• Food Science and Preservation
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• 제13권3호
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• pp.344-350
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• 2006

Soaking and drying were studied for seven grains and legumes including glutinous rice, brown rice, glutinous brown rice, glutinous barley, Seoritae, Heuktae and red bean to improve taste of cooked mixed grams and make easy to cook then Seoritae and Heuktae showed the highest water absorption and the rest were in the order of glutinous barley, glutinous rice, milled rice, brown glutinous rice, brown rice, and red bean. In regards with water absorption index by soaking temperature, the higher the temperature showed, the more water absorption and the shorter time to reach the water absorption balance, the more grinding legumes. showed the more water absorption and the shorter time to reach to the water absorption balance. The soaked samples were dried at mom temperature $30^{\circ}\C,\;50^{\circ}\C$, and microwave 300 W, 700 W and 1000 W power. As a result 700 W drying method br microwave can dry samples in the shortest time without damage to the samples. Therefore, it was considered as the best pretreatment conditions for mixed stains to dry with 700 W microwave after one-hour soaking at $30^{\circ}C$.

• Applied Biological Chemistry
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• 제28권4호
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• pp.261-270
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• 1985

This study was carried out he effects of water activity on the nonenzymatic browning reactions of dry milk powders. Samples (Dry Whole Milk DWM, Nonfat Dry Milk NFDM) stored at $55^{\circ}C$ were analyzed for $O_2,\;CO_2$ and $H_2O$ by Gas chromatographic method. The brown color which developed from the Maillard reaction was also measured by a reflective spectrophotometer. And linear regression equations and the correlation coeffcients were determined for $O_2,\;CO_2$ and brown color vs. storage, and the results are as follows. The amount of brown and off-flavor development increase as the water activities increase about 0.44 Aw during storage. Both DWM and NFDM milk products show a plateau in water absorption between the 0.33 and 0.44 water activities. DWM produced more browning than NFDM which may be partially due to the carbonyl amine reaction. The $CaCl_2$ solution may exude a water activity lower than 0.44 and varies greatly with temperatures. Oxygen is depleted as brown color development.

• Journal of Bio-Environment Control
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• 제15권2호
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• pp.167-172
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• 2006

The objective of this study was to determine the effects of substrate water content and electrical conductivity (EC) on the incidence of brown fruit stem and blossom end rot in glasshouse sweet pepper (Capsicum annuum cv. Special). Three levels of water content and EC had been treated since the first fruit reached 3cm in diameter: that is, 49 (low), 65 (medium), and 86% (high) for water content, and 2.4 (low), 4.2 (medium) and $6.3dS{\cdot}m^{-1}$(high) for EC. Shoot growth was reduced with decreasing water content, and it was lower in both high and low EC treatments than medium EC treatment. Fruit weight at harvest was greater in both medium and hish water content treatments than low water content treatment (158g vs 146g). High EC reduced fruit weight compared to or low EC treatments. The incidence of brown fruit stem increased with increasing water content and with decreasing EC. The highest incidence was shown in the high water content/low EC treatment (38%), which was considerably higher than 2.4% of the low water content/high EC treatment. Blossom end rot occurred in general in the low water content and/or high EC conditions. These results indicated that substrate water content and EC should be controlled differently according to the growth stage, to reduce the incidence of blossom end rot and brown fruit stem in glasshouse sweet pepper. First, to reduce blossom end rot incidence, water content should be maintained high (86%) and EC low ($2.4dS{\cdot}m^{-1}$) until Sweets after fruit set. Secondly, to reduce brown fruit stem incidence, water content should be maintained low (49%) and EC high ($6.3dS{\cdot}m^{-1}$), especially after completion of fruit growth.

• Korean Journal of Food Science and Technology
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• 제45권5호
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• pp.613-618
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• 2013

The quality characteristics of brown rice polished with grains of four rice varieties (Hwaseonchal, Baegjinju, Ilpum and Goami) were examined. For the physical properties of native and fried brown rice starches, the gelatinization temperatures and enthalpies (determined with differential scanning calorimetry) of brown rice starches decreased with increasing amylose content. The pasting viscosities of native brown rice starches in distilled water were higher than those in $HgCl_2$ solution (as an ${\alpha}$-amylase inhibitor). The highest viscosity of gelatinized starch was observed for the starch of Ilpum rice variety relative to other varieties. Cystal packing arrangement of brown rice starches subjected to deep-fat frying converted A-type (typically observed for cereal starches) into V-type (formed by retrogradation and recrystllization of amylose molecules).

