International Commission for Uniform Methods of Sugar Analysis
Encyclopedia
The International Commission for Uniform Methods of Sugar Analysis (ICUMSA) is an international standards body, founded in 1897, that publishes detailed laboratory procedures for the analysis of sugar
.
The ICUMSA Methods Book contains detailed instructions for analyzing raw, cane
, white, beet
, molasses
, plantation white and specialty sugars. Among these are methods for determination of dry solids content by polarimetry
, densimetry and refractometry
, color (extinction coefficient
at 420 nm), reducing sugar
s, and the presence of metals such as arsenic
and copper
. The Methods Book also contains polynomials and tables (derived from the polynomials) which relate the refractive index of solutions of pure sucrose, glucose, fructose and invert sugar to the strength of those solutions. These are to be used with the analysis methods that characterize sugars by refractometric means but find wide application outside the sugar industry as the sucrose polynomial is built into the firmware of modern refractometers and is the basis for calibration of purely optical refractometers which read in Brix
. Temperature correction factors, also derived from the polynomials, are the basis for the Automatic Temperature Compensation features found in those instruments. Thus a vintner measuring the Brix of juice from his grapes by means of a refractometer, accepts a sugar content reading based on the refractive properties of sucrose despite the fact that grape juice contains little, if any, of that sugar. This usually does not result in significant error.
The ICUMSA is constituted of representatives from national committees designated by the governments of major sugar importing and exporting countries; the votes of these representatives are weighted according to the amount of sugar their countries import and export.
Sugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...
.
The ICUMSA Methods Book contains detailed instructions for analyzing raw, cane
Sugarcane
Sugarcane refers to any of six to 37 species of tall perennial grasses of the genus Saccharum . Native to the warm temperate to tropical regions of South Asia, they have stout, jointed, fibrous stalks that are rich in sugar, and measure two to six metres tall...
, white, beet
Sugar beet
Sugar beet, a cultivated plant of Beta vulgaris, is a plant whose tuber contains a high concentration of sucrose. It is grown commercially for sugar production. Sugar beets and other B...
, molasses
Molasses
Molasses is a viscous by-product of the processing of sugar cane, grapes or sugar beets into sugar. The word molasses comes from the Portuguese word melaço, which ultimately comes from mel, the Latin word for "honey". The quality of molasses depends on the maturity of the sugar cane or sugar beet,...
, plantation white and specialty sugars. Among these are methods for determination of dry solids content by polarimetry
Polarimetry
Polarimetry is the measurement and interpretation of the polarization of transverse waves, most notably electromagnetic waves, such as radio or light waves...
, densimetry and refractometry
Refractometry
Refractometry is the method of measuring substances' refractive index in order to, for example, assess their composition or purity. A refractometer is the instrument used to measure refractive index...
, color (extinction coefficient
Extinction coefficient
Extinction coefficient refers to several different measures of the absorption of light in a medium:*In chemistry, biochemistry, molecular biology, or microbiology, the mass extinction coefficient and the molar extinction coefficient are parameters defining how strongly a substance absorbs light...
at 420 nm), reducing sugar
Reducing sugar
A reducing sugar is any sugar that either has an aldehyde group or is capable of forming one in solution through isomerisation. This functional group allows the sugar to act as a reducing agent, for example in the Tollens' test or Benedict's test.-Chemistry:...
s, and the presence of metals such as arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
and copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
. The Methods Book also contains polynomials and tables (derived from the polynomials) which relate the refractive index of solutions of pure sucrose, glucose, fructose and invert sugar to the strength of those solutions. These are to be used with the analysis methods that characterize sugars by refractometric means but find wide application outside the sugar industry as the sucrose polynomial is built into the firmware of modern refractometers and is the basis for calibration of purely optical refractometers which read in Brix
Brix
Degrees Brix is the sugar content of an aqueous solution.One degree Brix is 1 gram of sucrose in 100 grams of solution and represents the strength of the solution as percentage by weight . If the solution contains dissolved solids other than pure sucrose, then the °Bx is only approximate the...
. Temperature correction factors, also derived from the polynomials, are the basis for the Automatic Temperature Compensation features found in those instruments. Thus a vintner measuring the Brix of juice from his grapes by means of a refractometer, accepts a sugar content reading based on the refractive properties of sucrose despite the fact that grape juice contains little, if any, of that sugar. This usually does not result in significant error.
The ICUMSA is constituted of representatives from national committees designated by the governments of major sugar importing and exporting countries; the votes of these representatives are weighted according to the amount of sugar their countries import and export.