• 한국식품영양과학회지
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• 제28권4호
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• pp.780-785
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• 1999

The effect of addition in different amounts of leek(4, 8, 12% respectively) during fermentation of kimchi was investigated. Fermentation characteristics such as pH, acidity and total reducing sugars as well as microbiological properties were determined. During fermentation, pH was more slowly lowered in kimchi added with leek than in control and titrable acidity of these kimchi was lower than that of control. Viable cells of total bacteria and lactic acid bacteria in these kimchi were higher than that of control during fermentation. Content of total reducing sugars was higher than that of control. Three kinds of reducing sugars such as fructose, glucose and galactose were detected and the dominant one appeared to be fructose. These results suggested that addition of leek seems to retard fermentation of kimchi due to their anti microbial actvity.

• 한국식품조리과학회지
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• 제7권1호
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• pp.27-34
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• 1991

This study attempted to set up reasonable extraction time of Omija that was put in water for the various components to soak out. Changes of free sugars, organic acids, reducing sugar, total acid and tannin in Omija with various extraction times were investigated (together with the analysis of each components in Omija fruit). 1. High Performance Liquid Chromatography showed fructose, glucose, and sucrose to be the major free sugars of the Omija fruit. Free sugars and reducing sugar value in Omija beverage increased gradually in according with the extraction time, and marked 75.6% per total free sugars and 82.1% per total reducing sugar at 12 hours. 2. Gas Chromatography showed lactic acid, oxalic acid, fumaric acid, levulinic acid, succinic acid, malic acid, citric acid and pyroglutamic acid to be the major organic acids of the Omija fruit. Organic acids and total acids value in Omija beverage increased gradually on proportion to extraction time, and marked 97.0% per total organic acids at 9 hours and 79.0% per total acids at 12 hours. 3. Tannin content in Omija beverage was increased when extraction time was longer but it showed a low percentage as compared with the reducing sugar and total acid. Tannin content marked 48.8% per total tannin at 12 hours. 4. Sensory evaluation revealed that !1 hours of extraction produced the best quality products based in taste, flavor, color and over-all acceptability, considering the data, it seems possible to conclude that the optimum of time for extraction of Omija to water is 9 hours.

• Korean Chemical Engineering Research
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• 제61권3호
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• pp.412-418
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• 2023

The surge in the oil prices, increasing global population, climate change, and waste management problems are the major issues which have led to the development of biofuels from lignocellulosic wastes. Cellulosic or second generation (2G) bioethanol is produced from lignocellulosic biomass via pretreatment, hydrolysis, and fermentation. Pretreatment of lignocellulose is of considerable interest due to its influence on the technical, economic and environmental sustainability of cellulosic ethanol production. In this study, furniture waste sawdust was subjected to alkaline peroxide (H₂O₂) for the production of reducing sugars. Sawdust was pretreated at different concentrations from 1-3% H₂O₂ (v/v) loadings at a pH of 11.5 for a residence time of 15-240 min at 50, 75 and 90 ℃. Optimum pretreatment conditions, such as time of reaction, operating temperature, and concentration of H₂O₂, were varied and evaluated on the basis of the amount of total reducing sugars produced. It was found that the changes in the amount of lignin directly affected the yield of reducing sugars. A maximum of 50% reduction in the lignin composition was obtained, which yielded a maximum of 75.3% total reducing sugars yield and 3.76 g/L of glucose. At optimum pretreatment conditions of 2% H₂O₂ loading at 75 ℃ for 150 min, 3.46 g/L glucose concentration with a 69.26% total reducing sugars yield was obtained after 48 hr. of the hydrolysis process. Pretreatment resulted in lowering of crystallinity and distortion of the sawdust after the pretreatment, which was further confirmed by XRD and SEM results.

• 한국연초학회지
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• 제29권2호
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• pp.140-145
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• 2007

