1998 SPRI CONFERENCE
ABSTRACTS of PRESENTATIONS
Sugar Processing Research Institute, Inc.
March 22-25, 1998
Abstracts
are presented in alphabetical order according to first author. Abstracts of
poster presentations following this section are also according to first author.
STUDY
OF HMW COMPOUNDS THROUGH REFINING PROCESS USING GPC AND EVAPORATIVE LIGHT
SCATTERING DETECTOR, Luis S. M. Bento, Susana Sá,
R.A.R. - Refinarias de Açúcar
Reunidas,
The importance of HMW compounds in sugar refining is known. They can be associated with colour, have an important role in floc formation and their presence are detrimental on filtration, crystallisation, ion exchange resins decolourization, purging in centrifugals and carbonatation processes. Gel Permeation chromatography is used to study these compounds and make their separation by molecular weight. As some of these compounds are not coloured or have different absorvities, their detection using only spectrophotometric techniques do not give a complete information. Using an Evaporative Light Scattering Detector, these compounds can be detected, after GPC, even without pre-concentration of sugar samples. This technique is described in this paper.
ACID
BEVERAGE FLOC FROM BEET SUGARS, Margaret A. Clarke, Earl J. Roberts
and Mary An Godshall, Sugar Processing Research Institute, Inc.,
Acid beverage floc (ABF), a flocculated turbid material that can form in sugar sweetened, acidified, carbonated beverages after several days standing, is a customer problem to beverage bottlers and their suppliers of sugar. ABF from beet sugar has been reported (Eis, 1952; van der Poel, 1966) to be caused by a saponin from the beet plant. Recent work has shown the presence of several saponins in sugarbeet (Masiot, 1994; Ridout, 1994). Investigations at S.P.R.I. have confirmed that isolation and test procedures for saponins, as reported in the literature, are actually for oleanolic acid.
In this paper, observations on ABF and its causes are reported. ABF from beet sugar is proposed to have a two factor basis: a negatively charged component and a positively charged component interact at acid beverage pH, forming a coacervate and subsequently coagulating into a floc. The negatively charged factor can be oleanolic acid, any of the saponins that contain a glucuronic acid moiety, or beet cell wall polysaccharide containing uronic acids. The positively charged component can be protein or peptide, with isolectric point above the beverage pH of 2.5-3.0. ABF can be made readily by adding these components to non-floccing sugars.
Acid beverage floc and its causative factors can be removed by intense or tight filtration. The negatively charged components can be removed to a great degree by formation of their calcium complexes (at pH above 8.5) and subsequent filtration. Other procedures for prevention, testing and removal are discussed.
REPORT ON TREATMENT OF SUGARCANE JUICE WITH DISC-STACK
CENTRIFUGATION, Margaret A.
Clarke, John R. Vercellotti, Rebeca S. Blanco and Mary An
Godshall, Sugar Processing Research Institute, Inc.,
Work on membranes by the
In a search for a physical separation system to remove fine
suspended solids and colloidal materials, Alfa Laval (
With the increase in mechanical harvesting, there has been a concomitant increase in suspended solids in sugar, both direct white and raw sugar.
The goal of this study was to find a method to remove suspended solid material and fine particulate matter from sugarcane juice, to make it suitable for membrane filtration, for preparation of direct consumption sugar or to increase raw sugar yield at higher production efficiency.
The approaches for the study were several:
- Consider separation before membranes; pretreatment, such as centrifugation.
- Conduct feasibility
discussions in
- Conduct bench-scale tests at Alfa Laval (U.S.) on fresh cane juice and syrup samples.
- Conduct on-line testing of
process equipment at a cooperating factory in
BEET BREI ANALYSIS BY NEAR INFRARED SPECTROSCOPY, Vern S. Clarkson , Valerie A. Kingstrom and Jim E. Schueller, Southern Minnesota Beet Sugar Cooperative, Renville, Minnesota, USA
This presentation examines the feasibility of near infrared (NIR) spectroscopic methods for quality analysis used for the beet payment to the grower. Another subject is examination for the feasibility of tare laboratory automation and chemical use elimination.
SUGAR
DEGRADATION AND COLOUR FORMATION, Jan Maarten
de Bruijn,
Jan L. M. Struijs and Marjan
E.F., Bout-Diederen, CSM Suiker
bv, Centraal
laboratorium,
In beet sugar manufacture there are two chemical phenomena which should
be controlled as tightly as possible.
First, sugar degradation results in the loss of sugar and the concomitant
formation of (reactive) invert sugar.
Particularly extraction and evaporation are considered to be important
process steps in which a small, but significant, part of the sugar can be
degraded by acid hydrolysis.
The colour of the juices finds its origin in
juice purification, and will depend on both the quality of the processed beets
and the way the diffusion process and juice purification are carried out. In addition, a further colour
increase is generally observed in the evaporation station and the subsequent
crystallization steps. With respect to product quality a too high colour formation is undesirable and, therefore, should be
prevented.
The latest insights at CSM concerning both sugar degradation and colour formation in its beet sugar factories will be
presented. Emphasis will be given to the
sources and process parameters which may be responsible for colour
formation. A model laboratory study is
in progress in order to determine which juice components and/or process
parameters have to be considered as mainly responsible for the observed juice colour.
MARKER
COMPOUNDS IN SUGAR INDUSTRY SAMPLES INDICATING SUGAR LOSS, Gillian
Eggleston1, Margaret A. Clarke2 and Armand B.
Pepperman1 , 1USDA-ARS-SRRC, New Orleans, Louisiana, USA,
2Sugar Processing Research Institute, Inc.,
The most accurate determination of sugar losses in sugar manufacture and refining would be to analyze for a stable sugar degradation product that is a marker compound. Under alkaline conditions, glucose, fructose, mannose and, to a much lesser extent, psicose are in initial equilibrium via a reversible isomerization reaction. Detection of mannose in samples taken from industrial processes where alkaline conditions prevail, confirmed that alkaline degradation of glucose and fructose (invert) had occurred. Mannose can be used as marker compounds for invert losses.
