The study demonstrated the determination of iodine availability and iodine stability of these iodized salts at different conditions. Results revealed that almost all the salt samples gave positive results of iodine availability. However, study findings revealed that during the last 2 weeks minimum amount of iodine is observed in Brand C and Brand N during cooking.
On the other hand, loss of iodine was minimal in case of normal atmospheric condition. According to the International Council for the Control of Iodine Deficiency Disorders (ICCIDD), and the United Nations International Children's Emergency Fund (UNICEF): daily iodine intake requirement for children is 90 μg/d and adults need 150 μg/d and pregnant and lactating mother should intake 250 μg/d (UNICEF-ICCIDD, 2006). For this reason, table salt is fortified with iodine to meet our body's need for iodine.
The amount of iodine that we get from food depends on the percentage of iodine in the soil where the crop has been grown.
Aims and Specific Objectives
It was also announced that the exchange and manufacture of any non-iodized salt is a punishable crime (Raklrnan, 1982).
Literature Review
- Discovery and Early Investigations of Iodine
- Iodine
- Source
- Importance of iodine in human body
- Role of Iodine in Normal Metabolism
- Role of Iodine for Growth and Development of Child
- Role of Iodine as an Antioxidant
- Thyroid gland
- Iodine and Human Health
- Iodine Deficiency Disorders
- Magnitude of IDDs
- Clinical Diagnosis of Iodine Deficiency and Thyroid Dysfunction
- Factors Responsible for Iodine Deficiency Disorder
- Complications of Iodine Deficiency
- Consequences in Pregnancy
- Consequences in Neonates
- Consequences in Adult
- Present status of iodine in whole world
- Iodine status in Bangladesh
- Iodized Salt
- Reason Behind Salt Fortification with Iodine
- Universal Salt Iodization (USI)
- Iodine in Supplements and Multivitamins
- Factors which Reduce Iodine Content in Salt
- Methods used to determine iodine
- The Titrimetric Method
- Spectrophotometric Method
If the body does not receive the proper amount of iodine, it results in a lack of thyroid hormone production (Brownstein and David, 2008; Guyton and Hall, 2006). During the oxidation process, an excessive amount of iodine is absorbed by this algae (Küpper et al., 1998). It is estimated that almost 2 billion people consume very low amounts of iodine, which is responsible for iodine deficiency (Mottiar, 2013).
Those diseases closely related to lack of iodine intake can be defined as IDD (Zimmermann et al., 2008). Lack of iodine content in the human body is the biggest problem in the whole world. Currently, almost 20 million people suffer from IDD around the world due to the intake of a low amount of iodine (Benoist et al., 2008).
The presence of an iodine deficiency or excess depends on the urinary iodine concentration (UIC) of a given population rather than of an individual person (Jooste and Strydom, 2010). Although thyroid activity increases during this period, iodine levels are too low to synthesize thyroid hormone production (Zimmermann et al., 2015). Thus, intake of the right amount of iodine is essential to reduce iodine deficiency disorder in adults (Garcia et al., 1999).
It has been estimated from recent research that 266 million school-age children consume very low amounts of iodine (Benoist et al., 2008). According to that study, a high level of iodine deficiency was found across the country. According to many experts, the titration method is one of the most used methods to determine the amount of iodine in iodized salt.
On the other hand, the Rapid test kit is used in maximum household to determine the presence of iodine in iodized salt (Haldimann et al., 2005). This is one of the best quantitative methods for determining the percentage of iodine in iodized salt (Jooste and Strydom, 2010). This method is also popular because it can determine the amount of iodine in the form of iodide or iodine.
There are various studies available based on iodine, because iodine is important for proper metabolism of the human body.
Materials and Methods
- Sample Collection
- Study Period
- Titrimetric Method of Analysis
- Principle
- Preparation of 10% Potassium iodide solution
- Preparation of 2N sulfuric acid (H₂SO₄)
- Preparation of potassium iodate solution
- Preparation of saturated salt solution (for processing techniques)
- Preparation of 1% starch solution
- Preparation of potassium iodate solution
- Preparation of 0.005 N Sodium Thiosulphate (2Na₂S₂O₃) solution
- Standardization steps of (0.005 N) Sodium Thiosulphate (2Na₂S₂O₃) solution
- Standardization of Sodium thiosulfate solution
- Procedure for Titration of Sample
- Calculation
- UV-Spectroscopic Method
- Solution 1: Buffered KI solution
- Solution 2: 0.1 M H 2 SO 4
- Solution 3: 4.7 10-3 M KIO 3
- Solution 4: 4.7 10-5 M KIO 3
- Procedure 1 (preparation of Calibration solutions)
- Procedure 2 (Preparation Blank Solution)
- Procedure 3 (preparation of Sample solutions)
Released free iodine is calculated from the proportional relationship between the amount of free iodine and the amount of sodium. 50 ml of stock solution was taken out and it was diluted by adding distilled water which was adjusted to 1000 ml. 50 ml of stock solution was taken out and it was diluted to 1000 ml of distilled water in a volumetric flask.
Sodium thiosulfate solution (0.005 N) was placed in a burette. 25 ml of potassium iodate solution was taken in a conical flask. 2 ml of sulfuric acid 0.2 N was added and it was shaken to mix properly. Then it was titrated with 5 ml of potassium iodide (10% solution) and again shaken to mix. S1= Normality of sodium thiosulfate V1= volume of sodium thiosulfate S2= Normality of potassium iodate V2= volume of potassium iodate.
