Sugar Factory Definitions
BAGASSE
On the number of the mill it is referred to as first mill bagasse, second mill bagasse, etc. After a diffuser the residue is called diffuser bagasse. The final residue from a milling train or from the dewatering mills of a diffusion plant is called final bagasse or simply, bagasse.
BAGASSE EXTRACT
The liquid fraction decanted from the bagasse after blending with water in the cold digester.
BRIX
Refractometer brix The term used when a refractometer equipped with a scale, based on the relationship between refractive indices at 201 C and the percentage by mass of total soluble solids of a pure aqueous sucrose solution, is used instead of a hydrometer to test the solids concentration of a sucrose containing solution.
The South African sugar industry is now standardised on refractometer brix. The change from hydrometer brix was completed in the 1972/1973 season.
BRIX-FREE WATER
The water associated with the fibre in cane and bagasse. In some respects this sorpfion water behaves in a manner similar to water of hydration and it is not available for dissolving sucrose. It is driven off at elevated temperatures. The amount of brix-free water is assumed to be 25% on dry fibre.
DAC EXTRACT
The liquid fraction decanted from the cane after blending with water in the cold digester.
DAC FACTORS
Brix Factor: The percentage ratio of the total brix in mixed juice, final bagasse and where applicable, diffuser press water mud, to total brix in cane as determined by direct analysis.
Pol Factor The percentage ratio of the total pol in mixed juice, final bagasse and where applicable, diffuser press water mud, to total pol in cane as determined by direct analysis.
FIBRE
The water insoluble matter of cane and bagasse from which the brix-free water has been removed by drying.
Where associated with brix-free water, fibre is often called natural fibre.
DAC fibre
Fibre % cane derived from direct cane analysis and applying the formula
Fibre % cane = (100-M-3b)/(1-0.0125b)
in which
M= moisture % cane
b= brix % extract
INSOLUBLE SOLIDS
Insoluble material in mixed juice or press water mud, determined gravimetrically by filtration according to a prescribed method.
INTERMIXED CANE
That portion of cane on a cane carrier originating from the overlapping of different consignments. Its composition is unlikely to be representative of anyone consignment and it is therefore excluded from consignment sampling.
JUICE
Mixed juice The mixture of juices from the extraction plant delivered into the juice scales.
Press water The juice expressed in dewatering diffuser bagasse.
MUD
The material removed from the bottom part of the subsiders. The mud contains the settled insoluble solids.
NORMAL MASS
The mass of sample equal to the normal mass of sucrose.
That mass of pure dry sucrose which, when dissolved in water to a total volume of 100 cm3 at 20'C and read at the same temperature in a tube 200 mm long, gives a reading of 100 degrees on a saccharimeter scale. According to the International Sugar Scale the normal mass of sucrose is 26,000 g.
POL
The apparent sucrose content of any substance expressed as a percentage by mass and determined by the single or direct polarisation method. The term is used as if it were a real substance.
PURITY
The percentage ratio of sucrose (or pol) to the total soluble solids (or brix) in a sugar product. The following terms are in general use:
Refractive apparent purity: The percentage ratio of pol to refractometer brix.
G.C. sucrose refractometer brix purity: The percentage ratio of GC sucrose to refractometer brix.
SUCROSE
The pure disaccharide a-D-glucopyranosyl-b-D-fructofuranoside, known commonly as sugar.
In the South African Sugar Industry sucrose is determined by GC.
SUGAR CANE
Botanically a tall grass of the genus Saccharum and agriculturally the crop produced from hybrids which are the progeny of a number of Saccharum species commonly referred to as cane. Specifically for the determination and distribution of sucrose in cane it is the raw material accepted at the mill for processing.
Definitions as applied to the Methods for Factory Control
ASH
Carbonated ash: The residue remaining after incineration at 650ºC.
Conductivity ash: The conductivity ash of a product is the figure arrived at by correlating the specific conductance of the solution of that product with its sulphated ash.
