ABSTRACTS FOR SPRI 2000 CONFERENCE
ON
SUGAR PROCESSING RESEARCH
Porto, Portugal
New Ways to Valorize Sugar-Beet Pulp
Jean-Francois Thibault (Winner of the S.P.R.I. Science Award)
Unite de Recherche sur les Polysaccharides, INRA Nantes, France
Beet pulp is very abundant in Europe, and its valorization is an extremely important challenge for European agriculture. New ways of use have been proposed, either for the whole pulp or for some of its constituents.
Numerous studies have been devoted to the production of dietary fiber. Some treatments, e.g., autoclaving and extrusion cooking, have been used to modify the physicochemical properties of the fiber and to improve its potential in human nutrition. Beet pulp has also been proposed as a natural ion-exchanger for pollution control due to its high binding capacity for metal cations such as copper, cadmium and lead. This property is due to the presence of pectins in the pulp.
Pectins in beet pulp have poor gelling properties compared to apple or citrus pectins. It has been shown that the beet pectins bear some ferulic acid, and this structural feature can be used to produce chemical gels through oxidative coupling of the feruloyl groups. This result offers a third way (after the calcium gel for LM-pectins, and sucrose-acid gel for the HM-pectins) for the gelation of pectins, which is specific for the beet pectins. The resulting cross-linked pectins have remarkable water-holding properties, which are likely to be used in some non-food applications.
The presence of ferulic acid as a constituent of the pectins has led also to the original idea of producing "natural vanillin from sugar-beet pulp. Indeed, ferulic acid is a precursor of vanillin; the use of (safe, natural) enzymes to free the ferulic acid and of (safe, natural) microorganisms to biotransform this natural ferulic acid will produce "natural vanillin. To achieve this goal, the fine structure of the side-chains bearing the ferulic acid, the search for new enzymes able to liberate the ferulic acid, and the screening of microorganisms to produce vanilhin have been extensively studied, with very promising results.
The removal of pectins leaves a residue which is particularly enriched in cellulose. The esterification of the cellulose with fatty acids as well as the production of cellobiose by (controlled) enzymatic conversion of the residue have been investigated. It is therefore possible to produce cellulosic biodegradable films for food or non-food applications and cellobiose which may be used in some bioconversions, for example, to channel the transformation of ferulic acid into vanillin.
All these ways to add value may provide an integrated use of the pulp for different applications.
Vision 2020: How Green Chemistry Can Shape the Future of the Sugar Processing Industry
Robin D. Rogers, Department of Chemistry and Center for Green Manufacturing, University of Alabama, Tuscaloosa, AL
One of society's biggest challenges as we enter the new millennium, is the elimination of industrial pollution. It is incumbent upon the research community to explore the inherent benefits of alternative industrial technologies which could reduce the associated environmental and human health and safety concerns that accompany exposure to industrial pollution and which could lead to sustainable industrial practice. In a joint effort known as Vision 2020, staff members from the American Chemical Society, the Chemical Manufacturer's Association, the American Institute of Chemical Engineers, the Council for Chemical Research, and the Synthetic Organic Chemical Manufacturer's Association concluded "that growth and competitive advantage of our industry depend upon individual and collaborative efforts of industry, government, and academe to improve the nation's R&D enterprise. One of the goals listed in the report from this group, Technology Vision 2020: The US. Chemical Industry, is to "enable the (chemical) industry to continue to lead in technology development, manufacturing and profitability, while optimizing health and safety and ensuring environmental stewardship.
In order to develop a comprehensive international agenda for pollution prevention in industry, we must change the way people think about industrial processes. Green chemistry, engineering and technology must be integrated into the science and education curriculum at all levels of education so that students are exposed to the problems and can learn how to approach solving them. This presentation will discuss the concepts of the new paradigm of Green Chemistry, the role of chemists in sustainable industry, and the impact on the sugar processing industry. Aspects of the chemical and agricultural industries which will play major roles in future sustainable technologies will be highlighted.
Highlights of Twentieth Century Progress in Sugar Technology and the Prospects for the Twenty-First Century
Prof. Mohamed Mathlouthi, Laboratoire de Chimie Physique Industrielle, Faculté des Sciences, Universitê de Reims
Champagne-Ardenne, Reims France.