Oligosaccharides are formed in the breakdown of sucrose under acid and alkaline conditions, and have strong potential as possible stable markers. Potential oligosaccharide degradation product markers, formed across various sugarbeet and sugarcane unit processes are reported and discussed, and compared to degradation products in model study solutions. The model study sucrose degradation reactions were undertaken under simulated industrial conditions (65°Brix; constant pH 5.45-9.25; N2; 100°C).
Improved ion chromatography technologies for separation of sugar loss markers are discussed, as well as various methods of detection for the identification of markers.
IDENTIFICATION
OF ESTERIFIED PHENOLIC AND ORGANIC ACIDS IN THE HIGH MOLECULAR WEIGHT
COLORANT/POLYSACCHARIDE FRACTION IN CANE SUGAR PROCESSING, Mary A.
Godshall, Ingrid P. Buchler, Heather G. Boyle and
John R. Vercellotti, Sugar Processing Research
Institute, Inc.,
Plant cell walls, particularly those of grasses and grains, contain phenolic acid residues that contribute to the lignin-polysaccharide network that strengthens the structure of the plant. Soluble cell wall material from the sugarcane plant comprises part of the high molecular weight complex of colorant and polysaccharide that is present throughout cane sugar processing, is implicated in color increase, and has an affinity for the sucrose crystal. Base hydrolysis is a well established method for releasing esterified (“base labile”) compounds from polysaccharides. Base hydrolysis of the high molecular weight material from cane sugar processing materials released a high concentration of phenolic acids as well as a surprising number of organic acids. It is speculated that some of these acids, which include di- and tri-carboxylic acids, may contribute to the cross linking of colorant molecules to the polysaccharide matrix. This study examines the progression of base-labile components in various stages of processing as well as in several cane varieties.
USE
OF SCANNING ELECTRON MICROSCOPE-ELEMENTAL ANALYSIS TO IDENTIFY CONTAMINANTS IN
SUGAR PROCESSING, Wilton R. Goynes1, Bruce F. Ingber1,
Rebeca S. Blanco2, Margaret A. Clarke2
and Mary A. Godshall2 , 1USDA-ARS-SRRC, New Orleans,
Louisiana, USA, 2Sugar Processing Research Institute, Inc.,
During processing, sugar often retains traces of insoluble materials that cause discoloration or the appearance of turbidity of sediment. These insolubles may be present in small quantities, and are difficult to identify. The scanning electron microscope (SEM) with an auxiliary energy-dispersive analysis system has provided a tool for identifying these materials. The microscope provides magnifications great enough that the individual particles can be visualized. The energy-dispersive analysis system utilizes a spectroscopical x-ray analysis system to identify elements present in contaminants. Analysis of elements and the appearance of the particles provide a basis for identification of the contaminants. “Maps” of silicon, calcium and other elements in sediment particles will be presented. The types of materials that make up sediment or turbidity will be discussed. Ranges of composition for white and raw sugars have been determined. Relationship of sediment type to process conditions will be discussed. The innocuous nature of sediment composition will be emphasized. The basis for this micro-elemental analysis, and typical results will be discussed.
FUTURE
OF MEMBRANE TECHNOLOGY IN THE SUGAR INDUSTRY: IMPORTANCE OF PROPER TESTING,
Vadim N. Kochergin,
Amalgamated Research Inc.,
Current and potential applications for membrane technology in the beet and cane sugar industry are reviewed. Specific characteristics of sugar syrups, such as relatively high temperatures and viscosity, presence of abrasive particles, etc., define the specific requirements for membranes to be used in the sugar industry. The probability of elimination of certain components by membranes with different pore sizes is discussed. The effect of micro- or ultrafiltration on purity, color, hardness level and other properties is illustrated by experimental data obtained for various cane and beet juices. It is emphasized that integration of a new membrane technology into a sugar plant requires extensive testing of membrane performance as well as development of pretreatment of feed material and post treatment of retentate. The important issues related to a proper test program are addressed.
SUCROSE – RAW MATERIAL FOR CHEMISTRYAND
BIOCHEMISTRY, Markwart Kunz,
Südzucker AG, Mannheim/Ochsenfurt,
With its vast availability in an exceptionally pure condition, ease of transportation and storage in bulk quantities, sucrose may be regarded as a most suitable raw material for processing to value-added products.
The usually clear distinction between food and chemicals in the sense that chemicals are used only for non-food applications in not universally applicable, as for example starch and starch-derived products are used extensively not only in the food industry but also in paper and plastics. Therefore this paper will discuss only chemical or biochemical reactions including fermentations based on sugars.
The suitability of sucrose as raw material depends on:
- The gross economic conditions in the country in which you want to use it,
- The relative cost of a variety of different agricultural corps, for instance the competition between corn and beet,
- The relative cost of agricultural crops compared to crude oil and the special attributes the product in questions should have.
Sucrose or its constituents glucose and fructose can be put to different material uses:
- As fermentation feed stock mainly accompanied by a destruction of the carbohydrate structure,
- And by chemical or biochemical modifications accompanied by destruction, conservation or reorganization of the carbohydrate structure.
CANE TRASH: EFFECTS AND EVALUATION ON CANE QUALITY, Jesús E. Larrahondo, C. O. Briceno, C. Viveros, A. Palma, A. Navarrete and O. Ospina, Cenicaña, Cali, Colombia
The tops, leaves and field mud as extraneous matter incorporated during the harvest of sugarcane reduce the efficiency and sugar recovery at the factory; therefore its evaluation and control is very important and consumes much time, therefore a method based on juice extraction with a hydraulic press was used for a laboratory and a mill trial in which a good statistical correlation between extracted juice and cane trash was found. A reduction of 16% in juice extraction was detected in the laboratory for each 10% of extraneous matter. Similarly a loss of 10.7% for pol % cane was observed in the mill cane. The results allowed to conclude that sampling by core sampler followed by the evaluation of hidraulic press juice may be a practical methodology for trash evaluation of post harvest cane.
