• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.468-473
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• 2013

This study was conducted to make clustering analysis based on major physicochemical characteristics related to palatability of 394 Korean rice land-races. The items investigated were protein content, Mg content, K content, Mg/K ratio, Toyo-taste value, ADV (alkali digestion value) and amylose content. The range of the physicochemical characteristics such as amylose, protein, magnesium, potassium was from 12.4 to 28.9%, from 5.2 to 9.9%, from 12.7 to 37.7 mg and from 60.0 to 125.9 mg, respectively. In this experiment, the grain quality, properties significantly associated with the estimates of Toyo taste meter, were protein and amylose contents and hot viscosity. Also, at the expected taste as a cooking rice, using Toyo taste meter, a total 16 accessions were selected as good taste as "Ilpumbyeo". Also, IT173444, IT008530 and IT006554 were selected as remarkable sources for the cooking rice, in terms of gelatinated temperature and Toyo taste meter value.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.31-39
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• 2020

The effects of heat-moisture treatment (HMT) on the functional properties of high amylose rice starches (HARSes) purified from Korean rice varieties (A-type Goami and Singil and B-type Dodamssal and Goami2) were investigated. HMT was accomplished with moisture contents of 18 and 27% and heated at 100℃ for 16 h. While the amylose content, swelling power and solubility decreased after HMT, the water binding capacity and resistant starch (RS) content increased with increasing moisture content after HMT. The X-ray diffraction patterns of all HARSes did not change after HMT, but a decrease in the intensity of peak at 2θ=5° was observed in B-type HMT HARSes. While the starch granules aggregated after HMT, their shape and size remained unchanged. B-type HARSes exhibited higher gelatinization temperatures and lower pasting viscosities than A-type HARSes following HMT. The results, thus, suggest that while the crystalline intensity of B-type Dodamssal and Goami2 rice starches did not change after HMT, the RS content, water binding capacity, and pasting temperatures of all HARSes increased with increasing moisture content after HMT.

• Korean Journal of Food Science and Technology
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• v.1 no.1
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• pp.51-61
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• 1969

In order to eliminate the considerable loss of rice by insects, to protect the human body from toxin excreted by some microbes, and to promote the storage efficiency of rice by employing the irradiation, the following experiments were carried out. Two varieties of rice, Paldal and Nongkwang polished and unpolished by the conventional methods and were packaged in polyethylene bags. After irradiating to the doses of 6-400 Krad of gamma-radiation from a $Co-^{60}$ source the samples were stored at the room temperature $20^{\circ}C$ for 8 months. The effects of radiation in terms of the removal of insects and microbes and the changes of chemical components (such as moisture, amylose, free sugar, and rancidity) were determined monthly from march to October during the storage. 1) Infestation of insects was greatly influeneed by the packaging materials used. There was no infestation in rice being packaged in a polyethylene bag, while as the rice packaged in a straw sack was infested in two months of the storage. 2) Some yeast and molds survived 400 K rad of radiation. Sterilizing dose to inhibit reproduction and growth of microbes was presumed to be higher than 400 K rad. Yeast mainly were found on the surface of rice, but mold were embeded into rice kernels by mycelium. 3) Changes of moisture contents during storage was not affected by radiation but was by humidity of the storage room. 4) Amylose content in starch increased with increasing dose of radiation and with the length of storage time, indicating possible depolymerization of starch molecules. 5) Free reducing sugar content was not affected by radiation and decreased with storage time. 6) Rancidity also increased with does and storage time.