Enormous progress m sugar technology was made during the twentieth century. The trends in the development of the main steps (extraction, purification, concentration, crystallization) of sugar processing were the transition from batch to continuous processes, lime reduction, energy saving, automation and the use of computerized digital control. This evolution came with an increase in factory capacity, a decrease in manpower and resulted in higher profitability. Although unit operations (diffusion, separation, evaporation, crystallization) are comparable for cane and beet sugar manufactures, differences that are far from negligible remain between the two industries. These differences are mainly due to the diversity of composition of the non - sugar fraction extracted from the two plants.
Taking advantage of the rapid evolution of analytical methods, it was possible to investigate the nature and the structure of sugars, and non - sugars in sugar crops, processing, and products. Noteworthy is the advance in the knowledge of the polysaccharides from the sugar cane plant, from beet or from microbial origin and their effects in processing. This topic together with that of colour and colorants of high molecular weight which contribute to white sugar colour were extensively studied these last years.
Mastering sugar processing in the twenty-first century will require the continuation of exploration of the different reactions and processes at the molecular level. Determination of the properties of sugars, oligosaccharides, polysaccharides, colorants and other constituents such as their interactions with water (hydrophobicity, hydrophilicity), their structure, and their volume and surface characteristics in technical sugar solutions should allow control of operations devoted to their separation.
Methods of separation such as membrane technologies, chromatographic and ion exchange processes can then be optimized at the industrial level. Crystallization approached at a molecular level using the cooling procedure coupled with other separation techniques should lead to increased efficiency, low cost, environmentally compatible sugar processing.
After a rapid review of the progress accomplished in twentieth century sugar processing, we will detail the recent results on polysaccharides and colorants and their role in white sugar quality. As prospects for the twenty-first century, we envision that a molecular approach of the different steps of sugar processing should help in bringing further improvements.
Biotechnology and the North American Beet Sugar Industry
Thomas K. Schwartz, Executive Vice President, Beet Sugar Development Foundation, Denver, CO.
Biotechnology and the introduction of genetically enhanced varieties of agricultural crops have been topics of heated discussions this past year, not only in North America, but worldwide. For many years, plant breeders have worked to enhance and breed varieties that are adapted to specific conditions. These enhancements have been in such areas as pest resistance, yield enhancement, quality improvement, processing quality and a variety of other characteristics. Traditional tools of plant breeding required considerable time and labor. With the introduction of biotechnology, this time and labor requirement was able to be reduced significantly.
This paper will discuss the current state of biotechnology and genetic enhancement in the beet sugar industry in North America. It will also look toward the future and outline the areas that are currently under research and development through the use of biotechnology. It will concentrate on the scientific aspects of the subject, and where necessary, relate to the negative controversy, which has recently surrounded this issue.
New Approaches to Crystallization Theories
Pascal Cbristodoulou, Technical Director, Hellenic Sugar Industry, Thessaloniki, Greece
Two fundamental crystallization theories are briefly described: The theory of the adsorption layer, which deals with the crystal surface; and the diffusion theory, which mainly considers phenomena occurring at the crystal solution interface. Another approach is proposed based on the chaos and complexity theory. This approach is briefly outlined.
The chaos and complexity theory deals with the nonreversible thermodynamics of the conditions apart from equilibrium. It is correlated also with the concept of entropy, which, being a measure of disorder and uncertainty, becomes the cause for creation of new patterns of mass and energy dissipation. These are called "dissipative structures from the 1977 Nobel laureate Ilya Prigogine. Apart from the different levels of concentration, viscosity, temperature, pressure, supersaturation, etc., of the mother liquor, there are also the different impurities which influence sucrose crystal growth morphology, modifying the habit of the crystals. In the same strike, it is highly improbable that one crystal of sugar examined in atomic scale will be identical with another. It has been stated that no snowflake can be identical with another. The same seems to be valid for sugar crystals. After drying, sugar crystals are in equilibrium with the environment, but they bear in their surfaces, examined under an electron microscope, with dislocations and other irregularities of their crystal lattice, the irreversibilities of their growth. The sugar crystal is an "equilibrium structure but bears on its surface and on its inner structure the fingerprints, the history of a "dissipative process. The sugar crystal is a frozen, crystallized irreversible "dissipative structure.
An Innovative Process for White Sugar Production
Dr. Da Wei Gao, Research Scientist, and Dr. Y.G. Min, Visiting Scholar, Sugar Processing Research Institute, Inc., New Orleans, Louisiana.