The solution was kept for several minutes at room temperature and then 5 ml of 10% KI solution was added. The solution was then shaken to mix properly, the conical flask was covered with a watch glass and kept in a dark place for about 10 minutes. Titrate the solution until the color of the sample solution turned pale yellow. 1 ml of freshly prepared starch solution was added to the mixture, which turned the sample solution deep purple/blue.
The whole process was repeated two more times and an average value for the volume of sodium thiosulfate solution was determined. In principle, KIO3, KI, boric acid (H3BO3), sulfuric acid (H₂SO₄), sodium thiosulphate (Na₂S₂O3) and starch were used. 10 g of KI was added to this solution and after dilution it was made up to 1 L with distilled water.
10 ml of 0.1 M sulfuric acid (Solution 2) was taken and brought to 100 ml with distilled water in a volumetric flask. Finally, the entire mixture was transferred to a 100 ml volumetric flask and brought to 100 ml with buffered solution.
Results
- Analysis of Different Salts
- Brand A
- Brand F
- Brand C
- Brand N
- Brand Q
- Percentage of Iodine Loss
- Percentage of iodine stability reduction in normal atmospheric
- Percentage of Iodine Stability Reduction During Boiling
- Comparison of iodine concentration (using both UV Spectrophotometric and Titrimetric
Research results in Figure 5.1 also show that significant iodine loss occurred during cooking. Figure 3 illustrates the changes in iodine loss under both normal and boiling conditions. The iodine concentration under normal atmospheric conditions was 26.46 ppm in the first week and a continuous reduction in loss was observed in each week. The value was 22.111 ppm, 16.93 ppm and 8.35 ppm.
The highest iodine content was 24.34 ppm after opening the packet and the lowest concentration was observed in the last week at 6.31 ppm. The lower iodine content was examined after the third week between the boiling methods, namely 11.28 ppm, and after opening the value was 39.28 ppm. The present study deals with the measurement of iodine availability and iodine stability of these iodized salts under different conditions.
The following table represents the percentage loss of iodine stability of iodized salts under normal atmospheric conditions over a specified time interval (1 week). Table-5.1: Comparative table for percentage reduction rate of iodine in iodized salts at different time periods under normal atmospheric conditions. After storage under normal atmospheric environmental conditions, the percent loss of iodine stability was 74.08%.
The minimum loss of iodine found for Brand F and Brand Q was 12.95 % and 13.77 % after 1st week while maximum loss of iodine 80.20% was observed during cooking in Brand N after third week. Table-5.2: Comparison table for percentage reduction rate of iodine from iodized salts at different time period during boiling condition. UV spectrophotometric method was used to compare the concentration of iodine value with titrimetric method.
In normal atmospheric condition, the amount of iodine for brand C was 28.681 ppm, when the value of iodine was found 26.46 ppm in case of trimetric method. The figure illustrated that the concentration of iodine in UV spectrophotometry was slightly higher than titrimetric method.
Discussion
In the first week, the amount of iodine was higher for each sample, but gradually the concentration of iodine decreases. Iodine concentration was measured by titrimetric and spectrophotometric methods under normal atmospheric conditions. The amount of iodine content is slightly higher in the UV spectrophotometric method than in the titrimetric method for all samples.
Both graph 5 represents the percentage loss of iodine stability of iodized salts during normal atmospheric conditions at a specific time interval (1 week), where for each sample the gradual increase in the percentage of iodine loss was noted. However, shallow frying did not require water as a cooking medium, resulting in more iodine loss during cooking than shallow frying (Yasif et al., 2016). During cooking, the iodine concentration in these iodized salts was significantly reduced than under normal atmospheric conditions.
Significant loss of iodine is shown in Brand N and confidence salt in the 3rd to 4th week. This study also revealed that the maximum concentration of iodine is observed in fresh salt under boiling condition and the concentration of iodine is minimum in mark 1. From this measurement it was observed that the loss of iodine varied from a small amount when boiling at same procedure. to a large amount.
The highest percentage loss of iodine was 71.88 % observed in brand C salt after the third week, although the loss of iodine was recorded at 22.32 % during the first week. The minimum loss of iodine was observed for sample A in normal condition which was 42.92%, but when heat was applied the stability was greatly reduced and the percentage loss of iodine became 73.45%. This happened because of a possible connection of iodine with various food ingredients.
But from the second to the fourth week, the iodine concentration in each sample was gradually reduced during cooking. Thus, the iodine concentration in different brand salts was monitored in the order Brand F>Brand Q>Brand A>Brand C>Brand N.
Conclusion
Recommendations and Future perspectives
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Stability of iodine in iodized salt used for correction of iodine deficiency disorders II Food and Nutrition Bulletin. Methods for the determination of iodine in urine and salt, Best Practice & Research Clinical Endocrinology & Metabolism. Salt Iodization for the Elimination of Iodine Deficiency, MI/ICCIDD/UNICEF/WHO, ICCIDD, The Netherlands, 20–30.
Towards a global elimination of iodine deficiency brain damage: a global human development program with a model applied to a variety of health, social and environmental problems. Goitre and iodine deficiency in Europe: Report of the subcommittee to study endemic goitre and iodine deficiency of the European Thyroid Association. 2007. Expert consultation for the prevention and management of iodine deficiency in pregnant and lactating women and in children under two years of age.
