Sugar Processing Research Institute, Inc.

 

Technical Reports

 

SPRI Technical Reports are given at Board of Directors and Research Advisory and Review Committee meetings of Sugar Processing Research Institute Inc., to advise the board and committee members of the continual progress of the research for the given fiscal year. All additional technical Reports are available to sponsors technical staff for $15 US dollars each.

 

Technical Report Nr. SPRI 2001-1

Membrane Treatment of Low Purity Recovery House Streams: Potential New Products Development Using Membranes

Abstract

Membrane treatment of sugar processing streams holds great promise in reducing energy usage, reduction or elimination of chemical clarification and improved final product quality. Another promising area of application is in production of new products, such as organic sugar, or products from unusual sources in the process, such as the recovery house. The recovery house is an important area of the refinery, but one in which low purity samples are recycled back into the process to recover sugar, with the added expense of increased clarification demands and the introduction of additional impurities. A series of tests were undertaken using a Koch spiral membrane system to treat the various streams of the recovery house of a local refinery. Removal of total polysaccharides, starch, dextran, turbidity and color were noted, averaging 4 to 38% color removal, 93% turbidity removal, 73% starch removal, 63% dextran removal, and 73% total polysaccharide removal. The permeates from soft syrup (color>12,000 ICU) and affination syrup (color>20,000) were further processed into crystalline products. These "soft light" sugars, color<1000 had very pleasant aromas and appearance. The sensory characteristics of these new products are described.

 

Technical Report Nr. SPRI 2001-2

The Effects of Sulfur Dioxide in Sugar Processing Comparing Model Sucrose and Cane Juice Systems

Abstract

Sulphur dioxide (SO2) has been used for centuries to minimize color in food processing and fruit and vegetable storage. In the sugar industry, it is used routinely by sugar beet processors to reduce and prevent color formation in white refined sugar. Sugarcane processors throughout the world use SO2 to produce plantation white sugars. This study was undertaken to determine the effect of SO2 on pure sucrose solutions in comparison to real factory sugarcane juice streams. Sugar systems included 15 brix pure sucrose, clarified juice and mixed juice from a Louisiana sugarcane mill. Milk of lime was added to pH 8.0 and the pH then lowered to approximately pH 5.0 with either SO2 or HCL as the control. Samples, ranging from pH 5 to 8, were held at 85C for up to 120 min. Treated samples were analyzed for pH, residual SO2., color, calcium, and invert (used as a measure of sucrose loss).

Results indicated that the model system was much more sensitive to small levels of SO2 than real juice samples. The pH levels dropped rapidly and invert levels increased with time. There was 1.6% loss of sucrose in the SO2 trial as compared with no sucrose loss with HCL.

Clarified juice resisted changes in pH with both SO2 and HCL. Sucrose loss at 120 min of processing at pH 5.0 was minimal (0.88%) with either SO2 or HCL. There was a maximum color reduction of 10-20% in the SO2, whereas a color increase of about 7% occurred in the HCL treatment. No sucrose loss was observed with HCL.

The mixed juice was very resistant to pH changes, and a minimum pH of 5.0 was achieved with 4800 ppm SO2. No sucrose loss was observed in mixed raw juice with either SO2 or HCL even after 120 minutes. Color reduction was higher with HCL than SO2, except for the highest level of SO2, where both effected about 30% color decrease.

 

Technical Report Nr. SPRI 2001-03

Composition of the Soluble, Nondialyzable Material in Raw Cane Sugar

Abstract

The high molecular weight (HMW) material in cane sugar processing is of interest to processors because it is difficult to remove and has a tendency to be preferentially occluded in the sugar crystal, creating the potential for increased color and turbidity. The current work reports on the quantity and composition of HMW material in raw cane sugar.

The high molecular weight (HMW) material (>12,000 Da) of ten raw cane sugars from seven countries and two U.S. states was isolated by dialysis and analyzed by gel permeation chromatography (GPC). Simultaneous detection of colorant polymers and polysaccharides was accomplished by using two detectors in series: UV at 214 nm for colorant polymers and refractive index (RI) for carbohydrate polymers. The monosaccharide composition of the nondialyzable raw sugar fraction (the tenate) was determined by gas chromatography following hydrolysis. Aconitic acid was associated with the tenate. The raw sugars could be categorized into two types according to their GPC patterns and the aconitic acid content. Hydrolysis of individually collected GPC peaks demonstrated that one particular peak contained most of the aconitic acid.