In the production of cane refined sugar, starting with raw sugar of color ranging from 1500-6000 ICU, many unit processes are required to produce a sugar with 30-50 ICUMSA color. This is in contrast to the situation found in beet sugar processing where beet white sugar of 20-30 color can be directly boiled from a standard feed liquor color of 3000. This paper describes a method for pretreating colored sugar solutions to produce food grade white sugar with color ranging from 85 to 300 ICUMSA color, tailored to the needs of specific markets.
Process Design Criteria for a Modern Sugar Refinery
Dr. Chung C. Chou, Managing Director, Sugar Processing Research Institute, Inc., New Orleans, LA, and Mr. Chien-nan Chiu, Taiwan Sugar Corporation, Taipei, Taiwan
For a modern refinery to meet the challenges of the 21 ~ Century, certain design criteria must be met. The new refinery should be designed with five critical elements in mind: Minimal manning capacity of no more than four operators per shift (not including the packaging department); no more than 0.5 5% sucrose loss on raw sugar received; a total energy consumption of less than 75 liters of No. 6 oil per ton of raw sugar processed; input raw sugar pol averaging 98.3, with a lower limit of 97.5 pol; and sucrose carried to molasses not to exceed 1% of sucrose in raw sugar processed, assuming minimum sale of lower purity food products, e.g., brown sugar.
Numerous plant design requirements are needed in order to achieve the above critical elements, since there are over 25 points in the refining process where control points and critical limits must be specified for parameters such as temperature, pH, density, color, turbidity, conductivity, purity, vacuum pressure, etc. The use of on-line continuous testing instrumentation is an important aspect of control. The recommended design criteria for each refinery process will be discussed.
Electrodialysis in the Sugar Industry as a Purification Technology
Dr. Florence Lutin, Eurodia Industrie, S.A., Wissous, France
Thanks to improvements in both anion exchange membrane structures and electrodialysis stack design, electrodialysis can be considered one of the technologies which can contribute on a cost effective basis to:
Operating results of a commercial plant in Europe after four years operation are presented with detailed material balance. A sugar juice at 12 or 24 Brix is demineralized with 12 stacks arranged in three parallel lines, thus achieving 50% conductivity reduction. Sugar losses are less than 0.5% of sugar production. Electrical consumption is 1.1 KWH/rn3 for ion transport and pumping. CIP consumes only 0.045 L/m3 HCL 4%~ and 0.001 L/m3 NaOH 4%. The capital cost for a capacity of 40 m3/h is 1,700,000 Euro, with membrane replacement lower than 3,000 Euro/m3/year. In that mill, the customer has been able to double capacity of the demineralization plant, keeping pollution load at the same level, due to regeneration of ion exchange.
Studies on Phanerochaete chrysosporium Immobilization for Continuous Treatment of Ion Exchange Resin Effluent
Carla Guimaraes, RAR - Refmarias de Açücar Reunidas, S.A., Porto, Portugal
Adhesion of Phanerochaete chrysosporium to various solid carriers -- polyurethane foam, nylon web (Scotch-Brite'M), foam glass (Poraver~), polypropylene Rashig rings, and stainless steel Rashig rings -- were studied. The ability of the immobilized cultures to treat the effluent resulting from ion exchange resins regeneration was evaluated.
Processing of Frost Damaged Beets at CSM and the Use of Dextranase
Dr. Jan Maartin de Bruijn, CSM Suiker by, Centraal Laboratorium, Breda, The Netherlands.
The 1998 sugar beet campaign in the Netherlands suffered from severe weather conditions; i.e. subsequent periods of plentifi.il rainfall, frost and thaw. Thus, the harvest and processing quality of the beets became troublesome, which affected the processing capacity of the sugar factories. This paper will focus on the processing of frost respectively thawed beets.
A high-performance liquid chromatography method (HPAEC-PAD) was rapidly developed in order to monitor the degree of deterioration of the frost damaged beets. Both the invert sugar and dextran level were analyzed daily in raw juice samples. About 10 days after the outdoor temperature came again above 00C, the concentration of both sugar types sharply increased, thus causing processing problems.
Even at relative low levels of dextran in raw juice (i.e. 75 mg/l), the filtration rate of the 2nd carbonation slurry dropped markedly and, consequently, the slicing capacity decreased to 50%. The dosage of 10 ppm dextranase NOVO 50L enzyme to the extraction appeared to be sufficient to restore the slicing capacity to 90% of the nominal capacity.
