• Title/Summary/Keyword: Food fermentation

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Optimization of the Fermentation Period of Lightly Salted Oiji (Traditional Korean Cucumber Pickles) (저염 오이지의 최적 발효기간에 대한 연구)

  • Kim, Gumjung;Yang, Jiwon;Lee, Kyunghee
    • Journal of the Korean Society of Food Culture
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    • v.34 no.3
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    • pp.353-360
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    • 2019
  • To optimize the fermentation period of lightly salted Oiji, 3% salt was added to cucumbers that were fermented at $27{\pm}1^{\circ}C$ for 3, 4, 5, 6, or 7 days, after which their physical properties (moisture content, salinity, pH, acidity, hardness) and sensory characteristics (acceptance test, difference test) were evaluated. The moisture content was highest at day 6. Hardness slowly increased as fermentation time increased, but not significantly. The pH was highest after 3 days of fermentation, and tended to decrease as fermentation time increased, with the largest drop occurring between 4 and 5 days, and the lowest pH occurring between 6 and 7 days. Acidity was lowest after day 3 of fermentation and highest after day 7. Acidity tended to increase as fermentation period lengthened. The L-value tended to decrease as salt concentration increased. The a-value declined from day 3 to day 5, then increased significantly by day 7. The b-value was highest after 7 days, with a tendency to increase as the fermentation progressed. Acceptance test results were highest for taste and overall acceptance after 5 days of fermentation. The difference test showed that the optimal lightly salted Oiji fermentation period was approximately 5 days. These results indicate that lightly salted Oiji fermented for 5 days produced the highest acceptance.

Physicochemical Properties and Anti-inflammatory Effects of Astragalus membranaceus (Fisch.) Bunge Fermented by Aspergillus awamori (Aspergillus awamori로 발효한 황기 열수 추출물의 이화학적 특성과 항염증 효과)

  • Lee, Eun Jung;Lee, Da Bin;Song, Bit Na;Park, Bo Ram;Lee, Sung Hyen;Choi, Ji Ho;Park, Shin Young
    • Korean Journal of Medicinal Crop Science
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    • v.28 no.5
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    • pp.347-353
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    • 2020
  • Background: Fermentation of medicinal plants increases their absorption rate and bioavailability in the body. Astragalus membranaceus has been used as a raw material, but research in its use as a food ingredient is lacking. Therefore, the purpose of this study was to identify the physicochemical characteristics and anti-inflammatory effect of fermented Astragalus membranaceus. Methods and Results: Astragalus roots were fermented using Aspergillus awamori for 4 days and their extracts prepared using hot water. The pH, total acidity (%), and reducing sugar (%) of the extracts were then investigated. The pH and total acidity decreased during fermentation. After fermentation, the pH and total acidity decreased, whereas the reducing sugar level increased. The active ingredients in fermented Astragalus were calycosin-7-O-ßd-glucoside, ononin, calycosin and formononetin. The calycosin contents was highest in the hot-water extracted samples fermented for 4 days. The other components were similar to those in control. Nitric oxide level was lower in the hot-water extracted samples fermented for 4 days than in lipopolysaccharide control group. The sample fermented for 4 days was confirmed to inhibit the production of tumor necrosis factor-α and interleukin-1β. Conclusions: Our results showed the physicochemical properties and anti-inflammatory effects of A. membranaceus after fermentation using Aspergillus awamori. These results indicated that fermented Astragalus membranaceus can be used as a functional food.

Fermentation Characteristics of Honey Wine by Saccharomyces bayanus (Saccharomyces bayanus를 이용한 벌꿀 발효주의 양조 특성)

  • Jung, Soon-Teck;Rhim, Jong-Whan;Kim, Dong-Han
    • Korean Journal of Food Science and Technology
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    • v.31 no.4
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    • pp.1044-1049
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    • 1999
  • Fermentation characteristics for the production of honey wine (mead and melomel) was investigated. Among the yeast strains tested, Saccharomyces bayanus showed higher alcohol production and better fermentability than the other strains at low temperature. Optimum pH and temperature for the production of honey wine by Saccharomyces bayanus were pH 4.0 and $20^{\circ}C$, respectively, and optimum soluble solid content of diluted honey solution for the fermentation was between 24 and $27^{\circ}Brix$. Total acidity and pH of honey wine (mead) did not change considerably during the whole period of fermentation, but those of Tangerine and Japanese apricot honey wine (melomel) changed during the fermentation. As the fermentation progressed, reducing sugar decreased continuously until the late period of fermentation, while alcohol content increased continuously during the same period. After fermentation of 21 days, honey wine consisted of about $8.5{\sim}9.1^{\circ}Brix$ of soluble solid, $1.90{\sim}2.32%$ of reducing sugar with the conversion rate of $90{\sim}92%$. After 21 days of fermentation, alcohol contents of mead fermented with polyflower and acasia flower were 13.3 and 13.7%, respectively. Final alcohol content was not affected significantly by the source of honey. While pH of the osmotically extracted fruit honey juice decreased rapidly to pH $2.92{\sim}2.97$ after 13 days of fermentation, total titratable acidity of Tangerine and Japanese apricot honey wine were 0.30 and 0.53%, respectively. After 13 days of fermentation, reducing sugar of fruit honey wines were reduced to $2.03{\sim}2.87%$, alcohol content were reached up to 13.1 and 12.5% for Tangerine and Japanese apricot honey wine, respectively. Generally, honey extracted fruit juices were fermented more efficiently than diluted honey juice.

