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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Commodity Utilization Research » Research » Publications at this Location » Publication #342403
Title: Development of a factory/refinery method to measure total, soluble, and insoluble starch in sugar products

Author
item COLE, MARSHA - Orise Fellow
item Eggleston, Gillian

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/9/2017
Publication Date: 9/1/2017
Citation: Cole, M.R., Eggleston, G. 2017. Development of a factory/refinery method to measure total, soluble, and insoluble starch in sugar products. In: Proceedings of the Sugar Industry Technologists Conference, May 7-11, 2017, Tainan, Taiwan. p. 1-21.

Interpretive Summary: Increasing amounts of total starch, particularly insoluble starch, has generally increased in U.S. raw sugars manufactured from sugarcane and have also been persisting into refined sugars. The existing starch method used in the sugar industry does not accurately measure all starch because it cannot solubilize the insoluble starch well and is also limited by the color of the factory product. This has challenged attempts to mitigate starch issues by factory processors and refiners. Thus, a new factory and refinery method that can measure total, soluble, and insoluble starch was urgently needed. Using the previously and accurately developed USDA Starch Research method as a reference tool, this new high-throughput factory and refinery tool was developed with high accuracy, acceptable precision, and differs from the reference method by <6.5%. This method is also very rapid and easily transferable.

Technical Abstract: An easy, rapid, and inexpensive method was developed to measure total, soluble, and insoluble starch in products at the factory and refinery, using microwave-assisted neutralization chemistry. The method was optimized using the previously developed USDA Starch Research method as a reference. Optimal acid and base (alkali) combinations and concentrations plus microwave time and power were determined to completely solubilize an insoluble corn starch reference. The final method solubilizes <4,000 ppm insoluble starch in 2 min, has acceptable precision (7% CV, coefficient of variation), accuracy (=94%), uses a corn starch reference, and incorporates a color blank to remove contribution from natural colorants found in industrial samples. The method was validated using both simulated (5%) and factory samples and found applicable to sugarcane crusher juice (8% CV), clarified juice (12% CV), massecuite (2% CV), molasses (4% CV), syrup (2% CV), and raw sugar (8% CV) with 95.4% satisfactory performance z-scores. The USDA Starch Factory/Refinery and Research methods were very similar with an overall mean difference of ~6.5%.