DEVELOPMENTS
IN SUGARCANE AGRICULTURE THAT AFFECT PROCESSING, Benjamin L. Legendre1
and Margaret A. Clarke2 , 1USDA-ARS-Sugarcane Research
Center, Houma, Louisiana, USA, 2Sugar Processing Research Institute,
Inc.,
Extensive research has been published to show the direct benefits of sugarcane quality on sugar yield and quality. Sugarcane with a high level of sucrose and purity and a low fiber and trash content generally mills and processes well producing a high yield of good quality sugar. However, quality can be influenced by ever changing developments in sugarcane agriculture including cultivation of new varieties, use of chemical ripeners, changes in cultural practices and harvesting systems, and new disease and insect complexes. Although many of these developments can contribute greatly to maximizing the yield of sugar per unit area, they can also contribute to poorer cane and juice quality. Further, new disease and/or insect complexes have been shown to adversely affect certain cane and juice parameters that adversely impact processing. Additional research has shown that these changing developments can have serious deleterious affects on the concentration of Brix, sucrose, purity, fiber, reducing sugars, starch, dextran, and other polysaccharides, phenolics, inorganic ash, proanthocyanidin, and other parameters of cane or juice. This paper will discuss how these developments in sugarcane agriculture affect processing.
INDUSTRIALLY VIABLE CHEMICALS FROM KETOSES? STATUS AND PERSPECTIVES,
Frieder W. Lichtenthaler,
Although D-fructose, L-sorbose and isomaltulose are large scale-accessible and inexpensive, their utilization as organic raw materials for chemical industry is modest - not surprisingly since their basic chemistry is more capricious and considerable less developed than that of glucose and other hexoses.
An overview is given on the present state of chemically transforming these ketoses into building blocks with industrial application profiles, be it bulk, fine or speciality chemicals, or enantiopure intermediates for pharmaceuticals.
USE OF NIR FOR THE ONLINE ANALYSIS OF CHROMATOGRAPHIC SEPARATOR FEED AND PRODUCT STREAMS, Terry McGillivray, Beverly Jacobson, Steven Clausen and Mary Niehaus, American Crystal Sugar Company, East Grand Forks, Minnesota, USA
The conventional method of determining the composition of feed and product streams from a molasses chromatographic separation plant involves the collection of composite or grab samples followed by the analysis using conventional methods for solids content and sucrose by pol. Sucrose, raffinose, and betaine require the use of instrumental methods such as HPLC or GC. This paper discusses the use of NIR for online measurement of feed, raffinate, and product streams from a simulated moving bed chromatographic separation plant. Sucrose, solids, raffinose, betaine are all determined on line. This information is used to provide average compositional analysis, which can replace the conventional laboratory analysis. The development of the calibration curves is discussed, NIR predictions are compared to laboratory analysis, and repeatability of various measurements is discussed.
APPROACHES FOR THE REDUCTION OF WHITE SUGAR ODOR, Terry McGillivray, Mary Niehaus, Joye Bond and William J. Colonna, American Crystal Sugar Co., East Grand Forks, Minnesota, USA
Several ways to reduce/prevent white sugar odor were explored. One approach was to use alternate sources of factory water for centrifugal wash. Different evaporator condensates were used in the final wash step and the washed sugar evaluated via sensory panel. It was found that switching to alternative factory condensates as sources of wash water has little, if any, apparent effect on sugar odor.
The effect of wash water on sugar odor was tested another way. Sugar was crystallized from standard liquor in a pilot-scale pan. Half of the sugar crop was washed in the centrifugal with purified, research-grade water (~16-18 megaΩ); the remaining sugar was washed with factory condensate water. Water temperatures were ~100°C. The washed sugar was recovered, dried, then evaluated for odor by sensory panel. In most cases (~67%), sugar washed with pure water had lower odor than sugar washed with condensate. However, sugar washed with pure water still had a detectable odor, although it was of a noticeably different character than sugar washed with condensate. Odor in the former sugar is probably due to odorants which are trapped in the sugar during crystallization, and which eventually diffuse out of the crystals.
Aeration was also tested as a means of removing odor from sugar. Sugar obtained from the cooler in the factory was placed in a cylindrical conditioning bin and aerated at ambient temperature with purified air. Sugar samples were withdrawn after 0, 24 and 48 hours of aeration and evaluated for odor via sensory panel. In a total of 19 trials, aeration was found to produce a positive effect on odor in 13 (>68%) of the samples tested. In most cases, a significant odor reduction was observed after 24 hours of aeration. The data suggest that odor reduction of sugar in a factory setting can be accomplished through the use of a conditioning silo.
REVIEW
OF NEAR INFRA-RED REFLECTANCE (NIR) RESEARCH IN THE SOUTH AFRICAN SUGAR
INDUSTRY, Jan H. Meyer, South African Sugar Association
Sugar industries world wide are continuing to show increasing interest in the potential applications of near infra-red (NIR) analysis in the fields of cane and beet sugar quality testing, downstream sugar byproduct analysis, cane nutrition, soil fertility monitoring and in screening for resistance to certain pests and diseases. In South Africa, during the past decade both filter and scanning NIR spectrophotometers have been used to improve fertilizer use efficiency of sugarcane by matching the crop’s N requirement to soil N requirement to soil N mineralising potential and plant N status, both properties determined by NIR. Well over 70,000 leaf and 140,000 soil samples submitted by cane growers have been routinely tested by the Fertilizer Advisory Service using NIR in conjunction with other instrumental techniques. Major benefits have been substantial savings in N fertilizer use as well as reducing the risk of environmental pollution.