Acrylamide has been found in many foods. Acrylamide in foodstuffs were analyzed by a GC/MS after bromination of acrylamide or by a LC/MS for underivatized acylamide. Time consuming and laborious clean up procedures is applied for the purification of the extract, in these methods. In this study, a simple and fast method without clean up step for the analysis of acrylamide in mainstream cigarette smoke was developed by using liquid chromatography-tandem mass spectrometry (LC/MS/MS) and the effects of tobacco leaf constituents on acrylamide content was observed. The analysis of acrylamide in mainstream cigarette smoke started to collect TPM (total particulate matter) from smoking and to extract by 0.1 % acetic acid solution and then to detect by liquid chromatography tandem mass spectrometry using electrospray in the positive mode. The recovery of acrylamide in 2R4F reference cigarette was 98 % and the reproducibility was 2.5 % and the limit of detection was 1.6 ng/mL. Reducing sugars and amino acids are considered to be main precursors of acrylamide in foodstuffs. Cut tobacco contain substantial amounts of reducing sugars and amino acid which may be explained the occurrence of acrylamide in mainstream cigarette smoke. The effects of reducing sugars and total nitrogen studied in an experiment with a various tobacco types. This result indicated that reducing sugars are not limiting factor for acrylamide formation, but the level of acrylamide in cigarette smoke was significantly correlated with the total nitrogen contents.

• 한국식품영양학회지
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• 제31권3호
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• pp.335-344
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• 2018

This study aimed to develop and evaluate a sugars intake reduction program (SIRP) that was designed to increase the knowledge, attitude, and skills of Korean children aged 5 years regarding sugars intake reduction. A total of 101 children aged 5~6 years from 6 preschools participated in SIRP. SIRP consisted of 4 sessions including 10 activities (e.g., story-telling, arts, experiment, checking nutrition facts, pledge), delivered to children at preschools by nutritionists over a one-month period. Three letters were sent to parents throughout the program to inform them of the children's activities at the preschools and to provide additional information on reducing children's sugars intake. A total of 90 children completed the program; 83 parents of these children completed the SIRP evaluation survey. The children's sugars intake reduction score was significantly increased after attending SIRP. Teachers (n=6) who participated in this program agreed to improve their students' attitudes on reducing sugars intake and to decrease students' behaviors related to sugars intake. Parents agreed to improve their children's attitude on reducing sugars intake and to decrease children's behaviors related to sugars intake. The outcome showed SIRP improved participants' attitudes towards sugars reduction and increased the skills to reduce the sugars intake of children aged 5~6 years. Future studies should examine whether SIRP reduces actual sugars intake among children.

• 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.

• 한국식품영양학회지
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• 제33권3호
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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.

• Journal of Ginseng Research
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• 제9권1호
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• pp.104-111
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• 1985

The quality of concentrated red ginseng extract, which was prepared from Korean red ginseng tails, was studied with respect to the changes in the ethanol concentration in the range of 0-90% and temperature of 70-10$0^{\circ}C$ during 1-5 times of extraction. Each extraction time was taken 8 hours at given temperature. The ratio of free sugars to total sugar changed significantly with the number of extraction and ethanol concentrations. An increase in reducing sugar and free sugars and a decrease in extracted soluble starch were fond as ethanol concentration increased. Extraction temperature was found little effect on extractability of sugars and their ratios. Analysis of free sugars in red ginseng extract identified 6 frdd sugars such as rhamnose, xylose, fructose, glucose, sucrose and maltose, including sucrose to be major.

• Korean Chemical Engineering Research
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• 제50권1호
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• pp.141-148
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• 2012

바이오에탄올 생산을 위한 대체 바이오매스 자원으로 갈조류인 다시마의 활용 가능성을 평가하기 위하여 산 가수분해와 에탄올 발효 특성을 검토하였다. 산 가수분해는 발효 가능한 당류의 생산량을 증가시켜 에탄올 생산량을 크게 증가시켰다. 최대 환원당 생산량은 묽은 황산(1.0 N)을 이용하여 $130^{\circ}C$에서 6시간 가수분해하는 조건에서 다시마 건조무게 기준 135 mg/g이었다. Saccharomyces cerevisiae(ATCC 24858)는 글루코오스, 갈락토오스 및 만노오스와 같은 $C_6$-당을 에탄올로 발효시킬 수 있지만 아라비노오스나 자일로오스와 같은 $C_5$-당은 에탄올 발효기질로 이용하지 못하였다. 최적 발효시간은 글루코오스 48시간, 갈락토오스 72시간, 만노오스 96시간으로 단당류에 따라 달랐다. 그럼에도 불구하고 S. cerevisiae를 이용하여 $35^{\circ}C$에서 96시간 발효를 통해 가수분해물로부터 얻을 수 있는 에탄올 생산량은 가수분해물 중의 총환원당으로부터 얻을 수 있는 이론적 생산량에 비해 4배 정도 높은 다시마 건조무게 기준 242 mg/g에 달하였다. 이는 가수분해물에 용존되어 있는 비환원당과 올리고당류들이 에탄올 발효에서 중요한 역할을 하고 있음을 나타낸다. 가수분해 용액 대비 다시마의 주입비율을 1에서 5%(w/v)로 증가시킴에 따라 에탄올 농도는 2.4에서 9.2 g/L로 증가하는 반면 단위무게당 에탄올 생산량은 242에서 185 mg/g으로 감소하였다. 다시마의 에탄올 생산성은 대략 7,400~9,600 kg/ha/year 정도로 평가되어 다시마가 바이오에탄올 생산을 위한 바이오매스 자원으로 매우 유용함을 알 수 있었다.

