Glossary of Terms
- Affination: The first step in the refining of raw sugar, which involves blending the raw sugar with hot concentrated syrup and spinning off the softened outer syrup layer of the raw sugar crystal in a centrifugal.
- Agglomeration: The ‘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.
- Assignment: Assignment is an entitlement held by a cane grower which allows the holder to deliver to a mill for payment, cane grown on a number of hectares situated within the boundaries of a description of land assigned to the mill.
- Bagacillo: The fine fraction of bagasse obtained by screening or pneumatic separation, generally used as a filter aid in filtration.
- Bagasse: The final crushed sugar cane fibre remaining after milling. Cane residue leaving mills after extraction of juice.
- Boiling house: The 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: The difference between the temperature of a boiling sugar solution and the temperature of boiling pure water, both measured at the same pressure.
- Brix: The measure of dissolved solids in sugar juice, liquor or syrup using a refractometer, otherwise referred to as refractometric dry solids. For solutions containing only sugar and water, Brix = % sugar by mass. A unit used to express the concentration of solids in aqueous sugar solutions.
- 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 fibre by mechanical means but is driven off at elevated temperatures.
- Calandria: The tubular or plate heating element in a vacuum pan or evaporator vessel.
- Cane billets: The common name for the chopped lengths of cane (approx 250-300mm) produced by mechanical cane harvesters during the harvesting operation.
- Carbonatation: The clarification process of removing colloidal impurities including some colouring matter by the addition of lime and carbon dioxide to form calcium carbonate which traps the other impurities. This process is undertaken at a sugar refinery.
- Carbonatation gas: Gas rich in carbon dioxide for use in carbonatation.
- CCS (Commercial Cane Sugar): CCS represents the sugar content of cane as it is purchased by sugar mills. CCS is conventionally determined from the analysis for pol and brix of the first expressed juice at the first pair of rolls and the measurement of fibre in the variety of the cane. The CCS determines the payment made to the grower.
- Centrifugal: A perforated basket which spins inside a casing to separate sugar crystals from molasses
- Clarification: The process of separating insoluble suspended matter and some soluble substances from cane juice, to produce a clear juice.
- Clarified juice: Juice from clarifiers, also referred to as clear juice.
- Clarifier: An apparatus for the separation by sedimentation of suspended solids from a turbid sugar solution.
- Colour: Attenuation index, determined by absorption of light under defined conditions.
- 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).
- Crystallisation: The process of “growing” crystals by boiling them with syrup in a vessel (under vacuum). Nucleation and growth of crystals.
- Crystallisation scheme: Defines the number and arrangement of crystallization stages involved in producing sugar.
- Cush: The stream of wet bagasse or bagacillo separated from raw juice by the juice screens.
- Cut a pan: The process of discharging a portion of the massecuite from a pan, retaining a footing upon which to feed more syrup or molasses for crystallization.
- Decolourisation: The refinery process whereby the colour of filtered raw liquor is reduced by passing it over either bone char, granular carbon or ion exchange resin.
- Dissolved solids: All solute material which is in solution, including sucrose, monosaccharides, ash and other organic impurities.
- Drop a pan: The process of discharging 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.
- Dunder: Waste water which results from the production of ethanol by the fermentation of molasses.
- Entrainment separator: Apparatus for removing juice, syrup or massecuite entrained in the vapour.
- Enzymes: Proteins formed in living cells or synthetically produced which act as catalysts in chemical changes.
- Ethanol: Ethanol is the ethyl, or industrial, alcohol manufactured from fermented molasses. It can be used as a fuel and in a number of products including perfume, toiletries, bricks, cleaning products and shoe polish.
- Evaporator effect: One of a system of evaporators operating in series as a multiple effect system (e.g., first effect, second effect). Condensates and vapours are labelled correspondingly (e.g., first condensate and vapour one condensate and vapour from the first effect respectively).
- Exhaustion: Applied to a massecuite, it represents the grams 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.
- False grain: Undesirable small crystals, formed spontaneously by secondary nucleation when the supersaturation during crystallization is too high.
- Fibre: The dry fibrous insoluble structure of the cane plant in which juice is stored and through which plant food, dissolved in water, is distributed throughout the plant.
- Filter cake: Material retained on the filter screens and discharged from the filters after filtering clarifier muds.
- Filter mud: In clarifying cane juice, the insoluble matter extracted from the juice forms a mud which is removed from the clarifiers, filtered and washed to recover the sugar it contains. The solids consist of mainly field soil, fibre, calcium phosphate, denatured protein and a small amount of sugar. Also known as cuchasa.
- Filtrate: Liquid passed through the screens of the filters.
- Filtrability: The filtering quality of a raw sugar solution.
- Filtration: The refinery process whereby cloudy carbonated raw liquor is passed through a filter cloth to produce a clear liquor.
- Final molasses: The black syrup, commonly known as molasses or ‘C’ syrup, remaining after the sugar syrup has been boiled and passed through the centrifugal for the last time in a mill or refinery. The sugar it contains cannot be removed economically.
- 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.
- Fructose: A sugar which occurs in cane juice and sugar products. It is formed in equal quantity with glucose when sucrose is inverted. In solution, it rotates polarised light to the left. It has the chemical composition C2H9O6.
- Glucose: A sugar which occurs naturally in cane juice and sugar products. It has the chemical composition C6H7O6.
- Grist: Sugar grist refers to the proportions of varying sized crystals and is determined by sieving and then weighing the portions of crystals.
- 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.
- Inclusions: Impurities held within sugar crystals, rather than those adhering to the surface.
- Inversion: The conversion of sucrose in syrup into a mixture of equal amounts of glucose and fructose. The action is one of hydrolysis and may be carried out by the action of the enzyme invertase, or by heating with dilute acids. The liquid product from this process is called invert sugar.
