• Food Science and Biotechnology
• /
• 제18권5호
• /
• pp.1279-1283
• /
• 2009

Garlic has been used for condiments and also for medicines to cure various diseases since ancient times. Many studies on the processing of garlic have been published, however, few of them were related with fermentation because of the antimicrobial action of the garlic. In this study, to conduct garlic fermentation, 4 lactic acid bacteria (LAB) strains with growth abilities in garlic medium were selected. Addition of various nitrogen, carbon, and mineral sources generally did not improve the growth of experimental strains during garlic fermentation except for Lactobacillus casei KFRI 704 by yeast extract and Lactococcus lactis subsp. cremoris ATCC 19257 by mineral sources. High performance liquid chromatography (HPLC) analysis of 32 phenolic compounds during fermentation showed that formononetin was decreased time dependently. The concentrations of volatile compounds and alliin did not change during fermentation. The results of this study would provide the basic understanding of garlic fermentation by selected strains of LAB.

• Mycobiology
• /
• 제42권4호
• /
• pp.353-360
• /
• 2014

Makgeolli is a traditional Korean alcoholic beverage. The flavor of makgeolli is primarily determined by metabolic products such as free sugars, amino acids, organic acids, and aromatic compounds, which are produced during the fermentation of raw materials by molds and yeasts present in nuruk, a Korean fermentation starter. In this study, makgeolli was brewed using the wild yeast strain Saccharomyces cerevisiae Y98-5, and temporal changes in the metabolites during fermentation were analyzed by ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. The resultant data were analyzed by partial least squares-discriminant analysis (PLS-DA). Various metabolites, including amino acids, organic acids, sugar alcohols, small peptides, and nucleosides, were obviously altered by increasing the fermentation period. Changes in these metabolites allowed us to distinguish among makgeolli samples with different fermentation periods (1, 2, 3, 6, 7, and 8 days) on a PLS-DA score plot. In the makgeolli brewed in this study, the amounts of tyrosine ($463.13{\mu}g/mL$) and leucine ($362.77{\mu}g/mL$) were high. Therefore, our results indicate that monitoring the changes in metabolites during makgeolli fermentation might be important for brewing makgeolli with good nutritional quality.

• 한국식품영양과학회지
• /
• 제28권4호
• /
• pp.773-779
• /
• 1999

This study was conducted to determine the changes in the contents of vitamin C and fermentation characteristics of kimchi on different Chinese cabbage variety(Koreangji Yureum: KY, Kalak Shin Il Ho: KS) and fermentation temperature(5oC, 15oC). Kimchi were fermented at 5oC and 15oC for 140 days and 25 days respectively. In all samples, total acidity increased, and the pH, total sugar and reducing sugar content decreased as the fermentation proceeded. Also, the number of lactic acid bacteria reached the maximum at the optimum fermenting stage. On the other hand, total ascorbic acid, dehydroascorbic acid and ascorbic acid from individual kimchi solid tissue significantly decreased with fermentation periods, however, increased kimchi liquid at the 7day in KS 15(kimchi prepared with Kalak Shin Il Ho at 15oC), KY 15(kimchi prepared with Korangji Yureum at 15oC) and at the 65day in KY 5(kimchi prepared with Korangji Yureum at 5oC) respectively. Therefore, different fermentation temperature as well as variety affected ascorbic acid contents and chemical characteristics of kimchi.

• 한국축산시설환경학회지
• /
• 제16권3호
• /
• pp.227-236
• /
• 2010

본 시험은 가시광선을 이용한 돈분뇨 액비의 부숙여부를 구명하고, 이를 활용한 측정 장치의 개발을 목적으로 수행하였으며, 그 결과는 다음과 같다.가. 돈분뇨 액비 저장기간이 경과함에 따라 pH는 증가하고 EC는 낮아졌으며, 액비를 폭기처리하므로서 무처리에 비해 pH는 더 증가하고 EC는 더 낮아지는 경향을 나타내었다. 나. 돈분뇨 액비 저장기간이 경과함에 따라 주요 악취물질인 암모니아 ($NH_3$)와 황화수소($H_2S$) 농도가 낮아지는 경향을 나타냈으며, 폭기처리를 하므로서 악취농도가 현저하게 낮아지거나 없어지는 결과를 보였다. 다. 돈분뇨 액비의 종자발아율은 무 및 배추종자 공히 초기부터 6주 경과시까지는 전혀 전혀 발아되지 않았고, 7주가 지나고부터 서서히 서서히 발아율이 높아지는 경향이었으나, 무폭기처리한 액비의 종자발아율은 무 및 배추종자 공히 초기부터 시험종료시까지 전혀 전혀 발아되지 않았다. 라. 원형여지크로마토그래피법에 의한 돈 분뇨 액비 부숙여부 반응을 조사한 결과, 폭기처리한 액비의 경우 초기부터 10주까지는 부식반응을 보이지 않았으나, 10주가 지나고 톱니바퀴 모양이 조금씩 형성되면서 반응을 보이기 시작하였고, 무폭기 처리한 액비는 시험 종료시까지 반응을 보이지 않았다. 마. 돈분뇨 액비의 부숙에는 pH, EC, 종자 발아율, 악취농도 및 원형여지크로마토그래피 반응 등이 관련되는 것으로 나타났다. 바. 색도를 이용한 돈분뇨 액비 부숙도 축정을 위해 소프트웨어와 하드웨어를 개발하였으며, 클러스터링을 이용한 액비부숙도 분석 프로그램을 완성하였다. 사. 돈분뇨 액비 부숙도 측정장치는 텅스텐할로겐, 듀테륨램프, 시료투입구, 석영셀, 분광분석기, 악취측정기, 분석소프트웨어 등으로 구성되었으며, 액비의 부숙여부를 간편하고 신속하게 예측할 수 있었다.