Recent developments have centered on comparing the suitability of scanning NIR instruments for the rapid determination of various constituents in cane juice, shredded cane, bagasse, raw sugar, and molasses. The possibility of using NIR on shredded cane has been proposed as an alternative to direct analysis of individual cane consignments (DAC) following collaborative investigations by staff from the Sugar Milling Research Institute (SMRI) and Sugar Experiment Station (SASEX). Global calibrations developed for mixed cane juice and molasses constituents for daily process control management of raw sugar factories is also currently under investigation by SMRI staff.
Possible new applications of NIR that are discussed in the paper include partitioning the N pool in the cane plant, estimating photosynthesis, predicting yield potential, screening for pest and disease resistance and measuring the sustainability potential of soils.
A
SOUTH AFRICAN
An overview of recent experiences in analysing and monitoring oligosaccharides is presented. High performance anion exchange chromatography (HPAEC) with electrochemical detection has been used extensively to obtain typical “oligosaccharide” profiles. Analytical advantages and disadvantages are discussed.
Oligosaccharides have been found to be the principal cause of crystal elongation in the South African industry. Five major oligosaccharides have been identified in process. It has been demonstrated that one of these (theanderose) promotes c-axis elongation, but it is clearly not the only factor involved. This sugar has been detected in mixed juice, is strongly transferred to the crystal and can be used to differentiate cane and beet crystals.
The accumulation of oligosaccharides between harvesting and crushing of whole stalk cane has been monitored. Pilot plant studies have been used in an attempt to highlight how the presence of these sugars may impact on aspects of cane processing and sugar quality.
SENSORY AND CHEMICAL PROPERTIES OF LIQUID SUGAR, Per Pihlsgård1, Mats Larsson2, Anders Leufven1 and Hans Lingnert1 , 1SIK, The Swedish Institute for Food and Biotechnology, Göteborg, Sweden, 2Danisco Sugar, Malmö, Sweden
Liquid sugar may be manufactured from raw beet sugar with fewer crystallisation steps. This makes the overall process of beet sugar manufacture more efficient as more material can be considered as product and thus the amount of waste products will be lower. The odour and flavour intensity of these liquid sugars is higher due to fewer purifying crystallisation steps. Efficient adsorption techniques to purify the solutions must be used. Different food applications have different purity requirements.
In this investigation liquid
sugar samples from Danisco
LIME REDUCTION IN JUICE PURIFICATION, Emma J. Philip, Maria Teresa Garcia Cubero, David Sargent and Trevor C. Theobald
Although British Sugar has reduced its consumption of lime for purification of beet raw juice by about 50% over the last 15 years the costs of using lime are still significant. Costs are incurred in purchase and transport of lime and for coke to burn lime in conventional kilns. Offset against these is the benefit of the valuable used lime now sold as a more convenient high dry substance product. This paper looks at some experimental work carried out by British Sugar to develop practical means of further reducing lime consumption by the factories.
NANOFILTRATION
AS AN INDUSTRIAL ALTERNATIVE FOR USED BRINE FROM DECOLORIZATION RESINS,
M. A. Theoleyre1, S. Cartier1 and M. Decloux2 , 1Applexion Corp.,
2Ensia, Massy,
Disposal of the used brine, with a high chloride content, from decolorization resin is the main problem limiting resin development in the cane sugar industry. The use of nanofiltration membranes is a very efficient process to separate color bodies from salts, and allows recovery and recycling of salt from used brine.
Al least 90% of the salt can be recovered and reused. In the same step, 90% of the colorants are concentrated in 10% of the initial volume for further treatment: color bodies precipitation, mixing with the final molasses, and biological treatment.
This technology is now mature and available for industrial application.
COOLING
CRYSTALLIZATION APPLIED TO THE “EXTRACT” FRACTION OF A
CHROMATOGRAPHIC SEPARATION PROCESS (SMB) OF MOLASSES, Giuseppe Vaccari1,
Giorgio Mantovani1, G. Sgualdino1 and William J. Colonna2 , 1University of
Fractionation of sugarbeet molasses by the Simulated Moving Bed (SMB) Ion Exclusion Process is in commercial use in many countries. The sugar-rich fraction (i.e. extract) obtained from this process is utilized in various ways during and after the regular beet campaign. Extract contains colorants which can complicate processes into which it is introduced. This can be handled by reducing the initial extract color using ion exchange resin, although this can create other problems. An alternative approach is a crystallization technique, which enable the recovery of white sugar from highly-colored syrups. For the latter approach, we used cooling crystallization, as this has been successful with both highly-colored syrups and untreated raw juice. In our laboratory, a 3-stage cooling crystallization process was applied to extract. Commercial white sugar was obtained from 1st crystallization step, and by recycling the crystals recovered from the 2nd and 3rd stages. Elevated levels of betaine and raffinose (both of which reduce sucrose solubility) enable the recovery of a molasses which was ~93% exhausted by the crystallization process. The crystallization data are presented, along with a working model describing the cooling crystallization process for extract in a sugar factory operating independently of the regular beet campaign.
DETERMINATION
OF SOLIDS IN MOLASSES BY DRYING METHODS, John R. Vercellotti,
Margaret A. Clarke and Rebeca S. Blanco, Sugar
Processing Research Institute, Inc.,
Vacuum oven dry weights of molasses and syrups have been used as a measure of concentration and mass balance for many years as a confirmation of the accuracy of Brix refractometric measurements. The differences in solids between determination by refractive index and drying are often a few percentage points lower in the residue weight after vacuum drying than found by refractometry. Just the opposite might be expected since the greater error often found on drying substances is the inability to remove all the water during the treatment with heat and vacuum. In this work °Brix is compared with solids estimated by first drying a thin film (about 1 gram) of the molasses under ~0.1 mm Hg at 50°C overnight, followed by drying at 90°C to constant weight. The dried molasses or syrup did not show appreciable sucrose degradation with IC determination sugars. Gel permeation chromatography also did not reveal any new polymer development in the solid cake as a result of the drying conditions. Thin film drying of molasses and syrups under heated vacuum is a reliable check of refractometric solids.
