• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.3
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• pp.226-231
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• 2013

A total 11 Korean rice cultivar was prepared and investigated for its starch and quality characteristics. Amylose content, damaged starch contnent, water contnent, water absorption index (WAI), water solubility index (WSI), particle size and pasting properties of rice flours were measured. The amylose content of waxy, middle waxy and non waxy type domestic normal rice cultivars were 7.09%, 11.69% and 18.58-21.52%, respectively. Moisture content of 11 Korean rice cultivar were 7.19-13.89%. WAI and WSI did not show variations by amylose contents. Sample with high moisture contents was lower damaged starch contents. Particle size of samples was $27.61-189.67{\mu}m$. Final viscosity and pasting temperature of the samples was shown to rage from 45.54 to 313.94 RVA and from 71.03 to $87.98^{\circ}C$, respectively. In this study, results indicated that samples with low moisture contents tend to shown low particle size and high damaged starch contents regardless waxy, middle-waxy, and non waxy type.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.355-360
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• 2007

During the traditional production process of yugwa, a Korean traditional oil-puffed snack, three bacterial isolates, 12, 37, and B1 from waxy rice slurry were characterized by using the molecular techniques, and the quality of the yugwa prepared by using three isolates was examined in relation to physical and sensory properties. Isolates 37 and B1 were identified as Lactobacillus sp. by 16S rDNA sequence analysis, while isolate 12 was as Bacillus amyloliquefaciens by gyrA sequence analysis. Waxy rice inoculated with isolate 12 demonstrated the lowest hardness and the highest peak and [mal viscosity. Yugwa prepared from isolate 12-inoculated waxy rice indicated the lowest hardness and the highest volume expansion, the key characteristics of yugwa. This result presents the possibility for the use of a starter in the commercial production of yugwa and other rice-based snacks.

• Korean journal of food and cookery science
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• v.27 no.6
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• pp.745-754
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• 2011

To improve the textural properties of gluten free rice flour based products, the physicochemical and pasting properties of extruded non-waxy rice flours using extruder were investigated. The high yielding Tongil type rice variety, Hanarum was used. Hanarum rice flour was prepared by dry milling from soaked and dried rice grain. The operation conditions of twin screw extruder were 250 rpm of screw speed, $160^{\circ}C$ of barrel temperature, and 24, 27, and 30% of moisture content. Hanarum extruded rice flour (HERF) were lower in crude lipid and ash contents, but higher in crude protein than Hanarum rice flour (HRF). The color values of HERF showed significantly different (p<0.05) with different moisture contents. Water binding capacities, apparent amylose contents, and damaged starch of HERF were higher than those of HRF. Moisture contents affected water binding capacities of HERF. Solubility increased with increasing heating temperature and solubilities of HERF differed significantly (p<0.05). X-ray crystallinity was changed after extrusion cooking and that of HERF showed sharp peaks at $2{\theta}=18-20^{\circ}$. The pasting viscosities of HERF kept lower values (~ 10 RVU) constantly.

• Korean journal of food and cookery science
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• v.21 no.6 s.90
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• pp.942-949
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• 2005

To improve the textural properties and stabilize the structure and gel matrix of non-waxy rice starch gels, non-waxy rice starch/gum mixture gels were prepared from various food gums, gum arabic, guar, algin, deacyl gellan, xanthan and gellan gums. The morphological and textural properties and freeze-thaw stability of their gels were compared. Rice starch/gum mixture gels with various gums formed a more homogeneous gel matrix with smaller particle size than rice starch gel without Em, but the trends differed depending on the gum types. The textural properties of rice starch/gum mixture gels were changed with the gum types. The shape of the rice starch/gum mixture gel matrix was desirable when mixed with gellan and algin. The textural properties of gels hardened in the rice starch/algin mixture gel and softened in the rice starch/algin mixture gel. The rice starch gels showed V-type crystallinity by x-ray diffractometer, but the peak at $2\theta$ = $20^{o}$ was decreased with increasing gum addition. The freeze-thaw stability increased with increasing gum addition. Gellan and algin were especially effective.

• Food Science and Preservation
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• v.16 no.2
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• pp.266-275
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• 2009

To develop new high-quality Yakchobugak, features of Lactococcus lactis-fermented waxy rice paste after addition of some colored powdered agro-food products were investigated. Total and reducing sugars of waxy rice paste fermented by lactic acid bacteria were higher than those of control raw waxy rice paste. Total acidity gradually increased as powder concentration rose, being 1.02-1.56% and 0.96-1.87% in samples fermented with Cucurbita maxima and Capsicum annuum powders, respectively; these values were 3-4 times those in rice fermented with other powders. Fermented waxy rice paste viscosities were lower than those of non-fermented samples. The viscosities of samples fermented with Curcuma longa and Opuntia ficus powders were in the range $100-160{\times}10^4$ centipoise($mPa{\cdot}s$), and those of pastes fermented with Robus coreanus and Camellia sinensis extracts were under $40{\times}10^4mPa{\cdot}s$. Hunter color lightness(L) values decreased and yellowness(b) values rose after fermentation. Waxy rice paste fermented with Robus coreanus showed uniform particle size distribution, and many pores, by scanning electron micrography.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.55-59
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• 2001

Pressure-puffing system or extruder has been used to puff rice kernel or rice flour. Most of the study on rice puffing were the effect of process conditions such as moisture content and heating temperature on physical and chemical characteristics of popped rice. The study on mechanism and development of instant puffed rice like popcorn has been limited. Extruded waxy rice pellets were puffed in a microwave oven after drying and conditioning. Extruded pellets were formed with extrusion conditions of $20{\sim}27%$ moisture content, 2.76 MPa $CO_2$ gas injection pressure and 200 rpm screw speed. Under these conditions, puffed waxy rice pellets in microwave oven had low density and soft texture. Density and texture of puffed waxy rice pellet could be optimized by control of moisture content, $CO_2$ gas injection pressure and screw speed that affect significantly when puffing extruded waxy rice pellet.

