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In a previous study, gelatinized corn starch dispersions (GSD) containing different (∼7–59.6%) ghost phase fractions (GPF), i.e., insoluble amylopectin‐rich remnants with glycerol added as plasticizer were cast and dried to obtain films. GPF had both positive and negative effects on the films’ properties, but GPF of around 20–30%, provided films with good and balanced overall properties ((elongation‐at‐break (EB), ultimate tensile strength (UTS), opacity, and water vapor permeability (WVP)). Here, corn, wheat, and rice GSD were prepared containing GPF of 63.6, 61.3, and 58.2%. The GPF was separated from GSD, and films were prepared with solely the GPF and with the whole GSD. Ghost phase fraction films (GPFF) exhibited higher hydrophobicity and EB, lower WVP and retrogradation than those obtained from the whole gelatinized starch dispersion films (GSDF), with only UTS exhibiting lower values. It was postulated that the underlying reason for the improved overall performance displayed by the GPFF was that they practically did not retrograde, due to the depletion of the amylose‐rich viscous continuous phase, and that the ghosts played an important role as physical fillers imparting elasticity and as physical barriers hindering the transport of water. The ghosts’ particle size and concentration affected the surface morphology, accounting for the differences in properties found between the corn, wheat, and rice GPFF.

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Starch is an abundant renewable resource and is the raw material for the production of a wide range of products, many of which are obtained by hydrolysis. While the hydrolysis of starch by enzymes and acids has been extensively investigated, there are scant studies with respect to the use of solid acid catalysts for this purpose. In this work, the features of corn starch hydrolysis by alumina (Al) and mixed silica‐alumina (SiAl) oxides solid catalysts have been explored, as they are widely used due to their low cost and ease of synthesis. To this end, native corn starch (CS) aqueous dispersion (0.02 g g−1) is used as such or added with the Al or SiAl (1 g g−1 starch), and gelatinized/hydrolyzed at 90 °C for 180 min. The effect of hydrolysis time on morphology (optical and SEM microscopy), hydrolysis progression (based on total sugar production), apparent amylose content, and starch crystalline structural changes (FTIR) is monitored. It is found that the acidity of the solid acid catalyst is a key factor that affected all of the above‐mentioned parameters. The higher acidity (355.0 mmol NH3 · g−1) of SiAl produces higher maximum hydrolysis progression (90%) and apparent amylose contents (0.60 g g−1 residual starch) than Al (70% and 0.40 g g−1 residual starch, respectively), which exhibit lower acidity (84.0 mmol NH3 · g−1).