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Quality characteristics of Doenjang prepared with sweet potato (고구마를 이용한 된장의 품질 특성)

  • Cha, Su-Jin;Park, Sao-Ra;Kim, Dong-Han
    • Food Science and Preservation
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    • v.24 no.2
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    • pp.221-229
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    • 2017
  • The effect of sweet potato on the quality of Doenjang was investigated during fermentation. Viable cells of yeast decreased gradually after 4 weeks of fermentation, but those of aerobic bacteria increased in the late stage. Amylase activity of Doenjang was higher in the late stage of fermentation, while neutral protease maintained high activity during fermentation. Hunter L and b values of Doenjang decreased gradually during fermentation, while a value was increased. The pH of Doenjang decreased gradually until 10 weeks of fermentation, and the titratable acidity was low in the sweet potato added groups. The acid value was low in the Shinyulmi sweet potato added Doenjang. Water activity and oxidation-reduction potential of Doenjang decreased during fermentation. Reducing sugar of Doenjang decreased in the middle stage of fermentation, and it was low in sweet potato added groups. The alcohol content of Doenjang decreased after 2 weeks of fermentation. Amino and ammonia-type nitrogen of Doenjang increased during fermentation and reached the maximum after 10 and 12 weeks of fermentation, respectively. After 12 weeks fermentation, 8% of Shinyulmi sweet potato added Doenjang was more favorable taste, flavor and overall acceptability (p<0.05) than the control or the Yeonwhangmi sweet potato added groups.

Optimization of Fermentation Condition for Red Ginseng Wine Using Response Surface Methodology. (반응표면분석을 이용한 홍삼주 발효조건 최적화)

  • Kim, Seong-Ho;Kang, Bok-Hee;Noh, Sang-Gyun;Kim, Jong-Guk;Lee, Sang-Han;Lee, Jin-Man
    • Journal of Life Science
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    • v.18 no.4
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    • pp.556-564
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    • 2008
  • Response surface methodology was used to monitor the optimization of fermentation conditions for red ginseng wine. A central composite design was applied to investigate the effects of independent variables, fermentation temperature ($X_1$), fermentation time ($X_2$) and initial pH ($X_3$) on dependent variables, physicochemical characteristics and effective ingredients. Alcohol and total sugar content were significantly affected both by fermentation temperature and time. Crude saponin content was greatly affected by fermentation time, and pH was significantly affected by initial pH. Fermentation time and initial pH had a greater effect on ginsenoside content than fermentation temperature. Ginsenoside content increased along with fermentation time and initial pH. We elicited a regression formula for each variable, and superimposed the total optimum points of fermentation conditions for physicochemical characteristics and the effective constituents. The predicted values at the optimum fermentation conditions were at $21{\sim}27^{\circ}C$ for $15{\sim}20$ day in initial pH $4.6{\sim}5.2$.

Effects of Yeast Strains and Fermentation Temperatures in Production of Hydrogen Sulfide During Beer Fermentation (맥주의 발효과정에서 효모와 발효온도가 황화수소의 발생에 미치는 영향)

  • Kim, Young-Ran;Moon, Seung-Tae;Park, Seung-Kook
    • Korean Journal of Food Science and Technology
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    • v.40 no.2
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    • pp.238-242
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    • 2008
  • In this study, hydrogen sulfide ($H_2S$) production was examined during beer fermentation using two ale and two lager yeast strains. In the lager yeast fermentation, a large amount of $H_2S$ was produced in the early fermentation stages when the yeast were actively fermenting wort, indicating a positive relationship between the level of H2S production and the yeast growth rate during fermentation. The ale yeasts produced much lower levels of H2S than the lager yeasts. In the lager fermentation, a higher fermentation temperature shortened the fermentation period, but much higher levels of $H_2S$ were produced at higher temperatures. American pilsner lager yeast fermenting at $15^{\circ}C$ produced a relatively high level of $H_2S$ at the end of fermentation, which would require a longer aging time to remove this malodorous volatile sulfur compound. Not including the English ale strain, which produced a higher level of H2S at lower temperatures, the ale yeast produced lower levels of $H_2S$ at lower temperatures, suggesting that each strain has an optimum fermentation temperature for H2S production.

