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The formation of starch nanoparticles via hydrochloric acid vapor hydrolysis combined with ultrasonication treatment. [Display omitted] • Starch nanoparticles were produced by hydrochloric acid vapor with ultrasonication. • This method provided a high yield of starch nanoparticles (20–250 nm) up to 80.5%. • The nanoparticles showed a wide melting temperature range of 22.77 °C. • The morphology of the starch nanoparticles was spherical or ellipsoidal. • The highest relative crystallinity of obtained nanoparticles was 29.65%. The objective of this work was to develop a simple and efficient method to prepare waxy maize starch nanoparticles (SNPs) by hydrochloric acid (HCl) vapor hydrolysis combined with ultrasonication treatment. The size, morphology, thermal property, and crystal structure of the SNPs were systematically studied. HCl treatment introduces a smaller particle diameter of starch particles from 13.73 ± 0.93 μm to 1.52 ± 0.01–8.32 ± 0.63 μm. Further ultrasonication treatment formed SNPs that displayed desirable uniformity and near-perfect spherical and ellipsoidal shapes with a diameter of 150.65 ± 1.91–292.85 ± 0.07 nm. The highest yield of SNPs was 80.5%. Compared with the native starch, the gelatinization enthalpy changes of SNPs significantly decreased from 14.65 ± 1.58 J/g to 7.40 ± 1.27 J/g. Interestingly, the SNPs showed a wider melting temperature range of 22.77 ± 2.35 °C than native starch (10.94 ± 0.87 °C). The relative crystallinity of SNPs decreased to 29.65%, while long-time ultrasonication resulted in amorphization. HCl vapor hydrolysis combined with ultrasonication treatment can be an affordable and accessible method for the efficient large-scale production of SNPs. The SNPs developed by this method will have potential applications in the food, materials, and medicine industries. [ABSTRACT FROM AUTHOR]

• Starch nanocrystals (SNCs) were prepared using dry-heated oxalic acid hydrolysis. • The obtained SNCs had a high yield of 89.6% and preserved the A-type crystal. • The SNCs had a lower enthalpy change than native waxy corn starch. • The fabricated SNCs had a high crystallinity of 42.44%. In this study, we prepared waxy maize starch nanocrystals (SNCs) for the first time using dry-heated oxalic acid hydrolysis with or without ultrasonic treatment. The dry-heating treatment was subjected to oxalic acid hydrolysis to produce SNCs with a high yield of 89.6%. Dynamic light scattering showed that the size of the obtained SNCs was 46.58–197.15 nm, and the polydispersion index was 0.28–0.52. Atomic force microscopy investigation found that the SNCs had a major axis of about 211.5 nm and a height of about 9.4 nm. The thermogravimetric analysis revealed that the SNCs' thermal stability slightly improved compared with that of native starch. X-ray diffraction indicated that the produced SNCs preserved the A-type crystal form of native starch, with the relative crystallinities of 29.52%–42.44%. The newly fabricated SNCs have potential applications in agriculture, cosmetics, and advanced materials. [ABSTRACT FROM AUTHOR]

This research investigated the effect of lecithin on the complexation of lauric acid with maize starch, potato starch, waxy maize starch, and high amylose maize starch. Rapid visco analysis showed that lecithin altered the setback pattern of potato starch-lauric acid and maize starch-lauric acid mixtures but not waxy maize starch-lauric acid. Further investigation, including differential scanning calorimetry, complex index, and X-ray diffraction, showed that lecithin enhanced the complexation of maize starch, potato starch, and high amylose maize starch with lauric acid. Fourier transform infrared and Raman spectroscopy revealed increasingly ordered structures formed in maize starch-lauric acid-lecithin, potato starch-lauric acid-lecithin, and high amylose maize starch-lauric acid-lecithin systems compared to corresponding binary systems. These highly ordered complexes of maize starch, potato starch, and high amylose maize starch also demonstrated greater resistance to in vitro enzymatic hydrolysis. Waxy maize starch complexation however remained unaffected by lecithin. The results of this study show that lecithin impacts complexation between fatty acids and native starches containing amylose, with the starch source being critical. Lecithin minimally impacted the complexation of low amylose starch and fatty acids. • Lecithin facilitated complexation between starches rich in amylose and lauric acid. • Lecithin did not enhance the complexation of amylopectin. • The impact of lecithin was more pronounced in maize starch compared to potato starch. • The formation of more complexes resulted in reduced enzymatic hydrolysis. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a simple and green method to prepare debranched starch nanoparticles (DSNPs) by electrostatic spray. Debranched starch obtained by hydrolyzing waxy corn starch was gelatinized and sprayed into an alcohol tank by electrostatic spray. The physical and chemical properties, such as particle size and morphology, of the DSNPs were systematically studied by dynamic light scattering, transmission electron microscopy, and X-ray diffraction. The DSNPs had diameters between 243 and 337 nm and good dispersion. The DSNP obtained in 60%, 80%, and absolute ethanol showed A-type crystalline, A + V-type crystalline, and amorphous structures, respectively. This simple method for preparation of starch nanoparticles with different crystalline structures has potential applications in different fields, including food, biomedicine, and agriculture. [Display omitted] • Debranched starch nanoparticles (DSNPs) was prepared by electrostatic spraying. • The DSNPs had diameters between 243 and 337 nm with good monodispersity. • DSNPs showed A-type crystalline, A + V-type crystalline, and amorphous structures. • DSNPs with different structures will expand the application in different fields. [ABSTRACT FROM AUTHOR]