• 한국작물학회지
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• 제44권3호
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• pp.267-272
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• 1999

In order to determine the optimum harvest time of vegetable corns, the changes in sugars, soluble solids, and flavor of kernels of sweet (cv. ‘Golden Cross Bantam 70’), super sweet (cv. ‘Cocktail E-51’), and waxy corns (cv. ‘Chalok 2’) were observed at different ripening stages. Sucrose was a major sugar in the sweet and super sweet corns and the content increased from 15 to 21 and 27 days after silking (DAS), respectively and then decreased. Glucose and fructose contents of sweet and super sweet corns tended to decrease with kernel maturity. Total sugar content of the sweet corn analyzed by the anthrone method increased rapidly from 15 to 21 DAS, while that of the super sweet and the waxy corns increased slowly up to 24 and 26 DAS, respectively and decreased thereafter. The content of soluble solids in sweet corn was much higher than that of super sweet corn. Starch content of the sweet corn increased slowly from 15 to 33 DAS, while that of the super sweet corn increased a little rapidly from 15 to 21 DAS and then leveled off to 33 DAS. Starch content of the waxy corn increased continuously from 21 to 38 DAS. There was a positive correlation between the sum of individual sugars (sucrose, glucose, and fructose) and soluble solids in both sweet and super sweet corns, while the content of soluble solids was not related to the sum of individual sugars or total sugars. The flavor rate of sweet and super sweet corns maintained high between 21 and 27 DAS and that of waxy corn decreased from 24 to 33 DAS. The optimum harvest time for sweet, super sweet, and waxy corns was thought to be 21 to 24 DAS considering sugar and starch contents, flavor, and marketing.

• 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.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1527-1527
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• 2001

Glucose, fructose and sucrose being the main sugars that can be found in natural fruit juice. Many instrumental methods, such as GC, LC, electrochemical or spectrometric methods provide information about both the total content of sugars and the specific concentration of each carbohydrate[1]. The simplicity of sample handling and measurement in the near IR(NIR) wavelength region, which allows the use of long pathlength, optical glass cells and optical fibers, makes NIR a good alternative for sugar determination [2]. In the present study, six varieties of persian grapes were harvested at intervals through august to october and analysed for sugars by NIR. The results were processed by principal component regression (PCR) and partial least squares (PLS) analysis. Sample juice was prepared by squeezing through gauze from crashed grape. This solution was treated by zinc ferrocyanide prior to analysis in order to eliminate colored compounds and all optically active nonsugar substances. For glucose and fructose the most characteristic wavelengths were 1456nm corresponding to the first harmonic O-H stretching and the second at 2062nm corresponding to O-H stretching and deformation; secondary characteristic combination bands were also seen at 2265 nm (O-H and C-C stretching) and at 2240 nm (C-H and C-C stretching). However these spectra were taken over a wavelength range from 1100-2500nm at room temperature of 25-$30^{\circ}C$. To test the accuracy of the described procedure, samples of six varieties of grape were analysed by the proposed NIR and a standard method[2]. Good agreement were found between these two sets of the results. To perform the recovery studies , samples of grape juices previously analysed by the proposed method, were spiked with known amounts of each individual sugars and then analysed again. Relative standard deviations varied from 1.4 to 1.8% for six independent measurements of individual and total sugar concentration. In the analysis of real and synthetic samples, precise and accurate results were obtained , providing accuracy errors lower than 1.9% in all cases. Average recoveries of ${97}{\pm}{4%}$ for total sugar and between ${95}{\pm}{5%}$ and ${99}{\pm}{2%}$ for sing1e sugars demonstrate the applicability of the methodology developed to the direct analysis of grape Juice.

• 한국식품영양과학회지
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• 제23권4호
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• pp.680-685
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• 1994

Total nitrogen content, proline, free amino acids, sugars, invertase and diastase activities in native bee-honey (NBH) and foregin bee-honey (FBH) harvested from our different areas of Kangwon , Korea were determined. The total nitrogen contents of NBH and FBH were 0.077$\pm$0.033mg% and 0.055$\pm$0.022mg%, respectively. Proline content in NBH was 42$\pm$10mg% and waqs found to be much lower than that in FHB. Phenylalanine and proline were major free amino acids both in NBH and FBH . The content of total free amino acid in FBH were twice as much as that in NBH , however isomaltose content in NBH were almost two times more than that in FBH. Other sugars including fructose, glucos , sucrose and maltose were also analyzed. No differences were found between NBH and FBH in invertase activities, but comparing to these of FBH ,lower values of diastase activity in NBH were observed.

• 한국식품영양과학회지
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• 제24권6호
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• pp.917-924
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• 1995

재리식 메주, 고오지, 나토 메주, 고오지와 나토의 혼용 메주로 담금한 된장의 일반성분 유리당 및 지방산 조성은 다음과 같다. 조단백질은 10.3~14.6%로 재래식 메주 사용의 된장과 나토된장이 높았고 고오지 된장이 낮았다. 수분은 46.9~54.5% 범위로 숙성과정 중 다소 증가하였고 나토된장이 많았다. 에틸알코올은 숙성 75일 까지는 고오지와 나토의 혼용 된장에서 높았으나 숙성 90일에 고오지 된장이 2.8%로 최대치를 보였다.총당과 환원당은 숙성기간의 경과에 따라 감소하였으며 이들 당 함량은 고오지 된장, 고오지와 나토의 혼용된장, 재래식 메주사용의 된장, 나토된장의 순으로 높았다. 된장의 유리당으로 glucose, galactose, mannose, arabinose가 동정되었으며 이중 glucose, galactose가 타유리당 보다 많았다. 숙성 90일 후에는 glucose나 총 유리당 함량은 재래식 메주로 담근 된장에서 높았고, galactose는 고오지 된장에서 높았다. 된장의지방산으로 palmitic, stearic, oleic, linoleic, linolenic, arachidonic acid가 분리되었고, 이 중 oleic acid가 38.5~46.9%로 시험된장 모두에서 많은 비율로 나타났다. 그러나 숙성기간이나 시험구에 따른 지방산 조성 비율은 뚜렸한 차이가 없었다.

