• Journal of the Korean Society of Food Culture
• /
• v.9 no.2
• /
• pp.131-136
• /
• 1994

The ethylacetate extract of Lactuca dentata Makino showed 6 flavonoidal components as detected by ferric chloride solution. The flavonoidal constituent of Lactuca dentata Makino was isolated and purified by the series of column chromatography. The chemical structure of one of the flavonoidal component named as compound E was identified by UV, IR and NMR spectrometry. The melting point range of compound E was $249.5^{\circ}C-251^{\circ}C$. The UV and IR spectra of purified compound E, and its genin were measured with the various shifting agents. The results of UV analysis showed the free state of hydroxy group at 3rd and 4th carbon and binding of sugar at the 7th carbon of compound. The sugar bound to the compound E was identified as glucose by TLC. The IR spectrum showed the presense of hydroxy group, conjugated carbonyl group and aromatic group. The analysis of NMR spectrum was done to the purified compound and its derivatives. The chemical shifts against hydrogen atom, hydroxy group, and the moiety of luteolin were observed in the NMR spectrum along with their position and number as well as type of sugar bound. The isolated and purified compound was identified as $luteolin-7-0-{\beta}-D-glucoside$.

• Food Science and Preservation
• /
• v.6 no.4
• /
• pp.469-474
• /
• 1999

The chemical components of Hovenia dulcis leaf and fruit stalk naturally growing in Korea, were determined. Crude protein of leaf and total sugar of fruit stalk was 7.30 and 51.64%, respectively. The major mineral components were K, Ca, Mg, Na and Mn in that order. The content of vitamin C was 4.8 mg% for leaf and 3.8 mg% for fruit stalk and that of free sugar was 1.37% of fructose for leaf and 8.83% of sucrose for fruit stalk. The highest organic acid in leaf and fruit stalk was malic acid and its content was 1,715.21 mg% and 439.18 mg%, respectively. The highest component of total amino acids in leaf and fruit stalk was glutamic acid(497.99mg%) and proline(751.78mg%), respectively. The highest lady acid in leaf and fruit stalk was 43.54% of linolenic acid and 23.15% of palmitic acid, respectively. trans-Geraniol(124.36 ppm) and isobutyric acid(292.67 ppm) were predominant volatile compounds in leaf and fruit stalk, respectively.

• Journal of Sericultural and Entomological Science
• /
• v.45 no.2
• /
• pp.80-84
• /
• 2003

The component and content of free sugar in mulberry fruits were evaluated. In all accessions, fructose and glucose were identified as the major free sugar. The ratio of two components appeared in the same level. But CV (coefficient of variation. ％) of fructose and glucose were 23.6％, 23.4％, respectively. It might suggest that varietal variation exists in sugar contents. The mean of total free sugars were 9.11${\pm}$2.14％. Among the tested 49 accessions, ‘Geunanosang’ showed the highest total free sugars in 14.67％, whereas ‘Cheongsipyung’ showed the lowest total free sugars in 5.57％. Also fruity characteristics as well as total free sugars to select the desirable mulberry varieties for the production of fruit were researched and analyzed. From that results, four suitable varieties such as ‘Hwansipchosaeng’, ‘Junggojo’, ‘ Kaery-angchosaengsipmunja’, and ‘Geunanosang’ were selected.

• Applied Biological Chemistry
• /
• v.21 no.1
• /
• pp.16-21
• /
• 1978

In order to determine optimum condition for the Ko-Choo-Jang (red-pepper-paste) processing, chemical analysis, mixed ratio, and sensory teat, resulted as follows. 1. The best nutritional value could be obtained after three hours at $60^{\circ}C$, which proved to be the optimum temperature in koji digestion of starch paste. 2. The component ratio of wheat flour to koji-powder was two to one giving the best digestion. 3. The mixing ratio of salt and red-pepper-powder and flour-koji was determined as 1 : 1.5 : 3 by sensory tests. 4. The highest reducing sugar content appeared in a digested mixture using glutinous rice as a starch source and the reducing sugar increased continuously with decreasing, total sugar content in almost every mixture of starches. 5. As a starch source, glutinous rice powder produced the highest total sugar in the beginning stages, however, after 10 day's curing produced less sugar than rice powder. 6. The order of total nitrogen content in the cured paste was recorded as wheat-flour, rice-powder, corn-powder, glutinous-powder, barley-powder, and sweet potato-starch. 7. Amino-nitrogen was increased with curing and the highest, value was observed in the case of wheat flour. 8. In sensory test, Ko-Choo-Jang made of glutinous rice-powder resulted in the best taste.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.6
• /
• pp.921-926
• /
• 2022

