• Transactions of the Korean hydrogen and new energy society
• /
• v.23 no.4
• /
• pp.397-403
• /
• 2012

Galactose, an isomer of glucose with an opposite hydroxyl group at the 4-carbon, is a major fermentable sugar in various promising feedstock for hydrogen production including red algal biomass. In this study, hydrogen production characteristics of galactose-glucose mixture were investigated using batch fermentation experiments with heat-treated digester sludge as inoclua. Galactose showed a hydogen yield compatible with glucose. However, more complicated metabolic steps for galactose utilization caused a slower hydrogen production rate. The existence of glucose aggravated the hydrogen production rate, which would result from the regulation of galactose-utilizing enzymes by glucose. Hydrogen produciton rate at galactose to glucose ratio of 8:2 or 6:4 was 67% of the production rate for galactose and 33% for glucose, which could need approximately 1.5 and 3 times longer hydraulic retention time than galacgtose only condition and glucose only condition, respectively, in continuous fermentation. Hydrogen production rate, Hydrogen yield, and organic acid production at galactose to glucose ratio of 8:2 or 6:4 were 0.14 mL H2/mL/hr, 0.78 mol $H_2$/mol sugar, and 11.89 g COD/L, respectively. Galactose-rich biomass could be usable for hydogen fermenation, however, the fermentation time should be allowed enough.

• Journal of Environmental Science International
• /
• v.31 no.11
• /
• pp.951-958
• /
• 2022

The aim of this study was to determine the optimum level of carbon dioxide to maximize the quality and yields of strawberries cultivated in a greenhouse. Specifically, two strawberry cultivars, namely, 'Seolhyang' and 'Maehyang', were subjected to varying concentrations of carbon dioxide and patterns linked to their productivity were noted. Both cultivars showed improvements across various physical variables (i.e., leaf area, crown diameter, plant height, fresh weight, and dry weight) when carbon dioxide concentrations were at 1,500 ppm. The optimum carbon dioxide concentration for increased fruit yields and quality was 1,000 ppm. When carbon dioxide was at 1,000 ppm the yields of 'Seolhyang' and 'Maehyang' increased by 1.99 and 1.78 times, respectively, compared to control plants. The influence of carbon dioxide on fruit color was negligible. However, the carbon dioxide increased the sugar content and sugar-acid ratio of the experimental fruits compared to control plants. Specifically, the sugar-acid ratio, which is directly related to taste, was at its highest when the concentration of carbon dioxide was at 1,000 ppm (i.e., for both 'Seolhyang' and 'Maehyang'). Overall, the application of carbon dioxide culminated in improved yields and fruit quality for both cultivars of interest.

• Culinary science and hospitality research
• /
• v.20 no.1
• /
• pp.178-188
• /
• 2014

Two kinds of anticaking agents (dextrin, polydextrose) were combined with kiwifruit paste at 5% w/w ratio and freeze-dried to prepare a powdered material. The physiochemical characteristics of kiwifruit powders with anticaking agents were compared with those without anticaking agents as the control. The yield was higher in the powders with anticaking agents than the control. Moisture content, acidity, and total phenolics were lower in the powders with anticaking agents than the control. The contents of vitamin C was higher in the powders with anticaking agents than the control, but was no significant difference with different anticaking agent types. There were no significant differences in free sugar content (fructose, glucose, total sugar) and organic acid content (oxalic acid, lactic acid, total) depending on the anticaking agent types. Hunter's L-value was significantly high in the order of the samples with dextrin, the control, and polydextrose, while a-value showed an opposite tendency. Browning index, water solubility, and swelling power didn't show any significant difference. However, the hygroscopicities with elapsed time were lower in the powders with anticaking agents than the control. Therefore, the kiwifruit powder combined with dextrin or polydextrose as an anticaking agent at 5% w/w ratio could be used as a food biomaterial with a good quality in moisture, vitamim C, color value, browning index, water solubility, and hygroscopicity.