Sulphated ash: The residue remaining after incineration at 650ºC of a sample which was pre-treated with sulphuric acid.
ATTENUATION INDEX
The absorbance of a solution obtained at a specified wavelength expressed per unit cell length and unit concentration, e.g.
a*c420 = OD/b×c×10
where
a*c420= attenuation index at 420 nm wavelength of light
OD = absorbance
b= cell length (mm)
c= concentration (g/cm3)
BAGACILLO
Very small particles of bagasse separated either from pre-clarification juices or from the final bagasse for filtration or other purposes.
BOILING HOUSE
That part of the factory in which the processes of manufacture from mixed juice to sugar are carried out.
BOILING HOUSE RECOVERY
The percentage ratio of pol actually recovered in sugar to sucrose in mixed juice. If based on pol in mixed juice it is referred to as Boiling House Pol Recovery.
BRIX (DEGREES)
Unit divisions of the scale of a hydrometer, which, when placed in a pure aqueous sucrose solution at 20ºC, indicates the percentage by mass of dissolved solids in the solution. The reading obtained in an impure sucrose solution is usually accepted as an approximation of its percentage by mass of total soluble solids. The term brix is used in calculations as a measure of substance, e.g. tons brix.
See also refractometer brix in Chapter I A.
BULK DENSITY
The mass of material per unit of total volume occupied. Some useful values are:
| Shredded cane on the carrier | 280 | kg/m3 |
| Cut whole stick cane loosely piled | 200 | kg/m3 |
| Chopped cane from harvesters | 350 | kg/m3 |
| piled bagasse | 200 | kg/m3 |
| piled raw sugar | 880 | kg/m3 |
CANE TO SUGAR RATIO
OTons cane required to produce one ton of tel quel sugar.
CRYSTAL CONTENT
The percentage by mass of crystalline sugar present in a massecuite, magma or similar material.
CUSH-CUSH
The material removed from mill juice by straining.
DEXTRAN
A polysaccharide consisting of glucose units linked predominantly in a-(1®6) mode. It is sometimes present in appreciable concentrations in sugar cane and mill products due to microbial activity.
DRY SUBSTANCE
The material remaining after drying a product to constant mass, or for a specified period. The mass of dry substance can also be found by deducting from the mass of the product, the mass of moisture, as determined in a specified manner.
See also Total Solids.
ESCRIBED VOLUME
The volume escribed by a pair of mill rolls in a given time. It is equal to the roller length (in m) multiplied by the work opening (in m) multiplied by the surface speed of the rolls measured at the mean circumference (in m/sec) and is expressed in m3/sec.
EXTRACTION
The percentage ratio of sucrose in mixed juice to sucrose in cane. If based on pol it is referred to as Pol Extraction.
Corrected reduced extraction (CRE): Sometimes used to correct for the influence of sucrose and fibre on extraction and is calculated by the following formula:
CRE = 100 - (0.03936×(100 - E)×(100-Fc)×Pc)0.6/Fbc
Where
E= Extraction
Pc= Sucrose % cane
Fc= Fibre % cane (including insoluble solids in mixed juice)
Fbc= Fibre in bagasse % cane (excluding insoluble solids in mixed juice)
If based on pol it is referred to as Corrected Reduced Pol Extraction
ESTIMATED RECOVERABLE CRYSTAL (ERC)
The formula for ERC is
ERC=aS-bN-cF
where
S=sucrose%cane
N=non-sucrose%cane
F=fibre%cane
a = (polbagasse + polsugar + sucrosemolasses) / sucrosecane
b = sucrosemolasses / non-sucrosecane
c = polbagasse / fibrecane
Factors a, b, and c may vary slightly from year to year. Hence values are calculated at the end of every season using weighted averages and assuming that ERC is equal to the total crystal production of the industry.
FILTER CAKE
The residue removed from process by filtration including any added filter aid.