Sugar solutions (5%, 10%, 15% and 20%) were tested by seven sensors of Astree E-Tongue for selecting a sensor for sweetness. NMS sensor was chosen as a sensor for sweetness among two sensors (PKS and NMS sensors selected in first stage) by considering precision, linearity and accuracy. Sugar, fructose, glucose and xylitol (5%, 10% and 15%) were tested by E-tongue. The principal component analysis (PCA) result by E-Tongue with seven sensors at 5% concentration level of four sweetners was not satisfactory (Discrimination index was -0.1). On the other hand, the relative NMS sensor response values were derived as 1.08 (fructose), 0.99 (glucose) and 1.00 (xylitol) comparing to sugar. Only the E-Tongue relative glucose response 0.99 was different from 0.5~0.75 of the relative sweetness range reported as the human sensory test results. Considering the excellent precision (%RSD, 1.53~3.64%) of E-Tongue using NMS single sensor for three types of sweeteners compared to sugar in the concentration range of 5% to 15%, replacing sensory test of sweetened beverages by E-Tongue might be possible for new product development and quality control.

• Journal of Ginseng Research
• /
• v.37 no.3
• /
• pp.349-354
• /
• 2013

Dried ginseng (DG) is in fact the representing ginseng product in the worldwide market. Although it is made in various packages depending on the processing method, size and age of DG, basic scientific data reporting the chemical components are limited. In this study, 4-year-old curved ginseng (CG), one of the domestic DG products, was selected for further investigation. Eighty-six samples of 30 and 50 piece-grade CG, which are the most widely distributed in the market, were collected for 5 yr. Their major components, such as moisture, total sugar, acidic polysaccharides, total phenolic compounds, and saponins, were analyzed to figure out the standard quality characteristics. The moisture content of all CG samples was less than 15%. The total water-soluble sugar contents were 22.9% to 47.8% and 23.2% to 49.5% in the 30 and 50 piece-grade CG, respectively. The acidic polysaccharide contents were 3.6% to 6.7% and 2.9% to 6.9% in the 30 and 50 piece-grade CG, respectively. The total phenolic compound content was 0.4% to 0.5% in CG, regardless of the piece-grade. The crude saponin content, which represents the active component of ginseng, was over 2% in all samples. In 30 piece-grade CG samples, the contents of major ginsenosides, Rb1, Rf, and Rg1, were 2.2 to 4.7 mg/g, 0.4 to 1.3 mg/g, and 1.6 to 4.0 mg/g, respectively. The ginsenoside contents in 50 piece-grade CG samples were 2.1 to 3.9 mg/g (Rb1), 0.5 to 1.2 mg/g (Rf), and 1.3 to 3.4 mg/g (Rg1). Overall, since there were relatively high standard deviation and coefficient of variation in all the chemical component contents that were assessed, we found some difficulties in showing the CG standard chemical component characteristics by average, standard deviation, and other statistical analysis factors.

• Korean Journal of Food Science and Technology
• /
• v.41 no.2
• /
• pp.151-156
• /
• 2009

