• Journal of Biosystems Engineering
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• v.43 no.2
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• pp.110-118
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• 2018

Purpose: In this study, the potential for biogas production, degradation rates, and lag-phase of diauxic growth of carbohydrate-based material, which is one of the proximate compositions, were investigated. Methods: This study was conducted using starch as a carbohydrate-based material. In experimental condition 1, the biogas potential of carbohydrate-based material was measured. In experimental condition 2, the effect of feed to microorganism ratio (F/M ratio) on lag-phase of diauxic growth from carbohydrate-based material was tested. Biochemical methane potential tests were performed at five different feed to microorganism ratios (0.2, 0.4, 0.6, 0.8, and 1.0) under mesophilic conditions. The biogas production patterns, lag-phase, total volatile fatty acids to total alkalinity ratio (TVFA/TA ratio), and time required for 90 percent biogas production were used to evaluate biogas production based on the biochemical methane potential tests. Results: In experimental condition 1, unlike previous studies, biogas was produced in the TVFA/TA ratio ranging from 1.131 to 2.029 (approximately 13-19 days). The methane content in the biogas produced from the digesters was 7% on day 9 and increased rapidly until approximately day 27 (approximately 72%). In experimental condition 2, biogas yield was improved when the feed to microorganism ratio exceeded 0.6, with an initial lag-phase. Conclusions: Even if the TVFA/TA ratio was greater than 1.0, the biogas production was processed continuously, and the $CO_2$ content of the biogas production was as high as 60%. The biogas yield was improved when the F/M ratio was increased more than 0.6, but the lag-phase of carbohydrate-based material digestion became longer starting with high organic loading rate. To clarify the problem of the initial lag-phase, our future study will examine the microbial mechanisms during anaerobic digestion.

• Korean Journal of Plant Resources
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• v.21 no.3
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• pp.222-225
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• 2008

Chemical composition and enzymatic saccharification characteristics of hemp woody core were investigated by their chemical composition analysis and enzymatic saccharification with commercially available cellulases (Celluclast 1.5L and Novozym 342). Hemp woody core have higher xylan and lower lignin contents than its bast fiber. Based on hemicelluloses and lignin composition, hemp woody core is similar with hardwood biomass. However, cellulose was more easily converted to glucose than xylan to xylose and this trend was confirmed both hemp woody core and yellow poplar. Hemp woody core biomass shows higher saccharification than yellow poplar (hardwood biomass) based on cellulose and xylan hydrolysis. With easier enzymatic saccharification in cellulose and xylan, and similar chemical composition, hemp woody core have better biorefinery feedstock characteristics than hardwood biomass.

• Korean System Dynamics Review
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• v.6 no.1
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• pp.177-192
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• 2005

A system dynamics model is developed to investigate policies for the school-age child weights and heights. The model is based upon the system dynamic model of Soonhee lee(2003), the purpose of which was policy analysis for obese control of adult people. Although the purpose and target people are different, the main structure can be applied to in the same way. Besides the carbohydrate, protein, and fat material, the new model covers hormone and heights with new input mechanisms for foods and activities. The simulation results matches well with the average school-age children in Korea with the average inputs data (foods and activities). The model can be used for various purposes such as policy analyses, care plan for obese children, etc.

• Food Science and Industry
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• v.52 no.2
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• pp.171-187
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• 2019

Novel food materials can be produced based on biotechnology such as genetic recombination, microbial fermentation, and enzymatic engineering by utilizing living organisms such as animal, plant, and microorganism or by applying the enzymes isolated from them. Especially, exploration and development of novel prebiotics and probiotics attracted great attention worldwide in the food industry, of which the research and industrial trends in food biotechnology field are promoting the production of next generation sweeteners and proliferation of beneficial bacteria in gastrointestinal tract. Development and commercialization of novel food materials by domestic bioprocessing technology have been sluggish due to the GMO/LMO food safety issues. Meanwhile, the US and EU do not perceive badly about gene manipulation technology, and the research is most active in the fields of crops and GMMs, respectively. Genetic scissors, which are considered as next generation technology, are notable since foreign genes do not remain in final products.