 

Technical Report No. SPRI 2002-04

Commentary on HACCP in Raw Sugar Processing: Assuring Consumer Safety and Regulatory Compliance: A Look to the Future

Abstract

Hazard Analysis by Critical Control Point (HACCP) is a management tool used to ensure food safety. It is a proactive determination of potential health risks that focuses on prevention rather than after-the -fact remediation. It is an effective alternative to conventional end-point testing and response to problems after they have occurred. In the United States, HACCP systems are expected to reach the entire food spectrum within the next few years. With companies considering the production of food grade sugar at rew sugar mills, the expectation is that the principals of HACCP, along with GMPs (Good Manufacturing Practices) will be implemented in raw sugar mills. This commentary briefly reviews the principles and procedures of HACCP, some potential hazards in raw sugar manufacture and aspects of implementing a HACCP program in a sugar mill.

 

Technical Report Nr. SPRI 2002-05

Turbidity Measurement of Sugar: Comparing NTU and ICU Methods

Abstract

Turbidity is an important quality factor for white granulated sugar in many applications, especially for beverage manufacture. Most official sugar standards, such as Food Chemicals Codex (FCC), National Formulary (NF), and Codex Alimentarius, do not have a specification for turbidity. This is probably because turbidity is basically a quality parameter that is not likely to impact the health and nutritional status of sucrose. Nevertheless, sugar customers are interested in specifying reasonable turbidity standards for the products they buy. Two methods are available for turbidity measurement - nephelometry and a difference method using the ICUMSA color procedure (difference in ICU before and after filtering). Since both methods are in common use, this study was undertaken to determine if there was a correlation between the two methods. The results showed a strong correlation. Expected turbidity ranges for various types of sugars, in both ICU and NTU values, are shown.

 

Technical Report Nr. SPRI 2002-06

The Specialty Sucrose Market: A Look at an Important Niche

Abstract

The sugar industry basically has three areas for economic expansion: (1) Incremental improvements in processing that increase yield, energy efficiency, or other desirable processing parameter; (2) cogeneration and by-products, and (3) new uses of sucrose as a specialty food product or new types of specialty sugar. The first two avenues, incremental process improvements and by-products, have been covered elsewhere. The value-added specialty sucrose niche, on the other hand, has received less coverage. In recent years, "unrefined," "less refined," "natural" and organic products have developed a strong following and are growing at a rapid pace. Part of this is due to the appealing descriptions used in marketing campaigns, but a lot of the appeal also taps into the desire of many consumers to use less processed foods in their diet or to eat food products that are perceived as more environmentally friendly. This report reviews some of the sugar products on the market, the pitfalls and promise of specialty products, and some speculations as to what the future may hold.

 

Technical Report Nr. SPRI 2002-07

Effect of Macromolecules on Sugar Processing: Comparison of Cane and Beet Macromolecules

Abstract

The major macromolecules in sugar processing include colorant and polysaccharides, along with minor amounts of protein, soluble lignin, colloidal silicates and possibly calcium complexes. These high molecular weight components negatively affect sugar processing and have been implicated in the inclusion of color in crystals, formation of color on storage, processing problems, and final product quality issues, such as turbidity and acid beverage floc. It has long been accepted that the high molecular weight components are the most difficult to remove during refining. However, it is also of interest to note that the transfer of color (from syrup to crystal) is much higher in cane sugar processing than in beet sugar processing. White beet sugar, with color of 20-30 IC, can be boiled from 2000-3000 IC color syrup, but only from about 200 IC cane syrup. In chromatographically separated beet molasses extract, the color of the syrup can be as high as 5000-7000 IC and still produce a 30-50 IC sugar. What is the reason for this? This report presents recent studies that compare beet sugar and cane sugar colorant and polysaccharide. The results indicate that beet and cane colorant are fundamentally different: Beet colorant tends to be produced during processing, mainly from alkaline degradation of invert and melanoidin formation, while cane colorant enters the process in the cane juice as plant pigments associated with polysaccharide, and changes very little in process, due to the milder conditions associated with cane processing.