In fact, it was the high level of invert sugar in thawed beets (up to 4 g/l in raw juice!) which made the processing of this low-quality beet material most uneconomic. The high invert sugar content consumed (in juice purification) a lot of alkalinity, which could only be compensated by the addition of excessive amounts of caustic soda. Nevertheless, both the juice quality became very moderate (e.g. low juice purity, high lime salts content, high juice as well as sugar color) and the amount of sugar that ended up in the molasses reached an unacceptably high level.
Good Laboratory Practice and Laboratory Certification
Dr. Scott Spear, Research Chemist, and Mary An Godshall, Senior Scientist, Sugar Processing
Research Institute, Inc., New Orleans, LA
How does a user of laboratory service know when he or she is receiving high quality testing services? Should the customer/client simply assume that the quality of laboratory services is adequate? Laboratories can be certified by a governmental agency or accredited by a professional organization, but is this enough to have confidence in the laboratory? Guidelines on good laboratory practice are available, and the laboratory should be able to demonstrate and document their procedures as well as to explain how the accuracy and reproducibility of methods was established. The American Chemical Society has developed 10 principles for good laboratory practice and these will be presented, along with discussions about proficiency testing and the guidelines that have been adopted for assessing the competence of testing laboratories.
An R&D laboratory should subscribe to the same quality criteria as a commercial laboratory because the results of research, when published in the literature, are used by others for further work. The credibility of an R&D lab depends on its adherence to demonstrated good laboratory practices.
The Nature of Colorant
Mary An Godshall, Senior Scientist, and Dr. Chung C. Chou, Managing Director, Sugar Processing Research Institute, Inc., New Orleans, LA; and Dorrit Baunsgaard, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark
Much is known about the nature of cane and beet sugar colorant, but in recent years, the thinking about colorant has shifted. The goal of sugar refining has always been to remove color. The goal of much research on colorant has been to characterize it fully and understand its nature. However, it is also noted that color, per se, is not the only criterion for occlusion (transfer) of color into crystals, as shown by observations that a beet standard liquor (thick juice) of 2000- 3000 ICUMSA color can produce a 20-3 0 white sugar; however, cane final syrup color must be in the range of 200-3 00 to produce a white sugar of similar quality. Obviously, the color of most interest is that which transfers into the crystal; color that does not transfer into crystal is not a problem and therefore of less interest.
This paper will attempt to postulate factors in cane and beet sugar colorant that affect transfer of color into the sugar crystal, including studies that show the influence of turbidity, polysaccharides, and high molecular weight content. The nature of various colorants using fluorescent profiles will be demonstrated.
Analysis of Fluorescent Colorants and Color Precursors in Cane Sugar Manufacture Using Spectrofluorometry and Multivariate Data Analysis
Dorrit Baunsgaard, Lars Nørgaard and Mary An Godshall
The Royal Veterinary and Agricultural University Chemometrics Group, Food Technology, Department of Dairy and Food Science Frederiksberg C, Denmark: Sugar Processing Research Institute, Inc., New Orleans, Louisiana
It has been known for many years that cane sugars exhibit characteristic fluorescence, which can be used to obtain information about minor impurities in the sugar. Potential fluorophores include color precursors such as amino acids and polyphenolic compounds. Colorants formed during processing, such as the Maillard reaction products, also show fluorescent properties.
The best way to analyze complex samples using fluorescence is to measure several emission spectra at different excitation wavelengths, thus creating an excitation-emission landscape that covers the total area of fluorescence. The presentation of data in a landscape format is a good way to visualize the fluorescence characteristics of a sample, but it may be difficult to unravel the individual fluorophores. Chemometric analyses of fluorescence landscapes are therefore used to extract individual fluorophores from the fluorescence data.
In a similar approach, we have undertaken to study the fluorescence from cane sugar samples using chemometric analyses. In a fluorescence study of 47 raw cane sugar samples representing a varied selection, two-way and three-way chemometric models were used to extract the principal fluorophores that may be found in cane sugar. In another project we used fluorescence landscapes measured on model colorants to identify the fluorescent profiles of components associated with specific kinds of colorants formed by sugar degradation and Maillard reactions. The fluorophores resolved from the model colorant fluorescence are then compared to fluorophores resolved similarly from cane and beet sugar process samples.
