Conquering the control of insoluble and soluble starch with novel applications of amylase

Authors: Eggleston, Gillian; Cole, Marsha; TOYAMASU, TOSHIHISA - Amano Enzyme, Inc; Triplett, Alexa; MONTES, BELISARIO - Alma Plantation, Llc; Wartelle, Lynda; STEWART, DAVID - Alma Plantation, Llc

Submitted to: International Sugar Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2016
Publication Date: 7/5/2016
Citation: Eggleston, G., Cole, M., Toyamasu, T., Triplett, A., Montes, B., Wartelle, L., Stewart, D. 2016. Conquering the control of insoluble and soluble starch with novel applications of amylase. International Sugar Journal. 120:570-579.

Interpretive Summary: The new knowledge that there is markedly more insoluble starch than previously considered in products across the sugarcane factory and refinery has implicated the application of amylase enzymes in the factory to break down both soluble and insoluble starch. Via laboratory, pilot plant, and factory studies, it was shown that High-temperature (HT) stable amylases, and even intermediate-temperature (IT) stable amylases but to a lesser extent, are capable of hydrolyzing starch in 96 °C clarified juice in the first 10 min before their substantial deactivation. HT amylases, however, cause unwanted carry-over amylase activity even at a 1 ppm dose. Novel combinations and low doses of an IT stable amylase added to a clarification tank, next-to-the-last evaporator, and last evaporator are able to break down all starch forms.

Technical Abstract: The new knowledge that there is markedly more insoluble starch than previously considered in products across both the sugarcane factory and refinery has processing implications. This includes the application of a-amylases in the factory to control not only soluble but insoluble starch. Studies were conducted at the laboratory, pilot plant, and factory scales to optimize the application of amylase for control of both starch forms. High-temperature (HT) amylases, and even intermediate-temperature (IT) stable amylases but to a lesser extent, are capable of hydrolyzing starch in 96 °C clarified juice mostly in the first 10 min before their substantial denaturation. Amylases preferentially hydrolyze soluble starch>>>>>swollen starch>insoluble starch. HT amylases compared to IT amylase, however, cause unwanted carry-over amylase activity even at a 1 ppm dose. At a Louisiana factory, novel combinations and doses (0 to 10 ppm) of an IT stable amylase were added to a clarification tank, next-to-the-last evaporator, and/or last evaporator. Using the new USDA starch research method to measure total, insoluble, and soluble starch, a full picture of how starch is transformed and removed during clarification and evaporation was achieved. When IT amylase is first directly applied into a clarification tank, total starch is reduced by 25.3 to 31.2% which includes insoluble starch, and the control of the syrup viscosity inside the subsequent evaporators is also improved. Although most starch hydrolysis occurred in the next-to-the-last evaporator syrups, the greatest overall reductions (up to 99% depending on enzyme dose) in all starch forms occurs when IT amylase is simultaneously added into the clarification tank, next-to-the last evaporator, and last evaporator. Until a solution can be found to remove carry-over amylase, the latter treatment is recommended.