 

Technical Report Nr. SPRI 2002-08

A Rapid Starch Test For Use in Cane Mills

Abstract

A project entitled, "Rapid Screening Analysis for Starch in Cane Juice," was approved for additional funding to Sugar Processing Research Institute, New Orleans, Louisiana, from the American Sugar Cane League, for the 2001-2002 season. A simple, rapid, quantitative test for starch was developed and validated. The method is shown in Appendix 2 of this report. During the 2001/2002 season, SPRI personnel visited a Louisiana cane mill to use the rapid screening test on site with real-time samples. Samples were also taken back to the SPRI labs to determine the starch content by the standard starch method for comparison with the rapid test results. Results showed good correlation (>95%) between the calibration curves fo the standard method and the rapid method. The method can be used on raw juice, clarified juice and raw sugar. It is recommended to use the test on clarified juice, since the starch in clarified juice will reflect the starch content going forward in process. This can help factory personnel decide if amylase dosing is necessary. Currently, amylase enzyme is dosed continuously in most Louisiana mills. The method is simple and rapid, can be easily learned, does not use any new equipment not already on hand in most mill laboratories, and can be integrated into current laboratory practices. This study also showed the behavior of starch in the mill during the season.

The mean starch in raw mixed juice over the period studied was 1054 ppm, and in clarified juice, it was 844 ppm. This would indicate approximately 16% reduction in starch by clarification. Given the high levels of starch in the raw juice, this is not a significant decrease, and would indicate a need to continuously dose amylase enzyme.

 

Technical Report Nr. SPRI 2003-09

Comparison of Two Methods of Volatile Analysis for Determining the Causes of Off-Odors in White Beet Sugars - - SPME and Headspace.

Abstract

White beet sugars periodically have off-odors, causing them to be rejected by customers. An understanding of the nature and source of the compounds responsible will help in eventually eradicating the problems that cause them. However, determining volatile substances in white sugar is challenging because the amounts present are very small, often in the parts-per-million or even parts-per-billion range. In this study, we describe a set of white beet sugar samples that were received from several locations. Each sugar was given an over-all sensory rating of: 1 = acceptable; 2 = borderline; or 3 = reject, by a sensory panel. The samples were analyzed by two methods of volatile analysis. The two methods investigated were Solid-Phase Micro Extraction (SPME) and headspace analysis. Sample chromatograms were evaluated for compounds at mass to charge ratio (m/z) 60, where volatile fatty acids are found, with the exception of propionic acid. Representative chromatograms illustrating acceptable, borderline, and reject sugars are shown. It was found that samples in the acceptable and borderline categories appeared to have lower levels of the more volatile fatty acids than did the reject sugars. This was true for both SPME and Headspace. However, it was apparent that SPME was a better technique for volatile analysis.

 

Technical Report Nr. SPRI 2003-10

The Effect of Ozone on Off-Odors in Beet Sugar

Abstract

This study investigates ozone as a potential new polishing agent for the elimination of off-odors periodically present in beet sugars.

Ozone was directly applied to crystalline sugars to oxidize volatile compounds responsible for off-odors and various treatment times, temperatures and ozone concentrations were tested in order to determine the optimum conditions for best ozone action. Volatile off-odor compounds were extracted and analyzed using solid phase micro extraction-gas chromatography-mass spectrometry (SPMe-GC-MS). The effect of ozone on the volatile fatty acids (VFA) profile was closely monitored, since VFA have been established by SPRI and other researchers as the most significant source of off-odors and off-flavors in beet sugar.

Results showed that, depending on concentration, temperature and duration, ozone treatment could induce development of new compounds, increase some existing compounds or remove most of the volatiles from the treated sugar, eliminating all traces of off-odors (measured subjectively by sniff testing).

 

Technical Report Nr. SPRI 2006-11

STOC – Sucrose Thermal Oligosaccharide Caramel – A Potential New Use for Sucrose

Abstract

There is ongoing interest in creating new and useful products from sugar and sugar processing by-products.  An interesting category of potentially valuable products are those known as Sucrose Thermal Oligosaccharide Caramel (STOC), which can be used in animal feel, especially for poultry and pigs.  In poultry, STOC has been shown to enhance the growth of chickens and to decrease odor production in the manure of pigs.  It may also potentially reduce the amount of antibiotic required in animal feed.