Role of Invert in Processing (Color Formation), Part I
Dr. Linda Andrews, Research Scientist, Dr. Chung C. Chou, Managing Director, and Sara Moore, Research Technician, Sugar Processing Research Institute, Inc., New Orleans, LA
During evaporation processes in raw sugar manufacturing, chemical changes occur that affect sugar yield and color quality, mainly sucrose loss, invert gain, and invert loss correlated with color gain. Part I of these experiments was to examine sucrose conversion to invert sugar correlated with changes in color. A pure 65 Brixsucrose solution (99.99%) was treated with invert sugar levels ranging from 0-2.0% and adjusted to pH ranging from 7.0-9.0 and incubated at 85 0C for 0-6 hrs. A pure 15 Brix sucrose solution was treated with 0 and 1.0 % invert adjusted to pH 6.0, 7.5, and 9.0 then incubated at 800C for 0-6 hrs. Following incubation, samples were analyzed for color (IC), final pH, and residual invert (by HPIC).
At 65 Brix and pH below 7.5, there was no change in color but samples showed as much as a 25 % increase in invert sugars. At pH 8.0, there was no change in color or conversion of sucrose to invert sugars. (Sucrose is most stable at pH 8.2). At pH 8.5 and higher, there was rapid color increase in direct correlation with a reduction of residual invert. The glucose/fructose ratio increased from 1.0 with time of incubation. At 15 Brix and 1.0% invert, color changes were less pronounced but correlated with invert gain and loss at varying pH similar to the previous experiment. Initially sucrose is broken down by acid hydrolysis to D-glucose and D-fructose. Fructose is further converted to color compounds during thermal and alkaline degradation and condensation, with less loss in glucose. The color changes described here are unrelated to Maillard reactions or enzymatic browning of polyphenols, which further complicate color formation.
Parry Model for Recovery Estimation
Dr. P. Kotteeswaran, Parry Sugarcane R&D Centre, Tamil Nadu, India, and Dr. M. Krishnamurthi, Vice President., Mitr Phol Sugarcane Research Centre, Chaiyaphum, Thailand
The performance of different sugarcane varieties was analyzed, and based on the analytical data and the percentage of different varieties scheduled to be crushed, the recovery percent was forecasted every month during the season. A model has been worked out based on the estimated recovery and the actual recovery recorded every month, in order to narrow down the deviation between the estimated and actual recovery percent.
Cane Diffusion -- an Energy Efficient Way for Juice Extraction
M. Narendranath
Andhra Sugars, Tanuku, India
A milling tandem needs a tremendous amount of energy to extract juice from sugarcane. As part of extracted juice is reabsorbed by the bagasse, the energy applied for that portion of the juice is wasted. Moreover, mills are heavy and very expensive, both on purchase price and cost of operation and maintenance. A certain portion of juice contained in the cane cannot be extracted by pressure alone. The diffusion process is the most energy efficient way to extract juice. Cane diffusion is well established as a cost effective alternative to milling.
Effect of Clarification of Sugar Solution by Ultrafiltration on Crystallization of Sucrose
Shiro Kishihara, Kobe University, Kobe, Japan, and Satoshi Fujii, Kobe Gakuinn Women's Junior College, Kobe, Japan
Sugar crystallization is a principal process in sugar manufacturing, and sugar recovery through crystallization and quality of the sugar greatly depend on the kind and the quantity of impurities contained in the sugar solution. It is known that invert sugar and inorganic salts in the sugar solution hinder the crystallization of sucrose and increase the volume of molasses. However, it has hardly been reported how high molecular weight impurities (JIM) in the sugar solution affect the crystallization. Ultrafiltration (UF) is validly applicable to eliminate HM, although the elimination through the traditional clarification gets into trouble. The effect of clarification of sugar solutions by UF on crystallization of sucrose was studied. Also discussed is how UF improves the physical properties of the sugar solution, which influences the handling of pan boiling.
Sugar samples tested were an Australian raw sugar (Raw sugar A), an Australian high pol sugar (HP sugar A) and a Thailand high pol sugar (HP sugar T). UF was performed through a membrane with molecular weight cut-off of 100,000.
Sugar concentration (brix) in the mother liquors after crystallization of sucrose from the UF permeates of the three sample sugar solutions was smaller by 0.2~0.30 than that from the respective sugar solutions before UF. This fact implies that a larger amount of sucrose can be recovered from the permeates by crystallization. The brix in the mother liquor after crystallization from the UF permeate (purity 98.3) of Raw sugar A was smaller than that from HP sugar A (purity of 99.3) before UF. This observation suggests that HM might hinder the crystallization of sucrose. By crystallization tests from an artificial sugar solution, which is sucrose solution with added JIM, it was confirmed that HM has a hindering effect on crystallization. Through further crystallization tests using artificial sugar solutions with added invert sugar and KC1 as impurities, it was revealed that HM, rather than these two impurities, hindered more heavily the crystallization of sucrose.
