The objective of this study was to examine the effects of rice (R) and brown rice (BR) flour on the quality characteristics of morning bread. The quality characteristics of morning bread were determined by measuring the pH of the dough, dough raising power, moisture content, baking loss rate, specific volume, height, color value, texture analysis and sensory evaluations. The pH of the bread dough was highest on R1:BR2 and R0:BR3. The dough raising power and moisture content steadily and significantly decreased as the amount of added brown rice flour increased. The baking loss rate was highest on R3:BR0. The specific volume and height of morning bread were highest on R3:BR0 and R2:BR1. In color value, the L value decreased significantly as the amount of added brown rice flour increased, while a value and b value increased. The hardness, gumminess and chewiness of morning bread increased with an increase in brown rice flour. In consumer acceptability, R3:BR0, R2:BR1 and R1:BR2 showed the highest scores in all parameters. Characteristic intensity rating of roasted taste was lowest on R3:BR0. These results indicate that R2:BR1 showed similar quality characteristics as compared to morning bread without brown rice flour, with the optimal results appreciated with a 2:1 ratio of rice flour to brown rice flour.

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.

Ochratoxin A (OTA) is one of the most important mycotoxins due to its prominent nephrotoxicity as well as potential carcinogenicity to human. OTA has been detected in a wide range of agricultural commodities including cereal grains and their processed products. OTA is stable under most food processing conditions while the reduction of OTA is more rapid and extensive under higher temperature and alkaline conditions. In this study, the effects of extrusion cooking on the stability of OTA in spiked (100 μg/kg) rice flour (moisture content, 16% wet weight basis) in the presence and absence of baking soda was investigated using a laboratory scale twin-screw extruder. The extrusion variables were temperature (120 and 150°C), screw speed (150, 200, and 250 rpm), and baking soda (0, 0.5, and 1%, w/w). Both unextruded and extruded samples were analyzed for OTA by high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). The reduction of OTA was in the range of 78-82% with no added baking soda, whereas lesser reductions of 75-80% and 72-77% were observed at 0.5% and 1% baking soda, respectively. Both temperature and screw speed did not affect reduction of OTA during extrusion regardless of the presence or absence of baking soda. While the total color difference (ΔE) of extruded samples were increased with baking soda content, the radial expansion of extruded samples were decreased with baking soda content. These results suggest that OTA in rice flour may be reduced significantly by extrusion. In addition, added baking soda may negatively impact the reduction of OTA while its mechanism of action is unknown.

Although rice production gradually increased in Korea, rice consumption has been significantly reduced during the last decade. To increase rice consumption, it is necessary to develop a wide range of rice-processed foods and functional rice materials. In association with digestion in rice-functional materials, people are interested in resistant starch (RS). The purpose of this study was to develop the citrated organic rice flour by dry process with different treatments and to investigate its physicochemical properties. Citric acid (0, 20, 30, 40% dry basis) was mixed with organic rice flour and reacted at 105oC and 150oC for 5 h. The degree of substitution increased with increasing citric acid concentration and reaction temperature. In DSC, when reacted at 105oC, onset temperature gradually decreased with increasing citric acid concentration but no DSC thermal characteristics were observed when reacted at 150oC. Relative crystallinity determined by XRD did not greatly change at 105oC but dramatically decreased at 150oC. As citric acid concentration and reaction temperature increased, rapidly digestible starch, slowly digestible starch, and total starch decreased but RS significantly increased. Therefore, RS content in organic rice flour increased with dryprocessed citric acid treatment and this could be applicable to produce functional foods for diabetes.

The aim of this study was to investigate the optimum particle size of rice flour for making rice noodles. Rice noodles were prepared with rice variety such as Milyang 278 because it has 25.4% of high amylose content. The rice grains were pulverized by dry milling and passed through 3 different sized sieves (A: -60 ~ +100, B: -100 ~ +150, and C: -150 ~ +200 mesh). The average particle sizes of A, B, and C were 187.27, 103.79 and 74.88 um, respectively. Rice noodles were prepared at 35% of moisture content, 50/90/90/90°C of barrel temperature, and 200 rpm of screw speed in the twin screw extruder. Textural properties and cooking qualities were evaluated to determine the suitability for making rice noodles. Hardness of the dry noodles prepared with A, B, and C were 2.762, 4.546, and 2.065 N, respectively. Extension (R max) of the cooked rice noodles prepared with A, B, and C were 0.526, 0.857, and 0.534 N while Extensibility (E value) were 15.97, 18.03, and 16.78 mm, respectively. Cooking loss values were 4.47, 2.88, and 2.16%, respectively, while the turbidities of their cooking water were 0.177, 0.073, and 0.088, respectively. As the result the flour passed through -100 ~ +150 meshes was the most appropriate for making rice noodles. Control of particle size in rice flour with high-amylose content can be a useful way for making good quality rice noodles.