• Korean journal of food and cookery science
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• v.3 no.2
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• pp.59-67
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• 1987

In order to make use of Job's tears widely, Job's tears starch was analyzed and determinded the contents of amylose, amylographical and other physicochemical properties. And also the yeast breads and rice cakes were made from flour and rice flours with various mixing ratios of Job's tears flour and then they were tested for suitability to preparation of bread and rice cake. 1. The starch contents of Job's tears showed 12~20%. Which was about one third of rice or waxyrice starch. But amounts of crude proteins, fats, and total ashes in Job's tears were higher than rice or waxyrice. Job' tears starch was composed of amylopectins only, and was similar to that of waxyrice starch. 2. Depends upon the Amylogram of each starch, initial gelatinization temperature of Job's tears starch was the highest among three starches of rice, waxyrice, and Job's tears. Maximum viscosity of Job's tears starch was 860BU, then it was about two times of rice starch viscosity. 3. By the sensory evaluation results, the taste of bread prepared with mixing of 10% Job's tears flour was better than flour bread and the volume and grains of the bread made from mixing of 10%, 20% Job's tears flour were similar to that of flour bread, but the taste, volume and grains of bread made from 30% mixed flour were undesirable. The rice cake Prepared from mixed flour with 25% Job's tears flour has shown to be desirable.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.375-379
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• 2007

This study was carried out to examine the effects of storage duration on physico-chemical properties of milled rice. Rough rice of three rice ecotypes(Japonica, Tongil and F1 hybrids with Tongil back-ground) was stored for 4, 16, 28 and 40 months without artificial environmental control in seed warehouse. And this materials were investigated for seed germination rate, brown rice hardness, alkali digestion value(ADV), contents of protein, amylose, total sugar, and reducing sugar. Seed germination rate was significantly reduced with storage duration increased regardless of rice ecotypes : 66.7% from 16 months storage, 2.5% from 28, and nil from 40 months storage in Japonica rices. And 54.0%, 67.9% in Tongil, and F1 hybrid after 40 months storage, respectively. Brown rice hardness was not significantly affected by storage duration but showed significant genotypic differences. As the storage duration prolonged, sugar content and alkali digestion value increased, protein content declined while amylose content did not show clear tendency. Total and reducing sugar contents showed sharp increase upto 16 months storage and thereafter steady in crease, and the percentage of reducing sugar content out of total sugar content increased with extended storage duration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1279-1284
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• 2011

Gelatinization properties of crude starches from acorns harvested in various countries (domestic (KAS), Chinese (CAS), and North Korea (NAS)) were analyzed, especially blue value, amylose contents, amylogram, particle size, and SEM (scanning electron microscope). Amylose contents of NAS, KAS, and CAS were 33.65%, 32.00%, and 30.48%, respectively, and a similar tendency was observed in blue value. According to amylogram, initial paste temperature was $72^{\circ}C$ for NAS and CAS and $71^{\circ}C$ for KAS, whereas peak viscosity was 580 BU for KAS and NAS and 570 BU for CAS. The cooling viscosity and setback of NAS and CAS were higher than those of KAS. The average particle size was 23.17 microns for KAS, 23.53 microns for CAS, and 82.14 microns for NAS; particle size ranging from 5~40 microns was highly distributed in KAS (68.9%) and CAS (73.8%), whereas 57.1% distribution was observed for 5~40 microns and 27.2% for >80 microns in NAS. Gelatinization ranges of SEM photography of CAS and NAS showed a more swollen, extremely disintegrated, and folded structure than that of KAS. From these results, gelatinization properties, especially viscosity, setback of amylogram, particle size, and SEM photography, differed according to the country.

• Korean journal of food and cookery science
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• v.2 no.2
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• pp.32-42
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• 1986

Two Tongil type rice varieties and two Japonica rice varieties were prepared and experimented to investigate the effect of physicochemical properties on rice palatibility. Obtained results are as follows; (1) Width and thickness of unhunlled and unpolished grains of Tongil type rices were shorter than those of Japonica type rices and the length of the former was much longer than the latter. (2) Protein contents of Tonsil type varieties were greater than Japonica ones and amylose contents of the former is less than the latter. Alkali digestibility of them showed no significant differences. These means that the qualities of Tongil rices are not less than Japonica ones. (3) Sensory evaluation test showed that Japonica type rices are more excellent than Tongil types in expansion, glutinosity, flavour and taste while the former is inferior to the letter in gloss. (4) Preconceived ideas on the shape of rice seemed to affect most on its palatability.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.304-313
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• 2018

