• Journal of Applied Biological Chemistry
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• 제66권
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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.

• 한국작물학회지
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• 제44권4호
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• pp.355-363
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• 1999

The experiments were carried out to elucidate the varietal variation of retrogradation in aged cooked rice and its association with some physicochemical properties of milled rice. The fifteen rice materials were selected from forty-three low-amylose japonica and Tongil-type rice cultivars based on palatability and retrogradation of cooked rice stratified by preliminary sensory evaluation of warm and cooled cooked rice. One japonica glutinous rice variety was included for comparison of retrogradation of cooked rice. The $\alpha$-amylase-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The desirable checking time for evaluating the varietal difference in deterioration of aged cooked rice was four hours after storing in room temperature and two hours after preserving in refrigerator based on the largest coefficients of variations in degree of retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were Ilpumbyeo, Chucheongbyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tongil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, showed the relatively fast deterioration of cooked rice. The retrogadation index represented by the percentage of retrogradation difference between warm and cooled cooked rice to original estimates of warm cooked rice was significantly affected by the degree of retrogradation of cooled cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogradation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked nce. The varietal difference in retrogradation of cooked rice can be effectively classified by scatter diagram on the plane of upper two principal components based on some retrogradation properties of cooked rice. The deteriorated structural change in cooled cooked rice by observing through the scanning electron microscope was more conspicuous in the fastly retrograded cooked rice than in the slower one.

• 한국식품영양과학회지
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• 제20권2호
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• pp.173-178
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• 1991

The rheological properties of acorn crude starch gel and refined starch gel were investigated by puncture test, back-extrusion test and retrogradation test. Puncture test was a useful method to compare the different gel type and concentration, and to calculate the compression and shear coefficient. Maximum extrustion force and adhesiveness were also examined by performing back-extrustion test. The retrogradation rate was analysed by Avrami equation in retrogradation test.

• 한국식품영양과학회지
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• 제26권5호
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• pp.886-891
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• 1997

The interrelation between physicochemical properties of milled rice and retrogradation of rice bread during cold storage was examined to compare the varietal difference in maintenance of rice bread quality. Twelve rice materials showed big varietal difference on physicochemical properties of rice starch such as amylose content(0.0~29.2%), gel consistency(20~98mm), and alkali digestion value(2.0~7.0). Rice bread made from milled rice of Jungwonbyeo, AC 27 and IRAT 177 exhibited soft texture and late retrogradation of rice bread during cold storage(4$^{\circ}C$). The amylose content of milled rice was closely associated with gel consistency negatively and with springiness of rice bread positively. The retrogradation of rice bread texture during cold storage was correlated with gel consistency of rice flour positively and with alkali digestion value of milled rice negatively.

• 한국식품영양학회지
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• 제36권6호
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• pp.581-587
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• 2023

Brown rice has various health benefits; however, it is more difficult to cook and has a harder texture as compared to milled rice. In this study, the effect of the sous-vide cooking method on starch retrogradation and textural properties of brown rice was investigated by comparative analysis with conventionally cooked brown rice based on moisture content assay, evaluation of the textural property analysis, and differential scanning calorimetry (DSC). The results of the study are as follows: First, the moisture content of sous-vide cooked brown rice was higher than in the conventionally cooked brown rice. Second, the sous-vide cooked brown rice has lower hardness, higher adhesiveness, and lower retrogradation enthalpy during storage than conventionally cooked brown rice. Finally, the retrogradation properties of cooked brown rice during storage were analyzed by DSC. The enthalpy increased more rapidly in the case of conventional cooked brown rice, reaching 1.58 J/g after 3 days of storage. This indicated that sous-vide cooking is effective in preventing retrogradation of rice during storage.

• 한국식품영양학회지
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• 제22권2호
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• pp.185-191
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• 2009

This study investigated the effects of adding hard and soft wheat flour to Korean rice cakes(Karedduk) to retard retrogradation, by examining texture properties and descriptive sensory qualities after 2 and 24 hrs of storage at $5^{\circ}C$. The hard and soft wheat flour were combined with dry rice flour at levels of 0, 5, 10, and 20%. The texture properties, as analyzed by a Texture Analyzer, revealed that the springiness, cohesiveness, and adhesiveness of the rice cakes containing wheat flour were similar to those of the control, while chewiness, gumminess, and hardness were lower compared to the control. Also, in sensory analyses, hardness was significantly different in the rice cakes containing wheat flour compared to the control after 24 hrs of storage at $5^{\circ}C$. Overall, the instrumental texture properties were highly correlated with the sensory characteristics. These results suggest that adding hard and soft wheat flour to Korean rice cakes(Karedduk) is effective at retarding retrogradation.

• 한국식품영양과학회지
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• 제21권6호
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• pp.672-676
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• 1992

동부와 녹두 전분 gel의 텍스쳐 비교에 관한 연구의 일환으로 저장중의 노화 특성을 노화속도, 결정화도의 변화 및 이장량을 측정하여 비교하였다. 두 시료 전분 gel(30%)을 $20^{\circ}C$에서 저장하여 Avrami방정식으로 계산한 시간 상수는 동부 전분 gel이 1.9215일, 녹두 전분 gel이 1.984일로 거의 비슷하였으며 노화된 시료 전분 gel(10%)의 X-선 회절도는 모두 2${\theta}$ ; $17.2^{\circ},$ $22^{\circ},$ $24.0^{\circ}$ 에서 peak를 보여 B도형을 나타냈다. 한편 이장량은 두 전분 gel(6~10%) 모두 농도가 낮을수록 많았고, 저장 1, 2일째에 가장 많았으며 그 이후로 이장량의 증가율은 서서히 둔화되어 저장 6일째에 농도와 시료에 따라 17~34.9%에 이르렀다.

