• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.211.2-212
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• 2003

발아현미의 $\alpha$-amylase의 활성도는 발아 보리보다 작았으나 추출물의 함량 및 그 당도는 발아보리와 큰 차이가 없었다. 식혜제조시 발아 현미는 효소활성도가 낮아 보리 엿기름 대신 사용 할 가능성은 없으나 발아 현미를 백미 대신 식혜원료로 사용할 경운 현미 자체를 원료로 사용한 경우보다 당화속도도 빠른 것으로 나타났다. 백미를 이용한 식혜 제조시의 추출물 함량과 당도는 당화 초기 1시간 동안에는 급격히 증가하였으나 그 후에는 커다란 변화를 나타내지 않았다. 발아 현미와 무발아 현미를 이용한 식혜 제조시에는 당화 4시간까지 추출물 함량과 당도가 서서히 증가하는 경향을 나타내었다. 현미를 이용하여 제조한 식혜의 관능검사를 실시한 결과 백미로 제조한 식혜에 비하여 밥알의 조직감은 떨어졌으나 향기의 강도는 더 높았으며, 당도와 전체적인 기호도는 백미와 유의적인 차이를 나타내지 않았다.

• Journal of Applied Biological Chemistry
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• v.52 no.1
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• pp.33-37
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• 2009

A saccharified-rice was fermented using Leuconostoc(Ln.) mesenteroides KC51 strain in various dry matter (DM) contents (4%, 8%, and 12%) at $30^{\circ}C$ for 18 h. The changes of viable cell number, acid production and phytate degradation in saccharified-rice during fermentation were investigated. The viable cell population of Ln. mesenteroides KC51 was increased rapidly in proportion to DM contents during the 9 h of cultivation. The changes of pH and titratable acidity in saccharified-rice were dependent on DM contents. At high DM content (12%), the viable cell number of Ln. mesenteroides KC51 increased to 9.56 log CFU/g after 6 h of fermentation. The pH and titratable acidity reached to pH 3.38 and 0.93% after 18 h of fermentation, respectively. The phytate, known as an antinutrient factor, in saccharified-rice was degraded by Ln. mesenteroides KC51 cultivation. The decrease of phytate during fermentation approximately coincided with the increase of Ln. mesenteroides KC51 population observed in fermented saccharified-rice. Regardless of DM contents, the levels of phytate were reduced to around 50% of initial concentration.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.21-25
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• 2011

A lactic acid bacterial strain showing high acid production in saccharified-rice suspension was isolated from Kimchi. This strain was analyzed by API 50 CHL kit and 16S rRNA sequencing analysis and identified as Leuconostoc mesenteroides 310-12. Saccharified-rice suspension was fermented using L. mesenteroides 310-12 strain at $30^{\circ}C$ for 15 h. The changes of pH, titratable acidity and viable cell number during fermentation were determined. The pH and titratable acidity were reached to pH 3.57 and 0.40% after 15 h fermentation, respectively. The viable cell population of L. mesenteroides 310-12 was rapidly increased to $8.9{\times}10^8$ CFU/g during the 15 h of cultivation. The contents of lactic acid and acetic acid were determined to be 0.077% and 0.065% after 15 h fermentation, respectively. The rice-based fermented beverage was manufactured by blending L. mesenteroides 310-12 fermented broth and some food additives. When this beverage was stored at $4^{\circ}C$, the viable cells population was decreased to $1.0{\times}10^7$ CFU/g and pH was nearly maintained for 25 days.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.146-150
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• 1998

This study was conducted to investigate the possibility of using brown rice as a raw material for preparation of sikhe. The ${\alpha}-amylase$ activity of germinated brown rice was much lower than that of germinated barley; however, the extract and its sugar content of extract prepared from germinated brown rice was similar to those of germinated barley. The extract of sikhe prepared with brown rice at $60^{\circ}C$ for 4 hr was similar to that of milled rice for 1 hr. Sikhe prepared with brown rice did not differ from sikhe prepared from milled rice in sweetness, pH and acidity. Sensory evaluation of sikhe prepared with brown rice showed increase in aroma and decrease in texture compared with sikhe prepared with milled rice.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.101-106
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• 1997

