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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Plant Polymer Research » Research » Publications at this Location » Publication #368908
Research Project: Conversion of Polysaccharides and Other Bio-based Materials to High-Value, Commercial Products

Location: Plant Polymer Research

Title: Preparation of starch coconut fatty acid inclusion complexes by twin-screw extrusion

Author
item SELLING, GORDON - Retired ARS Employee
item Cermak, Steven - Steve
item Kenar, James - Jim
item FINKENSTADT, VICTORIA - National Institute Of Food And Agriculture (NIFA)

Submitted to: Starch
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/13/2024
Publication Date: 4/1/2024
Citation: Selling, G.W., Cermak, S.C., Kenar, J.A., Finkenstadt, V.L. 2024. Preparation of starch coconut fatty acid inclusion complexes by twin-screw extrusion. Starch. https://doi.org/10.1002/star.202300228.
DOI: https://doi.org/10.1002/star.202300228

Interpretive Summary: A new, natural, biobased insect deterrent has been designed for use against biting flies. The old method uses dilute solutions to form complexes, and its application method causes stress to farm animals. An insect deterrent made up of starch and coconut fatty acids can be processed in an extruder with high solids content rather than the current dilute cooking process. Over 70% of the coconut oil is released over four days. The material is dry rather than in solution and will provide energy and cost savings. In addition, the extruded formula has longer shelf-life as starch crystallinity was reduced.

Technical Abstract: Starch-guest molecule amylose inclusion complexes (AIC) are of interest to industry as a means to encapsulate and deliver compounds. Coconut fatty acids (CFA) consist predominantly of medium chain fatty acids having useful food and nonfood applications. This article describes the formation of high amylose corn (HAC)- or waxy corn starch (WC)-CFA AIC containing 0%, 2%, 7.5%, and 15% CFA using a continuous thermomechanical extrusion process at 20% feed moisture and a twin-screw extruder with a unique screw design. The extrusion conditions completely destructure both the HAC and waxy starch granules and the resulting materials are evaluated using SEM, XRD, FT-IR, FTIR-m, and TGA. The HAC-CFA materials are shown to contain AIC having 61 V type helical structure between amylose and the CFA that are confirmed by XRD and IR spectral analysis. By TGA, extruded HAC materials containing 15% CFA are shown to have excess CFA present in addition to formed AIC. In contrast, the WC is shown not to form AIC with the CFA and only trap the CFA within the starch matrix. The understanding gained from this study is helpful to design the processing of starch-based biopolymers to prepare AIC having improved functional properties for potential commercial applications.