• 한국식품과학회지
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• 제20권6호
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• pp.794-800
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• 1988

재래 찰벼 신선찰벼와 다수계 찰벼. 통일찰벼 및 찰보리(수원 227호), 찰수수, 차조, 율무등의 전분을 분리하여 노화 특성에 관하여 글루코아밀라아제에 의한 노화도 측정법, X-선 회절법, ${\beta}-amylolysis$등으로 비교 측정한 결과는 다음과 같다. 첫번째, 6종의 찰 전분을 $0{\sim}5^{\circ}C$에서 20일, 30일 저장했을 때와 냉동, 해동 반복을 20회, 30회 했을 때 노화 속도가 대단히 느리다. 두번째, 노화가 잘되는 순서는 찰수수 > 찰보리 > 차조 > 율무 > 통일찰벼 > 신선찰벼의 순이었으며 찰수수와 찰보리는 다른 전분에 비하여 노화가 잘 되었다. 세번째, 노화를 촉진하는 인자로서 냉동, 해동 30회 반복은 $0{\sim}5^{\circ}C$ 냉장 30일과 비슷한 경향을 보였다. 마지막으로, 우리나라에서 단 하나의 장려 품종인 찰보리(수원 227호)는 보리 한알속에 메 전분 입자가 약15% 혼입되어 있으며 앞으로 찰보리 육종에 참고로 하였으면 한다.

• 한국식품조리과학회지
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• 제13권1호
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• pp.7-15
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• 1997

The composition and polymeric structure of starch are the most important factors to determine the functional properties of rice. In an effort to relate the structural characteristics and its functional properties of starch in rice, molecular structural properties of starch from 6 rice cultivars were analysed. To relate the structure and function of starch the texture of Jeung-pyun made of rice were analyzed during retrogradation. The polymeric structure of rice starch was analyzed by debranching with isoamylase after gelatinization and fractionated with Sephadex G-75 gel filteration. The size fractionated debranched starch was categorized into four groups such as Fraction I, II, III and Intermediate Fraction depending in their max, The fractions with the max higher than 620 nm were designated as Fraction I, while those in the range of 600-620 nm and 540-600 nm as the Intermediate Fraction and Fraction II, respectively. The Fractions with the max lower than 540 were described as Fraction III. The average degree of polymerization (DP) of the Fraction I was estimated to be higher than 200, and those of other fractions, i.e. the Intermediate Fraction I, Fraction II and III were 150,45 and 25, respectively. The levels of Fraction I were varied from II to 35％ of total sugar. The Fraction I showed the linear relationship with the amylse contents, and the Intermediate Fraction, which might contain the mixture of short chain of amylose and debranched long chain of amylopectin, were measured to be in the range of 2.7∼8.4%. The levels of fraction II and III, both to be considered as the branches of amylopectin, were ranged 14.5∼23.6% and 39.7∼73.0%, respectively. The ratio of Fraction III to Fraction II describing the degree of branch or compactness of amylopectin was estimated to be around 4.0 for waxy varieties and around 2.0 for high amylose cultivars. With these results, it can be suggested that the degree of branch of the amylopectin may effect on amylose contents of starch or rice versa, To invertigate processing aptitude of different rice cultivars for the preparation of Jeung-pyun, its texture was analyzed by Instron, hardness, cohesiveness, elasticity, gumminess and chewiness of Jeung-pyun made of rice showed the significant relationship with the amylose content. Hardness was increased during retrogradation of product, but the relationship between hardness and amylose content due to not only difference in amylose content but also difference in structural characteristics of starch. In analysis of relationship between structure of rice starch and mechanical properties of Jeung-pyun during retrogradation elasticity did not show any relationship before retrogradation bur during retrogradation showed significant correlation. With these result, it can be suggested that the degree of branch of the amylopectin may effect on elasticity during retrogradation. However hardness, cohesiveness, gumminess and chewiness which were significant different before retrogradation, showed some correlation with structure of rice starch during retrigradation.

• 한국식품영양학회지
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• 제26권2호
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• pp.192-198
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• 2013

The quality characteristics of Korean rice cakes (Karedduk) with a mixture of maltooligosaccharide and OSA (octenyl succinic acid starch) added, after 2 and 24 hr of storage at $5^{\circ}C$, was analyzed. A central composite design was used for arrangement of treatment. The two independent variables selected for retarding retrogradation analysis were amounts of maltooligosaccharide (x) and OSA (y). Maltooligosaccharide was added at 0, 3, 6, 9, and 12% levels, and OSA added at 0, 0.3, 0.6, 0.9, and 1.2% levels, to dry rice flour. The texture properties analysis using a Texture Analyzer revealed that the springiness and cohesiveness (p<0.01), chewiness, gumminess and hardness (p<0.001) were significantly different after 24 hr of storage at $5^{\circ}C$. The effect of retarding retrogradation of Korean rice cakes with added mixtures of maltooligosaccharide and OSA showed an increasing trend as the amount of maltooligosaccharide increased. Overall, the instrumental texture properties were highly correlated with the sensory characteristics. These results suggest that adding a mixture of 6% maltooligosaccharide and 0.6% OSA to Korean rice cakes (Karedduk) is effective for retarding retrogradation.