• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.1-5
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• 2000

Physicochemical properties and gelatinization patterns of purple-fleshed sweet potato starch were studied. Shape of starch granule was round and polygonal, X-ray diffraction pattern was Ca-type. Amylose content was 14.4% which was lower than that of other sweet potato starch. Water binding capacity was 82.54%, swelling power and solubility at 8$0^{\circ}C$ were 27.94% and 15.35%, respectively. Initial temperature of gelatinization was 72$^{\circ}C$ using Brabender/Visco/Amylograph, consistency and setback were lower than those of other sweet potato starch. The peak temperature and enthalpy determined by DSC were 68.1$^{\circ}C$, 1.24cal/g, respectively. The transmittance of starch dispersions in alkaline solutions increased with NaOH concentration up to 0.17N, and then changed slowly at 0.19N or above. The apparent viscosities were similar to the transmittance of starch dispersions in alkaline solutions, but drastically increased above 0.21N.

• Korean journal of food and cookery science
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• v.14 no.3
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• pp.207-212
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• 1998

The changes in physicochemical properties of potato were investigated while steeping in water for 7 days at 30${\pm}$1$^{\circ}C$. The shape of raw starch granules was round or oval, the starch granule showed birefringence distinctly under polarized light and it was kept clearly even after steeping. X-ray diffraction pattern of the starch was B-type and there was no change in the pattern after steeping. However, crystallinity was increased up to the 4th day and then decreased. Amylose contents of raw starch and the starch steeped for 7 days were 19.3% and 13.1%, respectively. When the potato starch was gelatinized in 0.15 N sodium hydroxide solution, the viscosity was decreased until the 3rd day, but increased thereafter. Gel volume of the starch in KSCN solution was decreased during steeping.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.2
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• pp.88-98
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• 1978

Amylose content, water absorption and amylograph characteristics of waxy and nonwaxy barley varieties were studied. Amylose content of nonwaxy varieties ranged from 23.4% to 31. 5% and waxy varieties showed 5.4%-9.5%. Water absorption of waxy varieties was highest among the materials tested. Waxy barley showed lowest gelatinization temperature among the varieties. Gelatinization temperature was positively related with the maximum viscosity in all tested varieties. There was no relationships between amylose content and gelatinization temperature, gelatinization time and viscosity.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.1
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• pp.122-127
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• 2010

This study involved the making of sugar snap cookies with the addition of carrot powder at two to twelve percent which furnishes modern people with much lacking and needed dietary fiber. The review of the physiochemical properties, rheology and sensory evaluation of such contents resulted in the following findings: The sedimentation value and Pelshenke value all decreased in weak flour with the addition of more carrot powder, in comparison with the control group. The water retention capacity (WRC) and alkaline water retention capacity (AWRC) all increased in weak flour with the addition of more carrot powder in comparison with the control group. As for the gelatinization properties of the test samples measured by rapid visco-analysis, the addition of more carrot powder resulted in the initial pasting temperatures increasing in the case of weak flour, yet showing no significant difference between the control group and the carrot-added groups, as well as the maximum viscosity, minimum viscosity and final viscosity all showed the tendency of decreasing. The addition of more carrot powder led to the peak times in the mixographs for weak flour all exhibiting the tendency of decreasing, which might be interpreted as gradually weaker physical properties of the dough as well as less stability in the shape of the dough in turn.

• Culinary science and hospitality research
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• v.9 no.2
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• pp.85-97
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• 2003

This study is an attempt that Rheology changes are occurred by boiling, frying, and boiling potatoes with soy bean sauce. Three different methods are tested for chemical analysis, fine potato starch grain structural change, sensory evaluation. 1) Alkaline number and acidity number are changed (+)2.17 in raw, decreased (+)1.76 by boiling, increased (+)2.38 by frying, and (-)2.22 by boiling with soy bean sauce. 2) Potatoes are completely dissolved into the gelatinization when they are boiled at 10$0^{\circ}C$ for 15minutes(PB III), fried at 18$0^{\circ}C$ for 3 minutes(PF IV), and boiled with soy bean sauce l0$0^{\circ}C$ for 30 minutes(PS III). 3) The pectin content ratio is decreased according to frying (31.78$\mu\textrm{g}$/$m\ell$), boiling(44.20$\mu\textrm{g}$/$m\ell$), boiling soy bean sauce(36.37 $\mu\textrm{g}$/$m\ell$), Hemicellulose content ratio is decreased according to frying(1.19%), boiling(1.17%), boiling soy bean sauce(0.92%). And the contend of cellulose and lignin is still regardless of any cooking method. 4) The sensory evaluation conducted by 30 university students as panelists showed that there are more significant differences among four samples in appearance, flavour, texture. As a result, the optimum cooking condition for potatoes is that potatoes are boiled l0$0^{\circ}C$ for 15minutes, fried at 18$0^{\circ}C$ for 3minutes, and boiled with soy bean sauce at 1$0^{\circ}C$ for 30minutes.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.731-738
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• 2021