Recent next-generation sequencing and bioinformatic analysis methods for food microbiome research (식품 미생물 균총 연구를 위한 최신 마이크로바이옴 분석 기술)

  • Kwon, Joon-Gi;Kim, Seon-Kyun;Lee, Ju-Hoon
    • Food Science and Industry
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    • v.52 no.3
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    • pp.220-228
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    • 2019
  • Rapid development of next-generation sequencing (NGS) technology is available to study microbes in genomic level. This NGS has been widely used in DNA/RNA sequencing for genome sequencing, metagenomics, and transcriptomics. The food microbiology area could be categorized into three groups. Food microbes including probiotics and food-borne pathogens are studied in genomic level using NGS for microbial genomics. While food fermentation or food spoilage are more complicated, their genomic study needs to be done with metagenomics using NGS for compositional analysis. Furthermore, because microbial response in food environments are also important to understand their roles in food fermentation or spoilage, pattern analysis of RNA expression in the specific food microbe is conducted using RNA-Seq. These microbial genomics, metagenomics, and transcriptomics for food fermentation and spoilage would extend our knowledge on effective utilization of fermenting bacteria for health promotion as well as efficient control of food-borne pathogens for food safety.

Quality Characteristics of Soybean Paste Added with Krill (크릴이 첨가된 된장의 품질 특성)

  • Kim, Ji-Sang;Moon, Gap-Soon;Lee, Young-Soon
    • Journal of the East Asian Society of Dietary Life
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    • v.19 no.5
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    • pp.776-782
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    • 2009
  • This study was conducted to develop functional soybean paste with krill (Euphausiacea) as compared to a conventional soybean paste (S1). Soybean containing 10%, 20% and 30% (w/w) krill (S2~S4, respectively) was prepared and quality characteristics (moisture, crude fat, crude protein, ash, reducing sugar, pH, titratable acidity, total acidity and buffering power) were assessed during fermentation for 150 days. As well, antioxidative activities of krill soybean paste were compared to those of control soybean paste based on total phenolic compound content and free radical scavenging activity, including the 1,1-diphenyl-2-picryl-hydrazil (DPPH) scavenging activity and the thiobarbituric acid value (TBA value). The moisture content of all samples decreased to 41.91~53.47% during fermentation, while the crude fat increased to 1.98~5.21% with increasing addition of krill. Additionally, crude protein increased slightly to 8.24~14.08% with increasing addition of krill after 120 days of fermentation. Ash content was 15.96~18.92%. The reducing sugar content of S2, S3 and S4 was higher than those of S1 with increasing length of fermentation. S2, S3, and S4 displayed progressive decreases in pH and progressive increases in titratable acidity compared to S1. The total acidity of all samples was increased, while the buffering power was decreased with increasing fermentation. Especially, the buffering power of S1 was lower than that of S2, S3 and S4. DPPH radical scavenging activity of lipophilic extracts from S2, S3 and S4 was slightly higher than those of S1. However, the radical scavenging activity of hydrophilic extracts from all samples had similar tendencies, regardless of the krill content or fermentation period. Total phenolics increased with increasing fermentation time and TBA value increased with increasing fermentation time and krill content.

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Rapid Enzymatic Fermentation of Anchovy Sauce by Protease

  • Jeong, Yong-Jin;Seo, Ji-Hyung
    • Preventive Nutrition and Food Science
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    • v.9 no.3
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    • pp.213-217
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    • 2004
  • We evaluated the possibility of rapid fermentation of anchovy sauce using a commercial protease. The fermentation characteristics were monitored by response surface analysis. The content of total nitrogen was high (around 1 %) with fermentation at 51.7~57.5$^{\circ}C$ after 10.2~16.4 hours, but rapidly decreased at higher temperatures (6$0^{\circ}C$ or over), while the $R^2$ of polynomial equation was 0.9185 (p<0.05). The amino acid content rapidly decreased to approximately 600 mg% and less at high temperature (6$0^{\circ}C$ and over), and the $R^2$ was 0.9578 (p<0.01). The free amino acids were affected more by fermentation time when fermentation temperature was lower, and the $R^2$ for total free amino acids was 0.8496 (p<0.10). The $R^2$ for sweet free amino acids was 0.9144 (p<0.05). According to the results of this study, the optimal conditions for anchovy sauce fermentation were predicted to be 52.5~56.9$^{\circ}C$ and 13.3~16.4 hours, and the predicted values and actual values of each response variable were similar to each other when the fermentation was performed at a random point within the optimal range. Also, the comparison of the quality between the quick anchovy sauce and sauces currently on the market showed that the content of sweet amino acids was higher in the former than in the latter.

Optimization of Fermentation Process for Acetic Acid Production (초산 생성을 위한 발효공정의 최적화)

  • Shin, Jin-A;Oh, Nam-Soon
    • Food Engineering Progress
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    • v.14 no.3
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    • pp.217-221
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    • 2010
  • Various conditions of acetic acid fermentation by Acetobacter aceti B20 strain were investigated and evaluated to optimize the fermentative production of acetic acid. The effects of the initial ethanol concentration on growth and acid productivity in a flask and fermentor were also studied. The growth of A. aceti B20 strain was inhibited as the concentration of ethanol increased. However, the highest total acidity and fermentation yield were 5.34% and 56.1%, respectively when the initial concentration of ethanol was 7% in the batch fermentation. Although the concentration of initial glucose influenced the growth rate of B20 strain, it did not influence the total acidity in the flask culture. When the agitation speed increased, the growth, total acidity and fermentation yield were all improved. In fed-batch fermentation, total acidities and fermentation yields were 7.14-8.76% and 39.1-53.0%, respectively, and their values mostly depended on the feeding methods.