In 1993 researchers at the University of Montana developed a sucrose thermal oligosaccharide caramel product (STOC) using controlled pyrolysis of sucrose (Manley-Harris and Richards, 1993).  Amorphous sucrose, heated with citric acid, was found to produce fructoglucan in 30% yield.  It functions as a feeding supplement for enhancing the growth of broiler chickens (Orban, et al., 1997) and may have applications as a low calorie bulking agent or fat substitute in food.

The process is simple, involving only two ingredients, sucrose and citric acid, which are both readily available and cheap.  The basic technology includes grinding, cooking and cooling, which can be made continuous, and lends itself to large scale production.  If the product can indeed stimulate the growth of poultry and possibly other animals and replace some antibiotics, it should be a rather high value product, probably about ten times the cost of production.

 

Technical Report Nr. SPRI 2006-12

The Potential for Sucrose Esters In Detergent Compositions

Abstract

There is ongoing interest in creating new and useful products from sugar and sugar processing by-products. An interesting category of potentially valuable products are sucrose esters.  Although sucrose esters have been known for a long time and have many commercial uses, current interest in finding new products with a more environmentally friendly profile has led to increased interest in formulating detergents with sucrose esters.

In considering the use of sucrose esters in detergents, some important questions need to be addressed:

1.                  Who already produces sucrose esters?

2.                  How to penetrate the market?

3.                  What are the competing products and/or barriers to the use of sucrose esters?

4.                  Who will be the customers?

5.                  How much will it cost? Will it be profitable?

6.                  Should we produce the ester ingredients only, or get into the detergent and cosmetics business?

This report will give a brief overview of sucrose esters in detergents and their potential as detergent components.

Sucrose esters fall into the category of non-ionic surfactants.  Today, use of non-ionic compounds is increasing because ionic surfactants (cationic or anionic) can form complexes with various ions (iron, calcium) that can adversely affect performance.  Non-ionic surfactants are especially valuable in food production.  Sucrose esters have been shown to make excellent detergent materials.  There is no doubt that there is an expanding market for sucrose esters in the areas of food, cosmetics and detergents.  One must always keep in mind that China appears to be growing this segment.

Firms are looking for ways to enhance their premium products and looking to adapt their cleaning chemistries to less expensive products that can be sold in the developing world.  The laundry detergent business is slow growing, but it is still a lucrative ingredient market. Many textile care successes are from developing markets.  However, consumers in developing countries often can’t afford brands that contain premium ingredients.  Consequently, detergent markers are working to modify their formulas for sale in the developing world.

Proctor & Gamble, for example, developed P&G’s Tide Clean White, a Chinese brand that went through a unique development regime.  The process started with market research, which revealed that some of the ingredients used in conventional P&G products were not adding value in China, only expenses.  The company found out that the Chinese consumer wants basic cleaning.  As a result, P&G removed unnecessary ingredients and rebalanced the remaining ingredients and added ingredients the Chinese valued, including more brightener and a perfume system designed for Chinese preferences. (C&EN, 2005)

 

Technical Report Nr. SPRI 2006-13

Reduction of Lime Usage with Cationic Aluminum Coagulants in Juice Clarification

Abstract – Report to the American Sugar Cane League

This report is in reference to a Research Proposal made to the American Sugar Cane League by Sugar Processing Research in January 2005, which was funded for research during the 2005/2006 grinding season.

SPRI work on the potential of cationic aluminum coagulants in cane juice clarification has been ongoing since 2004, and is part of a larger research effort by SPRI to examine ways to improve clarification.  Earlier studies had looked at the effects of using dolomitic limestone and magnesium compounds as well as admixtures with soda ash in clarification.  Preliminary experiments treating raw cane juice with polyaluminum coagulants (PAC) on a bench scale in the laboratories of Sugar Processing Research Institute have shown a great deal of promise in the removal of Color, Turbidity and Polysaccharides.  During the course of the bench scale investigations in 2004, we noted that aluminum alone significantly removed turbidity, color and polysaccharides from the juice, leading to a proposal to investigate polyaluminum coagulants (PAC) as a means to decrease lime usage in the mill.