• Korean journal of food and cookery science
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• v.11 no.5
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• pp.479-486
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• 1995

The reological properties of doughs blended with cereal flours were investigated in the study. The doughs were prepared of wheat flours mixed with 10％, 20%, 30% and 40% ratio of rice flour, waxy-rice flour, brown-rice flour and soybean flour. Amylogram, farinogram, extensogram and SEM were used to measured thier special properties with graphs and photos. The results were obtained as followes; 1. Wheat dough formation after fermantation, showed "stringing" structure of small starch granules on the SEM photo. But the large starch granules contributed little to the structure formation in rice flours dough, and played relatively a little role in the structure formation of blended doughs of waxy-rice, brown-rice and soy- bean flours. 2. The absorption of flour composited rice and brown-rice, was lower than that of the control by Farinograph. It was decreased the farinograph absorption with the increase of replacement ratio of cereal flours. Dough development time of cereal blended flours decreased, but that time of waxy-rice and brown-rice were very similiar. Farinograph stability of rice, waxy-rice, brown-rice and soybean blended flours, had shorter than that of wheat-flour. 3. The results showed that cereal blended flours decreased the resistance to extention (elasticity) without affecting the extensibility in fermented dough by Extensograph. 4. The gelatinization temperature of wheat, rice, waxy-rice, and brown-rice were 55.0$^{\circ}C$, 64.0$^{\circ}C$, 58.0$^{\circ}C$ and 61.0$^{\circ}C$. But that of all cereal blended flours showed 58.0$^{\circ}C$ except 20% or 30% soybean blended flours. According to the amylogram, each maximum viscosity of rice flour and wheat flour was 1760 B.U.,760 B.U.. Soybean composite flours had significantly lowe. amylograph peak viscosity (300 B.U.) than that of the other composite flours (450 B.U.-1100 B.U.).

• Korean journal of food and cookery science
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• v.25 no.2
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• pp.127-133
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• 2009

The aim of this study was to determine the optimum amount of waxy millet flour (WMF) to add to rice flour in the preparation of Sulgidduk (waxy millet rice cakes). According to the results, increasing the level of WMF in the formulation caused the moisture contents of samples to increase ($37.14{\sim}38.81%$). The L-value decreased with increasing additions of WMF whereas the b-value increased and the a-value did not differ by the addition of the flour. According to the mechanical evaluation results, hardness increased with increasing amounts of added WMF. Adhesiveness, cohesiveness, gumminess, and brittleness did not differ significantly and springiness was highest at the 30% level of WMF. From the sensory evaluation results, the 30% WMF samples received the highest overall-acceptability scores. In conclusion, according to its sensory and mechanical qualities, the optimal Sulgidduk formulation consisted of 30% WMF added to rice flour.

• Korean journal of food and cookery science
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• v.16 no.4
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• pp.316-320
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• 2000

This study was carried out to standardize the recipe of Gaeseong-Juak. The formation and quality of the Juak were investigated under different treatment conditions. 1. The high ratio of medium flour(20%) in the flour mixture resulted in poor swelling. 2. The flour mixture with 10% strong flour showed higher volume of Gaeseong-Juak compared with the 10% mixture of medium flour, but the score of sensory evaluation was low. 3. The addition of Makkoli in the dough did not give significant difference in the formation of Juak, but the sensory score was low. 4. The deep-frying temperature in the range of 150$\^{C}$ to 170$\^{C}$ allowed the greatest swelling of Gaeseong-Juak, but the highest quality score was obtained at 160$\^{C}$ treatment. Overall, the best preparation condition of Gaeseong-Juak was that the mixture of waxy rice flour with 10% medium flour was kneaded with Makkoli and fried at 160$\^{C}$.

• Journal of Nutrition and Health
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• v.15 no.2
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• pp.83-90
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• 1982

This study was attempted to investigate the effects of adding gelatinized waxy rice flour, wheat flour, and Xanthan Gum to rice flour on the preparation and (quality) of dried noodles. 1) Rice flour demonstrated higher maximum viscosity value as determined by Amylograph than wheat flour. Among the composite flour mixture (Rice Flour 85+Gelatinized Waxy Rice Flour 15 + Xanthan Gum 2%) showed the highest viscosity value and (RF 35+ GWRF 15 + Wheat Flour 50) had the lowest. (RF 35 + GWRF 15 +WF 50) demonstrated gelatinization characteristics which is quite similar to that of wheat flour. 2) Forty and 50% replacement of rice flour and gelatinized waxy rice flour (15%) mixture by wheat flour improved significantly noodle making characteristics and cooking quality of noodles. 3) The addition of 2% XG to (RF 45 + GWRF 15 + WF 40) was effective on noodle making properties and on binding properties of cooked noodles. 4) The cooked noodle made of composite flour (RF 45 + GWRF 15 + WF 40 + XG 2%) received the highest total sensory evaluation score among the testing samples, and it was not significantly different from that of wheat flour.