A Look at the Relationship between Sugar Color and Grain Size

Marianne McKee, Ronnie Triche, Mary An Godshall, and Charley Richard, Sugar Processing Research Institute, Inc., New Orleans, LA, USA

                            ABSTRACT

Color is an important parameter indicating sugar quality.  SPRI has a long history in the examination of color of various types of sugar products.  It has shown that color of raw sugar changes over time during storage both in laboratory conditions as well as storage in the warehouse.  The objective of this study is to illustrate the importance of grain size in production of high quality raw sugar with good “storability.” Several raw sugars were collected from raw sugar factories and stored under laboratory conditions.  In this study of color during raw sugar storage, it was found that raw sugars with visually smaller crystals had a tendency to increase in color over time at a faster rate than sugars with larger crystals.  Additionally, it was observed that raw sugars with higher initial colors increased in color more than lower color raw sugars with identical storage conditions.  The sugars were also separated using a series to determine the grain size distribution of the raw sugars.  Various quality parameters were measured for the whole raw sugar as well as the various grain size portions of the sample.  Color increases in the raw sugar samples as grain size decreases.  Color over time, turbidity, ash, and starch in relation to grain size will also be discussed.  

Abstract for an oral presentation at the ASSCT – 42^nd Annual Joint Meeting, St. Pete Beach, FL on June 20-22, 2012 at the St. Pete Beach, FL, USA

Post-harvest Deterioration of Sugarcane

S. Solomon 

Received: 3 February, 2009; Accepted: 10 May, 2009

ABSTRACT

Sugarcane is a perishable commodity and must be processed into sugar quickly after it is harvested. Post harvest sucrose losses have been reported  from many cane producing countries and linked with low sugar recovery and several problems during sugar processing. Bio deterioration is associated with the inordinate delays between harvest to milling of sugarcane and aggravated by many intrinsic and extrinsic factors causing enormous depreciation in cane tonnage as well as sugar recovery. Besides harvest-to-mill delays, other factors such as ambient temperature, humidity, cane variety, period of storage, activities of invertases, maturity status etc. are responsible for decline in sugar recovery. The activity of invertases and proliferation of acid, ethanol and polysaccharides (dextran) producing microbes play a crucial role in the loss of recoverable sugars in cane and milled juice. In addition to loss in sugar recovery, its adverse affects has been noticed in the sugar manufacturing process and sucrose quality. Efforts have been made to reduce loss in tonnage and sucrose using physico-chemical methods. These include spraying of water, bactericidal solution, use of anti-inversion and anti-bacterial formulations and pre-harvest foliar and soil  application of zinc and mangnous compounds. An integrated mill sanitation program and simultaneous use of dextranase could further improve sugar recovery and minimize problems caused by dextran. The possibility of  electrolyzed water (EW) fogging  to reduce post harvest deterioration in field and mill yard has also been explored. Some of these methods are useful and present larger  options for the industry to minimize after-harvest quality losses in the field and milling tandem. 

Keywords  Post-harvest deterioration, acid invertase, dextran, commercial cane sugar, biocides, field control, dextranase