• Korean Chemical Engineering Research
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• 제50권1호
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• pp.141-148
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• 2012

바이오에탄올 생산을 위한 대체 바이오매스 자원으로 갈조류인 다시마의 활용 가능성을 평가하기 위하여 산 가수분해와 에탄올 발효 특성을 검토하였다. 산 가수분해는 발효 가능한 당류의 생산량을 증가시켜 에탄올 생산량을 크게 증가시켰다. 최대 환원당 생산량은 묽은 황산(1.0 N)을 이용하여 $130^{\circ}C$에서 6시간 가수분해하는 조건에서 다시마 건조무게 기준 135 mg/g이었다. Saccharomyces cerevisiae(ATCC 24858)는 글루코오스, 갈락토오스 및 만노오스와 같은 $C_6$-당을 에탄올로 발효시킬 수 있지만 아라비노오스나 자일로오스와 같은 $C_5$-당은 에탄올 발효기질로 이용하지 못하였다. 최적 발효시간은 글루코오스 48시간, 갈락토오스 72시간, 만노오스 96시간으로 단당류에 따라 달랐다. 그럼에도 불구하고 S. cerevisiae를 이용하여 $35^{\circ}C$에서 96시간 발효를 통해 가수분해물로부터 얻을 수 있는 에탄올 생산량은 가수분해물 중의 총환원당으로부터 얻을 수 있는 이론적 생산량에 비해 4배 정도 높은 다시마 건조무게 기준 242 mg/g에 달하였다. 이는 가수분해물에 용존되어 있는 비환원당과 올리고당류들이 에탄올 발효에서 중요한 역할을 하고 있음을 나타낸다. 가수분해 용액 대비 다시마의 주입비율을 1에서 5%(w/v)로 증가시킴에 따라 에탄올 농도는 2.4에서 9.2 g/L로 증가하는 반면 단위무게당 에탄올 생산량은 242에서 185 mg/g으로 감소하였다. 다시마의 에탄올 생산성은 대략 7,400~9,600 kg/ha/year 정도로 평가되어 다시마가 바이오에탄올 생산을 위한 바이오매스 자원으로 매우 유용함을 알 수 있었다.

• 한국식품영양학회지
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• 제31권4호
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• pp.559-564
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• 2018

Rehmannia glutinosa root (R. root) has been used as an traditional medicine, and is important resource for natural medicines and functional foods. However, R. root contains catalpol which is bitter, and undigested sugars, including stachyose and raffinose, which can cause diarrhea. Therefore, this study was performed to identify the changes in reducing sugar from undigested sugars and in catalpol contents in R. root slurry induced by aging treatments. R. root slurry was treated at $10{\sim}70^{\circ}C$ for up to 72 hr; and extracted with a 50% ethanol solution. The catalpol content was analyzed using HPLC-UVD. Reducing sugar content generated from undigested sugars was measured by the Nelson-Somogyi methods, and the reaction rates were calculated from their variation according to aging time and temperature. During the aging treatment, reducing sugar increased and catalpol decreased. Their formation and degradation rates were highest at $50^{\circ}C$ and $30{\sim}40^{\circ}C$, and their rates were $2.05mg/g{\cdot}hr$ and 23.09 to 23.33%/hr, respectively. These results indicated that aging treatment can positively affect the sweetness and digestibility of R. root slurry. Therefore, an aging treatment could be considered for improving the taste and digestibility of R. root.

• Journal of Ginseng Research
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• 제9권1호
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• pp.104-111
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• 1985

The quality of concentrated red ginseng extract, which was prepared from Korean red ginseng tails, was studied with respect to the changes in the ethanol concentration in the range of 0-90% and temperature of 70-10$0^{\circ}C$ during 1-5 times of extraction. Each extraction time was taken 8 hours at given temperature. The ratio of free sugars to total sugar changed significantly with the number of extraction and ethanol concentrations. An increase in reducing sugar and free sugars and a decrease in extracted soluble starch were fond as ethanol concentration increased. Extraction temperature was found little effect on extractability of sugars and their ratios. Analysis of free sugars in red ginseng extract identified 6 frdd sugars such as rhamnose, xylose, fructose, glucose, sucrose and maltose, including sucrose to be major.