Viscoelasticity of Raw sugar A solution was improved by UF; that is, viscosity and loss (viscous) modulus of viscoelasticity of the permeate were smaller than those of the sugar solution before UF. In crystallization from the permeate, it can be supposed that the massecuite in a boiling pan is more thoroughly stirred and crystallization of sucrose is accelerated. Surface tension of Raw sugar A solution became larger after UF, which demonstrated that surface active substances were eliminated. From this fact it can be supposed that foaming during pan boiling is depressed. Through the improvement of the physical properties (viscoelasticity and surface tension) of sugar solutions, it is expected that the handling of pan boiling may become easier, and the boiling time may be shortened.
Progress in Improving the Standards of Analysis in Factory Laboratories
Dr. Richard Simpson, Sugar Milling Research Institute, Durban, South Africa
The laboratories of the Sugar Milling Research Institute (SMRI) have the responsibility of maintaining and improving the standard of the analytical work within the SMRI itself and the South African sugar industry. This is achieved through the following:
The paper describes how the above is carried out and comments on the progress that has been made in the South African industry.
Overview of the Development and Application of Near Infrared Spectroscopy at American Crystal Sugar Company
Beverly J. Jacobson, Joseph H. Wallevand, Terry D. McGillivray and C. Gary Fischer, American Crystal Sugar Co., Moorhead, MN
This presentation describes the use of Near Infrared Spectroscopy (NIR) at American Crystal Sugar Company. It describes the use of on-line NIR in our molasses desugarization facility to determine sucrose, RDS, betaine, and solution absorbance. Our experience with implementation of AOTF technology is described. The development of calibrations for factory juices with both scanning and AOTF benchtop instruments is discussed. Experiences with transfer of the NIR technology to the factory laboratories are discussed.
Cane Juice Analysis by Near Infrared (NIR) to Determine Grower Payment
Tere Johnson, Sugar Cane Growers' Coop, Belle Glade, FL
As applications of NIR analysis are increasing in the grain and food industries, more options are becoming available for the method of analysis of incoming sugar cane in the factories. For the 1999-2000 crop season, Sugar Cane Growers Cooperative of Florida (SCGC), together with Florida Crystals Corporation, has adopted Near Infrared (NIR) spectroscopy as the standard method for cane juice analysis.
This paper will include a brief history of cane juice analysis at SCGC as it has evolved from polarization using lead clarification to polarization using NIR spectroscopy. Experiences with
data acquisition, equation development, and equation validation, necessary for implementing NIR analysis, will also be discussed.
Effect of Harvest Method and Storage Time on Sugarcane Deterioration,
Dr. Gillian Eggleston, Research Chemist/Lead Scientist, Southern Regional Research Center, USDA-ARS, New Orleans, LA; Dr. Benjamin Legendre, Research Leader, Sugarcane Research Unit, Southern Regional Research Center, USDA-ARS, Houma, LA; and Dr. Charley Richard, Vice President and Director of Research, American Sugar Cane League, Thibodaux, LA
The recent increase of billeted cane being mechanically harvested in Louisiana has often meant an increase in deteriorated cane being processed. Some of this deterioration in cane quality, i.e., the increase in associated trash (i.e. leaves, tops and field soil) is not necessarily a function of the newer harvest method, per se, but rather a function of mechanical harvesting in general. Further, there is the occurrence of sugar destruction in the cut cane between harvesting and crushing, regardless of the harvest system. There is a real need to establish new criteria for levels of deterioration in Louisiana cut cane, in order to better predict: 1) the quality of the cane to be processed and, 2) the effect on harvest methods and storage conditions.
In this study, there were eight cane supply treatments, with samples taken on each day for four consecutive days before laboratory milling. Treatments included handcut (control) green and burnt standing whole stalks taken from field plots each day. Soldier harvested burnt and green whole stalks were chosen to simulate cane from a heap or transloader stack each day. Burnt and green billeted cane were also taken to simulate cane from a billet wagon each day. Initial color for all cane treatments was associated with leaves and tops; color formed dramatically in the burnt billeted cane on storage time. Glucose and fructose were consistently greater in billeted than whole stalk cane. Dextran and oligosaccharide formation was also greater and more rapid in billeted cane than whole stalk cane, and concomitant with a decrease in pH. Billeted cane deterioration occurred earlier than in whole stalk cane, with burnt billeted cane deterioration more rapid and extensive than in green billeted cane.
