Evaluation of the physico-chemical properties of potato starch-based foods and their interactions with milk protein and soybean oil

Physico-chemical properties of potato starch-based foods (PSBF) interacted with milk protein (MP), and soybean oil (SBO) were investigated. Microstructures, rheological properties, and chemical bonding among those ingredients were determined. An emulsion-filled gel, in which oil droplets stabilized by MP and/or amylose-lipid complex (ALC) dispersed in a starch gel structure of PSBF was revealed by confocal laser scanning microscopy. Starch-starch, protein-oil, and protein-protein played the dominant interactions while ALC and starch-protein interaction were subordinates. Rheological data showed that MP induced a thinning effect on starch gel, while SBO seemed to reinforce the solid-like properties of the gel. The chemical interactions analyzed by FTIR, Raman, and X-ray diffraction suggested that these foods were lack in non-covalent crosslinks and were dominated by diverse physical interactions. However, the different preparation of such foods could induce chemical binding in a different way and MP and SBO could affect the properties of PSBF in this study.