• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.696-703
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• 1994

The purpose of this study was to investigate the gelatinization properties of potato starch heated with microwave. Two types of potato starches were prepared; In group A raw potato starch was heated with microwave and in group B potato starch was isolated from potato heated with microwave. Both groups were exposed to the microwave energy in a 560W, 2,450 MHz oven for 60, 120, 180 and 300 seconds. Gelatinization behaviour by DSC made a few differences according to the ratio of starch to water. As the microwave heating time took longer, gelatinization temperature and gelatinization $enthalpy({\bigtriangleup}H_1)$ were decreased in and melting $enthalpy({\bigtriangleup}H_2)$ was increased in group A. Whereas they were increased in group B. In both groups, maximum viscosity in gelatinization by Brabender amylogram was decreased by microwave heating. Then the peak of the maximum viscosity was shifted to higher temperature and cold viscosity was slightly increased. In group A, viscosity in gelatinization and light transmittance by NaOH was increased in initial stage and gel volume in gelatinization by KSCN was decreased. On the other hand, in group B, viscosity by alkali was slightly decreased, but light transmittance by NaOH was almost never changed. Gel volume is decreased like group A.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.428-435
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• 1992

Intrinsic viscosity and gelatinization properties of brown rice starches of Japonica and Tonsil type cultivars were investigated. The intrinsic viscosity was similar between the two cultivars. The gelatinization temperature of Japonica brown rice starch determined by differential scanning calorimetry was higher than that of Tonsil brown rice starch. However, the range of gelatinization temperature, gelatinization enthalpy and the water content for gelatinization were similar between the two starches. The treatment of starch at 6$0^{\circ}C$ for 24hr increased the gelatinization temperature and gelatinization enthalpy and decreased the range of geltinization temperature. The water content for gelatinization was negatively correlated with the range of gelatinization temperature in case of Japonica starch and with the intrinsic viscosity in case of Tonsil one. The in-trinsic viscosities of both Japonica and Tonsil starches were positively correlated with gelatinization enthalpy.

• Korean Journal of Food Science and Technology
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• v.24 no.1
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• pp.70-73
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• 1992

Gelatinization behaviour and gel properties of corn starch modified either by hydroxypropylation only or by cross-linking and hydroxypropylation were investigated. Gelatinization temperature of corn starch decreased greatly by hydroxypropylation, but increased slightly by cross-linking with epichlorohydrin. The treatment of both hydroxypropylation and cross-linking lowered the gelatinization temperature, although it was not significantly different from that of hydroxypropylated corn starch. The swelling power of the corn starch was reduced and gel strength was increased by both modifications. The results suggested that the gelatinization behaviour and gel properties of corn starch could be improved by both cross-linking and hydroxypropylation.

• Korean journal of food and cookery science
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• v.16 no.5
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• pp.431-436
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• 2000

Gelatinization properties of potato starches which were prepared by steeping at 10 ${\pm}$ 1$^{\circ}C$ or 25 ${\pm}$ 1$^{\circ}C$ for 11 days were investigated. The pasting and initial gelatinization temperatures measured by rapid visco-analyzer (RVA) were increased, but the peak and trough viscosities of potato starch were decreased by steeping. The onset temperature, peak temperature, conclusion temperature, and enthalpy of gelatinization were increased by steeping as measured by DSC. The contents of hot-water-soluble carbohydrate and amylose in potato starch were decreased by steeping.

• Applied Biological Chemistry
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• v.34 no.1
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• pp.75-76
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• 1991

Bran structure and gelatinization property of upland and lowland japonica waxy brown rice were compared. Dimension, weight and number of aleurone layer were similar between upland(Nonglimna 1) and lowland(Shinsunchalbyeo) rices, but the aleurone layer and pericarp of upland rice were thicker. Water uptake rate of upland rice at $60^{\circ}C$ was lower than that of lowland one. There was no difference in intrinsic viscosity between two rice starches. Upland rice starch had lower onset temperature, narrower gelatinization temperature and lower water content lot gelatinization compared with lowland rice starch.

• Food Engineering Progress
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• v.21 no.4
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• pp.341-350
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• 2017

The relationship of in vitro starch digestibility and gel strength was investigated at various concentrations (10-30%) of rice cultivars with different amylose contents (27.9, 17.9, and 5.2%). As the rice flour concentration increased, predicted glycemic index decreased, but gel strength increased regardless of amylose contents. Gel strength correlated strongly with amylose content, whereas in vitro starch digestibility was more highly affected by rice flour concentration than by amylose contents. Moreover, the impact of degree of gelatinization on in vitro starch digestibility of high amylose rice was also examined in terms of structural features and rheological properties. The digestion rate of fully gelatinized flour was 1.7 times higher than that of native flour, while the disrupted structure with a different gelatinization degree during starch digestion was visually demonstrated through the X-ray diffraction and molecular distribution analysis. The rice flour changed from an A-type to a V-type pattern and showed difference in crystalline melting. The low molecular weight distribution increased with increasing degree of gelatinization during starch digestion. The apparent viscosity also increased with degree of gelatinization. These results demonstrated that the starch digestibility of rice was more affected by concentration than by amylose content, as well as by the degree of gelatinization due to structural difference.

