• Journal of Dairy Science and Biotechnology
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• v.35 no.2
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• pp.99-104
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• 2017

The global consumption of fructose in the form of high-fructose corn syrup (HFCS) has increased considerably over the past several decades. The current intake of HFCS exceeds that of other major caloric sweeteners such as sucrose. Fructose has potentially adverse effects on human metabolism. Therefore, the objective of this study was to analyze the monosaccharide contents of 13 sweetened milk-based beverages by using high-performance liquid chromatography (HPLC). The total monosaccharide (fructose and glucose) contents of various sweetened milk-based beverages ranged from 0.60 g/100 mL (cheese) to 26.03 g/100 mL (maple caramel snack), while milk showed only 0 g/100 mL monosaccharides. The fructose-to-glucose ratio of various popular sweetened milk-based beverages ranged from not-detected (ND) to 2.24 g/100 mL, but the content of glucose was higher than that of fructose in only three samples, namely, strawberry flavored milk, shrimp chips, and maple caramel snack. The analyzed results revealed important basic information about monosaccharides in various milk-based sweetened beverages, presenting ideas for future fructose research.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.9-21
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• 2005

To study the biochemical and physiological role of the plastidic glucose transporter (pGlcT) in carbohydrate metabolism, we characterized transgenic plants with mutations in the pGlcT gene (GT), gt-1 and gt-2, as well double mutants of GT and the maltose transporter (MEX1) and GT and the triose phosphate/phosphate translocator (TPT), GT and the cytosolic fructose-1,6-bisphosphatase gene (cFBP), and MEX1 and TPT, gt-1/mex2, gt-1/tpt-2, gt-1/cfbp-1, mex1-1/tpt-2, respectively. Compared to the wild type, all mutants except the gt-1/cfbp-1 mutant lines displayed higher starch accumulation and higher levels of maltose. Starch accumulation is due to a decrease in starch turnover, leading to an imbalance between the rates of synthesis and degradation. Sucrose levels of gt alleles were higher than those in wild-type plants during the light period, suggesting possible nightly supplementation via the maltose transport pathway to maintain proper carbohydrate partitioning in the plant leaves. The gt plants displayed less growth retardation than mex1-1 mutant and gt-1/mex2 double mutant displayed accumulativesevere growth retardation as compared to individual gt-1 and mex1-1 mutants, implying that the maltose transporter-mediated pathway is a major route for carbohydrate partitioning at night. The gt-1/tpt-2, mex1-1/tpt-2 and gt-1/cfbp-1 double mutants had retarded growth and low chlorophyll content to differing degrees, indicating that photosynthetic capacity had diminished. Interestingly, the gt-1/tpt-2 line displayed a glucose-insensitive phenotype and higher germination rates than wild type, suggesting its involvement not only in carbon partitioning, but also in the sugar signaling network of the pGlcT and TPT.

• The Korean Journal of Food And Nutrition
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• v.30 no.1
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• pp.112-119
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• 2017

In this study, we investigated and compared some chemical properties of Korean natural honeys and sugar-fed honeys for their quality characteristics. The natural honey samples were monofloral from chestnut and acacia flowers, and the sugar-fed honey samples were collected from honeybees feeding on sugar cane and sugar beet. The chemical properties of the honey samples, such as moisture, total protein, total lipids, ash, carbohydrate, minerals, vitamins, and free amino acids were determined. The moisture content was $18.5{\pm}0.9%$ in natural acacia honey, $17.2{\pm}0.9%$ in natural chestnut honey, $19.6{\pm}0.9%$ in sugar cane-fed honey, and $24.8{\pm}%$ in sugar beet-fed honey. The total protein and ash contents were the highest in natural chestnut honey. Maltose and sucrose were not detected in natural honeys but were detected at 2~7% in sugar-fed honeys. The vitamin, mineral, and free amino acids contents of natural honeys were higher than sugar-fed honeys. The natural chestnut honey is the highest in honeys. These results confirmed that the quality of natural honey was better than that of sugar-fed honey. Also, the vitamin, mineral, and free amino acids contents are potential characteristics for distinguishing between natural and sugar-fed honeys.

• Journal of Korean Society of Forest Science
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• v.98 no.2
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• pp.142-147
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• 2009

Hyoscyamus species is sources of the hypnotic and sedative drugs hyoscyamine and scopolamine. Single cells of Hyoscyamus niger were dissociated from suspension cultures and adventitious roots obtained from single-cell clones which were cultured on B5 medium containing 3% (w/v) sucrose, 0.1 mg/L IBA and 0.4% (w/v) gelrite. H. niger adventitious root lines showed wide variation in tropane alkaloids production and growth. An effective selection of 200 root lines was made possible by the application of the 'Dragendorff's reagent' for qualitative detection of the alkaloids from root. A high correlation coefficient (r=0.9390) was observed between the values obtained with the two methods based on HPLC and Dragendorff's reagent analysis. Among the selected roots, the highest scopolamine content was 16.64 mg/g DW (Hn-59), which was 8.82-fold more productive than the lowest alkaloid producing line (Hn-25). Here, we established an efficient selection method on tropane alkaloids production and suggest that the Dragendorff's reagent is of great practical value in selection of invisible compounds.