GUMS
The precipitate, corrected for ash, consisting mainly of polysaccharides, which is obtained by treating sugar liquors with acidified ethyl alcohol.
IMBIBITION
The process in which water or juice is put on bagasse to mix with and dilute the juice present in the latter. The water so used is termed imbibition water. General terms in use are: single imbibition, double imbibition, compound imbibition, depending on the manner in which the water and / or juice is added.
INVERT SUGAR
A mixture of fifty percent glucose and fifty percent fructose obtained by the hydrolysis of sucrose.
JAVA RATIO
The percentage ratio of pol % cane to pol % first expressed juice.
Note: In calculating an average pol % first expressed juice the weighting given to the individual analyses is on the basis of the tons cane from which the respective first expressed juice samples were taken.
JUICE
- Absolute juice: A hypothetical juice, the mass of which is equal to the mass of cane minus the mass of fibre. It comprises all the dissolved solids in the cane plus the total water in cane.
- Clarified juice: The juice obtained as a result of the clarification process.
- Diffuser juice, also called draught juice: The juice which is withdrawn from a cane or bagasse diffuser.
- First expressed juice: The juice expressed by the first two rollers of a tandem.
- First mill juice: The juice expressed by the first mill of a tandem.
- Last expressed juice: The juice expressed by the last two rollers of a tandem.
- Last mill juice: The juice expressed by the last mill of a tandem.
- Primary juice: All the juice expressed before dilution begins.
- Residual juice: The juice left in intermediate or final bagasse.
- Secondary juice: The diluted juice which, together with the primary juice, forms the mixed juice.
- Undiluted juice: All the juice existing as such in the cane. Its mass is equal to the mass of cane minus the combined mass of fibre and brix-free water.
MACERATION
In the South African sugar industry the term is synonymous with imbibition. The latter is the preferred terminology.
MAGMA
A mixture of crystals and sugar liquor produced by mechanical means.
MASSECUITE
The mixture of crystals and mother liquor discharged from a vacuum pan. Massecuites are classified in order of descending purity as first, second, etc., or A, B, etc .
MILL SETTINGS
Mean circumference: mean diameter x p.
Mill ratio: The ratio of feed to discharge work openings.
Set opening: The distance between the circumferences escribed by the mean diameters of the top roller and feed or discharge roller with the mill running empty. This definition applies pari passu for the openings between underfeed and top roller and between pressure feeder rollers.
The mean diameter of a grooved roller is equal to the diameter of the equivalent (same volume and length) solid roller. In practice the arithmetic mean of the diameters over the tips of the teeth and at the roots of the grooves (neglecting any Messchaert grooves) affords a sufficiently close approximation.
Work opening: The work opening is equal to the set opening plus the increase in distance between the rollers resulting from the lift during milling operations.
MILLING LOSS
The percentage ratio of pol in bagasse to fibre in bagasse.
MOLASSES
The mother liquor separated from a massecuite by mechanical means. It is distinguished by the same prefixes as the massecuites from which it is separated.
Final molasses: The mother liquor separated from the final massecuite by mechanical means.
NON-POL
Brix minus pol.
NON-POL RATIO
The ratio between non-pol in sugar plus non-pol in final molasses and non-pol in mixed juice.
NON-SUCROSE
Dry substance minus sucrose.
NUTSCH SAMPLE
Any sample of molasses which is separated from a massecuite at any time prior to curing the massecuite in the factory centrifugals.
OVERALL RECOVERY*
The percentage ratio of pol actually recovered in sugar to sucrose in cane. If based on pol in cane it is referred to as overall Pol Recovery.
POLYSACCHARIDES
Polymers of medium to high molecular mass in which the units are mainly pentoses and/or hexoses.
PREPARATION INDEX
The percentage ratio of brix in the ruptured cells to total brix in cane.