MEMBRANE
SEPARATION CHEMISTRY IN SUGAR PROCESSING APPLICATIONS, John R. Vercellotti, Margaret A. Clarke, Xavier M. Miranda,
Angel K. Kelly, Frank Desimone and Rebeca S. Blanco, Sugar Processing Research Institute,
Inc.,
Membrane technology in the beet and cane sugar industries is being investigated to simplify clarification of juices, partition colorant prior to evaporation and crystallization, and to improve exhaustion of molasses for increased sugar recovery. The Sugar Processing Research Institute, Inc. (S.P.R.I.) has compared commercially available synthetic organic membrane systems as well as ceramic cross flow colloidal and ultrafilters to effect these processes. Chemists of S.P.R.I. have defined raw material such as crusher juice or molasses fractions entering the membrane streams as well as each of the fractions coming from the membrane retentates and permeates. Subfractionation of the material by membrane nominal molecular weight cutoff types afforded enriched high polymer and permeates of lower molecular weight colorant or components which were further analyzed by gel permeation chromatography, compositional analysis, and physical methods such as nuclear magnetic resonance spectroscopy. Colloidal chemistry of molasses retentates indicates that affinity of the natural components produces very high molecular weight aggregates which are implicated in membrane fouling or other inefficiencies of the process.
POSTERS
EFFECT OF CANE QUALITY ON SUGAR PRODUCTION, Henrique V. Amorim, A. J. Oliveira, L. F. L. F. Silva and A. Godoy, Fermentec S/C Ltda., Piracicaba S.P., Brasil
Several parameters such as soil, trash relative humidity of the air, rains, time from burning and crushing, bacterial infection in cane are correlated with several parameters of sugar production such as lime, sulfite, dextran, color, sugar loss in factory, etc.
APPROACHES
FOR THE REDUCTION OF WHITE SUGAR ODOR, Joye Bond, William J. Colonna,
Christine Fastnaught, Jim Heggeness,
Terry McGillivray and Mary Niehaus,
American Crystal Sugar Company Research Center, Morehead, Minnesota, USA
Several ways to reduce or prevent white sugar odor were explored. One approach was to use alternate sources of
factory water for centrifugal wash.
Different evaporator condensates were used in the final wash step and
the washed sugar evaluated via sensory panel.
It was found that switching to alternative factory condensates as
sources of wash water has little, if any, apparent effect on sugar odor.
The effect of wash water on sugar odor was
tested another way. Sugar was
crystallized from standard liquor in a pilot-scale pan. Half of the sugar crop was washed in the
centrifugal with purified, research-grade water (~ 16 ~18 megaΩ);
the remaining sugar was washed with factory condensate water. Water temperatures were ~100ºC. The washed sugar was recovered, dried, then evaluated for odor by sensory panel. In most cases (~67%), sugar washed with pure
water had lower odor than sugar washed with condensate. However, sugar washed with pure water still
had a detectable odor, although it was of a noticeably different character than
sugar washed with condensate. Odor in
the former sugar is probably due to odorants which are trapped in the sugar
during crystallization, and which eventually diffuse out of the crystals.
Aeration was also tested as a means of
removing odor from sugar. Sugar obtained
from the cooler in the factory was placed in a cylindrical conditioning bin and
aerated at ambient temperature with purified air. Sugar samples were withdrawn after 0,24 and 48 hours of aeration and evaluated for odor via
sensory panel. In a total of 17 trials,
aeration was found to produce a positive effect on odor in 11 (65%) of the
samples tested. In most cases, a
significant odor reduction was observed after 24 hours of aeration. The data suggest that odor reduction of sugar
in a factory can be accomplished through the use of a conditioning silo.
SUGARCANE
FACTORY TRIALS WITH DEXTRANASE ENZYME (FROM CHAETOMIUM GRACILE) ON CANE
JUICES AND SYRUPS, Margaret A. Clarke1, Les A. Edye*, Frank Cole2, Jane L. Kitchar3
and Deborah L. Harrell1 , 1Sugar Processing Research
Institute, Inc., New Orleans, Louisiana, USA, 2M. A. Patout & Son, Ltd.,
*Current address: Sugar Research
Institute,
Dextran levels in sugarcane factories become high when cane shipments are delayed by bad weather, or when cane is frozen and thawed. Trials on addition of dextranase enzyme (made from Chaetomium gracile) at two sugarcane factories, when high levels of dextran were reported, are described. In one factory enzyme was added to the juice before lime addition. In the other factory enzyme was added at the evaporator station. Effects were measured across crystallization and in sugar. Effectiveness of enzyme in syrups traveling through pan boiling is discussed.
MICROBIAL POLYSACCHARIDES FROM SUCROSE, Margaret A. Clarke1, Earl J. Roberts1 and Per J. Garegg2 , 1Sugar Processing Research Institute, Inc., New Orleans, Louisiana, USA, 2Stockholm University, Stockholm, Sweden
Polyfructose, a polymer of fructose made from sucrose by Bacillus polymyxa, has been prepared from pure sucrose, and from sucrose in sugarbeet and sugarcane juices, syrups and molasses (Clarke, M. A., A. V. Bailey, E. J. Roberts, and W. S. Tsang. 1991. Polyfructose: a new microbial polysaccharide. pp. 169-182. In Carbohydrates as Organic Raw Materials, ed. F. W. Lichtenthaler, VCH, Weinheim. 367 pp.). Polyfructose is a β→(2→6) linked polymer of fructose, with up to 12% branching at β→(1→2) branch points, with molecular weight about 2 million Daltons. Hydrolysis products of the high molecular weight compound have been prepared and studied. Preparative methods for these fractions are compared. Properties of modified fractions are reported, and applications for these, with emphasis on food processing applications, are discussed.
