regard to the specific test conditions. The grounds for the method development included the pressing challenge of identifying wine and fruit juices entering the consumer market. Many studies have found that the main source of free radicals and antioxidants in the human body, due to the high content of phenolic compounds, is alcohol-containing drinks (wine), tea, coffee, juices, vegetables and fruits. The insufficiency of food control methods does not allow timely registration of deviations from the standard and identification of the low-quality products [1].
The synthetic dyes are often used for the production of alcohol-containing drinks, juices and juice-containing drinks. The most important quality specification of alcohol-containing drinks and juices assessed by the consumers, is their organoleptic parameters, such as taste, color and aroma. Moreover, color is the very first quality indicator that the consumer pays attention to when selecting a product. We often use the product color to get an idea about its quality and even its aroma. However, in many cases, the products lose their natural and attractive color during the production and storage stages, and sometimes they do not initially have such color. The chemical flavors are hidden by the wine sweetness. Therefore, the semi-sweet, sweet, dessert, and potent wines often turn out to be counterfeit. Both natural and artificial substances approved for use in the food products are applied as the food colorants.
Initially, only natural dyes were used to color and give an attractive look. With the expansion of food production, a need occurred for a large number of coloring components.
Synthetic or artificial food colorants are the unnatural organic compounds. Almost all of them have been used in the global food industry for decades. The list of synthetic dyes is very long, and their use often causes concerns. According to the research studies, the use of some food colorants can have a harmful effect on the child behavior and attention. It would be better to make a warning about this on the label of the food product where this colorant is used. For example, such dyes include the synthetic dye Ponceau 4R E124. It is possible that the manufacturers are not even aware of this fact, since in the Russian market Ponceau 4R is often described by the “natural” names such as “carmine”, “carminic”, “cochineal red”.
From a chemical point of view, such colorants can be classified into the azo dyes, riarylmethane, quinolinic, and indigoid dyes [4]. The soluble dyes in the form of sodium salts are commonly used. If an insoluble dye is required, then the aluminum derivatives of these dyes are applied [5].
The colored natural fruits are notable for the presence of anthocyanins that are the compounds that determine their color and have high antioxidant activity. Since the anthocyanins stain the berries and plant leaves in a variety of shades, this property has been used to obtain the natural food colorants. The anthocyanins (E163) obtained from the grape skins, blueberries, blueberries, red cabbage, hibiscus and black carrots are used [1, 6]. The anthocyanins are the colored plant glycosides containing anthocyanides as an aglycone, namely the substituted 2‑phenylchromenes related to the flavanoids. The anthocyanins have several forms of isomers. An experimental study was performed at a pH value of 3–4 in the samples of natural wines and counterfeit wines made intentionally in the laboratory. This value corresponded to the pH value of natural red wine [3]. The general formula of anthocyanidins is shown in Fig.1. Depending on which functional groups are in the active molecule centers, anthocyanidins have various properties and chemical structure.
The color of anthocyanins and anthocyanidins is determined by their sensitivity to pH valie: in an acidic environment (pH<3), anthocyanins (and anthocyanidins) are available as red pyrylium salts. When the pH value is increased to 4–5, the hydroxide ion is added to form a colorless pseudobase; in the case of further increase in pH to 6–7, water is eliminated with generation of the blue quinoid form that, in turn, releases a proton to form purple phenolate at pH value of 7–8. Finally, at a pH value of over 8, the quinoid phenolate is hydrolyzed with chromene cycle disruption and generation of the relevant yellow chalcone.
The studies conducted in recent years in our country and abroad allow to conclude that the anthocyanin profile can be considered as the “fingerprints” of fruits colored with pigments. According to such studies, the main anthocyanin of the coloring fruits is cyanidin‑3-O-glucoside.
The employees of the Federal State Unitary Enterprise “All-Russian Scientific Research Institute for Physical-Engineering and Radiotechnical Metrology” have developed the method to detect the synthetic dyes in red wines using the optical density value. Advantages of the proposed method are as follows:
- express analysis that allows to detect a synthetic dye in the beverage in one minute;
- high profitability and, accordingly, a small contribution of measurements to the cost of the controlled product (economic feasibility);
- reproducibility at any stage of production, bottling, transportation and sale of the beverage.
The laboratory studies of the optical density of various natural juices were performed by comparing the optical density curves with the optical density curve and the extremum range of natural cyanidin 3-O-glucoside. Natural cyanidin can be found in such fruits as strawberries, cherries, chokeberries, lingonberries, blueberries, cranberries, blackberries, pomegranates, raspberries, plums, black cherries, grapes, black currants, red currants, and honeysuckle. The analytical result is obtained by spectrophotometry of the test sample and a comparative analysis of the typical curves obtained during spectrophotometry of a natural sample of cyanidin‑3-O-glucoside, as well as the synthetic dyes that increases the analysis accuracy with due regard to the specific test conditions. The optical density graphs obtained by spectrophotometry of juices of some of the above fruits are provided.
