Effects of preincubation on the gelatinization of cassava and corn starch suspensions containing sodium hydroxide as a main component of corrugating adhesives

TAPPI Journal ◽  
2019 ◽  
Vol 18 (5) ◽  
pp. 321-329
Author(s):  
TAKATOSHI KOYAKUMARU ◽  
HIROFUMI NAKANO
Keyword(s):  
Sodium Hydroxide ◽  
Corn Starch ◽  
Cassava Starch ◽  
Molar Ratio ◽  
Starch Granules ◽  
Gelatinization Temperature ◽  
Scanning Calorimetry ◽  
Long Time ◽  
C 50 ◽  
Main Component

Effects of the preincubation temperature and the caustic-ratio, the molar ratio of sodium hydroxide to starch glucose residue, on the gelatinization of cassava starch and corn starch suspensions were studied using differential scanning calorimetry in view of utilization for corrugating adhesives. The gelatinization temperature and enthalpy change of cassava starch suspensions after the preincubation at 30°C decreased as the caustic-ratio increased, similar to those of corn starch ones: The gelatinization starting temperature (Ts) decreased considerably more than the peak temperature and the conclusion temperature (Tc). Although Ts lowered and the width of gelatinization temperature expanded, compared with those of corn starch suspensions, the two starch suspensions with the same half gelatinization transition temperature showed similar gelatinization characteristics of almost the same Ts and Tc. During 1 h-preincubations at 30°C–50°C, the starch granules with Ts that were lowered considerably below each preincubation temperature by sodium hydroxide showed limited gelatinization. The gelatinization transition did not rapidly spread over the whole suspension, but progressed stepwise in response to the increase of the causticratio and the rise of the preincubation temperature. In a prolonged preincubation at a constant temperature, Ts gradually rose at higher caustic-ratios in which stepwise gelatinization commenced. Although the starch gelatinization was irreversible and not in a stable equilibrium state for a long time, we concluded that such stepwise gelatinization progress controlled the practical preparation and use of corrugating adhesives.

scholarly journals Thermal characterization of partially hydrolyzed cassava (Manihot esculenta) starch granules

2008 ◽  
Vol 51 (6) ◽  
pp. 1209-1215 ◽  
Author(s):  
Luiz Gustavo Lacerda ◽  
Jayme Augusto Menegassi Azevedo ◽  
Marco Aurélio da Silva Carvalho Filho ◽  
Ivo Mottin Demiate ◽  
Egon Schnitzler ◽  
...  
Keyword(s):  
Thermal Characterization ◽  
Cassava Starch ◽  
Starch Granules ◽  
Gelatinization Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Similar Range ◽  
Partial Degradation

Cassava starch, partially hydrolyzed by fungal á-amylase, was characterized using thermal analysis, light microscopy and X-ray diffraction. Thermal degradation was initiated at lower degradation temperatures after enzymatic treatment and the DSC (Differential scanning calorimetry) analysis showed almost similar range of gelatinization temperature, but the enthalpies of gelatinization were quite increased for the partially hydrolyzed starch granules. The results suggested that the partial degradation of the starch granules was concentrated in the amorphous regions.

scholarly journals THERMAL AND ELECTROCHEMICAL PROPERTIES OF SOLID BIOPOLYMER ELECTROLYTES FROM STARCH OF DIFFERENT BOTANICAL ORIGIN

2021 ◽  
Vol 18 (38) ◽  
pp. 137-148
Author(s):  
Alvaro ARRIETA
Keyword(s):  
Thermal Decomposition ◽  
Corn Starch ◽  
Potato Starch ◽  
Cassava Starch ◽  
Redox Potentials ◽  
Botanical Origin ◽  
Scanning Calorimetry ◽  
Biopolymer Electrolytes ◽  
Starch Films ◽  
Biopolymer Electrolyte

