This study evaluated the physicochemical characteristics of wheat-flour mixed powders and cooking properties of Sujebi based on the addition of ‘Baromi2’ rice flours for increased expansion of rice consumption. The addition rates at which a roll surface sheet was formed were selected as 0, 10, 20, 30, and 50% based on preliminary experiments with 0-90% addition rates of ‘Baromi2’. Results of physicochemical characterization showed that increasing the addition ratio of ‘Baromi2’ rice flour resulted in increased crude ash and crude fat levels, however crude protein and total starch decreased. The L*-value (lightness) increased with increasing addition ratio of ‘Baromi2’ rice flour; in contrast, a*-value (redness), b*-value (yellowness), and particle size decreased. Results of RVA showed that increasing the addition ratio of ‘Baromi2’ rice flour increased the peak, breakdown, and setback. Regarding textural properties, hardness and chewiness values were significantly reduced with increasing addition ratios of ‘Baromi2’ rice flour. Based on these results, a blending ratio of 20% or less of ‘Baromi2’ is considered suitable for producing Sujebi, and this result serves as basic data for the development of processed rice flour products using ‘Baromi2’.
Cabbage (Baechu) Kimchi in its truncated form was placed in four different packing materials, Ny/PE/LLDP, OPP/AL/PE, PP and PET, and quality changes were observed during storage. Changes in pH and total acidity showed an x-shaped cross-curve as pH decreased and total acidity increased during storage. PP tray showed the slowest change at $5^{\circ}C$ with time. The pH was initially 6.25, but decreased to 4.12~4.16 at 20 days, and total acidity showed a 4 to 4.8-fold increase after 20 days of storage compared to the initial value. During storage at $5^{\circ}C$, total bacterial count and lactic acid bacterial count rapidly increased after 4 days. The total bacterial quantity decreased after a period of time and there were differences according to packaging material; OPP/AL/PE packaging showed the most dramatic decrease. Change in microbial count mostly followed a similar pattern to that of total acidity for all packaging materials. Changes in the color of Kimchi liquid, when examined by color index in $L{\cdot}b$/a form, rapidly decreased over time, similar to pH. Small Ny/PE/PP and OPP/AL/PE packages of Kimchi were examined for changes in free volume inside the packaging. After 13 days of storage at $5^{\circ}C$, the volume was 243 mL, but storage at $20^{\circ}C$ resulted in a volume of 372 mL, a more than 1.5-fold increase in free volume. There were changes in the quality characteristics of small package Kimchi according to storage temperature and packaging material, and large changes in pH, total acidity, and microbial count were evident upon storage at $5^{\circ}C$ for 8 days, which was the optimum palatability period. Mostly, PP treatment showed the slowest quality changes upon storage at $5^{\circ}C$. However, due to small package Kimchi's fast consumption system, the appropriate choice of packaging material must consider the product's turnover ratio. Further, the varieties of small package Kimchi should be diversified according to different consumer preferences by offering Kimchi with different maturity levels. Further, since the leading consumer base ranges in age from the teens to thirties, the development of various products targeting such consumers is necessary.
The purpose of this study was to investigate alcohol content of commercial Korean fermented sources and to analyze the quality parameters such as titratable acidity, pH, salinity, reducing sugar, alcohol and yeast cell count. Eighty-seven samples of Doenjang, 68 samples of Kanjang and 57 samples of Kochujang were collected and divided into conventional and improved products depending on manufacturing method. As a result, the titratable acidities of conventional Doenjang, Kanjang and Kochujang were 1.72, 1.23 and 1.25%, and those of the improved products were 1.87, 1.80, and 1.00%, respectively. The pH values of conventional Doenjang and Kochujang were lower than those of the corresponding improved products and the pH of conventional Kanjang was higher than improved products. The salinities of the conventional products were higher than the improved products, and an the reducing sugar and alcohol content of the conventional products were lower than the improved products. The detection rate of alcohol (above 1%) in conventional Doenjang, Kanjang, and Kochujang were 6, 10 and 39%, respectively while the corresponding improved products showed much higher rates of 100, 76 and 100%, respectively. There was no significant difference in the yeast cell count between the alcohol-containing products and the alcohol-free products. Accordingly, further study is necessary to develop a manufacturing method using non-degradable sugar and salt control to reduce the production of alcohol in Korean source.