Oligosaccharide formation in cane is discussed in detail, with emphasis on both kestoses (up to GF5) and dextran oligosaccharides. A full statistical analysis is described. Optimum postharvest handling conditions to minimize grower and factory losses are discussed.
Effect of Cane Quality on Sugar Processing
Mary An Godshall, Senior Scientist, Sugar Processing Research Institute, Inc., New Orleans, LA; Dr. Benjamin L. Legendre, Research Leader, Sugarcane Research Unit, U.S. Department of Agriculture, Houma, LA; Dr. Charley Richard, Vice President and Director of Research, American Sugar Cane League, Thibodaux, LA; and Ron Triche, Research Technician, Sugar Processing Research Institute, Inc., New Orleans, LA
The Louisiana sugarcane industry is in the process of switching from whole stalk harvesting (soldier harvesting) to billet harvesting (combine harvesting) and from mostly burned cane to mostly green (unburned) cane. There has been a perception that the quality of cane juice is lower when it is combine harvested, but systematic tests have not been done to determine if there are differences in cane juice quality. The research reported here is part of a larger study involving SPRI, USDA, Louisiana State University, and the Louisiana Sugar Cane League, which is intended to answer critical questions related to cane quality issues and the harvest methods used in Louisiana.
A series of experiments were designed to test the harvest method (whole stalk vs billet), green vs burned, length of time cane is left in the field after it is cut, the effects of bad weather (cold and rain), and the effect of mud and trash admixtures on cane juice quality. The results reported in this study will concentrate on color, turbidity and polysaccharides as they are affected by the various treatments.
ABSTRACTS OF POSTER PRESENTATIONS
Fractal Structures for Uniform Fluid Distribution in the Sugar Industry (Poster)
Mike Kearney and Dr. Vadim Kochergin, Amalgamated Research Inc., Twin Falls, ID
Uniformity of fluid distribution is critical for improving the efficiency of most heat and mass transfer unit operations. It is equally important for large-scale absorption and distillation columns in the petrochemical industry as well as for preparative-scale equipment in the pharmaceutical industry. For years, the sugar industry has been using distribution-sensitive processes, such as industrial chromatography, softening, decolorization, etc. The performance of such devices can be drastically improved with the introduction of new, more efficient fluid distributors. Several years ago, Amalgamated Research Inc., developed and commercialized a distributor for chromatographic applications based on fractal geometry. Such distribution devices provide completely uniform fluid scaling to any desired level within manufacturing constraints. Because of this feature, many new potential applications appear very attractive from the technological point of view. Currently we are exploring the retrofit of the existing equipment and design of new equipment, which utilizes the benefits of fractal distributors. Results demonstrating the efficiency of fractal distributors are presented. Potential new applications for the sugar industry are discussed.
Mechanical Vapor Recompression Evaporation in the Sugar Beet Industry (Poster)
James D. Pope, Lorraine Owen, Lurgi PSI, Inc., Memphis, TN, and John K. Manno, Dedert Corporation, Olympia Fields, IL
Use of evaporation on process streams is well known in the sugar beet processing factory. Multiple-effect evaporator systems operating at low pressures have worked successfully and economically in the traditional factory process, energy balance and steam generation scheme. However, recent additions to the factory steam load caused by new facilities, such as molasses desugarization (MDS) and factory capacity expansions, are taking existing boilers to maximum capacities. Mechanical recompression evaporators have been successfully applied in other industries, such as corn wet milling, as a solution to these problems. At one sugar beet factory in the Red River Valley, mechanical vapor recompression (MVR) evaporators are being installed in a new MDS facility. By using these MVRS, the potential steam consumption was reduced by approximately 30%. The electrical requirement used instead is consumed by two 1250 horsepower motors and one 900 horsepower motor on turbo-fan recompressors. In this application, the additional capital cost for the MVRs versus a multiple-effect system is economically feasible compared to the additional capital cost of new steam boilers and requirements of air emissions permitting. The application of MVRs requires an in-depth analysis of the nature and volume of the evaporative loads as well as an understanding of the configuration alternative available.
Filterability Study of Raw Sugar (Poster)
Eng. Eduardo Vianna, Gerente Industrial, Cia. Energética Santa Elisa, Sertãozinho, Brazil
Filtration problems caused by impurities in raw sugar are well known in the refining industry. Among the impurities are starch, dextran, gums, waxes, protein, phosphates, other polysaccharides and other micro-particulates, which result in turbidity. Some authorities believe that the filtration impeding effects of these matters are primarily caused by their size rather than their chemical nature.