Our study has confirmed the assertion that the anthocyanin profile can be considered as the “fingerprints” of natural cyanidin‑3–0‑glucoside. Very similar curves were obtained for the juices of various berries containing this anthocyanin, with the values of extrema within the same wavelength range.
The same group of specialists from the VNIIFTRI has conducted a study of changes in the optical density extremes of natural wine at pH values of 1–10 in the samples of natural wines and counterfeit wines. They were using the methods of optical spectroscopy and measuring the shifts of the absorption band maximum (bathochromic shift – shift of the absorption band to the long-wavelength region of the spectrum; hypsochromic shift – shift of the absorption band to the short-wavelength region of the spectrum; hyperchromic and hypochromic shifts – increase and decrease in the intensity of the absorption band maximum, see Fig. 5).
With an increase in polarity of the analyzed wine sample due to the pH value increase of the natural wine solution, the long-wavelength absorption band is subject to a bathochromic shift. The resulting graphs (Fig. 6) of the optical density function of the natural wine samples at various pH values, propagating along the Ox axis, plotted at a fixed time point (t = const) have all types of absorption band shifts.
The dependency diagrams of optical density and the wavelength, as well as the absorption band shift value for all types of shifts are considered as the criteria for the wine naturality determination. Fig. 8 shows the dependency diagrams of optical density and the wavelength of natural wines Cabernet and Isabella and dyes E 122, E 180 and E 124. The extrema of optical density graphs of red wines with the available synthetic dyes at pH 3.0, 3.5 and 4.0 are out of control range.
Based on the red wine counterfeiting methods, the wine samples were prepared in the laboratory by adding the natural and synthetic dyes. Thus, the green plot shows the optical density of wine with the added dye E 163. The dye E163 is included in the list of additives approved for use in the food industry in Russia, Ukraine, Europe and other countries of the world. This additive is used for coloring the confectionery, wine, various sauces and soft drinks.
The orange plot indicates a wine sample based on the synthetic dye carmoisine (E 122). Azorubine, carmoisine is the synthetic azo dye represented by the small water-soluble red, burgundy or maroon granules or powder. Azorubine is a derivative of coal tar that causes hazard to human health. The food additive E122 is recognized as a carcinogen and poses a danger to the body. The light-blue plot corresponds to the wine sample with the addition of E 122. The blue plot demonstrates the natural wine without any additives and dyes. The pink plot is used for a sample of natural wine with the addition of chokeberry.
Thus, it has been established that the natural red wines that are in accordance with the regulatory documents for wine in terms of quality and, in particular, in terms of pH value, have specific spectra and an extremum. All values of the optical density extremum of the test sample that are not within this wavelength range (according to the bathochromic and hypsochromic shifts), confirm the available synthetic dye in the tested wine sample.
A database of the optical density numerical values for synthetic dyes used in the food industry for the production of wine, juices, juice-containing drinks and confectionery has been prepared. The database is a set of optical density spectrograms and extrema of synthetic dyes having an index in the European codification of food additives (E). The set of spectrograms is also presented in the form of a numerical table of the optical density spectrograms for synthetic dyes (at a pitch of 1 nm). The data format provides for the convenient navigation and helps to optimize the database operation process.
The fast, low-demanding and cost-effective method to assess the beverage naturality based on spectrophotometry in comparison with HPLC, mass spectrometry and other expensive analytical methods has been developed together with the Federal State Budgetary Research Institution “Gorbatov Federal Scientific Center for Food Systems” with participation of Panasyuk A. L., a doctor of engineering sciences, professor.
On the basis of researches performed, a FASK photospectrometric analyzer of synthetic dyes has been produced. The analyzer has small dimensions. However, it is able to identify the availability of synthetic components in the beverages in a few seconds. The device is very easy to use and allows express analysis of the beverages for the synthetic dyes. There is a simplest optical circuit, consisting of 385, 430, and 530 nm LEDs, that alternately turns on while transilluminating the sample cuvette. The digital light indicator transmits the obtained values to the microcontroller. The microcontroller displays the measurement result on the screen according to the data processing algorithm.
The continuous product quality improvement and enhanced consumer demands for the product safety lead to an increase in the role of quality control methodology. While solving the problems of maintaining a high level of product quality and safety, the employees of the VNIIFTRI are interested in harmonizing and expanding the capabilities of analyzing the food products, including the beverages.
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