• Journal of Nutrition and Health
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• 제51권5호
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• pp.433-444
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• 2018

전국 초등학교 영양교사를 대상으로 학교 기반 당류 섭취 줄이기 영양교육 프로그램에 대한 실태 및 요구도를 조사하여 초등학교에서 활용할 수 있는 어린이 당류 섭취 줄이기 교육 프로그램 개발의 기초자료를 마련하고자 하였다. 2017년 7월에 온라인 설문으로 이루어진 조사에 전국의 영양교사 230명이 최종적으로 참여하였다. 어린이 대상 당류 섭취 관련 영양교육 실태를 조사한 결과 당류 섭취 저감화를 주요 주제로 영양교육을 실시한 비율은 각각 33.9%였고, 교육 대상 학년은 4학년과 3학년이, 교육 회차는 연 1회, 영양교육 자료 수집 경로는 식약처 등 보건 관련 정부기관이 가장 많았다. 어린이의 당류 섭취 줄이기 관련 영양교육의 필요성에 대하여 81.8%가 필요하다고 답하였고, 정부 차원의 어린이 당류 섭취 줄이기 교육 프로그램의 개발 및 보급의 필요성에 대하여 99.1%가 필요하다고 하였다. 어린이의 당류 섭취 줄이기 영양교육이 가장 필요하다 생각하는 대상은 1학년이 가장 높았으나, 영양 교육이 현실적으로 적합하다고 응답한 대상은 3학년이 가장 높았다. 당류 섭취 관련 영양교육 프로그램에 대한 요구도 조사에서 초등학생 대상 당류 영양교육에서 꼭 다루어야 할 내용은 저학년의 경우 당류 섭취와 건강문제, 당류 함량이 높은 식품, 당류 섭취 줄이기 실천 행동으로 나타났고, 고학년의 경우 당류 섭취와 건강문제, 단맛 중독, 당류 영양표시 확인, 당류의 적정 섭취량, 당류 섭취 줄이기 실천행동의 비율이 높았다. 초등학생 대상 당류 영양교육에 효과적이라고 생각하는 교육방법으로는 저학년과 고학년 모두 실험활동이 가장 높았고, 다음으로 저학년은 교육 동화를 활용한 교육, 동영상/인터넷을 통한 교육으로 나타났으며, 고학년의 경우는 조리실습을 통한 교육, 동영상/인터넷을 통한 교육 등의 순으로 나타났다. 초등학생 대상 당류 영양교육에 효과적이라고 생각하는 교육매체는 저학년은 실물 또는 모형이 가장 높았고, 고학년은 실험키트가 가장 높게 나타났다. 교실 내 자유 활동 시간에 자율 참여에 의한 당류 섭취 줄이기 교육이 이루어질 수 있도록 유도하기 위한 매체로 저학년과 고학년 대상 모두에서 게임과 동영상의 비율이 높았다. 이상의 결과를 통해 초등학교에서 영양교사를 중심으로 한 당류 섭취 저감화 교육이 일부에서 시행되고 있으나, 교육 시간이 짧고 활동 유형이 제한되어 있었다. 또한, 초등학교 영양교사들의 당류 섭취 줄이기 영양교육의 필요성에 대한 인식과 요구는 매우 높은 것으로 나타났으며, 초등학교에서의 영양교육은 체험활동으로 이루어지기 때문에 저학년과 고학년에서 모두 실험 및 실습을 중심으로 한 교육 프로그램에 대한 요구가 높았고, 자율활동 시간을 활용한 교육 방법에 대하여서는 공통적으로 게임 교구에 대한 요구가 높게 나타났다. 따라서 초등학교 기반 당류 섭취 줄이기 영양교육 프로그램 개발과 보급의 시의성이 매우 높으며 개발 시 초등학생 및 교육 환경을 고려한 체험 활동 및 게임 교구 등의 개발이 이루어져야 할 것이다.