• Title/Summary/Keyword: D-(-)-lactic acid

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Selection of Lactic Acid Bacteria with Antibacterial Activity for Extension of Kimchi Shelf-life (김치의 저장성 향상을 위한 항균활성 우수 유산균 선발)

  • Choi, Hak-Jong;Kim, Yu Jin;Lee, Na Ra;Park, Hae Woong;Jang, Ja Young;Park, Sung-Hee;Kang, Miran;Kim, Hyun Ju;Lee, Jong-Hee;Lee, Jong-Hoon;Pyun, Yu-Ryang;Kim, Tae-Woon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.2
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    • pp.328-332
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    • 2014
  • A survey was conducted on the isolation of lactic acid bacteria with antibacterial activity to extend kimchi shelf-life. Antibacterial activity was tested against bacteria associated with acidification of kimchi, including Lactobacillus plantarum, Pediococcus pentosaceus, and Lactobacillus sakei, using agar-well diffusion assay. Two isolates from kimchi were identified as Lactococcus lactis subsp. lactis and Lactobacillus brevis by 16S rRNA gene sequence analysis and API 50 CHL assay, and they showed antibacterial effects against indicator strains. The isolates displayed acid tolerance at pH 3.5, salt tolerance in 5% NaCl, and growth at $4^{\circ}C$. These result imply that the selected strains might be used to extend kimchi shelf-life as a potential starter.

Effects of Alaska Pollack Addition on the Quality of Kimchi (Korean salted cabbage) (명태를 첨가한 김치의 품질특성)

  • Sung, Jung-Min;Choi, Hae-Yeon
    • Food Science and Preservation
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    • v.16 no.5
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    • pp.772-781
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    • 2009
  • We investigated the effects of Alaska pollack addition on the quality of Kimchi during 20 days of fermentation at 10C. Alaska pollack was added to salted cabbage at concentrations of 0%, 6%, 12%, or 18% (all w/w). The quality characteristics determined were pH, acidity, salinity, reducing sugar content, color, free amino acid level, and lactic acid bacterial counts, at 4 d intervals over 20 d, during progressive fermentation at constant temperature (10C). Changes in pH, acidity, and reducing sugar content during fermentation were increased when Alaska pollack was added, whereas salinity decreased. Total lactic acid bacterial counts achieved maximum levels on day 8 for Kimchi with 18% (w/w) Alaska pollack, and the other Kimchi samples attained their highest values on day 12. In terms of color, the L, a, and b values of Kimchi rose with addition of Alaska pollack. The free amino acid content of Kimchi increased as the level of added Alaska pollack rose but gradually fell as fermentation progressed. Upon sensory evaluation, Kimchi with 6% (w/w) Alaska pollack scored highest in terms of appearance, texture, taste, and overall acceptance. In conclusion, our results indicate that Alaska pollack has a positive effect on the quality of Kimchi, increasing the content of free amino acids.

FERMENTATION QUALITY EVALUATION OF ITALIAN RYEGRASS SILAGES BY USING THE BUFFER INDEX CURVE

  • Kim, K.H.;Tsujiguchi, J.;Uchida, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.4
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    • pp.737-740
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    • 1992
  • This study was conducted to demonstrate the practical use of the buffer index curve as a criterion of silage quality evaluation, Forty five samples of the ensiled Italian ryegrass were collected from farms in Okayama, Japan. Silages were devided into 4 groups by the pattern of buffer index curve. Heavy wilting silages (A group) showed no peak on buffer index curve and Flieg's score of 95.6. However, moderate or weak wilting silages (B group) with moisture content of 63.3 showed a peak at pH 4.0 and a Flieg's score of 67.8. Both of A and B groups were regarded as a good quality silage. Silages (C group) with a peak at pH 4.5 were of a medium quality with Flieg's score of 45.3. Poorly preserved silages (D group) with Flieg's score of 12.0 had a peak at pH 5.0. There was a high positive correlationship (p<0.01) between the peak value of buffer index curve and the organic acid content.

A study of mechanical properties with FDM 3D printing layer conditions (FDM 3D Printing 적층조건에 따른 기계적 물성의 연구)

  • Kim, Bum-Joon;Lee, Hong-Tae;Sohn, Il-Seon
    • Design & Manufacturing
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    • v.12 no.3
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    • pp.19-24
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    • 2018
  • Fused deposition Modeling (FDM) is one of the most widely used for the prototype of parts at ease. The FDM 3D printing method is a lamination manufacturing method that the resin is melted at a high temperature and piled up one by one. Another term is also referred to as FFF (Fused Filament Fabrication). 3D printing technology is mainly used only in the area of prototype production, not in production of commercial products. Therefore, if FDM 3D printer is applied to the product process of commercial products when considered, the strength and dimensional accuracy of the manufactured product is expected to be important. In this study, the mechanical properties of parts made by 3D printing with FDM method were investigated. The aim of this work is to examine how the mechanical properties of the FDM parts, by changing of processing FDM printing direction and the height of stacking layer is affected. The effect of the lamination direction and the height of the stacking layer, which are set as variables in the lamination process, by using the tensile specimen and impact specimen after the FDM manufacturing process were investigated and analyzed. The PLA (Poly Lactic Acid) was used as the filament materials for the 3D printing.

