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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

item Cermak, Steven - Steve
item SELLING, GORDON - Retired ARS Employee
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: N/A
Citation: N/A

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 work 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 were evaluated using SEM, XRD, FT-IR, FTIR-m, and TGA. The HAC-CFA materials were shown to contain AIC having 61V type helical structure between amylose and the CFA that were confirmed by XRD and IR spectral analysis. By TGA, extruded HAC materials containing 15% CFA, were shown to have excess CFA present in addition to formed AIC. In contrast, the WC was 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.