• Food Science and Biotechnology
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• 제16권4호
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• pp.543-548
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• 2007

Low-energy processing technology, which enhances the utility of defatted soybean flour (DSF), was developed using extrusion processing. DSF was extruded at different conditions using a twin screw extruder and then, dried at $40^{\circ}C$ for 20 hr. The nitrogen solubility index (NSI), viscosity, water solubility index (WSI), and water absorption index (WAI) of DSF increased after extrusion processing. The density of DSF extrudates decreased with the decrease in water content from 53 to 33% and the increase in extrusion temperature from 110 to $160^{\circ}C$. The addition of NaOH from 1.2 to 1.8% and citric acid from 1 to 5% increased the total solubility (TS) of DSF due to the decrease of protein coiling and hydrophobic bonds formation during extrusion processing. When viscozyme was reacted first, TS, NSI, and soluble carbohydrate content of DSF hydrolysates increased about 12, 6, and 7%, respectively, compared to them reacted with protease first. The TS and NSI of DSF hydrolysates were increased about 15 and 10%, respectively, by extrusion processing at alkaline and acidic pH. Extrusion processing at alkaline and acidic pH contributed the increase of efficiency to hydrolyze DSF samples using enzyme.

• Agricultural and Biosystems Engineering
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• 제6권2호
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• pp.70-76
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• 2005

Seed, stem and sprout of F. tataricum were separately milled using the ultra fine mill under the same condition to investigate the effect of roasting or extruding on the particle size, microstructure and water solubility of dietary fiber. The mean particle size of MR (roasting) is increased in stem and sprout, and that of ME (extruding) is increased in seed, compared to that of control. The microscopic views of seed show that control has the spherical shape but ME the larger and irregular shape, and those of stem and sprout show that control has the needle like shape but ME more rounded shape. Water solubility index of ME is much higher than that of control or MR in seed, stem and sprout. It shows that seed, stem and sprout are damaged more in extruding than in roasting, and the starch and cell wall structure must be destroyed to change the water insoluble dietary fiber into the water soluble dietary fiber.

• Food Science and Biotechnology
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• 제16권5호
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• pp.783-788
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• 2007

An advantage to the extrusion of raw potatoes is a reduction in the energy input required to process potato products; however, the effects of extrusion on the properties of raw potato have not been studied. The purposes of this study were to develop a workable extrusion process for raw potato and to study the effects of extrusion conditions on the pasting properties of extruded potato products. The peak viscosity, final viscosity, pasting temperature, water solubility index, and water absorption index of pressed and pressed-dried potato extrudates decreased as die exit temperature increased, whereas they did not change as screw speed increased. The peak viscosity, final viscosity, and water solubility of steam-cooked potato products decreased with extrusion processing; however, they did not change with increasing die exit temperature and screw speed. Potato products with different degrees of depolymerization of extruded potato starch, depending on die exit temperature, were produced from raw potatoes.

• 산업식품공학
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• 제15권2호
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• pp.148-154
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• 2011

사출구 구조가 압출성형의 목적변수인 팽화특성에 영향을 미치는지 알아보기 위하여 사출구의 기하학적 구조를 사출구상수로 산출하여 사출구상수와 수분함량에 따른 팽화특성을 비롯한 비기계적 에너지 투입량, 수분용해지수, 수분흡착지수를 분석하였다. 압출성형 공정변수는 수분함량(20, 25%), 사출구멍의 길이와 직경비(L/D 0.67, 1.67, 2.67), 내벽에서 좁아지는 각(57, $95^{\circ}$)이였다. 비기계적 에너지 투입량은 수분함량 20%, 사출구상수 2.23E-10 $m^3$에서 가장 높은 값을 나타내었다. 수분함량 20%에서 사출구상수가 증가하면, 직경팽화지수와 체적팽화지수는 증가하였다. 한편 수분함량 25%에서 직경팽화지수와 체적팽화지수는 사출구상수의 영향을 받지 않았다. 또한 길이팽화지수는 수분함량이 20%에서 25%로 증가할 때 증가하였으며 직경팽화지수와 음의 상관관계를 나타내었다. 수분흡착지수와 수분용해지수는 사출구상수에 영향을 받지 않았다.

• 한국식품과학회지
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• 제26권4호
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• pp.428-435
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• 1994

쌀전분의 다각적 이용을 위하여 고순도의 멥쌀전분과 찹쌀전분을 Alkali 침지법에 의해 제조하여 각각 드럼 건조기와 압출성형기로 변성전분을 제조한 후 특성을 검토하였다. 청값은 찹쌀전분이 가장 낮았으며 변성 후 L값이 감소하였다. 수분용해지수는 압출성형기로 제조한 변성전분들이 높은 값을 나타내었으며 수분흡수지수는 드럼건조기로 제조한 변성전분들이 높았다. Cold-Water-Solubility는 측정에서는 드럼건조기를 이용한 멥쌀변성전분이 가장 높았다. 각 시료들의 광투과도는 온도 증가에 따라 일정한 양상을 보이지 않았다. 드럼건조기로 제조한 멥쌀변성전분은 전단속도의 증가에 따라 점조성지수가 급격히 증가하였으며 항복응력도 가장 높은 값을 나타내었다. Gel Permeation Chromatography에 의하면 전분을 변성시킴에 따라 분자길이의 절단과 아밀로오스 분해가 일어남을 알 수 있었으며 X-선 간섭도형측정(XRI)에 의한 간섭도형은 피크를 상실한 V도형의 X-선 회절양상을 보임으로서 결정구조가 무정형으로 변화 된 것을 알 수 있었다.

