• Korean journal of food and cookery science
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• v.12 no.1
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• pp.46-53
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• 1996

To investigate physicochemical and cooking properties of parboiled rice, choochung paddy processed to parboiled rice by three methods (PL, PT, PA) milled and examined hydration, cooking qualities and firming rate of cooked parboiled rice. The results were obtained as follows. The longer the steaming time during parboiling the larger EMC of soaked parboiled rice. Water uptake rate constants (k) of all the parboiled rice during soaking except for PT rice were generally increased than those of raw rice. The longer the steaming time during parboiling the greater volume increase rate constants ( $k_{v}$) of parboiled rice samples. The glelatinization temperature of parboiled rice flour by DSC was more increased than that of raw rice flour. Gelatinized entalpy was decreased and gelatinization content (%SG: degree of starch gelatinization) was increased by parboiling process. In cooking tests, parboiled rices were harder than raw rice and softness (reciprocal of hardness) was greater PT30, PA, PL30 in turns the cooking time of the parboiled rice took longer 3-10 min than that of raw rice, PL30 took longer time than anyother rices. Cooking water of parboiled rices could be observed lighter turbidities than that of raw rice. Firming rate constants of cooked rice during storage 24 hours were generally decreased by parboiling-processing. The time constants, reciprocal of firming constants of cooked PL30 rice were 2 times slower than those of cooked raw rice.e.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.264-265
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• 1995

The effect of steeping (0, 6, 12, 18, 24, 30 hours) waxy rice on initial firmness and the firming rate of waxy rice cake were studied. The firming rate was decreased by 11%, 15% and about 35% by steeping the waxy for 6hrs, 12hrs and 18hrs or longer, respectively.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.877-881
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• 1996

The firming rate of cooked rice stored at $4^{\circ},\;20^{\circ}$ and $30^{\circ}C$ were analyzed. The initial and limiting firmness of cooked rice were decreased as the moisture content increased from 57.5 to 69.5%. The firming rate was inversely related to the storage temperature, but was fairly constant at moisture content between $60.5{\sim}65.9%$. The activation energy and $Q_{10}$ value for firming of cooked rice was $-4.07{\times}10^3\;cal/mole$ and 1.26, respectively. No significant difference in firming rate was observed among rice cultivars.

• Korean Journal of Food Science and Technology
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• v.17 no.4
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• pp.245-247
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• 1985

The effect of a polyphosphate having $P_2O_5$ content of 67% on the firming rate of nonwaxy (Akibare and Milyang 30) and waxy cooked rice stored at room temperature was investigated. The phosphate retarded the firming rate of Akibare and Milyang 30 by 14.0 and 27:00, respectively. The phosphate reduced the starch components available for crystallization of cooked nonwaxy rice. The phosphate exerted no effect on the firming rate of cooked waxy rice.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.451-452
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• 1987

The effect of cook temperatures, 100-$120^{\circ}C$, on firming rate of cooked rice stored at $4^{\circ}C$ for 72 hours was studied. The cook temperatures had a definite effect in retarding the firming rate of cooked rice. The time constants, reciprocal of firming rate constants, of cooked rice cooked at $110^{\circ}C$ and $120^{\circ}C$ were 1.2 and 1.5 times greater, respectively, than that at $100^{\circ}C$. The total material available for crystallization and the Portion of material that durings storage were decreased as the cook temperature increased.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1212-1217
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• 2003

Fifty-two Holstein cows with different phenotypes of $\kappa$-casein ($\kappa$-CN) and $\beta$-lactoglobulin ($\beta$-LG) were selected to provide weekly milk samples for heating at 30, 70, 75 and $80^{\circ}C$ for 2 min. Coagulating properties of heated milk samples measured as rennet clotting time, rate of curd firming and curd firmness at cutting were determined by a Formagraph. Milk samples were analysed for fat and casein. Least squares analyses of data, after adjustments were made for effect of milk casein and fat contents, indicated that although an increase in heating temperatures resulted in less desirable coagulating properties, the effect of milk types was inherent irrespective of heating temperatures. The shortest rennet clotting time (6.06 min), fastest rate of curd firming (5.61 min) and firmest curd (38.05 mm) were obtained from milk with the B variant for $\kappa$-CN and B variant for $\beta$ -LG when preheated at $30^{\circ}C$. It appears that milk bearing $\kappa$-CN B is more resistant to heat perturbation. All milk samples having the $\kappa$-casein AA (milk types AA/AA, AA/AB, AA/BB) did not have a measurable K20 value when preheated at $70^{\circ}C$. This effect was observed for $\kappa$-casein AB (milk types AB/AA, AB/AB, AB/BB) at $75^{\circ}C$ and $\kappa$-casein BB (milk types BB/AA, BB/AB, BB/BB) at $80^{\circ}C$.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.4
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• pp.254-259
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• 2014