- Invert sugar: Mixture of approximately equal parts of glucose and fructose (monosaccharides) resulting from the hydrolysis of sucrose (inversion).
- Invertase: An enzyme which hydrolyses sucrose to glucose and fructose.
- IPS (International Pol Scale): The international pol premium scale is a price adjustment scale, described in the Rules of the Sugar Association of London. It defines incremental price premiums applied to sugar of 96 degrees polarisation.
- Juice: Cane juice consists of water with sugar and other substances dissolved in it and a proportion of insoluble particles suspended in it.
- Liming: A process 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.
- Magma: Mixture of crystals and liquid (water, clarified juice, syrup or molasses) produced by mingling.
- Magma mixer: Mingler, where crystal sugar and liquid are mixed together.
- Massecuite: The mixture of crystals and mother liquor resulting from the crystallization in a vacuum pan. Massecuites are classified according to purity as A, B, or C massecuites. The term is French for ‘cooked mass’.
- Massecuite mixer: Apparatus from which massecuite is distributed to the centrifugals.
- Maximum Continuous Rating (MCR): The capability of steam boiler to produce and provide the stated quantity of steam continually and easily.
- Melter: Equipment in which dissolving of sugar takes place.
- 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.
- Non-sucrose: Dissolved solids contained in any process stream other than sucrose.
- Non-sugar: Common overall term for dissolved solids other than sugar contained in any process stream.
- Nucleation: The generation and development of small crystals capable of growth.
- Pan or vacuum pan: Vacuum evaporative crystallizer used in the sugar industry to crystallize sugar from liquor, syrup or molasses. Also, see ‘Vacuum pan’.
- Phosphatation: Clarification using phosphoric acid and lime, in which certain non-sugar components are removed by flotation.
- Polarimeter: See ‘Saccharimeter’.
- Polarisation (pol): An approximate measure of the sucrose content of the sugar. Polarisation is measured by preparing a standard solution from the sugar and measuring the optical rotation of polarised light passing through a cell containing the solution. Sugar of 98 degrees pol would contain about 98% sucrose.
- Purity: The true purity is the sucrose content as a percentage of the dry substance or dissolved solids content. The solids consist of sugar plus non-sucrose components such as invert, ash, and colorants. Apparent purity is expressed as polarization divided by refractometer Brix, multiplied by 100.
- Ratoon: Cane which grows from the stools left in the ground after a crop has been harvested.
- Raw liquor: In refineries the clarified sugar solution is known as raw liquor.
- Raw sugar: The sugar crystals separated from massecuite in a centrifugal in a raw sugar mill. Australian raw sugar is usually in two grades, either about 98.8% or 97.6% sucrose. Sucrose content is varied to satisfy the requirements of customers. Australian raw sugar is commonly made up of 98.8% sucrose, 0.22% reducing sugars, 0.3% other organic matter, 0.3% ash and 0.31% water. Australian refined sugar is made up of 99.93% sucrose, 0.01% reducing sugars, 0.01% other organic matter, 0.01% ash and 0.04% water.
- Raw sugar equivalent: A measure of the amount of raw sugar of normal quality that a sugar mill could be expected to make from a given amount of syrup.
- Raw value: A term used internationally to express raw and refined sugar on a common basis (96 pol equivalent). International sugar statistics are expressed in terms of metric tons raw value (mtrv).
- Reducing sugars: Reducing sugars are those which have the ability to chemically reduce (withdraw oxygen) certain other chemical compounds. In milling and refining, reducing sugars (mainly glucose and fructose) are regarded as impurities.
- Refining: The purification of sugar through chemical and physical methods, generally including some or all of clarification, filtration, decolourization and recrystallization.
- Refractometric Dry Solids (RDS): The 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.
- Saccharimeter and polarimeter: Instruments used in sugar analysis to measure the amount of rotation of polarised light when passed through a sugar solution. The amount of rotation provides an estimate of the amount of sucrose in the solution.
- Saturation: A sugar solution at saturation will not dissolve any more crystals at the temperature of the solution.
- Season: The crushing season, which usually commences in May/June and ends in November/December in Australia.
- Seed: Suspension of fine crystals in saturated solution of alcohol, or the initial grain resulting from seeding in a vacuum pan.
- Seeding: The process of introducing crystal fragments to induce nucleation, as a means of initiating the crystallization process; and the introduction of fine crystals in the form of a slurry (similar to full seeding) to start crystallization. Sometimes referred to as graining.
- Sett: A piece of cane stalk used as planting material.
- 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.
- SRI: Sugar Research Institute
- Strike: Massecuite as a completed boiling, all of which is discharged from the pan.
- Sucrose: A 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 β-D-fructofuranosyl @alpha;-D-glucopyranoside.
- Sugar cane: Sugar cane belongs to the vast family of grasses which include other crops such as barley, wheat, rice and maize.
- Sulfitation: The introduction of sulfur dioxide into juice or liquor.
- Supersaturation: The degree to which the sucrose content in solution is 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.
- Tel quel: Literally means ‘as it comes’. It is the weight of sugar regardless of polarisation. For example, 100 tonnes actual or tel quel of raw sugar will commonly equal about 106 tonnes raw value or basis 96 degrees polarisation.
- Tonne (metric ton): Equivalent to 1000kg or 2204.6lb
- Tonnes actual: The actual (physical) tonnes of raw sugar, sometimes referred to in the international sugar trade as tonnes tel quell.
- Vacuum pan: Cylindrical steel vessel in which a steam heated surface is used to boil sugar syrups under partial vacuum at relatively low temperatures.