• Journal of the Korean Society of Food Culture
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• v.37 no.4
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• pp.345-353
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• 2022

This study compared the physicochemical and gelatinization properties of naked barley, tetrastichum barley, and waxy barley. Compared to tetrastichum barley and waxy barley, naked barley had shorter and rounder grains with a 1.43 length/width ratio. Tetrastichum barley had lower crude protein, crude lipid, and crude ash content and higher amylose content compared to naked barley and waxy barley. The L, a, b color values of waxy barley were significantly higher than those of naked barley and tetrastichum barley. The water absorption index (WAI) and the water soluble index (WSI) were highest in waxy barley. The X-ray diffraction pattern was type A in all samples, and the peak intensity was highest in waxy barley. The maximum viscosity, cooling viscosity, breakdown, and setback of amylogram properties were the highest in tetrastichum barley. The thermal properties through the differential scanning calorimeter showed that the waxy barley had higher values of the onset, peak, conclusion temperature and enthalpy (?H). In conclusion, the variety of barley influenced the physicochemical and gelatinization properties, which could be important factors in the manufacture of processed foods. These results would thus useful inputs for the manufacturing of these foods using barley.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.90-97
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• 2023

The effect of citric acid on rice starch gelatinization and low-temperature (4 ℃) storage was studied in order to produce rice cake with a lower retrogradation rate. A citric acid solution in the ratio of 0, 0.5, 1.0, and 1.5% (w/w) of the water used during production was utilized. The gelatinization properties, gel strength, thermal properties, and texture analysis were evaluated to determine the retrogradation rate. The result showed that acid hydrolysis occurred in samples treated with citric acid. Thus, increasing citric acid decreased gelatinization temperature (58.63±1.98 to 45.84±1.24 ℃). The moduli of elasticity increased with increasing citric acid concentration, indicating an increased gel strength. Thermal analysis of starch showed that the onset, peak, and conclusion temperatures of retrogradation were increased significantly with the storage period and decreased with citric acid concentration. After 72 h of low-temperature storage (4 ℃), the retrogradation rate was lowest in the rice cake with 1.5% citric acid solution, with an increased ratio of 12.01 to 13.60% compared to the control sample, with a ratio of 12.99 to 43.54%. This shows a high retrogradation rate in the control sample. Additionally, sensory properties and retrogradation ratio suggest that the addition of 1.0% citric acid solution during rice cake production is efficient in retarding the retrogradation without an adverse effect on the rice cake modeling and acceptance.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.850-854
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• 2012

This study is carried out in order to develop food materials for the promotion of rice consumption. In this study, we researched the physicochemical properties of extruded rice flour (ER) and gelatinization popped rice flour (GPR) by the extrusion process and by the popped method with milled rice and brown rice. The extrusion process used a couple of screw extruders. The extrusion parameter was kept constant at a feed moisture content of 25%, barrel temperature of $120^{\circ}C$ and screw speed of 400 rpm. GPR was prepared by batch popping machine after gelatinization of rice. In order to evaluate the physicochemical properties of ER and GPR, as well as the gelatinization rate, water soluble index (WSI), water adsorption index (WAI), DPPH radical scavenging activity and total dietary fiber content, the color value was carried out. The gelatinization rate was similar to 71.1~73.8%. Further, the results of WSI and WAI were increased at ER and GPR compared to the raw materials; ER was also higher than GPR. DPPH radical scavenging activity and total dietary fiber content showed a tendency to reduce after extrution and popping. As a result of the color value, the L value of ER decreased more than the raw materials, whereas GPR increased at a and b values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.40-47
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• 1993

Gelatinization properties of the air-dried sediment of cowpea were investigated. The water-binding capacity of cowpea flour was drastically increased over the temperature range of 52~55$^{\circ}C$. The percent transmittance of flour suspension was linearly increased at temperature between $65^{\circ}C$ to 75$^{\circ}C$. The gelatinization temperature determined by differential scanning calorimetry was 63.4~76.$0^{\circ}C$. Cowpea flour showed a single-stage of swelling and a low solubility pattern. The minimum moisture content required for the gelatinization was 37.0% . The amylograph peak viscosity was greatly influenced by concentration of the flour, but was not affected by heating temperatures (85~94$^{\circ}C$) at a given concentration. The 20 min height and cold viscosity at 3$0^{\circ}C$ at a fixed concentration was negatively correlated (p<0.05) with heating temperatures.