• Food Science and Preservation
• /
• v.21 no.2
• /
• pp.199-205
• /
• 2014

This study was conducted to investigate the physicochemical properties and antioxidant activity of black Doragi-apple juice to increase the utilization of Doragi, which is known as a high-functional horticultural crop. To prepare the black Doragi, it was steamed for 15 days at $60^{\circ}C$ and was then dried at $30^{\circ}C$ for 3 h. The five types of black Doragi-apple juice were prepared based on different mixing ratios of black Doraji extract, apple extract, and jujube extract. The mixing ratios of black Doraji extract, apple extract, and jujube extract were 3:3:1, 4:2:1, 2:4:1, 2:2:1, and 2:6:1 for samples A, B, C, D, and E, respectively. The pH and acidity of black Doragi-apple juice were within the ranges of 3.9-4.15 and 1.26-1.51%, respectively. Black Doraji-apple juice E showed the highest sugar content (9.33 $^{\circ}Brix$), reducing sugar content (85.05 mg/mL), and sugar content/acid ratio (6.98). Based on the sensory evaluation, sample C was most preferable in terms of color, taste, sugar-acid ratio, and overall preference, except for the flavor. Black Doragi-apple juice D showed a higher total polyphenol content (706 ${\mu}g/mL$) than sample C (586.22 ${\mu}g/mL$), but there was no statistically significant difference between samples C and D in terms of antioxidant activities. Therefore, it is suggested that the best mixing ratio of black Doraji extract, apple extract, and jujube extract for the production of the best black Doragi-apple juice with excellent taste and antioxidant activities is 2:4:1 (sample C).

• Applied Biological Chemistry
• /
• v.34 no.1
• /
• pp.14-20
• /
• 1991

Changes in fruit quality and some components of Unshiu orange(Citrus Unshiu Marc. Hayashi) stored at $2^{\circ}C$ in air or a controlled atmosphere(CA, $O_2$ 10%, $CO_2$ 2%) for 111 days were studied. The incidence of rot fruits was higher in air(12.7%) than in CA condition(3.9%). The appearance of the fruits was better in CA condition than in air. There was no significant difference in the weight loss of whole fruits between both storage conditions. The ratio of the flesh weight In whole fruits under CA condition was slightly lower than those in air until 62 days of storage, while it showed no rapid decrease in the later period of storage. Under both storage conditions, the Brix in the flesh increased in the early Period of storage and then decreased slowly, while the free acid contents decreased gradually during storage. In comparison with the fruits stored in air, those under CA condition showed lower total sugar content. The sugar in the flesh of the fruits is composed of sucrose, fructose and glucose. The content of total sugar as well as each sugar showed no distinct difference under both storage conditions. In the flesh of the fruits, citric acid comprised about 90% of the organic acid and malic acid the second abundant acid. During storage, the contents of citric, malic and oxalic acid decreased. Significant difference in the decreasing rate of total organic acid between both stnrage conditions was not found. From the above results, it might be considered that CA could be applied lot the storage of Unshiu orange grown on Cheju

• Applied Biological Chemistry
• /
• v.47 no.1
• /
• pp.85-91
• /
• 2004

In order to improve foxtail millet wine, a traditional Jeju cereal wine, fermentation characteristics of millet Yakju with different types of Nuruks prepared using isolated Aspergillus sp. and Rhizopus sp. were investigated. When the millet wine was brewed with the Nuruk prepared in this study, the combination ratio of wheat flour: barley : wheat bran : millet = 8 : 1 : 1 : 0 (pellet) showed the highest level of alcohol concentration, and a more favorable score than Kuksundang Nuruk in sensory evaluation. The main organic acids in millet wine were lactic and acetic acids, and the minor organic acids were fumaric, oxalic, citric and malic acids. Analysis of sugar compositions showed that glucose, arabinose, and maltose were present in decreasing order, and that xylose was also detected. Flavor components of millet wine were mainly iso-amyl, iso-butyl and n-propyl alcohols. Ethylacetate and acetadehyde were also detected. The contents of iso-butyl and n-propyl alcohols were higher in the millet wine prepared with Kuksundang Nuruk than those prepared with other Nuruks.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.12
• /
• pp.1693-1700
• /
• 2012

In this study we examined the antioxidant activity and fermentation characteristics of black rice wine. The antioxidant activity of black rice wine was higher than the control, and DPPH radical scavenging activity showed a correlation with the anthocyanin content of rice wine. The pH remarkably decreased until 3 days of fermentation, and the gradually decreased. The reducing sugar and free sugar content reached a maximum at 1 day of fermentation due to enzyme activity. The amount of organic acids, especially lactic acid, increased during the fermentation period. Lactic acid bacteria and yeast count increased with time and amount of black rice. The L color value increased during fermentation regardless of treatments, and the a color value increased with ratio of black rice due to anthocyanin. For this reason, color was given a high score in black rice wine. But overall preference was high in rice wine made with less than 20% of black rice.