된장은 콩을 주원료로 한 우리나라의 대표적 발효, 숙성식품으로 식생활에서 주요 단백질 섭취원이자, 조미료로서 중요한 역할을 차지해왔다. 쌀된장은 쌀을 첨가한 전통된장으로 전통장류와 메주에서 분리한 효소활성 및 항균효과 우수균주 B. subtilis(HJ18-4), A. oryzae(MD05)를 starter로 이용하여, 흩임메주(Rice 1), disc형 메주(Rice 2), 일반육면체메주(Rice 3)로 제형을 달리한 쌀된장의 품질특성을 평가하였다. 발효기간에 따라 아미노태 질소, 암모니아태 질소, 환원당 함량, protease 활성, ${\alpha}$-amylase활성, 총 균수, 유산균수 변화를 측정하였다. 아미노태 질소 함량의 변화는 Rice 3이 21일까지 34.10~199.70 mg%로 급격히 증가하였으며, 암모니아태 질소함량은 다른 처리구에 비해 Rice 1이 639.29 mg%로 가장 높았다. 환원당 함량은 0.024~0.498%로 실험군별 큰 차이는 없었으며, 발효가 진행됨에 따라 증가하였다. Protease 활성은 Rice 2 및 3이 다른 처리구에 비해 95.55~95.92 unit/g으로 높았으며, 발효가 진행됨에 따라 증가하였다. ${\alpha}$-Amylase 활성은 Rice 2, 3이 발효 14일째 36.65~341.27 unti/g으로 급격한 증가를 보였다. 쌀된장의 숙성기간에 다른 총 균수 측정 결과 발효기간 동안 일정하였으며 Rice 1이 42일째 $4.2{\times}10^8$ CFU/g으로 가장 높은 총 균수를 나타내었다. 유산균수는 발효기간 동안 감소하는 경향을 보였다. 본 연구를 통해 B. subtillis와 A. oryzae를 접종하고, 메주 형태가 Rice 3(2,000 g, $20cm{\times}15cm{\times}5cm$)으로 제조 시 아미노태 질소, 암모니아태 질소 및 효소활성 측정 결과, 품질특성이 가장 좋았음을 알 수 있었다. 쌀된장의 숙성기간 동안 품질특성이 가장 좋은 Rice 3의 유기산과 유리아미노산 함량을 분석하였다. 유기산을 분석한 결과, citric, lactic, succinic, fumaric, malic acid가 동정되었다. 이들 유기산 중 citric acid과 lactic acid의 함량이 각각 1,190.1 및 517.28 mg/kg 순으로 가장 높았다. 유리아미노산 분석 결과, glutamic acid와 aspartic acid가 1,959.88 및 1,085.00 mg/100 g으로 함량이 가장 높았으며, leucine, lysine, valine 등의 순으로 함유되어 있었다. 본 연구결과로 효소활성이 우수한 균주로 활용된 쌀된장의 제조에 있어서 제형별 특징에 대한 기초자료를 제공하고자 하였다. This study evaluated the quality characteristics of rice-doenjang prepared with Aspergillus oryzae MD05 and Bacillus subtilis HJ18-4. The physicochemical characteristics of rice-doenjang prepared with three types of meju, such as grain type(Rice 1), disc shape(Rice 2), and brick shape(Rice 3), were compared. We determined amino and ammonia nitrogen contents, protease and amylase activities, reducing sugar content, and total aerobic counts and lactic acid bacteria counts. The amino nitrogen and reducing sugar contents in all meju types gradually increased during fermentation. The amino nitrogen contents reached 151.5~200.0 mg%. Rice 3 were had the highest levels among the 4 types of rice-doenjang. After 42 days of fermentation, amylase and protease activity of Rice 3 were 366.57 and 94.26 unit/g, respectively, which were the highest levels among the 4 types of rice-doenjang. The total aerobic bacteria counts were not changed during 42-day fermentation. This results suggest that high quality characteristics of brick-shaped meju(Rice 3) were better than those of the other meju preparations.