• Journal of Nutrition and Health
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• 제18권1호
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• pp.36-45
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• 1985

The effects of glucose, lactose, sucrose, and potato starch on kimchi fermentation and on the stability of ascorbic acid were investigated at $7^{\circ}C$. Kimchi samples with the sugars showed the higher PH and lower total acidity until 9th day of fermentation than kimchi without sugar. Changes in the pH and total acidity were not significantly different among the samples after the 12th day. Addition of the sugars did not show any effects on the growth of lactobacilli through the fermentation period. The amounts and changes in ascorbic acid content during the fermentation did not differ significantly between the control and sugar - added samples. Ascorbic acid in most samples decreased continuously by the 9th day of fermentation. After then the vitamin increased in all the samples and then again decreased slowly after 18th day. From the multiple comparison tests the 10- panel members indicated the better flavor of sugar - added samples than control sample. However the differences in flavor were not significant.

• 한국식품영양학회지
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• 제11권2호
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• pp.211-215
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• 1998

한국산 청주 두 종류, 일본산 청주 다섯 종류의 당을 HPLC 및 TLC로 비교 분석하였다. 총당은 한국산, 일본산 모두 평균 4.69%를 나타냈고, 한국산은 4.21% 및 4.93%를 나타냈다. 글루코오스는 평균 3.23%를 나타냈고, 한국산은 3.29%, 3.68%를 나타냈다. 말토오스에서 말토옥타오스까지의 말토올리고당은 평균 1.46%를 나타냈다. 청주의 당을 사람의 타액 $\alpha$-amylase와 Aspergillus awamori $\alpha$-glucosidase로 가수분해 한 결과 모두 글루코오스로 가수분해 되어 비피두스균 활성화 효과는 적은 것으로 나타났다.

• Journal of Ginseng Research
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• 제20권3호
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• pp.307-317
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• 1996

This study was undertaken to examine the effects of fresh ginseng addition on the chemical and sensory properties of dongchimi juice fermented under various conditions. The contents of free sugars in dongchimi juice during fermentation increased at the initial stage, but decreased at the palatable stage and then increased again thereafter. Free sugars were higher in dongchlml juice with 4% of ginseng addition than with Soye ginseng and without ginseng addition. Analyses of organic acid contents showed that all three groups contained relatively high amounts of citric, lactic and malic acids. It was also found that, as fermentation progressed, the amounts of tactic and acetic acids in- creased, while that of malic acid decreased at the palatable stage and increased again thereafter. Total saponins were highest in dongchimi juice fermented at 4$^{\circ}C$ with 4% of ginseng addition and panax atrlol ginsenosldes were found more than panaxadiol ginsenosides in dongchimi juice The results of sensory evaluation revealed that dongchimi juice prepared with the addition of $4^{\circ}C$ and 4% ginseng was lower in sour taste and moldy off flavor than the control, thus scoring high In total acceptability. Dongchimi juice with 4% of ginseng addition was best in most sensory characteristics.

• 한국식품영양과학회지
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• 제28권1호
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• pp.172-177
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• 1999

Branched maltodextrin which contains branched sugars as well as linear sugars was produced by Tranzyme L 500. Branched sugar content increased as reaction time between substrate(D.E. 19) and 0.05% of Tranzyme L 500 at pH 5.5, 55oC increased. Branched sugar content was 14.9% at 24 hr of reaction and reached 27% after 60 hr. Total branched sugar content increased regardless of substrate D.E. as enzyme concentration increased. However, when concentrations of enzyme were 0.1, 0.2%, production of branched sugars of which content were 46.6%, 52.6% respectively at those enzyme concentrations, was higher at D.E. 19 than any other conditions.

• 신재생에너지
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• 제7권3호
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• pp.6-16
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• 2011

In order to study the utilization of seaweeds as an alternative renewable feedstock for bioethanol production, their properties of hydrolysis and fermentation were investigated. The seaweeds were well hydrolyzed with diluted sulfuric acid. The weight loss of seaweeds reached 75-90%, but only 12-51% of them was converted into reducing sugars after the acid-hydrolysis at $130^{\circ}C$ for 4-6h. The yield of reducing sugars increased with increasing the hydrolysis time up to 4h and then decreased thereafter. In contrast, the ethanol yield from the hydrolysates increased with hydrolysis time except for green seaweeds maximizing at 4h. Optimal fermentation time by Saccharomyces cerevisiae (ATCC 24858) varied with seaweeds; 48h for green seaweeds, 96h for brown and red seaweeds. The ethanol yield from the hydrolysate reached 138${\pm}$37mg/g-dry for green seaweeds, 258${\pm}$29mg/g-dry for brown seaweeds, and 343${\pm}$53mg/g-dry for red seaweeds, which correspond to approximately 1.5-4.0 times more than the theoretical yield from total reducing sugars in the hydrolysates. The results obtained indicate clearly that the non-reducing sugars or oligosaccharides dissolved in the hydrolysate played an important role in producing bioethanol. Considering the productivity and production cost of each seaweed, brown seaweeds such as Laminaria japonica and Undaria pinnatifida seem to be a promissing feedstock for bioethanol production.