Background: Solid biopolymer electrolytes are a type of material with high technological potential used in the development of solar cells, batteries, fuel cells, among others, due to their biodegradable nature and low environmental impact. Aim: This study aimed to evaluate the effect of the botanical origin of the starch used to prepare solid biopolymeric electrolyte films on its electrochemical and thermal properties and to establish the variations in thermal decomposition temperatures and redox potentials depending on the botanical origin of the starch used. Methods: Films of solid biopolymer electrolyte were made by thermochemical synthesis processes using corn starch, cassava starch, potato starch, glycerol, polyethylene glycol, and glutaraldehyde as plasticizers and lithium perchlorate salt. The synthesis solutions were taken to an oven at 70 °C for 48 hours. The films were characterized electrochemically by cyclic voltammetry using a dry electrochemical cell and thermally by differential scanning calorimetry and thermogravimetric analysis. Results and Discussion: The results showed that the electrochemical behavior of the films was similar in terms of registered redox processes. However, the potential values of the oxidation and reduction were different, as are the stability and intensity of the processes. On the other hand, the thermal analysis allowed establishing two decomposition processes in each of the films studied; the first process was due to dehydration and depolymerization phenomena in the films. The temperatures recorded were 59.0 °C, 58.9 °C, and 89.9 °C for potato starch, cassava starch, and corn starch films. The second process evidenced the thermal decomposition at different temperatures, 267.7 °C in potato starch films, 280.6 °C in corn starch films, and 287.1 °C in cassava starch films. Conclusions: It could be concluded that the botanical origin of the starch used in the synthesis of solid biopolymer electrolyte films affects its behavior and electrochemical and thermal stability.

scholarly journals Effect of Dual Modification on the Spectroscopic, Calorimetric, Viscosimetric and Morphological Characteristics of Corn Starch

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 333 ◽  
Author(s):  
Ulin Basilio-Cortés ◽  
Leopoldo González-Cruz ◽  
Gonzalo Velazquez ◽  
Gerardo Teniente-Martínez ◽  
Carlos Gómez-Aldapa ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Short Range ◽  
Corn Starch ◽  
Morphological Characteristics ◽  
Industrial Applications ◽  
Peak Time ◽  
Starch Granules ◽  
Scanning Calorimetry ◽  
Pasting Temperature ◽  
Ftir And Raman Spectroscopy

The effect of dual modification of corn starch, including hydrolysis and succinylation, were evaluated through peak viscosity (PV) analysis, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. This dual modification was shown to increase the reaction efficiency (RE) and degree substitution (DS) compared with starches that were not subjected to acid hydrolysis pretreatment with a 44% and 45% increase respectively. After acid hydrolysis pretreatment, the surface of the corn starch granules exhibited exo-erosion and whitish points due to the accumulation of succinyl groups. The peak viscosity was reduced significantly with the acid hydrolysis pretreatment (between 3 and 3.5-fold decrease), which decreased the pasting temperature and peak time to 20 °C and 100 s respectively. In addition, the dual modification of corn starch altered certain thermal properties, including a reduction in the enthalpy of gelatinization (ΔH) and a higher range of gelatinization (around 6 °C), which may effectively improve industrial applications. Modifications on the FTIR spectra indicated that the dual modification affected the starch crystallinity, while the Raman spectra revealed that the dual modification disrupted the short-range molecular order in the starch. Rearrangement and molecular destabilization of the starch components promoted their granular amphiphilic properties.

Hydroxypropylation Reduces Gelatinization Temperature of Corn Starch for Textile Sizing

2021 ◽  
Author(s):  
Yanqin Shen ◽  
Yijun YAO ◽  
Zhongliang Wang ◽  
Hailiang Wu
Keyword(s):  
High Performance ◽  
Corn Starch ◽  
Water System ◽  
Hydroxyl Group ◽  
Resonance Spectroscopy ◽  
Gelatinization Temperature ◽  
Step Method ◽  
Scanning Calorimetry ◽  
Raw Starch ◽  
Substitution Level

Abstract A series of hydroxypropylated starch (HPS) that can be dissolved in water at 60-65℃ was obtained via two-step method in water system from corn starch. The structure and property of the HPS and its gelatinization temperature were characterized by Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance spectroscopy ( 1 H NMR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and transmission electron microscope (TEM). It was concluded that hydroxypropyl mainly bonded on the hydroxyl group at C 2 position from anhydroglucose unit of starch in the form of C-O-C, and the substitution level at C 6 position was slightly higher than that at C 3 position; and the crystallinity of starch decreased from 52.41% to 29.4% due to the introduction of hydroxypropyl and was confirmed by XRD. At the same time, the grooves on the surface of starch granules were observed by SEM. The above-mentioned two synergism promoted the permeation and transmission of water molecules in the starch microstructure. Moreover, the gelatinization temperatures and enthalpy of synthetic HPS was lower than that of raw corn starch, as further confirmed by DSC. This caused the HPS with a molar substitution greater than 0.1 soluble in water at 65℃, and the dissolution state was similar to that of at 95℃ (transmittance above 55%), as well as exhibited high slurry stability. Interestingly, compared with the raw starch, the HPS film showed excellent mechanical property at the relative humidity of 65%, which could be attributed to the hydrophilic ether bond and the flexible alkyl chain bonded on the structure of starch. This study will provide a new way for the preparation of high performance starch size for sizing yarn at medium low temperature.

