Rheology, Microstructure, and Storage Stability of Emulsion-Filled Gels Stabilized Solely by Maize Starch Modified with Octenyl Succinylation and Pregelatinization

• Main Authors: Myeongsu Jo, Min Jea Chang, Kelvin K. T. Goh, Choongjin Ban, Young Jin Choi
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Foods
• Subjects: emulsion-filled gels; octenyl succinic anhydride-modified and pregelatinized maize starch; rheological property; microstructure; storage stability
• Online Access: https://www.mdpi.com/2304-8158/10/4/837

We prepared emulsion-filled gels stabilized using octenyl succinic anhydride-modified and pregelatinized maize starch (OSA-PGS). The effect of the oil volume fraction (Φ, 0.05–0.20) and OSA-PGS concentration (3–10% <i>w</i>/<i>v</i>) on the rheological and microstructural properties of the emulsion-filled gels was evaluated. Confocal fluorescence images showed that OSA-PGS stabilized the emulsion, indicated by the formation of a thick layer surrounding the oil droplets, and simultaneously gelled the aqueous phase. All of the emulsions exhibited shear-thinning flow behavior, but only those with 10% <i>w</i>/<i>v</i> OSA-PGS were categorized as Herschel–Bulkley fluids. The rheological behavior of the emulsion-filled gels was significantly affected by both the OSA-PGS concentration and Φ. The mean diameters (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>D</mi><mrow><mn>1</mn><mo>,</mo><mn>0</mn></mrow></msub></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>D</mi><mrow><mn>3</mn><mo>,</mo><mn>2</mn></mrow></msub></mrow></semantics></math></inline-formula>, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>D</mi><mrow><mn>4</mn><mo>,</mo><mn>3</mn></mrow></msub></mrow></semantics></math></inline-formula>) of oil droplets with 10% <i>w</i>/<i>v</i> OSA-PGS were stable during 30 days of storage under ambient conditions, indicating good stability. These results provide a basis for the design of systems with potential applications within the food industry.