• 신재생에너지
• /
• 제9권1호
• /
• pp.25-32
• /
• 2013

It is indispensable to increase the conversion rate of a reducing sugars such as pentose and hexose derived from cellulosic wastes for a highly efficient bioethanol fermentation from food wastes. The saccharification liquid from cellulosic substrates such as vegetable food wastes contained lots of hexose like glucose and pentose like xylose. Since Saccharomyces-based yeasts could not convert xylose to bioethanol, Pichia stipitis which could directly ferment xylose to ethanol was chosen. After selecting Saccharomyces coreanus and P. stipitis, fermentation characteristics by mixture of two yeasts were investigated. As a result, it was verified the production of ethanol was enhanced by the co-fermentation, although there were somewhat differences between the fermentation characteristics by the aeration methods. Moreover, the consumption of pentose, hexose and disaccharide was obviously observed, and aeration in the process of fermentation seemed to stimulate the activity of P. stipitis.

• Food Science and Biotechnology
• /
• 제14권1호
• /
• pp.21-27
• /
• 2005

To improve Dongchimi (watery radish kimchi) quality and preservation, 0, 3, 5, 10, and 15% of gatt (Brassica juncea; leaf mustard) per radish was added. Chemical characteristics were determined during fermentation at $10^{\circ}C$ for 45 days. Total acidity increased slowly by addition of gatt during initial fermentation period, and 15% treatment showed lowest total acidity. Total vitamin C content increased initially in all treatments depending on gatt content, and decreased thereafter. Period for reaching maximum value was delayed by addition of gatt. Highest total vitamin C was found in 15% treatments. In the case of reducing sugar, 5% treatment showed highest contents. Lactic, succinic, and tartaric acid contents consistently increased during fermentation, while those of malic and citric decreased. Turbidity and total solid contents of Dongchimi liquid increased in all treatments as fermentation proceeded, although the extent was rather suppressed by addition of gatt. Colorimetric lightness values decreased, while the initial increased and then decreased in redness and yellowness. Addition of gatt at above 15% weight level per radish accelerated fermentation at the later fermentation stage thus it should be avoided. Most changes in typical characteristics of fermentation were similar depending on treatments. More acceptable Dongchimi could be prepared by fermenting at 5% gatt concentration under given conditions.

• 한국식품영양학회지
• /
• 제30권4호
• /
• pp.788-795
• /
• 2017

This research has attempted to investigate the volatile flavor compounds of onion products through acetic fermentation, and to create a natural beverage with beneficial biological properties which can also fulfill customer quality standards. Onion products (OAF (M): Onion extracts at five days of acetic fermentation, OAF (F): Onion extracts at ten days of acetic fermentation) were produced by acetic fermentation. Volatile flavor compounds from onion extracts, OAF (M) and OAF (F) were used by Mixxor liquid extractions and analyzed by GC/MSD. Compounds of 49, 75 and 69 were identified in onion extracts, OAF(M) and OAF(F) respectively. Among the major volatile flavor compounds classes, sulfur containing compounds (36.7%), acids (31.2%) and aldehydes (13.5%) in onion extracts were changed into acids (69.6%) and alcohols (24.6%) in OAF (M) and acids (80.6%) and alcohols (15.5%) in OAF (F). During acetic fermentation acetic acid, 1,3-butanediol (odorless) and 2,3-butanediol (onion flavor) increased remarkably, sulfur-containing compound such as 2,5-dimethylthiophene having anti-oxidant activities was detected by fermentation.