NEAR INFRARED (NIR) ROUTINE ANALYSIS OF SUGARCANE JUIES, Margaret A. Clarke1, Benjamin L. Legendre2, Les A. Edye3, and Chad V. Scott4 , 1Sugar Processing Research Institute, Inc., New Orleans, Louisiana, USA, 2USDA, ARS, Houma, Louisiana, USA, 3Sugar Research Institute, Mackay, Australia, 4Georgia Gulf Corporation, Plaquemine, Louisiana, USA.
A near infrared NIRSystems Beverage Analyzer was utilized at the Juice
Quality Laboratory, Ardoyne Farm,
VERIFICATION
OF SCREENING SIEVES, Marty Cormier1 and Michel Lechasseur2
, 1Lantic Sugar Ltd., Saint-John Refinery, 2Lantic
Sugar Ltd.,
This paper describes the methods and procedures used to establish tolerances and evaluate used screen sieves.
Granulated sugar samples are passed over certified screens to establish «true» weight fractions. Sugar is retained and passed over new screens to establish standard tolerances. Tests are repeated to establish statistical confidence.
By comparing the difference in results and calculating standard deviations, acceptable tolerances are developed for each screen size. Routine Verification checks are now performed as part of the ongoing maintenance of our Quality System. Verification procedures and results are presented for review.
THE
FATE OF SOLUBLE SUGARCANE POLYSACCHARIDES IN SUGAR MANUFACTURE, Les A. Edye*, John R. Vercellotti1 and Margaret A.
Clarke1 , *Current address: Sugar Research Institute, Mackay,
Queensland, Australia, 1Sugar Processing Research Institute, Inc.,
Milling of sugarcane (Saccharum officinarum)
produces a juice which contains sucrose, other soluble material and
particulates in suspension. After
clarification and concentration by evaporation the resulting syrup contains
sucrose and most of the original soluble material (viz., polysaccharides
and other organic and inorganic compounds).
The polysaccharides in juice, syrup and sugar are a mixture of extracted
plant polysaccharides and microbial polysaccharides. Among them are starch and hemicellulose
indigenous to the cane plant and dextran and possibly
other polysaccharides derived from microbial infection of either the cane plant
during harvest or material during processing.
These polysaccharides have deleterious effects on raw sugar manufacture
and some of them persist in the raw sugar product causing problems in further
refining. Evaporator syrups, molasses
and sugar samples collected during the 1995
IMPROVED
QUANTIFICATION OF SUCROSE, GLUCOSE AND FRUCTOSE IN MULTIPLE INDUSTRIAL SUGAR
SAMPLES USING ION CHROMATOGRAPHY, Gillian Eggleston, USDA-ARS-SRRC,
Ion chromatography with integrated pulsed amperometric detection (IC-IPAD) is gaining wide acceptance as the preferred technique for analyzing sucrose, glucose and fructose in industrial sugar samples, including juices and liquors. This article describes the further optimization of IC-IPAD to more accurately and repeatedly measure the amounts of sucrose, glucose and fructose in multiple industrial sugar samples. Using either a 16 to 160mM NaOH eluent gradient or a 100mM NaOH isocratic eluent method, the integration of peak areas, internal standard calibration with forced zero, linear calibration curves are shown to be the most accurate methods of quantitation. Check standards should be used to check the calibration accuracy. Calibration standard concentration effects were found to be responsible for the less accurate quantification of oligosaccharides compared to monosaccharides, and correct concentration ranges are described. For gradient or isocratic IC-IPAD chromatographic runs, end-run washing with strong alkali eluent (for example, 200mM NaOH) was found to improve quantitation, and is necessary to remove strongly adsorbed anions. Five sugars were evaluated for their suitability as internal standards and glucosamine was found to be the best. Troubleshooting of problems that sometimes occur is discussed. Guidelines for improved quantitation of sugars are listed.
CLARIFICATION
OF MIXED JUICE FROM FRESH AND STALE SUGARCANE: INVESTIGATION OF SUGAR LOSSES
, Gillian Eggleston1, Margaret A. Clarke2 and Armand
B. Pepperman1 , 1USDA-ARS-SRRC, New Orleans, Louisiana,
USA, 2Sugar Processing Research Institute, Inc.,
Changes in levels of sucrose, glucose and fructose, across a sugarcane factory’s clarification process were investigated. The cooperating factory uses a “cold liming” process, where lime is added to the mixed juice before heating, prior to clarification. Samples of mixed, limed, heated limed and clarified juice were obtained hourly over a seven hour sampling period. This sampling period was repeated seven times across the grinding season; in the last two sampling periods the crushed cane was stale because the field cane had been subjected to freezing, then warm, weather conditions. Ion chromatography with integrated pulsed amperometric detection (IC-IPAD), an accurate sugar analysis technique, was used to measure directly sucrose, glucose and fructose levels.
For the fresh cane, color, turbidity and pH of the mixed juice improved across the season because of increasing cane maturity. Generally, color formed in the lime tank because of the alkaline degradation of glucose and fructose (invert). Very high levels of glucose and fructose (both often >7% on a °Brix basis) occurred in the mixed juice from the stale cane, as well as high levels of dextran. Glucose/fructose ratios were also higher in stale cane, because of more associated trash, which have falsely high pols and purities. Turbidity removal in the clarification tanks was worse with stale cane. The stale cane was very acidic and pH control of its mixed juice in the lime tanks was exceptionally difficult, causing acid degradation of sucrose (inversion) to occur in the tanks. pH control in the lime tanks was erratic across the grinding season and it is, therefore, highly recommended that lime should be added as lime saccharate in the future. A full statistical analysis of the data is presented and discussed.