Quality characteristics such as texture and sensory properties of garaetteok(Korean rice cake)made with organic rice flour treated withcitric acid were investigated. Compared to rice flour without addition of citric acid,rice flour treated with citric acid showed a significantly lower viscosity and viscoelasticity level as the concentration of citric acid increased. Hardness of garaetteokmade with citric acid showed a similar trend in viscoelasticity changes, whereas cohesiveness was not significantly affected by the pretreatment of citric acid.Garaetteok of 0.5% citric acid pretreatment showed the highest scores in hardness, springiness, chewiness and overall acceptability.However,flavor and taste of garaetteokof citric acid pretreatment were lower than those of the control.

This study was carried out to investigated optimum additive ratio of barley flour for substitution of rice bran atcultivation of winter mushrooms. Mycerial growth was faster according to increase of barley flour ratio than those of controls, butonly some slow at the addition of 10% barley flour. Yields of fruiting body show the highest to 165.4g/850ml of medium whichare the addition 30% of barley flour and not significant difference of yields up to the addition of 70% barley flour. Diameter ofpileus was the highest at the addition of 30% barley flour. Hardness of pileus and stipes were the highest at the addition of 10%barley flour. The L value of stipes were the hight at the addition of barley flour, but the L value of pileus were decreased at theaddition of barley flour, but there was no significant difference in the a-value and the b-value.

본 연구에서는 자포니카 타입 품종 중 하나인 설갱을3가지(100, 200, 300mesh)입도크기로 나눠 제분하여 글루텐 프리 쌀 식빵을 제조하고 빵의 부피, crumb의 경도, 색도, 외관형태를 통해 제빵 적성에 가장 적합한 입도를 결정하였다. 100mesh를 통과한 쌀가루로 제조한 쌀 식빵의경우 기공이 일정하지 않고 crust의 갈라짐 현상이 발생하였고, 300mesh를 통과한 쌀가루로 제조한 쌀 식빵의 경우반죽을 형성하기 위한 물에 의해 발효과정이 적절하지 않게 진행되어 반죽이 부풀지 못해 좋지 않은 품질의 빵이제조되었다. 200mesh 체를 통과하여 제조된 쌀 식빵의 경우 가장 큰 비체적과 낮은 crumb의 경도, 균일한 기공모양등 제빵 적성에 적합한 것으로 나타났다. 쌀은 밀에 비해쌀알의 경도가 높아 미세한 입자크기를 갖도록 제분할 때전분에 손상이 과하게 발생하는 단점이 있는데, 이와 달리설갱 품종은 일반 쌀 품종에 비해 쌀알의 경도가 낮아200mesh 체를 통과하는 미세한 쌀가루를 제조하는 과정에서도 전분의 손상도가 낮게 제분할 수 있는 특징을 보였다.이러한 연구결과를 통해 글루텐 프리 쌀 식빵을 제조하는데 있어 가장 적합한 쌀가루의 입도를 결정할 수 있다.

0.8%(w/w) 밀가루를 첨가 시 증자 쌀가루 내부온도를 달리하여 제조한 가래떡을 4oC에서 28일간 저장하면서 노화억제효과를 분석하였다. 저장 기간에 따른 가래떡 전분의 표면미세구조는 처리구의 경우 저장 초기나 대조구에 비하여 표면에 작은 구멍이 보였으며 이는 저장 중 밀가루의 가수분해효소작용에 의한 것으로 판단된다. 저장 기간에 따른 blue value를 측정한 결과 대조구는 감소한 반면에 처리구는 증가하였다. 결정구조에서는 대조구와 첨가온도 95oC의 경우 저장 28일 후 B-type과 V-type이 혼합된 형태의 XRD pattern의 peak가 날카로워지면서 크기가 커지는 것을 관찰되었고 첨가온도 55oC와 75oC의 경우는 단일 피크의 XRD pattern을 그대로 유지하고 있었다. 저장기간에 따른 대조구의 용융엔탈피(ΔE)는 처리구보다 높게 나타났고 첨가온도 55oC가 가장 적은 용융엔탈피 값을 보였다. 저장 28일 후의 경도와 씹힘성은 첨가온도 55oC가 가장 낮았으며 각각 대조구의 0.7과 0.5% 수준이었다.

Rice can be the contaminating with soil-borne bacteria. Furthermore, the contaminated bacteria can be grown during immersion process for produce wet-milled rice flour. Therefore, disinfectants can be added during the immersion process. Antibacterial activities of the natural disinfectant, fermented rice spent water (FRSW), and the chemical disinfectants, chlorine dioxide (CD) and sodium benzoate (SB), were respectively determined when added in pure cultures of target bacteria such as Salmonella typhimurium, Escherichia coli, and Bacillus cereus or when added to immersion water in the immersion process. In addition, rinsing effects for removing bacteria were determined when rice was rinsed with water before and after the immersion process. Antibacterial activities were rapidly increased as increasing amounts of the disinfectants are added to the pure cultures of the target bacteria. Antibacterial activity of CD was the most effective among the three tested disinfectants when added to the pure cultures of the target bacteria, respectively. Those of the same disinfectants were increased when they were increasingly added to the immersion water. However those of the disinfectants were less effective when added to the immersion water. On the other hand, rinsing effects for removing bacteria were the most effective when rice was rinsed only with water without the immersion process. Collectively, rinsing rice with water only was more effective than using disinfectants in the immersion water during rice flour production.