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 한국에너지공학회 2006년도 에너지.가스.기후변화학회 연합춘계학술대회 및 특별심포지움
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• pp.262-262
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• 2006

The characteristics of Brown gas was experimentally studied in view of efficiency and flame propagation. For this study, the Brown gas stack with 7 cells was manufactured following the Brown gas related patents and reports. All measuring equipments were re-tested and calibrated by Korea Laboratory Accreditation Scheme (KOLAS) certified laboratories. Since the amount of produced gas is most crucial in determining the efficiency, we adopted two gas collecting methods such as bottle trap method and wet gas meter method. The energy efficiency of our own fabricated stack was measured to be 75%, which is comparable to general alkaline water electrolysis efficiency. In order to analyze the flame propagation characteristics of Brown gas, we measured the flame propagation pressure, velocity, and shape by using strain type pressure sensor, optical sensor, and high speed camera in conjunction with Schliren system, respectively. From the experimental results, it was found that the flame propagation behavior of Brown gas was almost the same as that of hydrogen and oxygen mixture gas in 2:1 molar ratio. Moreover, from the high speed camera analysis, we concluded that Brown gas flame exhibits explosion behavior as does mixture gas ($H_{2}:O_{2}=2:1$).

• Korean Journal of Food Science and Technology
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• 제25권3호
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• pp.220-224
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• 1993

Antioxidative activities of brown materials extracted from the three kinds of roasted coffee beans by water were examined. Antioxidative activity was assessed by the AOM at $120^{\circ}C$ and the oven test at $60^{\circ}C$ on lard. The brown materials of them showed the considerable antioxiant activity. The brown materials of Colombian coffee beans were more effective than those of Robusta or Brazil beans. The antioxidative activities of brown materials from Colombian coffee beans roasted at $210^{\circ}C$ increased in proportion to the browning intensity up to 16 minutes of roasting time, but the antioxidant activities of the brown materials upon further roasting time decreased gradually. In changes of extraction temperature from $30^{\circ}C\;to\;180^{\circ}C$ on the coffee beans roasted at $210^{\circ}C$ for 16 minutes, the antioxidative activities of brown materials did not change as the extraction temperature increased to $180^{\circ}C$. The antioxidative activities of the coffee extracts were thought to be caused by browning reaction materials produced during the roasting process only.

• Journal of the Korean Society of Food Science and Nutrition
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• 제36권4호
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• pp.383-388
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• 2007

Physiological activities of Agaricus bisporus extracts were examined. Nitrite-scavenging activity, superoxide dismutase (SOD)-like activity and electron-donating ability (EDA) of Agaricus bisporus extracted with water, 50%, and 100% ethanol were measured. Nitrite- scavenging activities at pH 1.2 were the most effective in water and 50% ethanol extracts from brown and white Agaricus bisporus samples. SOD-like activities of water and 50% ethanol extracts of both samples were $19.02{\sim}55.42%$ lower than those of 1.0% and 0.1% L-ascorbate solutions. SOD-like activities of brown Agaricus bisporus extracts were higher than those of white Agaricus bisporus extracts, and water extracts of the samples were the highest. EDAs of brown Agaricus bisporus extracts were higher $(40.35{\sim}66.54%)$ than those of white Agaricus bisporus extracts, while those of both extracts were lower than 1.0% and 0.1% L-ascorbate solutions. The results will be useful for understanding the physiological activities of Agaricus bisporus extracts.