Filterability tests were performed at the SPRI Laboratory, using a solution of various raw sugars at 55 Brix, 700C, and Celite 545 as a filtration aid. Filtration rate is defined as volume of solution collected in 35 minutes. The observed filtration rate was correlated to total polysaccharides, starch, dextran, turbidity, ash, color and pol. The results and conclusions are shown, and the most significant correlations are discussed.
The Non-sucrose Profile in Cane Sugar Mills (Poster)
Dr. Khalid Iqbal, Post Doctoral Fellow and Dr. Linda Andrews, Research Scientist, Sugar
Processing Research Institute, Inc., New Orleans, LA
The ultimate objective of sugar processing is to recover maximum sucrose from the cane entering the mills. A lot of chemical and physical changes occur in process streams during each phase of processing, which are reflected by different values of parameters. Specific effects of individual processes can reveal where sucrose is at greater risk for degradation, which could affect the quality and yield of sugar.
Samples from two Louisiana factories were evaluated during the 1999 harvest for pH, brix, purity, color, turbidity, invert, polysaccharides, cations and ash. Samples included mixed juice, clarified juice, syrup, A, B, and C sugars and A, B, and final molasses during the early, mid and late season.
The study of process stream parameters revealed a specific pattern of changes at different stages of the grinding season. The quality and purity of cane juice improved and remained constant as the cane matured and moderate weather conditions prevailed until first frost. In mixed juice, pH was observed to be fairly acidic, with normal values ranging from 5 - 6. Similarly, the levels of invert demonstrated a steady decline as the grinding season progressed. The other parameters which included color, turbidity, polysaccharides, cations, and ash demonstrated a mixed pattern of changes.
High Quality Paper Products from Bagasse (Poster)
Mr. Yang Wanshan, General Manager, Guangxi Guitang (Group) Co, Guangxi, Peoples' Republic of China
The presentation introduces the history, reality and prospect of research for paper- making from bagasse conducted by the Guangxi Guitang (Group) Co., Ltd., in China, and focuses upon Guitang's paper-making technical features and the outlook of the on-going technology studies. Wet-storage of bagasse that substantially preserves the integrity and strength of bagasse fibers and pollution control measures dealing with black liquor, bleach waste water and white water are described. Despite some unfavorable pulp properties, such as shorter fiber length, more sturdy and brittle cellulose compared with wood pulp, cultural paper and household tissue that satisfy the Class A quality standards of China have been successfully made from
bagasse stratified with a small portion of soft wood pulp and some necessary additive. Today, paper products contribute almost the equivalent industrial value to that of sugar.
Study of Sucrose Solubility and Crystallization Rate Using NMR Techniques (Poster)
Dr. Austin Schultz and Dr. Les A. Edye, Sugar Research Institute, Queensland, Australia
Sucrose solubility in molasses is indelibly linked to the study of molasses exhaustion, despite the fundamental differences between these two properties. Molasses exhaustion is the point where no appreciable quantities of sucrose can be economically recovered, whereas sucrose solubility relates to the equilibrium endpoint at which no further sucrose will crystallize. This study has examined sucrose solubility from an unconventional perspective by determining the apparent sucrose solubility under normal vacuum pan boiling conditions, and hence, under non-equilibrium conditions. Sugar boiling trials were conducted in a pilot batch vacuum pan, in which the massecuite crystal content was monitored continuously using modified low resolution NMR instrumentation. Crystal content readings were used in conjunction with mass balance data to determine the changes in sucrose solubility in relation to changes in molasses purity, impurity/water ratio, and impurity type. In addition, high resolution solid state NMR techniques have been employed to examine the microscopic interactions between sucrose, water and impurities.
Filtration of Clarified Cane Juice Using Spiral and Tubular Polymeric Membrane Configurations (Poster)
Anthony Eringis and Bruce Eaton, KOCH Membrane Systems, Inc. Wilmington, MA USA 01887
The advantages of spiral polymeric membranes for the filtration of clarified cane juice are enhanced by combining the spiral polymeric membrane system with a tubular polymeric membrane system. By processing the retentate of the spiral system with a polymeric tubular system the overall yield of this membrane filtration operation is increased. Satisfactory and consistent performance of the polymeric spiral and tubular membranes was demonstrated processing clarified cane juice at high temperatures in a sugar mill environment. This performance data from commercial scale polymeric spiral membrane systems and polymeric tubular membrane systems will be displayed.