In this paper, we describe construction of a wind stabilization demo-site and effects of output power control of wind turbines for suppression of ramp rate using ESS (Energy Storage System). It is difficult to control the output power of distributed generator such as wind turbine which of variation is very large. If the large capacity wind farm be interconnected into power system may cause blackout due to Power Quality. For these reasons, the international standards such as Grid-Code is limited to less than 10 [%/min] of renewable energy ramp rate. The case of Korea, government actively conducts propagating large-scale renewable energy for green growth policy, to interconnecting more renewable energy into power system is necessary for stabilization technology. For these reasons, the POSCO consortium has constructed a wind stabilization demo-site that is configured as 500 [kWh] battery energy storage systems can output up to 3 [C-Rate] and two wind turbines rated 750 [kW]. In POSCO consortium, which implements various methods stabilizing output power of wind turbine such as smoothing, section firming and ramp control, we derive the results of long-term demonstration that can be controlled to satisfy to the international standard about ramp rate [%/kW] of wind turbine output power.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.277-281
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• 1990

Injeulmi(Korean glutinous rice cake) was prepared without, 5, 10 and 15% of macerated tea leaves for utilizing unplucked low-graded tea leaves. The effect of firming rate by addition of tea leaf was determined using the Avrami's equation in terms of the texture parameters. Hardness of 5, 10 and 15% addition as compared with no addition was decreased gradually. Overall texture was softened in proportion to Increasing the content of added tea leaf and the addition of 5% and 10% were evaluated as the highest score as an acceptable sensory quality. Avrami exponents and time constant obtained from the Avrami's equation applicable for changes in hardness of without and 10% addition during 7days of storage at $20^{\circ}C$, $90{\sim}95%$ RH indicated 1.062, 15.3 and 0.989, 41.6, respectively, as showing the effect of delay on firming rate.

• Korean Journal of Food Science and Technology
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• v.14 no.1
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• pp.80-81
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• 1982

Staling rates of cooked rice from Akibare (Japonica) and Milyang 23 (Indica) stored at $21^{\circ}C$ and $72^{\circ}C$ were analyzed using the expression ${\theta}={\exp}\;(-kt^n)$, where ${\theta}$ in the fraction of uncrystallized material remaining after time t. The values for the rate constant (k) indicated that the firming process for both rices was not dependent on the variety, but was dependent on the storage temperature. The Avrami exponent (n) was found to be unity at two temperatures, suggesting that the staling of cooked rice is characterized by instantaneous nucleation followed by rod-like growth of starch crystals.

• The Korean Journal of Food And Nutrition
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• v.14 no.1
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• pp.40-45
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• 2001

This study was conducted to investigate the effects of various emulsifiers on the quality of the waxy rice cake. Falling numbers of the waxy rice flour with monoglyceride, lecithin and control were not significantly different, but with sugar esther 0.5% and 1% showed higher value as 88.4 and 81 than control Initial pasting temperature of the waxy rice flour was 66.78$\^{C}$ and others were 66.45 ∼ 67.05$\^{C}$ by adding 0.5%, 1% of emulsifiers such as monoglyceride, lecithin, sugar esther. Waxy rice flour with 1% sugar ester showed the highest peak viscosity as like as falling number. Waxy rice cake wish various emulsifiers showed tendency to be slowly firming rate as compared with control. In all case, waxy rice flour with sugar ester 1% was considered to be more effective to the decrease of firming rate. Waxy rice flour with lecithin showed worse visual color than others and sugar ester provided best visual and sensory quality. After 5 days cold storage, waxy rice flour with sugar ester 1%\`s Aw was 0.875 and control\`s 0.911. These results suggested that water holding capacity of sugar ester was the best during storage.