• 한국식품영양학회지
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• 제33권3호
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• pp.251-256
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• 2020

The aging treatment was applied to Rehmannia glutinosa rhizome (RGR) to improve the digestibility by the enzymatic hydrolysis of undigestible sugars. However, RGR spoils easily during the aging treatment. Thus, the purpose of this study was to investigate the influence of ethanol addition as preservatives on sugars and microbial growth of aged RGR. The RGR was treated with the addition of ethanol (0~10%) at 55℃ for eight days. Reducing, free sugars, and total bacterial counts of RGR with ethanol concentrations were analyzed during the aging periods. The aged RGR with 0-2% ethanol appeared spoiled in appearance, and total bacterial counts of these samples increased from 1.1×10⁵ to 2.2×10⁷ CFU and then decreased again. When treated with 4~10% ethanol, the total bacterial counts of aged RGR decreased by more than 99.9% at eight days. In all samples, reducing and digestible sugars increased, and stachyose decreased by the aging treatment. Sucrose content was highest in the 6% ethanol sample (18.2% at six days). These results indicate that the ethanol addition can be applied to the aging treatment of the RGR for improving qualities (sweetness, digestibility, and microbial growth), and can be considered for the stable production of high quality aged RGR.

• 대한영양사협회학술지
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• 제24권1호
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• pp.62-74
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• 2018

The purpose of this study was to investigate dietitians or nutrition teachers' perception of sugar reduction and usage of sugars in school meal service. A survey was conducted for dietitians or nutrition teachers at elementary, middle, and high schools in Gyeonggi and Incheon. Survey data were analyzed according to the experience period and school types of dietitians or nutrition teachers. The numbers of subjects according to work experience period were 134 (44.2%) for <5 years, 68 (22.4%) for ${\geq}5$ and <10 years, and 101 (33.3%) for ${\geq}10years$. Among the subjects, 168 (55.4%) were nutrition teachers at kindergarten/elementary schools, and 135 (44.6%) were at middle/high/special schools. Perceptions of sugar reduction programs were higher in kindergarten/elementary schools than in middle/high/special schools. The perception of added sugar use increased with more work experience, and interest in sugar reduction was higher in kindergarten/elementary schools than in middle/high/special schools. Practice for added sugar reduction increased with more work experience, and the most common method for reducing sugar was use of natural sugars. The main reason for not reducing added sugars in school meals was due to preference. Nutritional education for students increased with more work experience and was higher in kindergarten/elementary schools than in middle/high/special schools. The major nutritional education methods were using school homepage (37.4%), sending family letters (37.4%), and using principle's discretion time (18.4%). Organic sugar and rice taffy were used more at kindergarten/elementary schools, and white sugar, brown sugar, and white syrup were used more at middle/high/special schools. The most common menu using added sugars was stir-fried dishes (stir-fried pork, chicken, and vegetables).

• Applied Biological Chemistry
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• 제39권3호
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• pp.200-205
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• 1996

본 실험에서는 수박 (Citrullus vulgaris L.)과 멜론 (Cucumis melo val. reticulatus Naud.)에 있어서 서로 다른 부위에 함유되어 있는 주요 유리당 (glucose, fructose, sucrose, maltose)을 분리, 정량하기 위해서 HPLC (High Performance Liquid Chromatography)를 이용하였다. 수박과 멜론에 있어서 주로 존재하는 유리당들은 fructose, glucose, sucrose 등이며, 이 유리당들의 함량은 부위별로 다양한 변이를 보였다. 부위별 유리당의 총함량은 stem end 부위에서의 함량보다 stylar end와 side 부위에서의 함량이 더 높았다. 이러한 결과는 수박과 멜론에서 같은 양상이었다. 수박의 경우 전체 유리당 함량은 과피 부위에서 중심 부위로 갈수록 약간씩 증가하는 경향을 보였고, 멜론의 경우 종자를 포함하는 중심 부위를 제외한 가식 부위에서는 과피 부위에서 중심 부위로 진행될수록 증가하였다. 환원당과 비환원당의 비율[(fructose+glucose)/sucrose]은 수박의 경우 과피 부위에서 중간 부위로 갈수록 약간식 감소하였으나 중심 부위에서는 오히려 높았다. 멜론의 경우 가식 부위중 과피 부위에서 중간 부위로 갈수록 감소하였으며 중심 부위와 중간 부위 간에는 유의적 차이가 없었다. 수박에서는 과피 부위에서 중심 부위로 갈수록 환원당과 비환원당 모두가 증가하였지만, 반면에 멜론에서는 환원당의 감소를 보였다.