• Journal of Nutrition and Health
• /
• v.31 no.3
• /
• pp.315-323
• /
• 1998

This study was performed to investigate the serum lipid levels and fatty acid composition in middle-aged men and the influence of cardiovscular risk factors on them. Data for dietary intake, anthropometry , blood pressure, and general environmental factors were obtained and their relationship to serum lipid levels and fatty acid composition were analyzed in 303 healthy male subjects with a mean age of 43.8$\pm$6.4 years from June 1 to 22 , 1995. The prevalence of obesity was 26.7% by BMI and 11.2% by WHR criteria . The percentage of hypertensive subjects were 13.5% and 22.4% by systolic and diastolic blood pressure, respectively. Retinol, calcium , and roboflavin intakes were lower than the RDA for Koreans. The ratio of carbohydrate intake to total calories of the subjects was 70%. Ratios of P/M and n-6/n-3 were 1.02/1.05/1.00 and 11.1/1, respectively. The percentage of subjects who had serum TG, TC, LDL-C leves beyond the normal range were 19.5% , 13.5% and 8.6% respectively. Palmitic comprised 26.4% of serum total fatty acids, linoleic acid 19.4% and oleic acid 16.4. The waist circumference and ration of carbohydrate intake were related positively to TG level. Serum cholesterol level had positive relations with waist circumference, DBP, sugar intake, and income. There were positive relationships between SFA and bone fishes and vegetable oil intakes, MUFA and DBP while a negative a negative relationship was observed between PUFA and animal fat intake. Serum n-6 fatty acid was related negatively to carbohydrate intake and hot taste preference. N-3 fatty acid was related positively to fish intake and negatively to egg intake. These results suggest that to maintain adequate serum lipid levels and fatty acid composition, sugar, animal fat, and carbohydrate intakes have to be reduced, while consumption of vegetable oil and fish must be increased. It is also essential to control abdominal fat accumulation and blood pressure.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.4
• /
• pp.618-624
• /
• 1998

This study was conducted to standardize ingredient ratios of wooung kimchi. The ingredient ratios of model wooung kimchiwere determined by the survey in Pusan and Kyungnam province and using the literatures including cooking books. Several kinds of wooung kimchi were prepared by adjusting the ingredient ratios fo the model wooung kimchi within standard deviation. The wooung kimchi with different ingredient ratios were fermented for 6 days at 15$^{\circ}C$. The chemical, microbial and sensory properties of the wooung kimchi were investigated. There was little change in pH but the counts of lactic acid bacteria were decreased, as the ratio of pickled anchovy juice became high. The wooung kimchi adding 9.4% pickled anchovy juice obtained high score in appearance and overall acceptability. The counts of lactic acid bacteria were increased in wooung kimchi adding 5% red pepper powder, and there was obtained better result in appearance, texture and overall acceptability than the other groups. The activity, reducing sugar and counts of lactic acid bacteria were increased, as the ratio of glutinous rice paste became high. The wooung kimchi including 6% glutinous rice paste showed the highest score in overall acceptability. The fermentation process of wooung kimchi accelerated, as the ratio of garlic became high. The wooung kimchi adding 3% garlic showed good appearance and acceptability. In addition to these, the addition of 1.3% ginger ehhanced the appearance, texture and overall acceptability fermented anchovy juice, 5.0% red pepper powder, 6.0% glutinous rice paste, 3.0% crushed garlic and 1.3% crushed ginger.

• Journal of the East Asian Society of Dietary Life
• /
• v.16 no.6
• /
• pp.740-746
• /
• 2006

The proximates, vitamin C, minerals, and fatty acids of five potato cultivars were evaluated by AOAC methods, the hydrazine method, ICP-AES, and gas chromatography, respectively. The proximate analyses; vitamin C, reducing sugar, and soluble solid contents; and mineral and fatty acid compositions were significantly different among the five cultivars. The Superior cultivar contained a higher carbohydrate content and higher Ca/P ratio and lower levels of crude protein and Na. The Atlantic cultivar contained significantly higher amount of energy, carbohydrate, reducing sugar, vitamin C, SEA, and MUFA, and significantly lower amount of minerals and PUFA. The Shepody cultivar contained significantly higher amount of carbohydrate and MUFA, and significantly lower amount of soluble solid, vitamin C, and SFA. In addition, the P, Fe, Mg, Cu, and Al levels were significantly higher in Shepody, and Zn content was significantly lower. The Jopung cultivar contained significantly higher levels of moisture and Na, and significantly lower levels of soluble content, reducing sugar, carbohydrate, crude protein, and fat. Finally, the Namsuh cultivar contained significantly higher amount of soluble solid, crude protein, K, Mg, and Al, and significantly lower amount of reducing sugar.