PURITY
The percentage of sucrose in total solids in a sugar product. The following purity terms are in general use:
Purityapparent = pol / brix × 100
Puritygravity = sucrose / brix × 100
Puritytrue = sucrose / total solids × 100
In order to specify purity without ambiguity it is necessary to indicate the methods used to determine both the numerator and denominator in obtaining the result.
Target purity: A reference purity of final molasses taking into account the effect of the non-sucrose present on its exhaustion. In South Africa the formula reads:
Puritytarget = 33.9 - 13.9×log[(f + g)/a]
Where
f = fructose % molasses (determined by GC)
g = glucose % molasses (determined by GC)
a = sulphated ash % molasses
Target purity difference: The difference between the true purity as determined from GC sucrose and Karl Fischer solids and the target purity as calculated above.
REDUCING SUGARS
The reducing substances in cane and its products determined as described in Chapter 8 and calculated as invert sugar. Major reducing sugars are glucose and fructose.
REDUCING SUGAR/ASH RATIO
The ratio of reducing sugars to sulphated ash.
REDUCING SUGAR/POL RATIO
The percentage ratio of reducing sugars to pol and often referred to as reducing sugar ratio.
SAFETY FACTOR
A number designed to indicate the probable keeping quality of a fresh raw sugar having a pol of less than 99,0ºS. It is calculated by dividing the percentage moisture in the sugar by 100 minus the pol of the sugar.
For satisfactory keeping quality the safety factor should have a value less than 0,23.
SATURATED SOLUTION
A saturated solution is one which would neither dissolve nor crystallise solute in the presence of undissolved solute.
SOIL IN CANE AND BAGASSE
Inorganic material determined by ashing a sample and correcting for the ash % clean sample.
SOLUBILITY
The concentration of a solute in a solvent in a saturated solution. It is dependent on temperature, the nature and concentration of impurities and in the case of gases, on pressure.
SOLUBILITY COEFFICIENT OF SUCROSE
The ratio of the solubility of sucrose in the sample to that in pure water at the same temperature (both expressed as g sucrose/g water).
SUGAR
The main product of a sugar factory consisting of crystals of sucrose as removed from a massecuite and containing more or less impurities, depending on the type of sugar.
- Refined sugar: A white sugar as specified in Table 15.
- Very high pol sugar (VHP): Raw sugar with a pol of not less than 99,3ºS.
- High pol sugar (HP): Raw sugar with a pol between 98,0 and 99,3ºS.
- Low pol sugar (LP): Raw sugar with a pol below 98,0ºS.
- Brown sugar: A direct consumption raw sugar.
- Tel quel sugar: The bulk product without reference to its quality.
SUGAR CANE
Botanically a tall grass of the genus Saccharum and agriculturally the crop produced from hybrids which are the progeny of a number of Saccharum species commonly referred to as cane. Specifically for the determination and distribution of sucrose in cane it is the raw material accepted at the mill for processing.
- Clean cane stalk: Cane which has been cut above the highest subterranean roots; has been topped below the level of the growing point; has no leaves or adhering foreign matter and has not died and dried out.
- Cane tops: The portion of the stalk above the natural breaking point, plus all green leaves and sheaths attached to that part of the stalk.
- Extraneous matter: Any solid material delivered with clean cane stalk, including dead and dried out stalks.
- Trash: Leaves and sheaths delivered with the clean cane stalk.
SUPERSATURATION COEFFICIENT OF SUCROSE
The ratio of the concentration of sucrose in the sample to the solubility of sucrose in the sample at the same temperature (both expressed as g sucrose/ g water).
SYRUP
Concentrated clear juice having a brix of between 60' and 70'.
TOTAL SOLIDS
The solids concentration of an aqueous solution determined either by drying or by analysing for the water content using the Karl Fischer method.
See also Dry Substance.
WASH
The diluted liquor thrown off by the centrifugals during washing and/or steaming of massecuites or the total liquor separated from a magma.