Hydrolysis of Lactose in Whey by the BetavD-Galactosidase (Beta-D-Galactosidase에 의한 유청에 함유된 유당의 가수분해)

  • 최미진;허태련
    • Microbiology and Biotechnology Letters
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    • v.20 no.1
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    • pp.46-52
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    • 1992
  • The optimum condition for the developement of a whey beverage from the concentrated whey was studied. Reverse osmosis system was used to obtain concentrated lactose from cheese whey. The hydrolysis degree of lactose by $\beta$-D-galactosidase was determined using HPLC (high performance liquid chromatography). The order of hydrolysis degree was 1:1, 2:l and 3:l concentrated lactose. It resulted from the concentrated salt which slightly inhibited $\beta$-D-galactosidase with constant enzyme dosage. The optimum condition for enzyme dosage was 2% in non-concentrated lactose, 3% in 2:l and 3% in 3:l concentrated lactose after 4 hours of reaction. When the 3:l concentrated lactose was used, more than 70% was hydrolyzed by 3% enzyme dosage. Furthermore the change of fermented whey by lactic acid bacteria was investigated. Based on the result of sensory test, the most favorable response was obtained at pH 4.2 and titratable acidity of 0.7% about 6 hours of fermentation at $37^{\circ}C$ with 2%: thermophilic starter.

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Associations of Probiotics with Vitamin D and Leptin Receptors and their Effects on Colon Cancer

  • Ranji, Peyman;Akbarzadeh, Abolfazl;Rahmati-Yamchi, Mohammad
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3621-3627
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    • 2015
  • Colorectal cancer (CRC) is one of most common causes of cancer-related death worldwide. Recent studies have suggested that microbial and environmental factors including diet and lifestyle can impact on colon cancer development. Vitamin D deficiency and dysfunction of vitamin D receptor (VDR) also correlate with colon cancer. Moreover, leptin, a 16-kDa polypeptide, participates in the regulation of food intake and is associated with other environmental factors affecting colon cancer through the leptin receptor. Altered levels of serum leptin and patterns of expression of its receptor (LPR) may be observed in human colon tumours. Furthermore, the collected data from in vitro and in vivo studies have indicated that consuming probiotic non-pathogenic lactic acid bacteria have beneficial effects on colon cancer. Probiotics, inflammation and vitamin D/VDR have been correlated with leptin and its receptor and are also with colon cancer. Thus, in this paper, we review recent progress on the roles of probiotic, vitamin D/VDR and leptin/LPR in inflammation and colon cancer.

Characterization of culturable yeast species associating with whole crop corn and total mixed ration silage

  • Wang, Huili;Hao, Wei;Ning, Tingting;Zheng, Mingli;Xu, Chuncheng
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.2
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    • pp.198-207
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    • 2018
  • Objective: This study investigated the association of yeast species with improved aerobic stability of total mixed ration (TMR) silages with prolonged ensiling, and clarified the characteristics of yeast species and their role during aerobic deterioration. Methods: Whole crop corn (WCC) silages and TMR silages formulated with WCC were ensiled for 7, 14, 28, and 56 d and used for an aerobic stability test. Predominant yeast species were isolated from different periods and identified by sequencing analyses of the 26S rRNA gene D1/D2 domain. Characteristics (assimilation and tolerance) of the yeast species and their role during aerobic deterioration were investigated. Results: In addition to species of Candida glabrata and Pichia kudriavzevii (P. kudriavzevii) previously isolated in WCC and TMR, Pichia manshurica (P. manshurica), Candida ethanolica (C. ethanolica), and Zygosaccharomyces bailii (Z. bailii) isolated at great frequency during deterioration, were capable of assimilating lactic or acetic acid and tolerant to acetic acid and might function more in deteriorating TMR silages at early fermentation (7 d and 14 d). With ensiling prolonged to 28 d, silages became more (p<0.01) stable when exposed to air, coinciding with the inhibition of yeast to below the detection limit. Species of P. manshurica that were predominant in deteriorating WCC silages were not detectable in TMR silages. In addition, the predominant yeast species of Z. bailii in deteriorating TMR silages at later fermentation (28 d and 56 d) were not observed in both WCC and WCC silages. Conclusion: The inhibition of yeasts, particularly P. kudriavzevii, probably account for the improved aerobic stability of TMR silages at later fermentation. Fewer species seemed to be involved in aerobic deterioration of silages at later fermentation and Z. bailii was most likely to initiate the aerobic deterioration of TMR silages at later fermentation. The use of WCC in TMR might not influence the predominant yeast species during aerobic deterioration of TMR silages.