• Bulletin of the Korean Chemical Society
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• v.25 no.1
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• pp.63-68
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• 2004

Sugar-based gelator p-dodecanoyl-aminophenyl- ${\beta}$-D-aldopyranosides (1-3) have been shown to self-assemble in the presence of p-aminophenyl aldopyranosides. The hydrogel 1+4 showed the double-helical structure with 3-25 nm outer diameters, which is quite different from that of 1. The gel 2+5 revealed twisted ribbon structure with 30-50 nm in widths and a few micrometers of length whereas the gel 3+4 revealed the single and the bundled fiber structures. The difference in these gel supramolecular structures has successfully been transcribed into silica structures by sol-gel polymerization of tetraethoxysilane (TEOS), resulting in the doublehelical, the twisted-ribbon, the single and the multiple (lotus-shaped) hollow fiber structures. These results indicate that novel silica structures can be created by transcription of various superstructures formed in binary gels through the hydrogen-bonding interaction, and the amino group of the p-aminophenyl aldopyranosides acts as an efficient driving force to create novel silica nanotubes. Furthermore, electron energy-loss spectroscopy (ELLS) provided strong evidence for the inner hollow structure of the double-helical silica nanotube. This is a novel and successful example that a variety of new silica structures can be created using a library of carbohydrate gel fibers as their templates.

• Korean Journal of Community Nutrition
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• v.20 no.1
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• pp.21-29
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• 2015

Objectives: Maintaining a balanced diet is very crucial for adolescents. However, adolescents, who may have a short notion about the amount of food, find it difficult to plan daily meals by applying the target pattern proposed by the Korean Nutrition Society. This study was carried out to revise the target pattern based on cooked dishes instead of raw material food groups as an easier way for Korean adolescents to plan their meals. Methods: Target pattern for Korean adolescents were revised based on the following: $1^{st}$, categorize dish groups, $2^{nd}$, calculate representative values of each dish based on the adolescent' intake amount. $3^{rd}$, assign the recommended number of intake for each dish. Validity of the target pattern for Korean adolescent meal plan was examined by the energy content, energy contribution ratio, and NAR & INQ of nutrients. Results: The 11 dish groups categorized were bab; gook tang gigae; side dishes of meat, fish, egg, legume, kimchi, vegetable, seaweed; and between meal of fruit, and milk dairy product. Based on the representative energy values, recommended number of intake were assigned to each dish. For boys, bab and gook tang gigae: 3 each; meat, fish, egg, and legume: 1 each; kimchi and vegetable: 3 each; seaweed: 1; fruit and milk dairy product: 2 each were assigned. For girls, bab and gook tang gigae: 2 each; meat, fish, egg, and legume: choice of 3 dishes, 1 each; kimchi and vegetable: 3 each; seaweed: 1; fruit and milk dairy product: 2 each were assigned. Energy contents, energy contribution ratio of carbohydrate, protein, and fat for boys and girls were in adequate range. The NARs were 1.0 and INQs were ${\geq}1.0$ for all nutrients examined. Conclusions: Revised dish-based, instead of food-based adolescent target patterns for boys and girls were easier and a valid way of Korean adolescent meal planning.

• The Journal of Korean Medicine
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• v.24 no.1
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• pp.84-91
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• 2003

Sasang Constitutional Medicine (SCM) is based on the theory of Sasang (Taeyang, Soyang, Taeum, Soeum) in Traditional Korean Medicine (TKM). It is hypothesized that all of the things in the material world can be divided into the four categories of SCM. We made a new attempt to combine nutritive components, and patterns in physical activities with SCM. At first, we hypothetically divided the nutrients into 4 compartments according to SCM theory, and human body composition as well. These factors could be basically related to Sasangin Exercise Treatment (SET). Therefore, we applied sasangin theory to exercise prescription. As a research method, we hypothesized that human beings' types can be distinguished by mind and body. Mind was focused on exercise psychological aspects, and body also handled by nutrients, body compositions, body shapes, and exercise physiological aspects. For application of sasang theory to the exercise prescriptions, Taeumin as a sample sasangin was selected in this study. We concluded that in perspective of general traits, Taeumin have to reduce their carbohydrate intake volume, but greatly increase their intake of vitamins, minerals, and water in daily diet. They are also recommended exercises that can increase cardiorespiratory function and make them sweat, like endurance running, hiking, swimming, cycling, etc.

