Structural and thermal properties of the amaranth starch granule obtained by high-impact wet milling

Abstract

In this study, amaranth starch was extracted by high-impact wet milling and its structural and thermal properties and the effect of NaOH and SDS concentrations on extraction yield were evaluated. The best condition was 55 g of starch/100 g of amaranth, with a decrease from 2.5 to 3.5 kJ/g using different milling energies. The decrease in the protein content of the starch granule is due to an effect of the interaction between surfactant and alkali, preventing the destruction of granules. All starches presented a degree of crystallinity between 21 and 28%. The internal structural changes of the starch granule were monitored by attenuated total reflectance - Fourier-transform infrared (ATR-FTIR) in the region of 990 to 1060 cm−1. Spectra showed significant differences between the peaks at 1032 and 1005 cm−1, corresponding to the crystalline/amorphous region of the starch structure. Changes in viscosity profiles were observed between 0.302 and 1.163 Pa s.

Structural Characterization and Antioxidant Capacity of Quinoa Cultivars Using Techniques of FT-MIR and UHPLC/ESI-Orbitrap MS Spectroscopy

“…To elaborate a structural analysis with the goal to deeply learn about the secondary protein structures of each cultivar, spectrum deconvolution techniques were performed on 1633 cm −1 [26]. Deconvolution of the 1016 cm −1 band can relate to the crystallinity of a shapeless starch granule [27]. This turned out to be an important fact, because the functional flour does not only depend on the protein and starch concentrations but, also, on its organization and molecular conformation.…”

Study of morphological, structural, and thermal changes of biodegradable material in simulated natural environmental conditions

“…A Happ‐Genzel apodization was used, with a magnitude phase correction. A flat tip was used to obtain intimate contact between sample and crystal, without pressure control (Roa‐Acosta et al., 2020). Each sample scan was completed with a background in the air (without sample) obtained prior to sample measurement at the ATR sampling stage.…”

“…The spectra were read in a range of 4000-500 cm −1 , in triplicate using the ATR technique at a resolution of 4 cm −1 with a scan average of 100 scans at 25 • C. A Happ-Genzel apodization was used, with a magnitude phase correction. A flat tip was used to obtain intimate contact between sample and crystal, without pressure control (Roa- Acosta et al, 2020). Each sample scan was completed with a background in the air (without sample) obtained prior to sample measurement at the ATR sampling stage.…”

Propiedades reológicas de quinua (Chenopodium quinoa Wild) obtenidas mediante molienda abrasiva y tratamiento térmico

“…La figura 2 muestra el comportamiento de las dispersiones a concentraciones del 6% y 12%, cuando son sometidas a diferentes velocidades de corte, en este caso el rango de velocidad de cizalla fue de 0 s -1 a 200 s -1 con el fin de evitar el efecto que tienen la alta velocidad de cizalla. La dispersión C-10-125-6% (figura 2a) presentó mayor contenido de almidón y proteína que la muestra C-40-125-6% (figura 2c), esto podría confirmarse por espectroscopia FTIR (Roa et al, 2020). Independientemente de la composición de las harinas, las dispersiones (6% p/v) mostraron comportamiento dilatante antes del calentamiento (puntos azules) con valores de índice de flujo (1.437 y 1.338) para las dispersiones C-10 y C-40, respectivamente.…”