• 한국식품영양학회지
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• 제7권2호
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• pp.137-143
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• 1994

To optimize extrusion cooking condition of single screw extuder for production of puffed rice extrudate using response surface methodology (RSM), moisture content, barrel temperature and screw speed were determined from contour maps, showing relationship between dependent (hardness, expansion ratio, water absorption index, water solubility Index, degree of gelatinization) and independent variables. Optimum operational conditions for production of puffed rice extrudate with suitable quality properties were moisture content 17%, barrel temperature 1$25^{\circ}C$ and screw speed 210 rpm, respectively.

• 한국식품과학회지
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• 제31권6호
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• pp.1542-1548
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• 1999

아밀로오스 함량이 서로 다른 7가지(수원조, 수원 232. BG276-5, IR44, IR41999-139, 수원230, 용주벼) 쌀품종에 대해 입자크기$(106-425\;{\mu}m)$에 따른 쌀가루의 일반성분, 아밀로그램 특성, 수분흡수지수 및 수분용해지수 등을 조사하였다. 아밀로오스 함량은 수원조가 27.1%로 가장 높았고, 용주벼는 17.2%로 가장 낮은 값을 나타내었다. 단백질 함량은 수원조가 11.4%로 가장 높았고 IR44가 6.8%로 가장 낮았다. Pin mill을 이용하여 일정한 조건에서 분쇄한 쌀가루의 입자크기에 따른 단백질 함량은 입자크기가 감소함에 따라 감소하였다. 모든 품종에서 입자크기가 감소함에 따라 백색도는 증가하였으며 b값 및 ${\Delta}E$값은 감소하였다. 입자크기에 따른 아밀로그래프 특성은 모든 품종에서 입자크기가 감소할수록 호화개시온도는 감소하였으나 최고점도, 냉각시의 점도, breakdown 및 total setback은 증가하였다. 그러나 setback의 값은 입자크기에 따라 일정치 않았다. 최고 점도는 품종별로 입자크기가 증가함에 따라 증가하는 정도가 많은 차이를 보여주었다. 수분흡수지수 및 수분용해지수는 입자크기가 감소하고 온도가 증가함에 따라 증가하는 경향을 나타내었으며 품종간에도 차이를 보여주었다.

• 한국식품영양학회지
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• 제30권4호
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• pp.635-643
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• 2017

The properties of rice were studied, and 8 rice flour cultivars were used to study the effect of particle size on the physicochemical properties, color value, RVA viscosities, water absorption index (WAI), and water solubility index (WSI) of rice flours. The mean particle size by the 3 particle size classification of 150 mesh, 200 mesh, and 250 mesh was, $90.75{\mu}m$, $60.73{\mu}m$, $39.94{\mu}m$, respectively. Thai rice had the highest amylose content and Samkwang rice had the lowest amylose content. Protein content of rice flours prepared was decreased as the particle size of rice flour decreased. In terms of color values, the L-value and the a-value of rice flour were increased as the particle size of rice flours decreased, while the b-value was decreased as the particle size of rice flours decreased. Using a rapid visco analyzer (RVA), the initial pasting temperature of Thai rice cultivar was found to be the highest; the peak viscosities of Sunpum cultivar and Misomi cultivar, and Samkwang rice were higher than those of other rice flours. The water absorption index and water solubility index were increased as the particle size of rice flour decreased. In order to use processed rice flour for the development of processed foods, proper characteristics of the cultivars and particle size should be considered.

• 한국식품영양학회지
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• 제33권3호
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• pp.287-298
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• 2020

When producing rice products, it is very important to select suitable raw materials. Therefore, in this study, the quality characteristics of 16 rice cultivars were quantified to determine the criteria for evaluating the machinability of raw rice. The L value, which can affect the color of porridge prepared from rice, was the greatest for Hwaseonchalbyeo (84.17). The water-binding capacity, related to water interaction, was high in Hyangcheola (113.2%), and water solubility was high in Shingil (22.3%). Dodamssal (42.3%, 70.7 RVU) and Hwaseonchalbyeo (4.7%, 27.8 RVU) showed lower final viscosity compared to the cultivars in which the amylose content was medium groups (16.4~21.2%, 173.6~277.2 RVU). Specifically, cultivars with high or low amylose content had a low viscosity. The characteristics of the distribution of raw rice quality data were confirmed through 11 histograms. Furthermore, amylose content vs. water solubility, water solubility vs. peak viscosity, and peak viscosity vs. final viscosity showed high correlations (r=0.542, -0.569, and 0.836 respectively, p<0.01), and clear cultivar discrimination by the standard error of the mean (0.765~10.811). In conclusion, amylose content, water solubility, and peak viscosity were considered the most suitable characteristics for the quality evaluation of raw rice.

• 한국식생활문화학회지
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• 제36권5호
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• pp.484-491
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• 2021

This study investigated the effect of dry heat treatment (DHT) on the physicochemical properties of hard type (HR) and floury type (FR) rice to improve the processing aptitude of rice flour. The rice flour was heated at 130℃ for 0, 2 and 4 hours, and the color value, water absorption index (WAI), water soluble index (WSI), swelling power, solubility, pasting properties, particle shape and the X-ray diffraction were measured. After DHT, the L value of rice flour decreased, and the b value increased. The WAI, WSI, swelling power and solubility of HR and FR increased with the increase of treatment time. The cold viscosity and setback increased, while breakdown decreased. Cracks and lumps formed with fine particles were observed. The X-ray diffraction pattern was A-type, while the diffraction intensity decreased. According to the results of the two-way analysis of variance (ANOVA) test, the hydration and pasting properties were significantly different between HR and FR and were affected by DHT time. The results suggest that the properties of modified rice flour by DHT can be used in the food industry.