• Korean journal of food and cookery science
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• v.14 no.3
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• pp.219-224
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• 1998

Kochujang was prepared by using retrograded rice cakes (Song Pyun, Sym rice cake, Ssuk rice cake, Pat rice cake) as a source starch and the physiochemical and sensory characteristics were compared with traditional kochujang during aging for 60 days. Moisture content of all kochujang groups increased slowly but crude fat content decreased according to aging process. Changes of pH values of all kochujang reduced gradually during aging and the pH of saccharified kochujang was lowered than that of traditional one. Total reducing sugar contents in saccharified kochujang reached the maximum value at 50th day, and decreased thereafter. In contrast, the reducing sugar content in traditional kochujang was the highest at 30-day-aging. After 60 days of aging, the total contents of organic acids were 28.57 mg for P$\_$1/, 27.9 mg for P$\_$4/, 27.05 mg for P$\_$3/ 24.60 mg for P$\_$2/, and 22.30 mg for P$\_$0/. By sensory evaluation, saccharified kochujang prepared with Siru rice cake showed the highest sensory score in its appearance, flavor, texture, color, and taste.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.584-587
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• 2007

The effect of molar substitution (MS, 0.030-0.118) on the dynamic rheological properties of hydroxypropylated rice starch pastes (5%, w/w) was investigated by small-deformation oscillatory measurements during aging. The magnitudes of storage (G#) and loss (G") moduli measured at $4^{\circ}C$ before aging increased with an increase in MS in the range of 0.030-0.118, while those of tan ${\delta}$ (the ratio of G"/G#) decreased. The G# values of hydroxypropylated rice starches, as a function of aging time (10 hr) at $4^{\circ}C$, increased rapidly at the initial stage, and then reached a plateau region at shorter aging times. However, for the native starch, the plateau values were not observed for G# after a long aging time. Increasing the MS resulted in a decrease in plateau values. The rate constant (K) for structure development during aging was described by first-order kinetics. The K values of hydroxypropylated rice starches at 0.086 and 0.118 MS were much lower than the K value at 0.030 MS.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.83-89
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• 1995

Changes in physical, chemical and microbiological characteristics of rice-doenjang prepared with two different methods with or without soak treatment were investigated during 60 days of aging at $32^{\circ}C$ and $15^{\circ}C$. The pH of soak-treated rice-doenjang decreased slowly, but that of nonsoak-treated rice-doenjang decreased rapidly at the initial aging stage with the aging temperature of $32^{\circ}C$, resulting in pH 5.1 after the 60 days of aging time. Reducing sugar contents increased up to the $30{\sim}50$ days of aging time and decreased thereafter. The contents of soluble nitrogen, formol nitrogen, ammoniacal nitrogen and amino nitrogen were more affected by preparation methods than by aging temperatures. Color values depended not only on preparation methods but also on aging temperatures. There were no significant differences in the bacterial counts of rice-doenjang, while apparent differences in the yeast and mold counts by aging temperatures were observed. These results suggested that the properties of soak-treated rice-doenjang were less changed than those of nonsoak-treated rice-doenjang by aging time and temperature. And, with a view point of nitrogen compounds, aging time could be reduced by soak treatment.

• Food Science and Preservation
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• v.18 no.6
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• pp.859-868
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• 2011

This study was conducted to determine the appropriate mixing ratio of Koji and rice Doenjang. Brown rice Doenjang (BR) was prepared with three different ratios of cooked soybean to brown rice Koji [1.5:1 (BR-1); 2:1 (BR-2); and 3:1 (BR-3)], and polished-rice Doenjang (PR) was prepared with cooked soybean and polished-rice Koji (2:1). The components related to the quality of Doenjang were analyzed during 60-day aging. No significant differences were found in the moisture and salt contents between the brown rice Doenjang and the polished-rice Doenjang. The pH, titratable acidity, and bacteria cells increased at 20-30 days aging time, and decreased thereafter. The reducing-sugar and ethyl alcohol contents, on the other hand, increased at 10-20 days previously. These analytical values of the physicochemical and microbiological characteristics increased with the increase in the percentage of koji in each Doenjang. The amino-nitrogen and free-amino-acid contents showed the highest levels in BR-1: 887.6 and $4047.0{\pm}1.5$ mg%, respectively. The ${\gamma}$-aminobutyric-acid (GABA) contents slightly increased with increasing aging time. In the color of Doenjang, the lightness and yellowness increased along with the aging time, but the redness decreased as the aging time increased. These results showed that BR-1 processed the fermentation the fastest compared with the others. Moreover, the reducing-sugar, ethanol, and free-amino-acid contents as palatable components increased rapidly until 30 days aging time.

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.23-25
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• 1994

To evaluate the quality difference between rice starch syrup Kochujang (RSSK) and rice flour Kochujang(RFK), moisture content, pH, titrable acidity, reducing sugar, amino nitrogen and color were measured for 90 days. Moisture content was no great difference between samples and was slowly increased during aging. pH of RSSK was 6.03 and that of RFK was 5.94 after mashing. And it was slowly decreased during aging. Titrable acidity was increased with no great difference between RSSK and RFK. Reducing sugar content of RSSK and RFK was 17.0% and 5.8% after mashing respectively. Reducing sugar content was increased till 40 days, but was decreased thereafter. Amino nitrogen content of RSSK was 123.6 mg% and that of RFK was 93.0 mg% after 20 day aging. Lightness of RSSK was higher than that of RFK, but redness was similar between RSSK and RFK.

