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Glossary of Sugar Processing Terminology

This glossary of technical terms commonly used in sugar processing is provided by P. W. Rein, referenced from his book entitled, "Cane Sugar Engineering", that will be published in 2006 by Bartens, a world-renowned sugar sweetener publisher. 

A | B | C | D | E | F | I L | M | N | P | R | S | T

Affination

 

Treatment of raw sugar crystals to remove the film of adhering molasses. This is achieved by mixing sugar with a concentrated syrup and then centrifuging the magma with or without water washing.

Affinated sugar

Sugar purified by affination.

Agglomeration

Sticking together of two or more crystals during the centrifuging and drying operations.

Ash content







Solid residue determined gravimetrically after incineration in the presence of oxygen. In analysis of sugar products, sulfuric acid is added to the sample, and this residue as sulfated ash heated to 525 °C is taken to be a measure of the inorganic constituents. Sometimes determined indirectly by measurement of electrical conductivity of the product in solution (see Conductivity ash).


 

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Bagacillo

 

Fine fraction of bagasse obtained by screening or pneumatic separation, generally used as a filter aid in filtration.

Bagasse

Cane residue leaving mills after extraction of juice.

Boiling house

That part of the sugar mill in which the processes of production of sugar from raw juice are carried out. It is also referred to as the back-end or raw house.

Boiling point elevation

Difference between the temperature of a boiling sugar solution and the temperature of boiling pure water, both measured at the same pressure.

Brix

Measure of dissolved solids in sugar liquor or syrup using a refractometer, otherwise referred to as refractometric dry solids. For solutions containing only sugar and water, Brix = % sugar by mass. Spindle Brix is determined using a hydrometer, but is now seldom used.

Brix-free water

 

Water forming part of the cellulosic structure of the cane, and hence not part of the juice expressed in milling. It cannot be separated from natural fiber by mechanical means but is driven off at elevated temperatures.

 

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Calandria

Tubular or plate heating element in a vacuum pan or evaporator vessel.

Carbonatation

Process involving introduction of carbon dioxide gas into limed juice or syrup to remove color and nonsugar solids.

Carbonatation gas

Gas rich in carbon dioxide for use in carbonatation.

Centrifugal

Centrifuge used to separate sugar from mother liquor.

Clarifier

Apparatus for the separation by sedimentation of suspended solids from a turbid sugar solution.

Clarified juice

Juice from clarifiers, also referred to as clear juice.

Color

Attenuation index, determined by absorption of light under defined conditions. Generally measured using the ICUMSA method at 420 nm, and referred to as ICUMSA units or IU.

Conductivity ash

Estimate of ash content by measurement of the conductivity of the solution.

Conglomerate

Two or more crystals grown together during pan boiling.

Cooling crystallization

Crystallization by cooling of the massecuite.

Crystal content

Proportion by mass of crystals in massecuite, often expressed as a percentage, and referred to total massecuite mass or to massecuite dry substance (Brix).

Crystallization

Nucleation and growth of crystals.

Crystallization scheme

Defines the number and arrangement of crystallization stages involved in producing sugar.

Cush cush

The stream of wet bagasse or bagacillo separated from raw juice by the juice screens.

Cut a pan

 

Discharge a portion of the massecuite from a pan, retaining a footing upon which to feed more syrup or molasses for crystallization.


 

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Dissolved solids

 

All solute material which is in solution, including sucrose, monosaccharides, ash and other organic impurities.

Drop a pan

Discharge all of the massecuite from a pan. Also referred to as striking a pan.

Dry substance

A measure of total solids obtained from evaporating a solution or massecuite under vacuum to dryness. Also referred to as total solids by drying or dry solids.


 

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Entrainment separator 

Apparatus for removing juice, syrup or massecuite entrained in the vapor.

Evaporator effect

One of a system of evaporators operating in series as a multiple effect system (e.g., first effect, second effect). Condensates and vapors are labeled correspondingly (e.g., first condensate and vapor one: condensate and vapor from the first effect respectively).

Exhaustion

Applied to a massecuite, it represents the g of sucrose present in crystalline form per 100g of sucrose.

Extraction

Proportion of sugar extracted from cane in the extraction plant; equals mass of sugar in raw juice as a percentage of mass of sugar in cane.

Extraneous matter

All cane leaves and tops, mud, soil, roots, rocks, stones and tramp iron delivered with the cane.


 

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False grain

Undesirable small crystals, formed spontaneously by secondary nucleation when the supersaturation during crystallization is too high.

Fiber

The dry fibrous insoluble structure of the cane plant. Generally taken to mean all insoluble material in the cane delivered to a mill, and therefore includes soil or other extraneous insoluble matter in cane.

Filter cake

Material retained on the filter screens and discharged from the filters after filtering clarifier muds.

Filtrate

Liquid passed through the screens of the filters.

Flocculant

Polyelectrolyte in solution added to juice to assist clarification.

Footing



A charge of massecuite retained in or transferred to a pan as the start of a massecuite boiling.


 

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Imbibition



 

The process of adding imbibition water to the extraction plant to increase extraction. Sometimes incorrectly referred to as maceration (steeping cane in juice). Water added is called imbibition water.

Invert sugar


Mixture of approximately equal parts of glucose and fructose (monosaccharides) resulting from the hydrolysis of sucrose (inversion).


