Dns method for sugar estimation. Determination of Redusing Sugar Using Dns Method Analysis Essay Example 2022-10-11
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The DNS (dinitrosalicylic acid) method is a widely used analytical technique for the determination of reducing sugars, such as glucose and fructose, in various samples. The method is based on the formation of a colored complex between the reducing sugars and DNS reagent, which is a solution of dinitrosalicylic acid and sodium hydroxide. The intensity of the color produced is directly proportional to the concentration of reducing sugars present in the sample.
The DNS method involves the following steps:
Preparation of the sample: The sample, which can be a food product or a biological sample, is first homogenized and then a known volume is taken for analysis.
Preparation of the DNS reagent: The DNS reagent is prepared by dissolving a known quantity of dinitrosalicylic acid in a solution of sodium hydroxide. The concentration of the reagent should be standardized before use to ensure accurate results.
Reaction between the sample and the DNS reagent: The sample is mixed with the DNS reagent and the mixture is heated to a temperature of around 100°C for a specific time period. During this process, the reducing sugars present in the sample react with the DNS reagent to form a colored complex.
Measurement of the absorbance: The absorbance of the colored complex is measured using a spectrophotometer at a wavelength of 540 nm. The absorbance is directly proportional to the concentration of reducing sugars in the sample.
Calculation of the sugar concentration: The concentration of reducing sugars in the sample is calculated using a standard curve that is prepared by analyzing a series of standard solutions of known concentrations of reducing sugars.
The DNS method has several advantages, including its simplicity, low cost, and high sensitivity. It is also relatively quick, with most analyses taking less than an hour to complete. However, the method has some limitations, including the need for specialized equipment, such as a spectrophotometer, and the fact that it can only detect reducing sugars, not non-reducing sugars or other types of sugars.
Overall, the DNS method is a reliable and widely used analytical technique for the determination of reducing sugars in various samples. It is a useful tool for various applications, including the quality control of food products, the analysis of biological samples, and the study of metabolic processes.
Comparison of Two Methods for Assaying Reducing Sugars in the Determination of Carbohydrase Activities
The first sample was operated as blank for zero. Being familiar with the background information about reducing sugars and various methods used to identify them, Biotechnology students were provided with a Fructose sample solution and were required to find its concentration Maltose can be used as a standard for estimating reducing sugar in unknown samples. How do I use DNS method? As a consequence, carboxymethyl cellulose can affect the calibration curve by enhancing the intensity of the developed color. Conclusions In summary, when cellulase activities against CMC are measured, the DNS assay gives activity values of similar magnitude as those obtained by the NS assay, the first method typically providing 40—50% higher numbers. During acid hydrolysis, an increase of time reaction improves reducing sugars production. The dilutions of a solution of known concentration are used to determine the concentration of unknown.
James Clark School of Engineering S. The sugar concentration of unknown sample can then be read off a calibration curve standard curve created using known sugar concentrations. The formation of 3-amino-5-nitrosalicylic acid results in a change in the amount of light absorbed A reducing sugar is any sugar that, in a solution, has a free aldehyde or a ketone group. Thus by this estimation method one can estimate the amount of non-reducing sugar after hydrolysis. The methods are: 1. How DNS reagent is prepared? The Na-K tartarate solution intensifies and fixes the colour of the solution. A reducing sugar is one that in a basic solution forms an aldehyde or ketone.
Estimation of reducing sugar by dinitrosalicylic acid method
The dilutions of a solution of known concentration are used to determine the concentration of unknown. The mixture was incubated at 50°C for 10 min 5 min in the case of CMCase and β-glucanase activities ; the reaction was stopped by addition of 0. A reducing sugar is one that in a basic solution forms an aldehyde or ketone. Any carbohydrate that is capable of causing the reduction of some other substances without being hydrolyzed first is the reducing sugar whereas sugars that do not possess a free ketone or an aldehyde group are called the non-reducing sugar. The stock solution was prepared in order to find the unknown concentration of carbohydrate cereals powder, jam total sugar content and jams reducing sugar content. When the β-glucanase, β-mannanase, or xylanase activity against arabinoxylan is measured, the overestimations by the DNS assay become more pronounced up to 13-fold.
The increase in the absorbance upon the second color development is equivalent to the incremental amount of sugar added. Five such identical sets are made along with 2 control sets which do not contain sugar solution, instead they contain 5 ml of water. This allows the sugar to act as a reducing agent. For sugar estmation an alternative to Nelson-Somogyi method is the dinitrosalicylic acid method — simple, sensitive and adoptable during handling of a large number of samples at a time. The colour intensity thus developed is determined at 620 nm red filter against a control blank set containing 2 ml of water and 0.
Thus, by colorimetric estimation, the colour intensity is determined and a standard curve for known concentrations of sugar is also prepared. MATERIALS AND METHODS 3. This intensity change in colour is measured using a colorimeter as the absorbance at 540nm wavelength. This involves the oxidation of the aldehyde functional group present in, for example, glucose and the ketone functional group in fructose. By using pipette, 16 mL of distilled water was added into the test tubes accurately to make a volume of 20 mL. What is the hexokinase method? In particular, cellulase complexes produced by Trichoderma sp. Finally, by iodo-metric assay method, residual available oxidized metallic salt is determined to denote the amount of reduced metallic salt formed by the reducing sugars.
Determination of Redusing Sugar Using Dns Method Analysis Essay Example
There are the frequent methods based on Cu II or Fe III reduction by RS, and complexation of reduced transition metal ions with suitable Reducing sugars concentrations were determined by spectrophotometry using the 3, 5 dinitrosalicylic acid DNS method. The 3- to 13-fold higher activity values for xylanase, β-glucanase, and β-mannanase obtained with the DNS assay allow making a conclusion that the comparison of experimental data from various researchers exploiting different RS assays is hardly possible, even if the same substrate is used in activity measurements. Colorimetric Method Using Anthrone Reagent. One such reagent is 3,5-dinitrosalicylic acid DNS. A ketose is a monosaccharide containing one ketone group per molecule. Estimation of reducing sugar by dinitrosalicylic acid method. The nelson-somogyi method is used to measure reducing sugar by using copper reagents and arsenolmolibdat.
Estimation of Reducing Sugars by the Dinitro Salicylic Acid (DNS) Method
Then 5 ml of reducing sugars or hydrolysed non-reducing sugar sample is taken in a sugar heating tube and to it 5 ml of A and B mixture is added. Twenty laboratories participated in this collaborative investigation; thirteen of them used the DNS assay while three laboratories used the NS assay. J Biol Chem 47:5—9 Google Scholar Sumner JB 1925 A more specific reagent for the determination of sugar in urine. Introduction Sugar is an important ingredient of fruit and fruit product. It is used in electroplating, in electronics and piezoelectricity, and as a combustion accelerator in cigarette paper similar to an oxidizer in pyrotechnics. When the solutions turn reddish and brick-red precipitation is deposited at the bottom of the tubes, then the tubes are placed in ice cold water to cool the contents.
Estimation of glucose or lactose (reducing sugars) using DNSA method
The increase in the absorbance upon the second color development is equivalent to the incremental amount of sugar added. Working… Subscribe Subscribed Unsubscribe 446. When cellulase activities against CMC were measured, the DNS assay gave activity values, which were typically 40—50% higher than those obtained with the NS assay. Read extinction at 540 mm against the blank. The concentration of the colored complex was determined with the spectrophotometer at absorbance 540nm. For the same reason lactose is a reducing sugar. Pre—treatment is usually preformed by energy intensive physical methods, high temperature and pressure or the uses of a chemical solvent.