Background

Aluminum-based compounds are used to purify water to remove color and sediment in waster water from other industries.  Aluminum compounds are used to remove organics, phosphate, color, iron and suspended particles from water.  Aluminum sulfate and polyaluminum chloride (PAC) are the primary chemicals used to treat drinking water.  Aluminum sulfate is used in the yeast industry to remove phosphate and color from molasses waste water after fermentation, to make it acceptable for discharge into waterways.  Aluminum oxides are scavengers of phosphate and silicate.  There are reports of the ability of aluminum to remove arsenic and fluoride from groundwater.  Aluminum chlorohydrate is used around the world as an alternative to lead clarification in polarization of sugar solutions.

Use of aluminum is sugar processing is not widespread.  A report on the potential of aluminum compounds for raw sugar decolorizing was published in 1999.  A 1999 patent described the use of PAC to decolorize sugars solutions, sugar alcohols and betaine.  It was recently reported that PAC has been used in Brazil at the level of 400-800 ppm to produce direct consumption white sugar to avoid sulfitation and also in India for the same purpose at the level of 1000 ppm.

 

Technical Report Nr. SPRI 2006-14

Isolation of Proanthocyanidins and Other Antioxidants from Cane Juice

Abstract – Report to the American Sugar Cane League

Interest in phenolics in food has increased greatly because of their antioxidant and free radical scavenging abilities, which contribute a number of health benefits in the diet, including anti-cancer and cholesterol-lowing functions.  The food supplement industry has taken note of research showing the content of beneficial phenolic compounds in various agricultural products and sells extracts containing these.  Among the most sought after ingredients are those with antioxidant properties, in particular, the proanthocyanidins and condensed tannins.

The cane plant contains several polyphenolic compounds which have been identified as antioxidants.  Proanthocyanidins, also known as condensed tannins, are a class of compounds with a high antioxidant value.  These compounds are identified by their conversion to red pigments (anthocyanidins) when treated with heat and acid.  Work at Sugar Processing Research showed that sugarcane juice from several varieties contain significant quantities of these types of compounds.  SPRI developed a simple method for extracting a deep red anthocyanidin pigment from variety CP72-370 cane juice.

In this study, we measured the antioxidant strength of cane juice from nine cane varieties using the RandOx Total Antioxidant Status test kit.  We also measured the production of anthocyanidins in the juice of nine cane varieties.  The anthocyanidins are developed when the cane juice pH is adjusted to 3.2 - 3.5 and heated briefly to about 70-80ēC, causing hydrolysis of the condensed tannins.

 

Technical Report Nr. SPRI 2007-15

Laboratory Studies on the Effect of Enzymes on Color, Turbidity and Total Polysaccharides in Sugarbeet and Sugarcane Juice

Abstract

Control of color, turbidity and polysaccharides is important in sugarbeet and sugarcane processing.  Controlling these parameters as early as possible in the process will provide benefits to the manufacturer in terms of lowered use of processing aids, improved filtration, better sugar recovery, and higher quality products.  Twenty-eight commercial enzymes with targeted functionalities were examined for their ability to reduce color, turbidity and/or polysaccharides in raw beet and raw cane juice.  Juices were treated with 500 ppm enzyme for 30 min at 50° C and monitored for reduction of color, turbidity and total polysaccharide content.  For beet juice, enzymes with hemicellulase, pectinase, xylanase, and glucanase activity removed significant color or polysaccharide.  For cane juice, enzymes with hemicellulase, cellulase, xylanase, and glucosidase activity were the most effective.  Several enzymes also decreased turbidity.

 

Technical Report Nr. SPRI 2010-16

Floc Prediction in Refined White Cane Sugar: The SPRI Rapid Floc Test

Abstract

As a result of research conducted by SPRI, a rapid test to predict floc formation in refined white cane sugar has been developed.  The test is based on the association SPRI has discovered between an absorbance ratio (AR) and floc potential.  Numerous refined white cane sugars have been tested in our laboratory and a strong correlation exists between the AR ratio and the currently used 10-day floc prediction test.  A white sugar solution is prepared and filtered to remove turbidity.  The absorbance is measured at two different pH levels.  The ratio of the absorbances is known as the Absorbance Ratio (AR).  SPRI has studied many quality parameters of white sugar such as pH, color, turbidity, and total polysaccharide but AR seems to be the quality parameter which correlates best to the floccing potential of the sugar.