scholarly journals Thermal and physicochemical properties of starches from three Colombian rice varieties

2017 ◽  
Vol 35 (1) ◽  
pp. 116-124 ◽  
Author(s):  
Diego Rodríguez-Torres ◽  
Walter Murillo-Arango ◽  
Henry Alexander Vaquiro-Herrera ◽  
José F. Solanilla-Duque
Keyword(s):  
Thermal Properties ◽  
Amylose Content ◽  
Pasting Properties ◽  
Granule Size ◽  
Starch Granules ◽  
Gelatinization Temperature ◽  
Scanning Calorimetry ◽  
Rice Varieties ◽  
Swelling Capacity ◽  
Average Size

Samples of starch from broken grains of three rice varieties grown in Colombia were analyzed to determine their physicochemical and thermal properties: Fedearroz 473 (F473), Fedearroz 50 (F50) and Fedearroz 60 (F60). The granule size, solubility, swelling capacity, amylose content, syneresis, turbidity, thermal and pasting properties of starches were determined. The average size of starch granules was 9.4, 7.4 and 7.2 µm for F473, F50 and F60 samples, respectively. The amylose content showed significant differences between the studied varieties and ranged between 21.4% and 23.0%. Turbidity ranged between 1.95 and 2.34 absorbance units at 620 nm. Thermal properties, evaluated by differential scanning calorimetry (DSC), registered values between 61.6 and 64.6°C for the onset temperature, between 66.6 and 69.3°C for the peak temperature, between 72.1 and 73.9°C for the end temperature, and between 8.38 and 9.47 J g-1 for the gelatinization enthalpy. The higher amylose content the higher grain size, turbidity, syneresis, viscosity, gelatinization temperature and enthalpy, and the lower swelling capacity and solubility. This paper is the first reported research on physicochemical and functional properties of starches from these Colombian rice varieties.

scholarly journals Synthesis of thiocol oligomer based on sodium tetrasulphide, epichlorhydrine and ammonium phosphate

2021 ◽  
pp. 32-37
Keyword(s):  
Differential Scanning Calorimetry ◽  
Reaction Time ◽  
Ir Spectroscopy ◽  
Ammonium Phosphate ◽  
Molar Ratio ◽  
Target Product ◽  
Optimal Conditions ◽  
Scanning Calorimetry ◽  
Molar Ratios ◽  
Main Component

The aim is to synthesize and study thiokol oligomer NEP-12 based on sodium tetrasulfide, epichlorohydrin and ammonium phosphate, which is intended for use as the main component of thiokol sealant. To achieve this goal, a thiokol oligomer based on sodium tetrasulfide, epichlorohydrin, and ammonium phosphate has been synthesized and investigated, and the optimal conditions for the synthesis of a thiokol oligomer have been determined. Research has been carried out on the influence of the molar ratios of the starting substances on the composition and physicochemical properties of the synthesized thiocol oligomer. 80 °C was taken as the optimum polycondensation temperature, the reaction time in this case is 1.5-2 hours, as a result, the yield of the target product reaches 94%. The thiokol oligomer with the best performance was obtained at a 1: 1: 1 molar ratio of sodium tetrasulfide, epichlorohydrin, and ammonium phosphate, respectively. Based on the results of IR spectroscopy and differential scanning calorimetry, a reaction for the formation of a thiokol oligomer is proposed.

scholarly journals Thermal and functional properties of starch extracted from tubers cultivated in the Ecuadorian Andean region

2021 ◽  
Vol 117 (2) ◽  
pp. 1
Author(s):  
Lady Mireya QUEZADA-CORREA ◽  
Oscar CONTRERAS-DIOSES ◽  
Edison Omar MARTÍNEZ-MORA ◽  
Carlos Alberto GÓMEZ-ALDAPA ◽  
Esther RAMÍREZ-MORENO ◽  
...  
Keyword(s):  
Functional Properties ◽  
Starch Granules ◽  
Gelatinization Temperature ◽  
Wet Milling ◽  
Scanning Calorimetry ◽  
Total Dietary Fiber ◽  
Physicochemical Composition ◽  
Swelling Capacity ◽  
Milling Method ◽  
Total Carbohydrates