This study investigated the physicochemical properties of rice starch isolated from broken rice using alkaline steeping (AKL) and enzymatic digestion (ENZ) methods. Broken rice starch (BRS) by AKL and ENZ possessed crude protein contents (0.6-1.4%) acceptable to commercial products of native starch and belonged to an intermediate amylose rice starch. AKL-BRS and ENZ-BRS showed a typical A-type crystal packing arrangement with small variations in their relative crystallinity. ENZ-BRS exhibited higher gelatinization onset and peak temperatures, and a narrower gelatinization temperature range than AKL-BRS, indicating that annealing occurred in ENZ-BRS. Lower swelling power and solubility were generally observed in the ENZ-BRS. ENZ-BRS also showed slower viscosity development, higher peak and trough viscosities, and lower breakdown, final, and setback viscosities, compared to those in AKL-BRS. These results are ascribed to the annealing phenomenon in ENZ-BRS. Overall, BRS from cheap broken rice using AKL and ENZ could contribute to the expansion of rice starch utilization in food and non-food industries.

• The Korean Journal of Food And Nutrition
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• v.23 no.2
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• pp.162-170
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• 2010

This study investigated the effect of addition of pumpkin on the physicochemical properties of rice sponge cakes. Water retention capacity(WRC) was lowest in control preparations to which no pumpkin flour was added. WRC increased as more pumpkin flour was added and rice flour with 25% of added pumpkin flour showed a WRC of 89.0%. Similar to WRC, alkaline water retention capacity(AWRC) also increased as more pumpkin flour was added and ranged from 69.7% to 80.7%. As the amount of pumpkin flour added increased, the pH increased. Similar to the sedimentation value, the Pelshenke value also increased as the amount of the added pumpkin flour increased. The gelatinization temperature did not vary significantly between the samples(p<0.05). The midline peak height, which is the height of the peak point from the baseline, showed the same tendency with that of the midline peak time, but was not significantly different between samples(p<0.05). Volume was decreased as the amount of the added pumpkin flour increased. The weight of the rice sponge cakes showed significant difference increasing with the increasing added pumpkin flour(p<0.05). There was significant difference as the specific loaf volume decreased with the increasing pumpkin flour(p<0.05).

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.11-16
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• 1984

Rheological properties of waxy and non-waxy rice starch solutions were evaluated with a narrow gap rotational and Cannon Fenske viscometers. The gelatinized rice starch solutions containing 0.2-1.0% starch displayed pseudoplastic flow behavior. At higher starch level, degree of pseudoplasticity of waxy rice starch solutions increased, while that of non-waxy rice did not changed apparently. The consistency coefficient (K) of non-waxy rice starch solutions increased with increasing gelatinization temperature, but waxy rice starch solutions remained constant, and in alkaline aqueous solutions both of them showed increasing K values. The value of K increased exponentially with an increase in concentration. The effect of the temperature on the viscosity of the solutions followed Arrhenius' type equation, and the activation energies were in the range of 3.675-3.775 kcal/g-mol that were near to that of pure water. The changes of reduced viscosity with concentration were followed Huggin's equation and the values of intrinsic viscosity and interaction coefficient were 0.78-1.59 dl/g and 0.67-2.75, respectively.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.749-755
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• 2021

The objective of this study was to investigate the physicochemical properties of rice starch extracted from stale rice using alkaline steeping (AKL) and improved enzymatic digestion (iENZ) methods. The crude protein content (0.5-0.7%) of stale rice starch (SRS) was less than 1% by iENZ, but not so when measured by the existing ENZ methods. SRS is an intermediate amylose rice starch. AKL-SRS and iENZ-SRS exhibited typical A-type crystal packing arrangements with similar relative crystallinities. iENZ-SRS showed higher gelatinization onset and peak temperatures with a narrower gelatinization temperature range, compared to those of AKL-SRS, indicating that iENZ annealed SRS. Thus, iENZ-SRS exhibited lower swelling power and solubility, and higher pasting viscosities with delayed viscosity development. Overall, the use of stale rice as a rice starch source could make economical production of rice starch possible, and iENZ may diversify rice starch characteristics, which expands the utilization of rice starch in food and non-food industries.

• Food Engineering Progress
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• v.23 no.3
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• pp.193-199
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• 2019

This study aimed to investigate the impact of protease treatments on the yield of rice starch (RST) from frozen rice flours, and to compare the physicochemical properties of RST by alkaline steeping (control) and enzymatic isolation (E-RST) methods. Although the yield of E-RST, prepared according to conditions designed by the modified 23 complete factorial design, was lower than the control, the opposite trends were observed in its purity. E-RST (RST1, isolated for 8 h at 15℃ with 0.5% protease; RST2, isolated for 24 h at 15℃ with 1.5% protease; RST3, isolated for 24 h at 15℃ with 0.5% protease) with the yields above 50% were selected. Amylose contents did not significantly differ for the control and RST2. Relative to the control, solubilities were higher for all E-RST, but swelling power did not significantly differ for E-RST except for RST1. Although all E-RST revealed higher gelatinization temperatures than the control, the reversed trends were found in the gelatinization enthalpy. The pasting viscosities of all E-RST were lower than those of the control. Consequently, the enzymatic isolation method using protease would be a more time-saving and eco-friendly way of preparing RST than the alkaline steeping method, even though its characteristics are different.