Samhaeju is a traditional Korean noble rice wine, in which its processing is performed at low temperatures for an extended fermentation time and with three brewing steps. In this study, Samhaeju was prepared by different brewing methods that were modified from the method in the literature. Chemical composition of samples were determined to evaluate the quality of the Samhaeju. The Samhaeju was analyzed for pH, total acids, amino nitrogen, Hunter color values, free sugars, organic acids, and volatile components. Before the addition of the second and third mashing, pH values had decreased slightly and total acids had rapidly increased. Free sugar and amino nitrogen contents were high in final product. After addition of the third mashing as the advanced step, a dilution effect was shown. Glucose (A: 0.77-7.0%, B: 0.77-3.81%) was a major free sugar, and lactic acid (A: 0-2,840mg%, B: 0-3,375mg%) was a major organic acid during the entire period of fermentation. Based on principal component analysis of electronic nose data for the components, the stages of Samhaeju fermentation were primarily separated along the first principal component (PC, proportion : 98.67%). The first PC component (PC1) was moved from negative value(-6.16) to positive value(9.00) with increasing fermentation time. The change patterns for pH and total acid during the fermentation period were similar to those of PC1 from the data obtained by electronic nose based on mass spectrometry.

• Applied Biological Chemistry
• /
• v.32 no.1
• /
• pp.14-22
• /
• 1989

Chemical composition of the oyster mushroom(Pleurotus spp.) at different cropping stage were analyzed. The contents of crude protein, soluble protein, reducing sugar, total sugar and crude fat in Pleurotus ostreatus 201 were a little higher than those of Pleurotus sajorcaju. The Component contents were not different from the first to the second flush, while the contents were slightly decreased from the third flush. A11 component contents were highest in $3{\sim}5cm$ pileus size, the contents were slightly decreased as pileus size increase to over $3{\sim}5cm$, except for reducing sugar. Crude fiber content in Pleurotus sajor-caju were a little more than Pleurotus ostreatus 201, and in course of increasing cropping time, ash contens of two strains were simmilar, and were decreased after the second flush. These component contents mere increased by the growth of the pileus. The sugars were identified as xylose, glucose, mannitol and trehalose in Pleurotus sajor-caju, and xylose, fructose, glucose, mannitol and trehalose in Pleurotus ostreatus 201, respectively. Mannitol and trehalose contents in Pleurotus sajor-caju were a little more than that in Pleurotus ostreatus 201. Glucose content of Pleurotus sajor-caju and Pleurotus ostreatus 201 was highest in $1{\sim}3cm$ pileus size, while other sugars in $3{\sim}5cm$ pileus size, and the sugar contents were decreased at over the above size of the pileus.

• Culinary science and hospitality research
• /
• v.20 no.5
• /
• pp.34-42
• /
• 2014

The study explores the sensory properties of Backsulgi prepared with dry non-glutinous rice flour sweetened with various sweeteners(sugar, honey, oligosaccharide, trehalos, erythritol and accesulfame K). Sensory attributes of Backsulgi were evaluated by quantitative descriptive analysis(QDA), PCA and PLSR. The QDA results revealed that the sample sweetened with trehalose showed highest value in dryness, and samples with accesulfame K, honey and erythriol had relatively high levels in moisture and springiness. Principle component analysis (PCA) results showed 78.89 % of the total variation with PC1 (54.92%) and PC2 (23.98%), respectively. The samples with accesulfame K(AF) and honey, which showed high values in moisture level, springiness and sweet taste, showed similar attributes which led to a positive direction of PC1. The correlation between the sensory attributes and consumer acceptance showed that the most important factors for high consumer acceptance were moistness, springiness, sweet taste and sweet flavor. Overall, the samples with accesulfame K(AF) had the closest position in the PLSR results with highest overall consumer satisfaction.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.6
• /
• pp.820-825
• /
• 1999

A bacterial strain WN9, which produced a new type of extracellular polysaccharide, was isolated from soil samples. By morphological, physiological, biochemical, and phylogenetic studies, strain WN9 was identified as a Paenibacillus sp. and it was named as Paenibacillus sp. WN9, which produced a high molecular extracellular polysaccharide from glucose. The molecular weight of the exopolysaccharide (EPS-WN9) was estimated to be about 31.5 mega-Da. The FT-IR spectrum of EPS-WN9 revealed typical characteristics of polysaccharides. EPS- WN9 consisted of D-glucose and D-mannose with a molar ratio of 1:1.4 being identified as a neutral sugar component. The acidic component of EPS- WN9 was tyrosine. Rheological analysis of EPS- WN9 revealed that the pseudoplastic property and its apparent viscosity remained stable at various temperatures and pHs.