Sugarcane, Sugar Beet, and Sweet Sorghum Processing: Similarities and Differences to Underpin Sustainable Practices

Authors: EGGLESTON, GILLIAN - LSU Agcenter; AITA, GIOVANNA - LSU Agcenter; Lima, Isabel; Bruni, Gillian; Terrell, Evan

Submitted to: Sugar Tech
Publication Type: Review Article
Publication Acceptance Date: 8/12/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Sugar and sugar products are produced primarily from three crops: sugarcane, sugar beet, and sweet sorghum. Each of these crops has some key differences related to growing, harvesting, and processing. Sugarcane and sugar beet make up the great majority of global sugar production, with sweet sorghum representing a much smaller market. Considering that global population has been increasing, with sugar demand having a corresponding increase, it is necessary to implement sustainable practices in sugar production. These include efforts for improving cultivation, processing, product development, packaging, and waste or by-product utilization. This review paper highlights key similarities and differences between the three sugar crops (sugarcane, sugar beet, and sweet sorghum), with emphasis on opportunities for enhancing sustainability.

Technical Abstract: Sugar crop industries are increasingly implementing sustainable practices to supply natural sugar and other products, following a circular approach which spans the entire sugar product life cycle and requires action from suppliers to consumers. These include sustainable cultivation practices, processes, products, and packaging to optimize economic gain while markedly reducing environmental and social losses. Sustainable practices must be tailored to each sugar crop due to differences in composition which strongly impact harvesting and processing, although there are some similarities. Sugarcane (Saccharum officinarum), sugar beet (Beta vulgaris) and sweet sorghum (Sorghum bicolor) are all rich sources of sucrose. As a general rule, sugar beet (tuberous root) contains (based on total soluble sugars) 98.9% sucrose, 0.12% fructose and 0.12% glucose, sugarcane (grass stalk) contains 94% sucrose, 3% glucose and 3% fructose, while sweet sorghum (grass stalk with seed head) contains 80% sucrose, 10% glucose and 10% fructose. The considerably lower invert sugars and higher amounts of nitrogen-containing compounds in beet than cane allow them to be deliberately degraded at higher alkaline pH processes during beet-sugar manufacturing to prevent Maillard color reactions. The high relative contents of glucose, fructose, starch, and aconitic acid in sweet sorghum currently make the manufacture of white sugar from this sugar crop techno-economically unfeasible. This partially explains why sweet sorghum for syrup production remains a smaller, cottage-type industry whereas the sugarcane and sugar beet industries are worldwide commodity industries. One of the most profound differences between beet and cane-sugar processes is that during white sugar manufacture the colorants are more easily removed during the beet process, which is also a major reason why industrial chromatography is used to recover more sugar from beet molasses but not sugarcane molasses. Sugarcane, and particularly sweet sorghum are rich sources of phenolic antioxidant colorants which need to be further exploited. Other differences and similarities in the processing of the crops are discussed as well as the integrated production of refined sugar from both cane and beets at the same plant.