 

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Liming

 

Process step in juice purification in which lime is introduced into the sugar juice in the form of milk of lime or lime saccharate solution.

Liquid sugar

Refined sugar products in liquid form (e.g. liquid sucrose, liquid invert).

Liquor

A sugar syrup, a term generally used in sugar refining.


 

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Magma

 

Mixture of crystals and liquid (water, clarified juice, syrup or molasses) produced by mingling.

Magma mixer

Mingler, where crystal and liquid are mixed together.

Massecuite

The mixture of crystals and mother liquor resulting from the crystallization process. Massecuites are classified according to purity as A, B, or C massecuites.

Massecuite mixer

Apparatus from which massecuite is distributed to the centrifugals.

Melter

Equipment in which dissolving of sugar takes place.

Melting

Another term for dissolving of sugar crystals.

Molasses

The mother liquor separated from the crystals by centrifuging. A, B or C molasses is derived from the corresponding massecuites. C molasses is also referred to as final molasses.

Mother liquor

Liquid phase in the massecuite during crystallization; refers to syrup or liquor in which the crystals are growing.


 

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Nonsucrose

 

Dissolved solids contained in any process stream other than sucrose.

Nonsugar

Common overall term for dissolved solids other than sugar contained in any process stream.

Nucleation



 

Generation and development of small crystals capable of growth.

 

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Pan or vacuum pan

 

Vacuum evaporative crystallizer used in the sugar industry to crystallize sugar from liquor, syrup or molasses.

Phosphatation

Clarification using phosphoric acid and lime, in which certain nonsugar components are removed by flotation.

Polarization (or pol)

The apparent sucrose content expressed as a mass percent measured by the optical rotation of polarized light passing through a sugar solution. This is accurate only for pure sucrose solutions.

Press water

Juice expressed from dewatering mills after a diffuser.

Purity


 

The true purity is the sucrose content as a percent of the dry substance or dissolved solids content. The solids consist of sugar plus nonsucrose components such as invert, ash, and colorants. Apparent purity is expressed as polarization divided by refractometer Brix, multiplied by 100.


 

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Raw juice

 

Juice obtained from the cane extraction process. Also referred to as mixed juice (from mills) or draft juice (from diffusers).

Raw sugar

Brown sugar produced in a raw sugar mill generally destined for further processing to white sugar in a refinery.

Reducing sugars

Generally referred to and/or interpreted as invert sugar, determined by measuring reducing substance content by laboratory analysis.

Refining

Purification of sugar through chemical and physical methods, generally including some or all of clarification, filtration, decolorization and recrystallization.

Refractometric dry solids (RDS)

Measurement of total dissolved solids in a sugar liquor or syrup using a refractometer. For solutions containing only sugar and water, % RDS = °Brix = % sugar by mass.

Remelt

A syrup made from centrifuged low-grade sugar which is dissolved or remelted and returned to the high grade boilings.

Runoff

General term for syrups or molasses produced on centrifuging a massecuite.


 

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Safety factor

 

Number to indicate keeping quality of raw sugar, calculated from pol and moisture content (= moisture (g/100g sugar) / (100 – pol)).

Saturation

A sugar solution at saturation will not dissolve any more crystals at the temperature of the solution.

Seeding

(a) Introducing crystal fragments to induce nucleation, as a means of initiating the crystallization process; (b) introduction of fine crystal in the form of a slurry (similar to full seeding) to start crystallization. Sometimes referred to as graining.

Seed

Suspension of fine crystals in saturated solution of alcohol, or the initial grain resulting from seeding in a vacuum pan.

Solubility coefficient

Ratio of concentration of sucrose in impure saturated solution to the concentration in a pure sucrose solution saturated at the same temperature (with concentration expressed as sucrose/water ratio). Referred to as saturation coefficient in the beet sugar industry.

Strike

Massecuite as a completed boiling, all of which is discharged from the pan.

Sucrose

Pure chemical compound C12H22O11 known as white sugar, generally measured by polarization in pure solution or by GC or HPLC in impure solution. The chemical term is a-D-glucopyranosyl-b-D-fructofuranoside.

Sugar

Term for the disaccharide sucrose and products of the sugar industry, essentially composed of sucrose.

Sulfitation

Introduction of sulfur dioxide into juice or liquor.

Supersaturation

The degree to which the sucrose content in solution in greater than the sucrose content in a saturated solution.

Supersaturation coefficient

Calculated as the quotient formed by dividing the sugar/water ratio of the supersaturated solution by the sugar/water ratio of a saturated solution under the same conditions (temperature and purity or nonsucrose/water ratio). It shows whether the solution is unsaturated (<1), saturated (=1) or supersaturated (>1).

Supersaturation, critical

Supersaturation at which nucleation begins spontaneously.

Suspended solids

Insoluble solids in juice or other liquid, removable by mechanical means.

Sweet water

Wash water or water containing a small amount of sugar.

Syrup

The concentrated juice from the evaporators.


 

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Target purity

 

Equilibrium purity of final molasses, derived from a formula taking into account the effect of nonsucrose on its exhaustibility. Sometimes referred to as expected molasses purity.

Trash

Cane tops, leaves, dead stalks of cane and any other vegetable matter delivered with the cane.

 

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Posted on: 3/30/2006 2:22:01 PM

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