SURVEY OF ACIDS IN FREEZE DAMAGED CANE JUICE, Mary A. Godshall1, Benjamin L. Legendre2 and Ingrid P. Buchler1 , 1Sugar Processing Research Institute, Inc., New Orleans, Louisiana, USA, 2USDA-ARS-Sugarcane Research Center, Houma, Louisiana, USA
At the end of the 1996 crop year,
IDENTIFICATION
AND MEASUREMENT OF COMPOUNDS IN THE SURFACE FILM OF WHITE BEET SUGARS, Mary A. Godshall, Ingrid P. Buchler
and Margaret A. Clarke, Sugar Processing Research Institute, Inc.,
The tendency of a white sugar to
form color on storage is an important element of quality. Previous studies at S.P.R.I. have examined
the role of high molecular weight material occluded within the crystal on color
development. Another source of potential
color-forming reactions is the syrup coating on the crystal. In this study, trace components on the
surface of representative white sugars from the
CHANGES
IN WHITE SUGARS UNDER ACCELERATED STORAGE CONDITIONS, Mary A. Godshall,
Ingrid P. Buchler, Heather G. Boyle and Margaret A.
Clarke, Sugar Processing Research Institute, Inc.,
In a previous study, a number of components, encompassing organic acids, phenolic acids and fatty acids were identified on the surface film of white beet sugars. The formation of color and the changes in these constituents over time under accelerated storage conditions were examined in a series of beet and cane white sugars. It was noted that high quality white sugars are stable for an extended period of time when stored at 55°C. The effect of various storage conditions will be discussed.
DEGRADATION
OF COLOURANTS PRESENT IN A SUGAR REFINERY EFFLUENT BY PHANEROCHAETE
CHRYSOSPORIUM, Carla Guimarães1, Luis S. M.
Bento1 and Manuel Mota2 , 1R.A.R. - Refinarias de Açúcar Reunidas, S.A., Porto, Portugal, 2Dep.
Colour in the sugar industry consists of a complex mixture of different types of colourants, the most important being: (1) phenolic compounds, coming from the cane plant, (2) caramels, which are produced by thermal degradation and condensation reactions of sugars, (3) melanoidins, formed from sugar-amino acid reactions via the Maillard reaction and (4) hexoses alkaline degradation products (HADPs). At RAR, colourants are removed, at least in part, from the sugar liquor by anion-exchange resins. The pre-regeneration of these resins is made with 50 g/l NaCl, giving rise to an effluent containing those types of colourants. This effluent presents an environmental problem due to the presence of phenolic compounds, intense colouration and high organic load (COD).
The organic load can be eliminated, at least in part, using traditional biological treatments but the compounds responsible for the intense colouration are poorly degraded by the organisms normally involved in these treatments (Ohmomo et al., 1987).
The white-rot fungus Phanerochaete chrysosporium is a potentially useful microorganism in waste treatment systems because it is able to degrade a broad spectrum of structurally diverse organic compounds. Evidence suggests that the unique ability of P. chrysosporium to degrade those compounds is mainly due to the lignin degrading enzymatic system of this microorganism (Bumpus et al., 1985, Bumpus and Aust, 1987).
Previous studies made in our laboratory demonstrated that P. chrysosporium was able to degrade the phenolic compounds present in the pre-regeneration effluent. In this paper we show that P. chrysosporium is also able to degrade the other colourants existing in the effluent - caramels, melanoidins and HADPs. The involvement of the lignin degrading enzymatic system in the degradation performed by the fungus is discussed.
MICROSCOPICAL EXAMINATION OF INSOLUBLE
MATERIALS FROM SUGAR PROCESSNIG, Bruce F. Ingber1,
Insoluble materials that may be initially present or introduced during the various stages of sugar processing ultimately affect the quality of the finished product. Imaging by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDS) can assist in the identification of insoluble materials found in sugar. Samples from several types of sugars showed the usefulness of both of these techniques. Specific methods, such as centrifugation, dialysis, and filtration, were used to separate the insoluble materials from the sugar samples. The separated particles were studied microscopically by SEM and analyzed chemically by EDS to obtain elemental composition. Examples of the isolated materials included fibers, crystals, microorganisms, and plant materials. EDS analysis found silicon, calcium, phosphorus, iron, and aluminum in these particles. The combination of these techniques can provide the sugar processing industry with the means to identify sediments in sugar samples and suggest methods to alleviate them.
AB INITIO QUANTUM MECHANICS AND MOLECULAR MECHANICS STUDIES OF A SUCROSE ANALOG, Anne-Marie Kelterer1 and Alfred D. French2 , 1Institut für Physikalische and Theoretische Chemie
TU
The inherent conformational preferences of a tetrahydropyran-tetrahydrofuran analog of sucrose have been studied by HF/6-31G* energy minimizations over the entire range of possible orientations about the bonds of the glycosidic linkage. Mimima and saddle points have been further optimized at the MP2/6-31G* level. Although the geometry is substantially improved with these much more expensive calculations, the relative energies of the stationary points are not changed much. Analyses of the electronic distribution are being carried out to learn why the O5'-C2'-O-C1 torsion angle can take a value of nearly 0 and the molecule will still have a low energy. This work supersedes previous work done over a limited range of conformational space with lower level quantum theory. The extended range has been useful in understanding the differences with the molecular mechanics studies (MM3(96)) which are localized in the region of greatest interest, i.e. where the crystalline conformations are found. As noted previously, the conformations of several compounds containing the sucrose moiety have improbably high energies, even though similar analysis of reducing disaccharides do not have similar problems. This study has also been of interest in development of more robust methods for conformational analysis because the flexible furanose ring causes some problems in producing a valid energy surface when conventional methods are used.
APPLICATION
OF MICROWAVE TECHNOLOGY IN THE SUGAR INDUSTRY: DIFFUSION AND CRYSTALLIZTION,
Li Lin, Guo Siyuan, Li Bing
and Huang Yanping, Light Industry and Chemical
Engineering Research, South China University of Technology, Guangzhou, China
On the basis of the microwave thermal effect, microwave heating
technology was used in the sugar industry to improve the diffusion and the
crystallization of sucrose. It was
illustrated in the experiments that the extraction of sugar juice can be
greatly improved by microwave owing to the good denaturation
of cane tissues, and the growth rate of sucrose crystal can also be increased
by microwave irradiation because of the modification of heat transfer and
crystal structure. The analysis time for
sucrose content in bagasse can be reduced to a
greater extent if the mixture of bagasse and the hot
water are treated with microwave.