• Journal of Microbiology and Biotechnology
• /
• 제23권4호
• /
• pp.534-538
• /
• 2013

The effects of lights with different wavelengths on the growth and the yield of extracellular polysaccharides of Nostoc flagelliforme cells were investigated in a liquid cultivation. N. flagelliforme cells were cultured for 16 days in 500 ml conical flasks containing BG11 culture medium under $27{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light intensity and $25^{\circ}C$ on a rotary shaker (140 rpm). The chlorophyll a, phycocyanin, allophycocyanin, and phycoerythrin contents in N. flagelliforme cells under the lights of different wavelengths were also measured. It was found that the cell biomass and the yield of polysaccharide changed with different wavelengths of light. The biomass and the yield of extracellular polysaccharides under the red or violet light were higher than those under other light colors. Chlorophyll a, phycocyanin, and allophycocyanin are the main pigments in N. flagelliforme cells. The results showed that N. flagelliforme, like other cyanobacteria, has the ability of adjusting the contents and relative ratio of its pigments with the light quality. As a conclusion, N. flagelliforme cells favor red and violet lights and perform the complementary chromatic adaptation ability to acclimate to the changes of the light quality in the environment.

• 한국식품영양과학회지
• /
• 제31권2호
• /
• pp.196-203
• /
• 2002

깍두기에 xanthan gum을 0, 0.05, 0.15 및 0.25% 첨가하여 2$0^{\circ}C$에서 숙성시키면서 이화학적 관능적 특성을 측정한 결과는 다음과 같다. Xanthan gum 첨가군의 PH는 대조군에 비해 숙성 전 기간동안 높았고, 0.05% 및 0.15% xanthan gum 첨가군은 숙성 전 기간동안 대조군보다 산도가 낮게 유지되었다. Xanthan gum 첨가 깍두기는 담금 직후 대조군에 비해 유산균 수가 약간 많았으나 숙성 3일에는 0.05% 첨가군이 대조군보다 약간 적었다. 가용성고형 물 함량은 담금 직후에는 xanthan gum 첨가군이 대조군보다 높았으나 숙성이 진행되면서 감소하여 대조군과 유사하였다 Xanthan gum 첨가군이 대조군에 비해 포도당과 과당 함량이 많았으며 특히 만니톨은 숙성 말기에 증가하였다. 깍두기 액의 양은 숙성 전 기간동안 0.05% xanthan gum 첨가군이 대조군보다 낮았다. Xanthan gum 첨가량이 많을수록 점도가 높았으며 모든 군에서 초기 점도가 숙성 말기까지 유지되었다. Texture Analyser에 의한 경도값은 xanthan gum 첨가군이 대조군에 비해 높게 유지되었고 특히 xanthan gum 0.05% 첨가군은 숙성 7일에 유의적으로 높았다(p<0.05). '파쇄성'과 '씹힘성'은 시료간에 유의적인 차이가 없었다. 관능적 특성으로 '외관'에 대한 점수는 숙성 5일째 0.05% 첨가군이 0.25% 첨가군보다 유의적으로 높았다. '신냄새', '군덕내', '신맛', '감칠맛'은 시료간에 유의적인 차이는 없었다. '전분맛'은 0.05% 첨가군은 대조군과 유의적인 차이가 없었으나, 0.15%나 0.25% 첨가군에서는 유의적으로 높았다. '점도'는 대조군은 숙성 기간이 경과됨 에 따라 감소하였으나 xanthan gum 첨가군은 대조군보다 높은 값을 유지하였다. '경도'와 '아삭아삭한 정도'는 0.05 %첨가군이 숙성 7일에 대조군에 비해 높았다. '전반적인 기호도'는 숙성 7일째 0.05% 첨가군은 대조군보다 유의적으로 차이가 없었으며 숙성 7일에도 높은 값을 나타내었다.

• 미생물학회지
• /
• 제54권4호
• /
• pp.379-383
• /
• 2018

맥주는 가장 대중적인 알코올 발효주이지만 퓨린(purine) 함량이 높아 고요산혈증 및 통풍 발생과 연관이 있다고 알려져 있다. 본 연구에서는 맥주 발효 온도를 달리함으로써 맥주의 퓨린 함량을 낮출 수 있는지 알아보았다. 맥주 제조의 주된 발효법인 상면 발효와 하면 발효에서 주로 사용되는 $20^{\circ}C$와 $10^{\circ}C$ 온도에서 맥주를 발효한 후, 각각에서 대표적 퓨린 화합물인 adenine, guanine 그리고 xanthine들의 함량을 high performance liquid chromatography 방법으로 측정하였다. 그 결과, $10^{\circ}C$ 발효 맥주가 $20^{\circ}C$ 발효 맥주에 비해 총 퓨린 함량이 낮았으며, 특히 adenine의 함량이 의미있게 낮아져 있음을 확인하였다.