(M1030-08-44) Probing Surface Chemical Analysis of Banana Starches in Functional Applications

Purpose: The structure of starch granules is normally evaluated by a physical or chemical method that measures the bulk properties of the materials, without considering a surface chemical approach. Performance characteristics like flowability and digestability are dependent not only on particle structure such a particle size, granule morphology, bulk structure, but also chemical composition at the surface. Flow properties of the materials need to be quantified in industrial processing applications as part of the manufacturing and final product compliance; digestability is important to ensure benefits of the food healthy products. In one case, particles need to interact during flow properties of the materials in direct contact at the surface, in the other case, enzymatic affinity to starch particle in hydrolysis affect granule chemical reactivity at the surface in the process of digestability. We introduce a surface characterization approach to explain the applicability of surface analysis as a contribution to the evaluation of desirable performance characteristics of starch.

Methods: Surface characterization techniques such as inverse gas chromatography (iGC), X-ray photoelectron spectroscopy (XPS) were used to obtain thermodynamic and chemical composition of the materials to evaluate the surface interphase. Powder performance, flowability was measured by FT4 powder rheometer, and digestability by resistant starch megazyme’s method.

Results: Surface analysis exhibited distinct chemical composition on materials, those affecting particle interaction and functional performance. Thermodynamic properties of starches, at the surface level, were associated with digestability properties. Enthalpy of sorption was between 28-32 kJ/MolK for the materials with lower insoluble dietary fiber of 43-51 IDF, in contrast, higher insoluble fiber materials 54-67 IDF indicated 26-29 kJ/MolK, figures 1 and 2 showed the results. This suggests that surface composition influences the energetic adsorption sites, inducing preferential enzyme hydrolysis of the starch.

Conclusion: The applicability of surface composition and interactions of materials can be assessed by using surface analytical tools. In this study, we found that surface energy, chemical composition as well as thermodynamic evaluation offer a fundamental insight of the flow behavior of starch and the affinity of the enzyme to hydrolysis.

References: Carolina, P. Mora., Martinez-Alejo, J. M., Roman, L., Martinez, M. M., Carvajal, T., Pinal, R., & Mora-Huertas, C. E. (2020). Molecular and physical characterization of octenyl succinic anhydride-modified starches with potential applications in pharmaceutics. International Journal of Pharmaceutics, 579, 119163–119163.
Chavez-Montes, E., Martínez-Alejo, J., Lozano-Perez, H., Gumy, J., Zemlyanov, D., & Carvajal, M. (2019). A surface characterization platform approach to study Flowability of food powders. Powder techonology, 357, 269-280.
Yee, Josephine., Roman, L., Pico, J., Aguirre-Cruz, A., Bello-Perez, L. A., Bertoft, E., & Martinez, M. M. (2021). The molecular structure of starch from different Musa genotypes: Higher branching density of amylose chains seems to promote enzyme-resistant structures. Food Hydrocolloids, 112. 106351