GRAIN
SIZE DETERMINATION OF WHITE SUGARS, Xavier M. Miranda1,
Margaret A. Clarke1,
Grain size determination of white sugars is traditionally measured in a series of size-calibrated sieves. Noise generated by the sieve holders requires precautions for protection of employees’ hearing.
A new sieve
holder system (Retsch. Co.,
The calibration of crystal size fractions by Near Infrared (NIR) spectroscopy is also presented.
ON-LINE
COLOR MEASUREMENT OF RAW AND WASHED RAW CANE SUGARS, Bjarne
Chr. Nielsen1, Margaret A. Clarke2
and Luis R. S. M. Bento3 , 1Neltec
2Sugar Processing Research Institute, Inc., New Orleans, Louisiana, USA, 3R.A.R. - Refinarias de Açúcar Reunidas, S.A.
The on-line color measurement system, for color of solid sugars on a moving belt or screw conveyor, has been applied to determination of color in whole and washed (affinated) raw cane sugars. The goal is to assess the color of washed raw sugar entering the refining process.
Factors such as degree of washing, crystal size, and nature of sugar colorants in the crystal and crystal coating are considered for their effects on the measurement. Comparison is made with ICUMSA color measurement at 420 nm.
CONTROL
OF THERMOPHILIC SPORE-FORMING BACTERIA IN SUGAR PROCESS REFINING
Maria Emília
S. Pereira and Luis S. M. Bento, R.A.R. - Refinarias
de Açúcar Reunidas,
Thermophilic spore forming bacteria are of concern for sugar processing technologists. Their resistance to thermal treatments and, on the other side, the needs of customers, specially the “canners”, demand vigilance.
In this work we examine the capacity of each process unit operation, to remove these bacteria.
PRELIMINARY STUDY OF SOME SUGARCANE VARIETIES AGAINST “ROUNDUPTM” APPLICATION, Lourdes Quesada, Ulisses Osegueda and Otto Kopper, Consultores Asociados Lourdes Quesada, S.A., Genecia Agrícola e Industrial del Ingenio Hacienda Juan Viñas, Juan Viñas, Costa Rica
For five consecutive weeks, seven
different Hawaiian sugarcane varieties, of 13 months average age, were tested
in
The purpose of this study was to find out if there was a difference in the cane composition between treated and untreated cane that could affect yield in the factory. For several years, the factory had been experiencing problems with high viscosity and poor crystal recovery. The parameters chosen for analysis included polarization, reducing sugars by high performance liquid chromatography (HPLC), Brix, filter cake, mud quantity, sucrose by HPLC, dextran and starch. Cooperators from the Department of Agriculture helped to choose the field sampling sites.
EFFECT OF FLUIDIZATION ON SUCROSE CRYSTALLIZATION, Guo Siyuan, Li Lin and Zhang Xiaoping, Light Industry and Chemical Engineering Research, South China University of Technology, Guangzhou, China
Experiments were carried out in a three-phase fluidized bed. Concentration distributions of binary sucrose crystal mixtures for different operating conditions were obtained both by measuring pressure gradients and by sampling. A solid mixing (diffusion) model was developed to evaluate the solid mixing and segregation behaviors for the crystals of each size in the mixture. The results indicated that at a given liquid velocity, axial mixing extent of both larger and smaller particles increase sharply with an increase in the gas velocity, whereas decrease slightly with an increase in the liquid velocity at a given gas velocity and with increasing weight ratio.
MONITORING
BEET SUGAR EVAPORATOR SYRUP INVERT AND SUCROSE COMPOSITION BY ION
CHROMATOGRAPHY, John R. Vercellotti, Frank
Desimone and Margaret A. Clarke, Sugar Processing
Research Institute, Inc.,
Samples of beet sugar evaporator syrups were received from a sponsoring corporation in the sugarbeet processing industry to examine concentrations of sucrose and invert syrup across the six stages of their evaporators from thin juice to thick juice. Sample dilution was a particularly difficult choice to make so that replicate runs could be made to estimate both total sucrose as well as invert sugar forming across the battery of evaporator pans. In general, based on a °Brix solids dilution, a 1% solution of solids from the syrup was again diluted 1 to 100 to afford a total injection in the low parts per million range. It was found to be helpful that after an isocratic 100 mM elution of the sugars, a short 200 mM sodium hydroxide wash of the column was introduced during the gradient program. This stabilized the column separation characteristics. Day to day operation of the sugarbeet factory on the selected dates of sampling shows variations in the protocols. Although the invert sugar and sucrose are probably not exactly the same response scale or perhaps its most linear region, these data accurately log the total sugar mass balance in the concentration process. Unknown peaks in the evaporator syrups seem to follow no particular pattern during the concentration. Although only limited pol values were available for comparison, sucrose purity by ion chromatographic determination of sucrose concentration accurately reflects sucrose purity and its degradation to invert.
THE
OCCURRENCE AND ISOMERISATION OF ACONITIC ACID IN FACTORY PROCESSING
Stephen N. Walford,
Sugar Milling Research Institute,
Aconitic acid is the major non-nitrogenous acid found in cane process streams and occurs as two geometrical isomers (cis and trans). HPLC analysis reveals very little cis isomer in freshly extracted cane with levels being significantly increased toward the back-end of the factory. Isomerisation of the trans to the cis form occurs during factory unit operations (extraction, clarification, evaporation and boiling down) leading to this increase. The influence of process conditions (pH, temperature and ionic concentration) on the cis/trans isomerisation and possible practical implications will be discussed.
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