Influence of Different Strains of Agrobacterium rhizogenes on Hairy Root Induction and Rosmarinic Acid Production in Agastache rugosa Kuntze (Agrobacterium rhizogenes strains이 배초향 모상근 유도와 Rosmarinic acid 생산에 미치는 영향)

  • Kim, Jong-Se;Oh, Eun-Jeong;Lee, Sook-Young
    • Korean Journal of Plant Resources
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    • v.23 no.1
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    • pp.14-18
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    • 2010
  • Rosmarinic acid, an ester of caffeic acid with 3,4-dihydroxyphenyl lactic acid, is one of the main active constituents of Agastache rugosa Kuntze and has an astringent property, antioxidant capacity, anti-inflammatory activity, antimutagenic ability, antimicrobial capacity, and an antiviral property. Five different strains of Agrobacterium rhizogenes differed in their ability to induce Korean mint (Agastache rugosa Kuntze) hairy roots and also showed varying effects on the growth and rosmarinic acid production in hairy root cultures. A. rhizogenes R1601 is the most effective strain for the induction (72.90%), growth (13.50 g/l) and rosmarinic acid production (22.60 mg/g) in hairy root of Korean mint. Our results demonstrate that use of suitable strains of A. rhizogenes may allow study of the regulation of rosmarinic acid biosynthesis in hairy root cultures of Agastache rugosa.

Effects of additives on the fermentation quality, in vitro digestibility and aerobic stability of mulberry (Morus alba L.) leaves silage

  • Dong, Zhihao;Wang, Siran;Zhao, Jie;Li, Junfeng;Shao, Tao
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.8
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    • pp.1292-1300
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    • 2020
  • Objective: To explore feed resources capable of replacing regular poor-quality fodder, this study was conducted to evaluate the effects of additives on the fermentation quality, in vitro digestibility and aerobic stability of mulberry leaves silage. Methods: The mulberry leaves were ensiled either untreated (control) or treated with 1×106 cfu/g fresh matter Lactobacillus plantarum (L), 1% glucose (G), 3% molasses (M), a combination of 1% glucose and Lactobacillus plantarum (L+G), and a combination of 3% molasses and Lactobacillus plantarum (L+M). The fermentation quality and chemical composition were analyzed after 7, 14, 30, and 60 d, respectively. The 60-d silages were subjected to an aerobic stability test and fermented with buffered rumen fluid to measure the digestibility. Results: Inoculating lactic acid bacteria (LAB) resulted in more rapid increase in lactic acid concentrations and decline in pH of mulberry leaves silage as compared control. Higher acetic acid and lower ethanol and ammonia nitrogen concentrations (p<0.05) were observed in the LAB-inoculated silages as opposed to control during ensiling. The LAB-inoculated silages contained lower water-soluble carbohydrates compared with control during the first 14 d of ensiling, and lower neutral detergent fibre (p<0.05) concentrations as compared with non-LAB inoculated silages. Adding molasses alone increased (p<0.05) the digestibility of dry matter (DM). The aerobic stability of mulberry leaves silage was increased by LAB inoculation, whereas decreased by adding glucose or molasses. Conclusion: The LAB inoculation improved fermentation quality and aerobic stability of mulberry leaves silage, while adding glucose or molasses failed to affect the fermentation and impaired the aerobic stability. Inoculating LAB alone is recommended for mulberry leaves especially when ensiled at a relatively high DM.

Effects of wild or mutated inoculants on rye silage and its rumen fermentation indices

  • Paradhipta, Dimas Hand Vidya;Joo, Young Ho;Lee, Hyuk Jun;Lee, Seong Shin;Kwak, Youn Sig;Han, Ouk Kyu;Kim, Dong Hyeon;Kim, Sam Churl
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.6
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    • pp.949-956
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    • 2020
  • Objective: This study was conducted to confirm the effects of new inoculants producing-antifungal or esterase substances on rye silage and its rumen fermentation indices by comparing wild with mutated types. Methods: Rye harvested at dough stage was ensiled into 3 L mini bucket silo (1 kg) for 90 d in triplicate following: distilled water at 20 μL/g (CON); Lactobacillus brevis 100D8 (AT) and its inactivation of antifungal genes (AT-m) at 1.2×105 cfu/g, respectively; and Leuconostoc holzapfelii 5H4 (FD) and its inactivation of esterase genes (FD-est) at 1.0×105 cfu/g, respectively. After silo opened, silage was sub-sampled for the analysis of ensiling quality and its rumen fermentation indices. Results: Among the wild type inoculants (CON vs AT vs FD), FD inoculant had higher (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber, the total degradable fraction, and total volatile fatty acid in rumen, while AT inoculant had higher (p<0.05) lactate, acetate, and lactic acid bacteria in silage. Silage pH and the potentially degradable fraction in rumen increased (p<0.05) by inactivation of antifungal activity (AT vs AT-m), but lactate, acetate, and lactic acid bacteria of silage decreased (p<0.05). In silage, acetate increased (p<0.05) by inactivation of esterase activity (FD vs FD-est) with decreases (p<0.05) of pH, ammonia-N, lactate, and yeast. Moreover, inactivation of esterase activity clearly decreased (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber, the total degradable fraction, and total volatile fatty acid in the rumen. Conclusion: This study concluded that FD inoculant confirmed esterase activity on rye silage harvested at dough stage, while AT inoculant could not be confirmed with antifungal activity due to the absence of mold in all silages.