This study was to investigate the effects of differences in the temperature of steamed rice powder at the additionof wheat flour on the quality characteristics of Injeolmi after storage for 7 days at 4℃. The L values in color ofthe control and with 75℃ and 95℃ treatments decreased after storage whereas that of the 55℃ treatment increasedfrom 94.24 to 96.07. The amylose content of the control increased from 4.13% to 12.43%, while that of the 55℃,75℃, and 95℃ treatments increased from 5.10%, 5.28%, and 5.14% to 20.43%, 19.8%, and 19.34% respectively.Hardness of the 55℃, 75℃, and 95℃ treatments after storage increased by 109.2%, 2,023.2%, and 2,886.5%respectively compared with that at the initial storage stage. Hardness of the 55℃ treatment after storage was 3.17%compared with that of the control, which shows that the 55℃ treatment significantly reduced retrogradation inInjeolmi during storage. Total aerobic bacteria content of the control and the 55℃ treatment was 3.55 and 3.98 logCFU/g respectively, which were slightly higher numbers than those of the 75℃ (3.62log CFU/g) and 95℃ (3.30logCFU/g) treatments after storage for 7 days at 4℃.

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℃ 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.

Korea. Two kinds of jochung products were prepared from steamed rice(SR) and wet-milled rice flour(WRF) by rice cultivated from 2006 to 2010. It is common to add a liquefying enzyme for rice liquefaction(4 ㎖/1, 000 g rice, at 90～95℃, 3 h) and saccharogenic enzyme with malt(45 g/1, 000 g rice, at 55～57℃, 6 h). In order to evaluate the quality characteristics of jochung, producing rate, pH, solidity, reducing sugar, dextrose equivalence(D.E.), viscosity, total phenolic compound, color value and sensory evaluation were carried out. In terms of the producing rate of jochung, WRF jochung was produced about 7.4% much more than SR jochung. There was no difference in producing rate between the jochung cultivated from 2006 to 2010 rice. The pH varied from 4.86～5.66, solidity was 79.48～82.28%. Color L value was 25.82～27.92, a value of 1.28～2.81, b value were 2.98～4.33. The results of sensory evaluation for jochung, as a whole, received higher score than for the commercial product(Daesang Co., Ltd, Seoul, Korea), overall acceptability score was the highest in the 2008SR. Reducing sugar, dextrose equivalence(D.E.) and total phenolic compounds were determined to be higher WRF jochung than SR jochung, while viscosity was lower WRF jochung than SR jochung. These results are thought to be due to increased surface area of rice by milling. SR jochung manufacturd by wet-milled rice flour will increase the producing rate for jochung, thereby saving manufacturing time and costs.

쌀가루를 온도와 수분함량을 조절하여 압출 한 쌀가루의 특성과 밀가루와 7:3의 비율로 혼합된 쿠키의 품질을 경도, 색도, 관능평가를 실시하여 쿠키에 적용가능성을 확인하였다. 압출 쌀가루는 호화가 이루어져 α 화 되었으며 압출온도가 100oC에서 130oC로 증가할수록 점도가 급격하게 감소되었으며 수분함량이 25%에서 27%로 증가할수록 점도가 다소 감소되는 것을 확인하였다. 압출쌀가루의 수분흡수력, 수분용해도, 팽윤력은 대체적으로 높게 측정되었으며 30oC와 80oC에서 수분용해도와 팽윤력은 생쌀가루에 비해 높게 측정되었으나 80oC에서는 130oC 압출쌀가루는 생쌀가루와 비슷하였다. 압출 공정 온도가 증가할수록 수분용해도는 급격하게 증가하였다. 밀가루와 각 압출쌀가루가 혼합된 쿠키는 밀가루 쿠키와 비교하여 경도가 높았으며 퍼짐성지수는 낮았다. 100oC 압출쌀가루가 첨가된 쿠키는 색이 짙었으며 130oC 압출쌀가루가 첨가된 쿠키는 밀가루와 비슷하였다. 압출쌀가루가 첨가된 쿠키는 관능 평가에서는 향기, 맛, 전체적인 기호도가 높았으며, 부드러운 정도는 비슷한 평가를 받았다. 압출쌀가루를 사용하여 밀가루 함량을 감소시키기 위한 연구를 실시한 결과, 압출쌀가루는 밀가루 함량을 줄여 사용할 때 가공적성문제점을 보완할 수 있었다. 또한 다양한 분야로 압출쌀가루 연구를 통해 쌀의 활용을 확대될 가능성이 있음을 확인하였다.