• Journal of the Korean Society of Food Culture
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• v.38 no.6
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• pp.456-464
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• 2023

The purpose of this study was to investigate nutritional and functional ingredients and antioxidant activity after fermenting rice bran using Lactobacillus brevis for 24, 36, and 48 hours. The results of the analysis of the nutritional ingredients revealed that there was no significant difference in the carbohydrate, crude protein, crude fat and ash content regardless of the fermentation process and fermentation time. The amount of dietary fiber was significantly different between the unfermented and fermented rice bran and was observed to be the highest after a 48-hour fermentation. The γ-oryzanol, gamma-aminobutyric acid (GABA) and total phenolic contents were significantly higher in the fermented rice bran compared to the unfermented rice bran (p<0.05) and the GABA and total phenolic contents increased significantly as the fermentation time increased (p<0.05). The 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), superoxide and hydroxyl radical scavenging activities used to measure antioxidant effects significantly increased as the fermentation time increased (p<0.05). From these results, it was confirmed that the antioxidant effect and functional components, namely γ-oryzanol, GABA, and the total phenolic content of rice bran improved with fermentation. Based on these results, fermented rice bran could be presented as a functional material for use in high value-added industries.

• The Korean Journal of Food And Nutrition
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• v.33 no.1
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• pp.91-97
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• 2020

The purpose of this study was to provide the basic data of butternut squash (Cucurbita moschata) according to the drying methods. The proximate composition and chromaticity of freeze-dried and hot air-dried Cucurbita moschata powders were evaluated, and the antioxidant effects of these ethanolic extracts were analyzed by DPPH, ABTS, FRAP, reducing power activity, total phenolic, and flavonoid content. As a result, Cucurbita moschata was revealed to have high carbohydrate and crude protein contents, while crude ash and crude fat contents were relatively low. Also, it was confirmed that the hot air-dried Cucurbita moschata had lower L, a, and b values than the freeze-dried Cucurbita moschata. Additionally, as a result of analyzing the antioxidant activity of Cucurbita moschata ethanolic extracts, hot air-dried Cucurbita moschata ethanolic extract showed significantly superior antioxidant activity than freeze-dried Cucurbita moschata ethanolic extract. Also, hot air-dried Cucurbita moschata ethanolic extract was revealed to have a higher polyphenol content, but slightly lower flavonoid content than freeze-dried Cucurbita moschata ethanolic extract. Based on the data from this study, further experiments on Cucurbita moschata material are necessary.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1294-1299
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• 2002

The study aimed to evaluate the influence of molasses in ensiling cassava and Gliricidia tops, common crop residues in the farming systems of Vietnam. Four levels of sugarcane molasses: 0, 30, 60 and 90 kg per tonne of fresh material, and two storage periods (2 and 4 months) for each of the two plant species: Cassava (Manihot esculenta, Crantz) and Gliricidia (Gliricidia sepium, Jacq.) were allocated in a 4${\times}$2 factorial completely randomized block design with 3 replicates. A total of 48 plastic bags, each one containing 10 kg herbage were used. Based on the colour, smell and mold appearance, all the silages were considered to be acceptable but with more spoiled silages with higher levels of additives. DM of herbages (25.8% and 22.4% in cassava and Gliricidia tops, respectively) were not changed during ensiling and the molasses additive had no significant effect on the silage DM. Contents of CP and NDF in the cassava tops silage decreased significantly with increased level of molasses and storage period, respectively. The mean pH values of non-molasses silages were 4.39 in cassava tops and 4.60 in Gliricidia tops. Increased additive levels significantly reduced silage pH in Gliricidia (p<0.01) but not in cassava tops silage (p=0.10). Longer storage period significantly reduced pH in both silages. The water soluble carbohydrate (WSC) concentrations of cassava tops and Gliricidia tops were reduced by 90 and 80%, respectively, after ensiling. Molasses addition increased significantly the silage WSC concentrations. HCN contents in the fresh cassava and Gliricidia tops were reduced by 68 and 43%, respectively, after 2 months ensiling, and were continuously reduced during storage. A reduction of 25% and 42% in the tannin content of fresh cassava and Gliricidia tops, respectively was found after ensiling. Storage time and molasses additive had little affect on the tannin content. Silage lactic acid concentrations were around 1,0% of DM in cassava and 1.7% of DM in Gliricidia top silages, and no effect of molasses additive and storage time was found. It is concluded that cassava and Gliricidia tops residues can be preserved successfully by ensiling, and only low levels of molasses additive are needed to improve silage fermentation.