The objective of this study was to investigate the resistance starch(RS) content and in vitro hydrolysis index of roasted rice flours for low GI food development. This study used intermediate and high amylose rice varieties containing resistant starch. The intermediate amylose rice varieties 'Ilmi' and high amylose rice varieties, 'Goami4' and 'Dodamssal' were tested. The crude fat and crude protein contents of the rice cultivars ranged 2.12~3.08% and 6.2~7.63%, respectively. The RS and amylose contents of Dodamssal and Goami4 were higher than those of Ilmi. RS content of Ilmi was not significantly different before and after roasting treatment. The RS content of Goami4 before roasting was significantly higher than that of Dodamssal, but the RS content of Dodamssal was higher than that of Goami4 at temperatures above $210^{\circ}C$ of roasting. The soluble starch decreased after roasting in Goami4 and Dodamssal. Starch hydrolysis index (HI) and expected glycemic index (GI) were higher in order of Imi, Goami4 and Dodamssal regardless of roasting treatment. The sensory evaluation showed high scores in Dodamssal for color, flavor, bitter taste, bitter taste, sweet taste and sweetness at $240^{\circ}C$ for 10 min and $210^{\circ}C$ for 30 min. The results of this study indicate that Dodamssal was suitable varieties for powder meal with low GI.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1407-1414
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• 2014

Physicochemical properties of rice-based expanded snacks extruded with rice flour, high amylose starch, and isolated soy protein were investigated using a twin-screw extruder. The ingredients were extruded at various feed moisture contents (19~23%) and screw speeds (200~400 rpm) at a constant feed rate (43.4 kg/hr). Bulk density and apparent density of rice snacks were 0.06~0.21, and 0.55~0.65 respectively. Bulk density, apparent density, water absorption index, and breaking strength of rice snacks increased with increasing feed moisture content and decreasing screw speed. However, expansion and water solubility index of rice snacks increased with decreasing feed moisture content and increasing screw speed. Hunter's color L values of rice snacks was lower with increasing screw speed at feed moisture contents of 19% and 21%, but was not significantly different from a feed moisture content of 23%. On the other hand, a and b values of rice snacks were higher with increasing screw speed a feed moisture content of 19%. X-ray diffraction intensity of rice snacks decreased with decreasing feed moisture content and increasing screw speed. X-ray diffraction of rice snacks was V-type at feed moisture contents of 19% and 21% and screw speeds of 300, and 400 rpm. In the microstructure of the cross section of rice snacks, air cells in rice snacks were not well formed, and cell walls were thicker with increasing feed moisture content and decreasing screw speed.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.5
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• pp.760-765
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• 2008

This study was performed to analyze the properties of the endosperm components of two pigmented rice varieties, glutinous and non-glutinous rice. Apparent amylose contents (AAC) of starch endosperm were 13.72% and 12.05% in pigmented non-glutinous rice and pigmented glutinous rice, respectively. Both initial temperatures for gelatinization of the two pigmented rice varieties were lower than that of milled rice. The enthalpy for gelatinization of pigmented non-glutinous rice was similar to that of milled rice, but higher than that of pigmented glutinous rice. Pigmented glutinous rice showed the highest Mg/K ratio, which affected the glutinosity in cooked rice. No difference was found in amino acid content among the various groups; however, the lysine contents were higher in the two pigmented rice varieties compared to milled rice. There was no difference in the fatty acid composition among the groups tested. Moreover, the major components of fatty acids were palmitic acid, oleic acid, and linoleic acid in the two pigmented rice varieties and milled rice. The breakdown value of gelatinization property by RVA (Rapid Visco Analyzer) was lowest in pigmented non-glutinous rice.