• Korean Journal of Food Science and Technology
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• 제34권5호
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• pp.842-845
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• 2002

Physicochemical properties and water uptake rate of pigmented rice were determined. The median and mean particle sizes of pigmented rice flour were 15.18 and $38.53\;{\mu}m$, whereas brown rice flour were 11.46 and $33.41\;{\mu}m$, respectively. Water-binding capacity, swelling power, and solubility of pigmented rice flour were higher than those of brown rice flour. X-ray diffraction patterns showed traditional A type of cereals. Moisture gain of pigmented rice kernels increased continuously up to 60 min at soaking temperature $(20{\sim}25^{\circ}C)$. Water uptake rate constants of pigmented rice during soaking at $20{\sim}25^{\circ}C$ also increased.

• Journal of the Korean Society of Food Science and Nutrition
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• 제39권8호
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• pp.1201-1206
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• 2010

As a means to increase the production and consumption of the brown colored rice with high content of GABA ($\gamma$-aminobutyric acid), this study was conducted to develop brown colored rice tea. After roasting at various temperatures and times, color values and GABA content of the brown colored rice were analyzed. Physicochemical properties such as browning, turbidity, reducing sugar, soluble solid, total polyphenol and pH of brown colored rice tea were determined after the rice powder was put into tea bags and leached in hot water. Sensory characteristics were investigated for three kinds of tea roasted at $170^{\circ}C$ for 10, 20 and 30 min. As the roasting temperature and time increased, L, a and b values decreased as well as GABA content. The brown colored rice roasted at $170^{\circ}C$ for 10 min contained the highest content of GABA. Browning, turbidity, reducing sugar, soluble solid and total polyphenol of the brown colored rice tea increased as the roasting temperature and time increased, on the contrary, pH decreased. The brown colored rice tea roasted for 30 min was preferred the most in color, flavor, taste and overall acceptance. From this result, the brown colored rice tea needs to be manufactured by a combination of the brown colored rice roasted at $170^{\circ}C$ for 10 min and 30 min to satisfy the consumer's preference and high content of GABA.

• Journal of the Korean Society of Food Culture
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• 제24권1호
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• pp.69-76
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• 2009

This study was conducted to determine the optimal cooking conditions for brown rice using an electric pressure rice cooker. The effects of steeping conditions and cooking pressure on the hydration, gelatinization, texture and palatable properties of cooked brown rice were evaluated. Based on water uptake and DSC data, the optimal steeping time and temperature for brown rice were determined to be 25 minutes and ${\sim}60^{\circ}C$, respectively. The cooking conditions for brown rice were then divided into the following 6 categories: steeping at $25^{\circ}C$ for 25 minutes and cooking at an atmospheric pressure of 1.7 (25P) or 1.9 (25HP), steeping at $57^{\circ}C$ for 25 minutes and cooking at an atmospheric pressure of 1.7 (57P) or 1.9 (57HP), steeping at $85^{\circ}C$ for 15 minutes and cooking at an atmospheric pressure of 1.7 (85P) or 1.9 (85HP). The susceptibility of cooked brown rice starch to degradation into maltose by ${\alpha}$-amylase, which is related to the degree of gelatinization and in vitro digestibility, were then determined. The amount of maltose produced by cooked brown rice samples was highest in the 57HP group, followed by the 57P and 85HP groups. Storing cooked brown rice at $73^{\circ}C$ for 24 hours resulted in significantly higher amounts of starch being degraded into maltose in the 57P, 57HP and 85HP groups than in the other groups. Textural analysis demonstrated that the 57P, 57HP and 85HP groups had significantly lower gumminess and chewiness values when compared to the other groups, and that 57HP received had the lowest hardness of all treatments. These results were confirmed by the results of the sensory evaluations. Furthermore, the 57P and 57HP groups were found to have a higher glossiness, stickiness aroma and taste score than the other groups. These findings were taken to indicate that steeping conditions and pressure exerted a positive synergistic effect on the cooking quality of brown rice. The texture analyzer also revealed that storing the cooked rice at $73^{\circ}C$ for 24 hours only led to significantly lower scores in gumminess, hardness and chewiness in the 57P and 57HP groups, which indicates that these groups underwent a lesser degree of retrogradation than other groups. Taken together, the results of the present study demonstrate that steeping brown rice at $57^{\circ}C$ for 25 minutes and a higher cooking pressure improved the palatability and in vitro digestibility of brown rice significantly.