This study was carried out to examine the possibility of using brown rice or paddy as raw materials for sikhe. Brown rice and paddy were soaked in water at $15^{\circ}C$ for 2 days and then germinated at $15,\;20,\;25,\;30^{\circ}C$ for upto 10 days. The higher the germination temperature, the higher the germination speed, the increase of ${\alpha}-amylase$ activity, and the increase of extract amount and its sugar content. The viscosity of extract rapidly decreased first and then slightly increased during germination. The activities of ${\alpha}-amylase$ of germinated brown rice and paddy were much smaller than those of germinated barley; however, the extract amount and its sugar content of germinated brown rice and paddy were similar to those of germinated barley. The germinated brown rice can be used for sikhe not as a saccharifying agent but as a substitute for white rice.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1092-1096
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• 1998

This work was to study the possibility of using germinated colored rice as a raw material for sikhe. Colored rice was soaked in water at $15^{\circ}C$ for 2 days and then germinated at 15, 20, 25 and $30^{\circ}C$ for upto 10 days. The higher the germination temperature, the higher the germination speed, the rate of increase in ${\alpha}-amylase$ activity, and the rate of increase in extract and its sugar content. The viscosity of extract rapidly decreased first and then slightly increased during germination. The germination speed of colored rice was lower than that of brown rice at $25^{\circ}C$. The germinated colored rice can be used for sikhe not as a saccharifying agent but as a substitute for white rice for the nutritional purpose.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47
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• pp.15-32
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• 2002

The endeavors enhancing the grain quality of high-yielding japonica rice were steadily continued during 1980s-1990s along with the self-sufficiency of rice production and the increasing demands of high-quality rices. During this time, considerably great progress and success was obtained in development of high-quality japonica cultivars and quality evaluation techniques including the elucidation of interrelationship between the physicochemical properties of rice grain and the physical or palatability components of cooked rice. In 1990s, some high-quality japonica rice cultivars and special rices adaptable for food processing such as large kernel, chalky endosperm, aromatic and colored rices were developed and its objective preference and utility was also examined by a palatability meter, rapid-visco analyzer and texture analyzer, Recently, new special rices such as extremely low-amylose dull or opaque non-glutinous endosperm mutants were developed. Also, a high-lysine rice variety was developed for higher nutritional utility. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice and the palatability of cooked rice. The water/rice ratio (in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was average to 2.63(in v/v basis). The major physicochemical components of rice grain associated with the palatability of cooked rice were examined using japonica rice materials showing narrow varietal variation in grain size and shape, alkali digestibility, gel consistency, amylose and protein contents, but considerable difference in appearance and texture of cooked rice. The glossiness or gross palatability score of cooked rice were closely associated with the peak, hot paste and consistency viscosities of viscosities with year difference. The high-quality rice variety "IIpumbyeo" showed less portion of amylose on the outer layer of milled rice grain and less and slower change in iodine blue value of extracted paste during twenty minutes of boiling. This highly palatable rice also exhibited very fine net structure in outer layer and fine-spongy and well-swollen shape of gelatinized starch granules in inner layer and core of cooked rice kernel compared with the poor palatable rice through image of scanning electronic microscope. Gross sensory score of cooked rice could be estimated by multiple linear regression formula, deduced from relationship between rice quality components mentioned above and eating quality of cooked rice, with high probability of determination. The $\alpha$-amylose-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were IIpumbyeo, Chucheongyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tonsil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, showed the relatively fast deterioration of cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogradation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked rice. The softer gel consistency and lower amylose content in milled rice revealed the higher ratio of popped rice and larger bulk density of popping. The stronger hardness of rice grain showed relatively higher ratio of popping and the more chalky or less translucent rice exhibited the lower ratio of intact popped brown rice. The potassium and magnesium contents of milled rice were negatively associated with gross score of noodle making mixed with wheat flour in half and the better rice for noodle making revealed relatively less amount of solid extraction during boiling. The more volume expansion of batters for making brown rice bread resulted the better loaf formation and more springiness in rice breed. The higher protein rices produced relatively the more moist white rice bread. The springiness of rice bread was also significantly correlated with high amylose content and hard gel consistency. The completely chalky and large grain rices showed better suitability far fermentation and brewing. The glutinous rice were classified into nine different varietal groups based on various physicochemical and structural characteristics of endosperm. There was some close associations among these grain properties and large varietal difference in suitability to various traditional food processing. Our breeding efforts on improvement of rice quality for high palatability and processing utility or value-adding products in the future should focus on not only continuous enhancement of marketing and eating qualities but also the diversification in morphological, physicochemical and nutritional characteristics of rice grain suitable for processing various value-added rice foods.ice foods.