• Journal of Ginseng Research
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• 제5권2호
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• pp.122-131
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• 1981

An aqueous extract s of fresh ginseng roots was heated at loot for 64 hrs. and the changes of color intensity, pH and the amount of free sugars and amino acids during the various intervals of the heating time were investigated. Color intensity and absorbance of the solution at 490nm were increased in proportion to the length of the heating time. Most of brown pigments produced during the treatment were water soluble, and pH 5.1 at initial stage of the solution, was slightly decreased at the final stages of the reaction. Sucrose, glucose and fructose were major free sugars in ginseng roots, and the amounts of sucrose was over 90 % of total free sugars. Sucrose. was largely decreased approximately 50%, by 64 hrs of the treatment, whereas sharp increase in the amount of glucose and fructose was observed during the reaction in the solution. The observed increase in reducing sugars, glucose and fructose was presumed due to hydrolysis of sucrose. Evidently, glucose and fructose were not important factor to control the browning reaction of the solution. Most of free amino acids and peptides except alanine and isoleucine especially arginine, serine and threonine, were sharply decreased up to 40 : 50% of the original concentration within 2 hrs. Accordingly, the content of free amino acids and peptides seems to be extremely important factor to control the browning reaction in ginseng. A free amino acid, presumed to be nor-leucine, was found in fresh ginseng root on the basis of re mention on liquid chromatography. Kinetic analysis of the browning reaction indicated a pseudo second order with respect to amino acid concentration at the initial stage.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.514-523
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• 2017

Carbon catabolite repression is a crucial regulation mechanism in microorganisms, but its characteristic in Rhizopus is still unclear. We extracted a carbon regulation gene, cre, that encoded a carbon catabolite repressor protein (CRE) from Rhizopus stolonifer TP-02, and studied the regulation of CRE by real-time qPCR. CRE responded to glucose in a certain range, where it could significantly regulate part of the cellulase genes (eg, bg, and cbh2) without cbh1. In the comparison of the response of cre and four cellulase genes to carboxymethylcellulose sodium and a simple carbon source (lactose), the effect of CRE was only related to the concentration of reducing sugars. By regulating the reducing sugars to range from 0.4% to 0.6%, a glucose-containing medium with lactose as the inducer could effectively induce cellulases without the repression of CRE. This regulation method could potentially reduce the cost of enzymes produced in industries and provide a possible solution to achieve the largescale synthesis of cellulases.

• 농업과학연구
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• 제41권2호
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• pp.107-112
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• 2014

Coloring agents in food materials plays important roles in the development of attractive products as well as in the functionality of food such as antioxidant or vitamin supplementation. Carrot has been used as an orange coloring agent in the decoration of food but also a major source of vitamin A complex. Though orange has been considered a typical color of carrot, the Rainbow carrot has been developed recently, which exhibit the various colors such as red, pale yellow, purple, orange or their mixtures. After categorization onto 8 groups by their colors, vitamin A complex (${\beta}$-carotene, lycopene and lutein) and soluble sugars (glucose, fructose, and sucrose) have been analyzed in carrots. The ${\beta}$-carotene was abundant in the groups of orange (Group-O) or groups with the orange color (group-OP, and group-YOP). The content of lycopene content was exclusively high in the red color carrot (group-R). The highest lutein contents were observed from the yellow-purple (group-YP) group. Meanwhile, little amounts of lycopene and ${\beta}$-carotene were observed in yellow-purple (group-YP) nor yellow (group-Y) on yellow (group-Y). Among the reducing sugars in 'rainbow carrots', the amount of sucrose was two times higher than those of fructose and glucose. However, the content of glucose, fructose and sucrose as well as the total reducing sugars did not differ between color groups suggesting little variations on their tastes.

• 펄프종이기술
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• 제42권5호
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• pp.15-23
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• 2010

Bio-ethanol is the most potential next generation automotive fuel for reducing both consumption of crude oil and environmental pollution from renewable resources such as wood, forest residuals, agricultural leftovers and urban wastes. Lignocellulosic based materials can be broken down into individual sugars. Therefore, saccharification is one of the important steps for producing sugars, such as 6-C glucose, galactose, mannose and 5-C xylose, mannose and rhamnose. These sugars can be further broken down and fermented into ethanol. The main objective of this research is to study the feasibility and optimize saccharification and fermentation process for the conversion of lignocellulosic biomass to low cost bioethanol.