Effect of amylose/amylopectin content and succinylation on properties of corn starch nanoparticles as encapsulants of anthocyanins.

In this study, succinylated nanoparticles from normal (NPS-N), high-amylose (NPS-H), and high-amylopectin corn starch (NPS-W) were synthesized, characterized, and studied for the nanoencapsulation of the Ardisia compressa anthocyanins. The nanoparticle‒anthocyanin interaction was also investigated. The succinylated starch nanoparticles (S-SNPs) had hydrodynamic sizes of 65-390 nm, degrees of substitution (DS) of 0.014-0.032, ζ-potential values of up to -34 mV and a nanocolloid behavior. NPS-N and NPS-W showed the highest (p < 0.05) encapsulation efficiencies (EE) (52 and 49 %, respectively) compared than NPS-H (45 %). Thereby, the lowest DS obtained, and the branched amylopectin structure favored the EE. The nanoparticle-anthocyanin interaction occurred through hydrophobic and electrostatic interactions and influenced significantly (p < 0.05) the hydrodynamic size and surface properties of the resulting nanocapsules. The relative crystallinity (RC) decreased significantly (p < 0.05) in the S-SNPs, but the nanocapsules mostly experimented a structural recrystallization and showed melting temperatures>150 °C.

Microencapsulation of Red Sorghum Phenolic Compounds with Esterified Sorghum Starch as Encapsulant Materials by Spray Drying.

Phenolic compounds with antioxidant properties are highly sensitive molecules, which limits their application. In response, extruded esterified starch has been proposed as efficient encapsulating material. In this work, we aim to describe the encapsulation of red sorghum phenolic compounds by spray drying using extruded phosphorylated, acetylated and double esterified sorghum starch as wall material. Their respective encapsulation yields were 77.4, 67.4 and 56.8%, and encapsulation efficiency 91.4, 89.7 and 84.6%. Degree of substitution confirmed esterification of the sorghum starch and Fourier transform infrared spectroscopy showed the significant chemical and structural changes in the extruded esterified starch loaded with phenolic compounds. Microcapsules from phosphorylated sorghum starch showed the highest endothermic transition (173.89 °C) and provided a greater protection of the phenolic compounds during storage at 60 °C for 35 days than the other wall materials. Extruded esterified sorghum starch proved to be effective material for the protection of phenolic compounds due to its high encapsulation efficiency and stability during storage.

Synthesis and succinylation of starch nanoparticles by means of a single step using sonochemical energy.

In the present research work, esterified nanoparticles with 2-octen-1-ylsuccinic anhydride were synthesized from waxy corn starch, to our knowledge for the first time, in a single step of ultrasonic treatment. First, the ultrasound time to produce non-esterified nanoparticles was studied. The results showed that non-esterified nanoparticles had sizes ranging from 63 to 48 nm, as well as polydispersity indexes (PDI) ranging from 0.458 to 0.224 and ζ-potential values ranging from -16 to -24 mV in ultrasonication times ranging from 20 to 100 min. Succinylated nanoparticles were obtained at 80 min with two degrees of substitution i.e., 0.003 and 0.01, hydrodynamic sizes of 57 and 83 nm, PDI of 0.479 and 0.91, and ζ-potential values of -6.27 and -14.03 mV, respectively. The succinylation of nanoparticles was confirmed by FTIR spectroscopy, and it was possible to elucidate the conversion of amylopectin molecules into amylose blocks. The nanoparticles showed stability during storage in aqueous suspension at 4 °C. By means of the ultrasonic technology, destructuring of the waxy corn starch and, at the same time, the succinylation of the nanoparticles in a total time of 120 min was effectively achieved.