메밀 속성장 유래 세포외효소(protease, amylase, cellulase, lipase, xylanase) 분비능이 우수한 균주를 분리하여 혈전 용해능, 항균 활성 및 내염성을 분석하였다. 선발된 균주 중 HJ0-3을 비롯한 13개 균주는 표준 균주 B. subtilis KACC 10114보다 우수한 protease 활성을 보였다. Amylase 분비능의 경우, HJ18-4을 포함한 10개 균주는 표준 균주 B. subtilis KACC 10114보다 우수한 효소 활성을 보였다. HJ11-19 등 5균주는 표준 균주 B. subtilis KACC 10114보다 cellulase 분비능이 우수함을 확인할 수 있었다. 선별된 23개 균주 중에서 HJ5-21(21.12%), HJ18-4(86.11%), HJ18-9(31.16%), HJ18-13(63.80%)가 높은 혈전 용해능을 보였다. 선별된 23개 균주 중, 5개 균주(HJ18-4, HJ18-9, HJ18-13, HJ25-6, HJ25-11)는 3개 이상의 병원성 균에 대해 항균 활성을 나타내었고, 특히 HJ18-4는 모든 병원성 균에 대하여 항균활성을 나타내었으나 표준 균주 B. subtilis KACC 10114는 항균 활성이 나타나지 않았다. 메밀 속성장 유래 분리 균주 중 세포외효소 활성 및 혈전 용해능, 항균 활성이 우수한 균주 HJ18-4(AB601598)는 API kit 분석결과 B. subtilis(89.6%), 16S rDNA 염기서열 분석으로는 B. subtilis(99%)로 동정되었다. HJ18-4는 표준 균주 B. subtilis KACC 10114와 마찬가지로 NaCl의 농도가 높아질수록 생육이 억제되나 5%와 10%의 NaCl 농도에서 표준 균주 B. subtilis KACC 10114 보다 HJ18-4가 우수한 생육 특성을 나타내었다. 이는 HJ18-4가 염 농도 5-10%에서 우수한 생육특성을 가짐으로써 저염 및 고염 장류 제조에 있어서 starter로 사용이 가능함을 보여주었다. Bealmijang is a short-term fermented regional product that is prepared with soybean and extra ingredients. In this study, starter strain candidates were screened from Bealmijang for fermented soybean paste products. Twenty one bacterial strains producing extracellular enzymes (amylase, cellulase, protease, xylanase and lipase) were isolated from Bealmijang, buckwheat sokseongjang. The isolates were assessed for fibrinolytic and antibacterial activities, and salt tolerance. Strain HJ18-4, identified as Bacillus subtilis (AB601598) by biochemical properties (89.6%) and 16S rDNA sequencing (100%), showed the highest enzymatic, fibrinolytic, and antibacterial activities among the isolates. Although the growth of HJ18-4 was inhibited by the increase of NaCl concentration, the growth still exceeded that of B. subtilis KACC 10114 at 5% and 10% NaCl. These results suggest that B. subtilis HJ18-4 is suitable as a starter for soybean paste manufacture.
Rice is gluten-free and a staple food in many Asian countries.This study was conducted to investigate ways to improve the physicochemical properties and functionality of rice noodles made from high-amylose rice containing resistant starch.Two rice cultivars were used to make the rice noodles: Dodamssal and Joeunheugmi (black rice, BR).The pasting properties, texture, resistant starch content, glycemic index, polyphenol content, and antioxidant activity of the rice noodles were analyzed.Under conditions of 50% water absorption, extruded rice noodles at 112°C, containing 5%, 10%, 15%, 20%, 25%, and 30% BR were prepared.Three types of noodles, namely extruded noodles (EN), dried EN (DN, dried at 40°C for 48 h), and frozen EN (FN, frozen at -20°C for 48 h), were prepared and cooked.The peak and trough viscosity values decreased with the addition of 5 to 20% BR but increased again with the addition of 25% and 30% BR.The hardness, springiness, and cohesiveness also decreased with the addition of BR.The hardness of the rice noodles was found to be in the following order: EN< FN< DN.The resistant starch and soluble starch content decreased with the addition of BR.The total polyphenol content, ABTS, and DPPH radical scavenging activities increased with the addition of BR, with activities in the following order: FN> EN> DN.The in vitro glycemic index of the rice noodles with the addition of 5% BR was significantly lower.The addition of BR can thus reduce the hardness and improve the functionality of extruded rice noodles made with Dodamssal.
This study investigated the effects of a Hwangki (Astragalus membranaceus) extract on the quality of Chungkukjang fermented by Bacillus subtilis KCCM 12148, at 30, 40, and , for 4 days. Changes in moisture contents, protein levels, pH values, ammonia-type nitrogen levels, color, angiotensin-converting-enzyme (ACE) inhibition rates, and fibrinolytic activities, were all determined. For both control and test, the moisture contents decreased gradually with time and the protein levels increased slightly. The pH values fell at the beginning of fermentation and then rose. The content of ammonia-type nitrogen was higher in Hwangki with Chungkukjang than in control, until 24 hr after fermentation commenced. After that time, the content of ammonia-type nitrogen control was higher in the control than in the Hwangki with Chungkukjang sample. Color features, such as lightness, redness, and yellowness, all decreased during fermentation, in both control and test. The highest ACE inhibition rates during fermentation at were 90.9% in the control (48 hr after fermentation commenced) and 95.3% in Hwangki with Chungkukjang(24 hr). Fibrinolytic activities of Chungkukjang and Hwangki Chungkukjang were 100.7 and 74.4% respectively. The content of 2,6-dimethyl pyrazine in the control was higher than that in Hwangki with Chungkukjang. Sensory evaluationtests showed that the addition of Hwangki significantly improved the overall palatability of Chungkukjang.