• Food Science and Preservation
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• v.24 no.4
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• pp.491-496
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• 2017

Paddy rice is typically stored during postharvest until rice grain is processed into brown rice and milled rice by hulling and milling procedure, respectively. Recently, instead of storing paddy rice, storage of brown rice has been in the spotlight because it is more convenient and economically feasible. Different brown rice cultivars with varying amylose contents including waxy rice, medium-waxy rice, and non-glutinous rice were stored in room temperature storage for four months, and the changes in grain qualities of brown rice were evaluated. Amylose content significantly affected pasting properties in which rice cultivar with higher amylose content showed longer pasting time and higher peak viscosity. Storage also affected pasting viscosities, showing an increase in peak viscosity, but a decrease in breakdown viscosity. The changes in pasting viscosity during storage could be an important starch property for aged brown rice utilization. Waxy brown rice showed the weakest aging property in terms of free fatty acids (FFA) accumulation, whereas non-glutinous rice was more substantial grain quality against aging. The FFA values of two months storage were not significantly different from the initial FFA contents, suggesting that brown rice stored in room temperature for two months could be feasible for direct consumption of brown rice.

• Journal of Biosystems Engineering
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• v.40 no.2
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• pp.124-136
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• 2015

Purpose: Grain quality is a general concept that covers many characteristics, ranging from physical to biochemical and physiochemical properties. Rice aging during storage is currently a challenge in the rice industry, and is a complicated process involving changes in all of the above properties. Spectroscopic techniques can be used to obtain information on the quality of rice samples in a non-destructive manner. Methods: The objective of this review was to highlight the factors that contribute to rice quality and aging, and to describe various spectroscopic modalities, particularly vibrational and hyperspectral imaging, for the assessment of rice quality. Results: Starch and protein are the main components of the rice endosperm, and are therefore key factors contributing to eating and cooking quality. While the overall starch, protein, and lipid content in the rice grain remains essentially unchanged during storage, structural changes do occur. These changes affect pasting and gel properties, and ultimately the flavor of cooked rice. In addition, grain quality is significantly affected by growing and environmental conditions, such as water availability, temperature, fertilizer application, and salinity stress. These properties can be evaluated using spectroscopic techniques, and rice samples can be discriminated by using multivariate statistical analysis methods. Conclusion: Hyperspectral imaging and vibrational spectroscopy techniques have good potential for determining rice quality properties in a non-invasive manner, i.e., not requiring the introduction of instruments into the rice grain.

• Korean Journal of Human Ecology
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• v.14 no.6
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• pp.1037-1046
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• 2005

Using three consecutive years' harvested rices and their starches isolated from rice flours by alkaline method, it was found that no significant aging effect on rice flour and starch was observed based on following results. Proximate data of flours or starches showed in similarity, except high level of crude fat in rice flour and rice starch harvested in 2002. In SEM, the surface of aged rice flour had slightly layered shape due to possible abrasion during storage, and that of aged starch showed more smooth and less rigid polygonal shape. X-ray diffraction patterns of flours and starches were all A type, and crystallinity of rice starch harvested in 2000 had the smallest. From tristimulus colorimetry (Hunterlab Color), total color difference ($\Delta$E) calculated from L, a, and b gave less color difference with the darkest in 2002 harvested one among flours and the lightest in 2001 one among starches. WBCs of both 2002 rice flour and starch were the lowest among samples studied. At 80$^{\circ}C$, swelling power and solubility of rice starches harvested in 2000, 2001 and 2002 were 14.35, 9.75; 14.04, 9.6; and 12.49, 8.82, respectively. The highest peak viscosities measured by RVA were shown both in 2001 rice flour and in its starch. Starch and milled rice flour harvested in 2000 had higher hydrolytic $\alpha$-amylase, compared to other flour and starch samples.

• Journal of the Korean Home Economics Association
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• v.8 no.1
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• pp.100-119
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• 1970

In finding an improved and generalized method of making Jung-pyun, a type of scientific experimental cookey has been attempted with the use of yeast in place of Korean native rice wine named "Takju" The result is shown as follows; 1. Starta prepared with yeast and rice powder was mixed again with fresh rice powder as fermenting and aging agents in Jung-pyum making. 2. Recommendable methods of starta making are shown as follows; a. Recipe Rice powder--Certain amount Yeast--1% Sugar--10% Water--65%(by volume) b. Temperature and Time of Fermentation Temperature--30$^{\circ}C$ Time--20 hrs. 3. Recommendable method of dough making are shown as follows; a. Recipe Starta--Certain amount Rice powder--Two times the starta(2-3 times) Sugar--10% Water--50%(by volume) b. Temperature and Time of Aging Temperature--35$^{\circ}C$ Time--3 hrs. (3-4 hrs) 4. Steaming Time 25-30 min.

• Korean Journal of Agricultural Science
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• v.43 no.1
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• pp.144-151
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• 2016

With an aging population in rural areas, farm owners in South Korea are also aging. In particular, this phenomenon leads to the lack of human resources in rural areas and agriculture, worsening the deterioration of the rural economy. This study aimed, firstly, to analyze the criticality of the lack of human resources and high production cost issues for farmers, before using the farm as cooperative nursery of rice seedlings. Secondly, the study analyzed farmer satisfaction after using the farm cooperative. Analysis results are as follows. The motives of the research subjects for using the co-nursery were the aging of the farming population, the expected reduction of production costs, and farmers' failure in raising seedlings. Importance-performance analysis measured the importance for the farms for cooperative raising of rice seedling at 3.49 and the performance for the farms at 3.41, with a difference of 0.07 between them. The four importance-performance matrix areas, used were as follows: concentrated efforts required (Quadrant I: concentrate here), continuous maintenance (Quadrant II: keep up the good work), gradual improvement (Quadrant III: low priority), and avoiding excessive efforts (Quadrant IV: possible overkill). Based on the results, it was concluded that improvements and efforts would be necessary for each of these areas. And, there is a need to improve services through the initiation of farmer use of this rice co-nursery.