• Preventive Nutrition and Food Science
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• v.9 no.2
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• pp.113-120
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• 2004

Selected microbiological and biochemical characteristics of the steeping process for the production of yukwa, a traditional Korean oil-puffed snack made of waxy rice, were investigated during steeping of waxy rice in water for 15 days. The lengthy steeping process was largely predominated by lactic acid bacteria (LAB), particularly, Lactobacillus and Leuconostoc. The predominat type of bacterium isolated was the Y26 strain tentatively identified as Lactobacillus plantarum. The titratable acidity of the steeping medium increased from 0.01 to 1.13%, in parallel with the decrease in pH ranging from 6.3 to 4.2 as the steeping period increased from 0 to 15 days. A high amount of lactic acid and to a much lesser extent, butyric acid, acetic acid, propionic acid, and succinic acid were detected during the steeping process. The amount of reducing sugars in the steeping medium increased from 0.61 to 10.43 mg/mL, whereas sucrose decreased from 0.46 mg% to an undetectable level. Starch degradation products including glucose, maltose and oligosaccharides ranging G3-G7 were not initially noticed, but their content increased during the steeping process until completion. However, no oligosaccharides larger than G8 were detected in the steeping medium. The activities of $\alpha$-amylase, $\beta$-amylase and protease in the steeping medium of waxy rice tended to rise increase with time during the steeping process. From these results, the lengthy steeping process in yukwa production can be characterized as the spontaneous fermentation, dominated by lactic acid bacteria, which is a necessary process for inducing biochemical modification of waxy rice.

• Analytical Science and Technology
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• v.8 no.2
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• pp.181-186
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• 1995

The contents of sucrose and reducing sugars of cotyledons and hypocotyls of Ricinus communis L were increased slightly during cold treatment at $4^{\circ}C$. The concentration of total amino acids was increased continuosly during cold treatment. But the contents of hydrophilic amino acids, Asp/Asn, Glu/Gln, Thr, Ser, Ala and cationic amino acids, Arg and Lys were varied dramatically with the cold treated time. The cold treatment induced 24, 52, 54, 55, 56 and 73.5kD of proteins in cotyledons and 55, 56 and 73.5kD of proteins in hypocotyls. 24, 42, 49 and 52kD of proteins in cotyledons and hypocotyls were boiling stable. They were not denatrated by boiling at $100^{\circ}C$.

• Journal of Plant Biotechnology
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• v.5 no.1
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• pp.1-6
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• 2003

The adventitious root of Panax ginseng C.A. Meyer is regarded as an efficient alternative to cell culture or hairy root culture for biomass production due to its fast growth and stable metabolite production. To determine optimal culture conditions for the bioreactor culture of ginseng roots, experiments have been conducted on physical and chemical factors such as bioreactor type, dissolved oxygen, gas supply, aeration, medium type, macro- and micro-elements, medium supplement during culture period, sucrose concentration, osmotic agents, medium pH and light. Elicitation is a key step to increase ginsenoside accumulation in the adventitious roots but biomass growth is severely inhibited by elicitor treatment. To obtain high ginsenoside content with avoiding biomass decrease, we applied two-stage bioreactor culture system. Ginseng adventitious roots were cultured for 40 days to maximize biomass increase followed by elicitation for 7 days to enhance ginsenoside accumulation. We also experimented on types and concentrations of jasmonate to determine optimal elicitation methods. In this paper, we discussed several factors affecting the root propagation and ginsenoside accumulation. Based on the results obtained from previous experiments we have established large-scale bioreactor system (1 ton-10 ton) for the efficient production of ginseng adventitious roots and bioactive compounds including ginsenoside. Still, experiments are on going in our laboratory to determine other bioactive compounds having effects on diet, high blood pressure, DPPH elimination and increasing memories.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.293-297
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• 2005

This experiment was carried to investigate the optimum concentration of abscisic acid (ABA) treatment for enhancing fruit coloration of 'Kyoho' grapes. Cluster and berry weights showed a tendency that increased in proportion to concentration of ABA treatment, but were not significant in all treatments. Also, soluble solids and titratable acidity were not significant during fruit development in all treatments. L-phenylalanine ammonia-lyase (PAL) activity showed a tendency that decreased after rapidly increased in all treatments, and was the highest in 1000 mg/l ABA treatment at final harvest. Anthocyanin and total phenolics contents were high in proportion to ABA treatment concentration, and anthocyanin content in 1000 mg/l ABA treatment was 2.5 folds of that in control. Fructose and glucose as soluble sugars were detected, but sucrose was not detected. Both fructose and glucose contents increased during fruit development, but showed little difference in all treatments.

• The Korean Journal of Food And Nutrition
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• v.33 no.3
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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.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.863-868
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• 1989

In comparison of contents of the components related to the quality of kiwifruit depended on the cultivars, the obtained results were as follows; Abbott showed the highest values in soluble solid, crude fat, firmness and specific gravity. Potassium, phosphorus, calcium and magnesium were estimated as the major minerals in kiwifruit and Bruno contained the highest amounts of potassium and magnesium. Bruno also had high concentrations of ascorbic, maleic, citric and fumaric acid when compared with the other cultivars. The changes in chemical components of kiwifruit (Hayward) by ripening stage were as follows; During ripening, the glucose and fructose contents were increased with decrease of sucrose content. Ascorbic, maleic, fumaric and succinic acid contents were considerably increased during ripening From the investigation of changes in protein pattern by electrophoresis! the new bands with about 17,000-23,50kd were shown during ripening.