Thermal and functional properties of starch extracted from American taro and Indian shot were determined to assess their use in food products. Starch was extracted by the wet-milling method. Physicochemical composition was determined following the Association of Official Agricultural Chemists (AOAC) protocols. Total fibre was measured by the Total Dietary Fiber Assay Kit. The morphology of starch granules was observed by scanning electronic microscopy (SEM). Gelatinization temperature and viscosity were measured by Differential Scanning Calorimetry (DSC) and with a rapid viscosity analyser (RVA), respectively. Swelling capacity, solubility index, and absorption index were measured at 15, 60, 70, 80, and 90 °C. The yield for Indian shot (72.5 %) was higher of that for taro (60.2 %). No significant differences (p > 0.05) were found for moisture, ashes, total fibres, and protein; significant differences were found for fat content, total carbohydrates, amylose, and amylopectin. Granules of Indian shot starch featured ovoid shapes (diameter, 30 µm), while granules of American taro starch presented round shapes (diameter, 15 µm. Gelatinization temperature for American taro (78.33 °C) was higher of that for Indian shot (65.28 °C). Maximum viscosity in Indian shot (3,535.5 cP) was higher of that in American taro (2,446.5 cP). Concerning functional properties, Indian shot starch yielded higher values. Moreover, at high temperature values, American taro starch presented better gelling results than those in Indian shot.

scholarly journals Thermal behavior of corn starch granules modified by acid treatment at 30 and 50°C

2008 ◽  
Vol 33 (3) ◽  
pp. 13-18 ◽  
Author(s):  
C. Beninca ◽  
I. M. Demiate ◽  
L. G. Lacerda ◽  
M. A. S. Carvalho Filho ◽  
M. Ionashiro ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Optical Microscopy ◽  
Acid Treatment ◽  
Corn Starch ◽  
Starch Granules ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Thermoanalytical Techniques ◽  
Physical Chemical

Unprocessed native starches are structurally too weak and functionally too restricted for application in today's advanced food technologies. Processing is necessary to engender a range of functionality. Naturals or natives starches can be modified by using several methods physical, chemical, enzymatic or combined, according industrial purposes. In this work, native corn starch was hydrolyzed by hydrochloric acid solution and investigated by using thermoanalytical techniques (thermogravimetry - TG, differential thermal analysis - DTA and differential scanning calorimetry - DSC), as well as optical microscopy and X-ray diffractometry. After acid treatment at 30 and 50°C, a decrease of gelatinization enthalpy (ΔHgel) was verified. Optical microscopy and X-ray diffractometry allowed us to verify the granules contorn and rugosity typical of cereal starches.

scholarly journals Rapid Estimation of Parameters for Gelatinization of Waxy Corn Starch

Foods ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 556
Author(s):  
Robert Bertrand ◽  
William Holmes ◽  
Cory Orgeron ◽  
Carl McIntyre ◽  
Rafael Hernandez ◽  
...  
Keyword(s):  
Corn Starch ◽  
Rapid Determination ◽  
Thermal Characteristics ◽  
Gelatinization Temperature ◽  
Estimation Of Parameters ◽  
Scanning Calorimetry ◽  
Starch Gelatinization ◽  
Waxy Corn Starch ◽  
Waxy Corn

Starch gelatinization is an important process due to the prevalence of starch usage in industries such as cosmetics and food production. In this study, the gelatinization of waxy corn starch (WCS) was investigated with the goal of providing an option for the rapid determination of starch gelatinization characteristics. The procedure used in the study was solely based on differential scanning calorimetry (DSC), which is an established technique for the determination of thermal characteristics of starches. A sequence of experiments was conducted to determine the excess water condition, an estimate of the minimum gelatinization temperature, and gelatinization time. These parameters were found to be ≥65 wt.% water, 75–85 °C, and 10 min, respectively. The estimation of the minimum gelatinization temperature was determined from the thermal properties of the WCS as obtained by DSC. The obtained parameters resulted in complete WCS gelatinization, and, thus, the sequence of procedures used in the study could possibly be used for rapid waxy starch evaluation.

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