The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
J A Narvhus - One of the best experts on this subject based on the ideXlab platform.
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utilization of various starter cultures in the production of amasi a zimbabwean naturally fermented raw milk product
International Journal of Food Microbiology, 2003Co-Authors: H. M. Gran, H. T. Gadaga, J A NarvhusAbstract:Abstract Fermented milk was prepared from unpasteurised milk using natural Fermentation (R), back-slopping (B) and by addition of two different starter cultures (C1 and DL). The numbers of Escherichia coli , coliforms, lactic acid bacteria (LAB) and the changes in pH, carbohydrates, organic acids and volatile compounds were recorded during 48-h Fermentation. After 48-h Fermentation, the highest numbers of E. coli were found in R and B Fermentations and the lowest in the DL Fermentation. The DL culture reduced the pH faster than the other starter cultures. The DL and C1 had higher levels of LAB in the beginning of the Fermentation than the other two. Galactose and lactic acid increased fastest in the DL and C1 Fermentation, and R was slowest. The highest levels of succinate, ethanol and malty compounds were found in the R and B Fermentations. Lower levels of LAB in the first part of the Fermentations, but higher number of E. coli could explain the increased levels of succinate, ethanol and malty compounds.
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Utilization of various starter cultures in the production of Amasi, a Zimbabwean naturally fermented raw milk product
International Journal of Food Microbiology, 2003Co-Authors: H. M. Gran, H. T. Gadaga, J A NarvhusAbstract:Fermented milk was prepared from unpasteurised milk using natural Fermentation (R), back-slopping (B) and by addition of two different starter cultures (C1 and DL). The numbers of Escherichia coli, coliforms, lactic acid bacteria (LAB) and the changes in pH, carbohydrates, organic acids and volatile compounds were recorded during 48-h Fermentation. After 48-h Fermentation, the highest numbers of E. coli were found in R and B Fermentations and the lowest in the DL Fermentation. The DL culture reduced the pH faster than the other starter cultures. The DL and C1 had higher levels of LAB in the beginning of the Fermentation than the other two. Galactose and lactic acid increased fastest in the DL and C1 Fermentation, and R was slowest. The highest levels of succinate, ethanol and malty compounds were found in the R and B Fermentations. Lower levels of LAB in the first part of the Fermentations, but higher number of E. coli could explain the increased levels of succinate, ethanol and malty compounds. © 2003 Elsevier Science B.V. All rights reserved.
Athanasios A. Koutinas - One of the best experts on this subject based on the ideXlab platform.
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New Trends in Kefir Yeast Technology
New Horizons in Biotechnology, 2020Co-Authors: Athanasios A. KoutinasAbstract:The development of new biotechnologies and foodstuffs using kefir yeast are reviewed. The strategy adopted was to examine Fermentations of synthetic media containing sugars of raw materials and wastes of food production. Kefir cell growth was also examined. An important efficiency of kefir yeast in glucose, fructose, sucrose and lactose Fermentations have been proven. Fermentations were performed in comparison with immobilized biocatalysts prepared by immobilization of kefir on delignified cellulosic (DC) materials, gluten and mineral kissiris. DC material supported kefir is suitable for low-temperature alcoholic Fermentation in the range of 5–15°C.
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Lactose uptake rate measurements by14C-labelled lactose reveals promotional activity of porous cellulose in whey Fermentation by kefir yeast
Food Chemistry, 2012Co-Authors: Aristidis Golfinopoulos, Konstantina Tsaousi, Magdalini Soupioni, Nikolaos Kopsahelis, Athanasios A. KoutinasAbstract:Lactose uptake rate by kefir yeast, immobilized on tubular cellulose and gluten pellets during Fermentation of lactose and whey, was monitored using14C-labelled lactose. Results illustrated that, in all cases, lactose uptake rate was strongly correlated with Fermentation rate and the Fermentation's kinetic parameters were improved by kefir yeast entrapped in tubular cellulose. As a result, twofold faster Fermentations were achieved in comparison with kefir yeast immobilized on gluten. This is probably due to cluster and hydrogen bonds formation between cellulose and inhibitors, such as Ca++and generated lactic acid, by which they leave the liquid medium. The findings, regarding the promotional effect of cellulose, seem promising for application in industrial whey Fermentations. © 2012 Elsevier Ltd. All rights reserved.
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Fermentation efficiency of thermally dried kefir.
Bioresource Technology, 2008Co-Authors: Harris Papapostolou, Loulouda A. Bosnea, Athanasios A. Koutinas, Maria KanellakiAbstract:Abstract Three thermal drying methods (conventional, vacuum and convective) were used for drying of kefir biomass and their effect on cell viability, Fermentation rate and other kinetic parameters of lactose and whey Fermentation were studied. Convective drying rate was higher than conventional and even higher than vacuum at each studied temperature (28, 33 and 38 °C). After that, Fermentations were performed by kefir biomass dried by the three drying methods. Ethanol concentration, ethanol productivity and ethanol yield are higher in whey Fermentations performed by kefir biomass dried with convective drying method. Regarding lactic acid production, Fermentation performed by kefir biomass dried with conventional drying method gave higher concentrations, compared to other drying methods. Storage of kefir biomass convectively dried at 33 °C for 4 months, without any precaution decreases its fermentability and thus reduces ethanol (31%) and lactic acid productivity (20%), but remains a promising technology, since a significant part of its initial fermentative activity is retained.
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Fermentation efficiency of thermally dried kefir
Bioresource Technology, 2008Co-Authors: Harris Papapostolou, Loulouda A. Bosnea, Athanasios A. Koutinas, Maria KanellakiAbstract:Three thermal drying methods (conventional, vacuum and convective) were used for drying of kefir biomass and their effect on cell viability, Fermentation rate and other kinetic parameters of lactose and whey Fermentation were studied. Convective drying rate was higher than conventional and even higher than vacuum at each studied temperature (28, 33 and 38 °C). After that, Fermentations were performed by kefir biomass dried by the three drying methods. Ethanol concentration, ethanol productivity and ethanol yield are higher in whey Fermentations performed by kefir biomass dried with convective drying method. Regarding lactic acid production, Fermentation performed by kefir biomass dried with conventional drying method gave higher concentrations, compared to other drying methods. Storage of kefir biomass convectively dried at 33 °C for 4 months, without any precaution decreases its fermentability and thus reduces ethanol (31%) and lactic acid productivity (20%), but remains a promising technology, since a significant part of its initial fermentative activity is retained. © 2008 Elsevier Ltd. All rights reserved.
Tatjana Pauli - One of the best experts on this subject based on the ideXlab platform.
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impurity and cost considerations for nutrient supplementation of whey permeate Fermentations to produce lactic acid for biodegradable plastics
International Dairy Journal, 2003Co-Authors: J.j. Fitzpatrick, C Murphy, F M Mota, Tatjana PauliAbstract:Abstract A potential application for whey permeate is to ferment it to lactic acid for use in the manufacture of biodegradable plastics. High purity lactic acid is required, thus the separation of impurities after Fermentation is a major process cost. For batch Fermentations, whey permeate requires nutrient supplementation, which can add to impurity levels at the end of Fermentation. This work presents the results of whey permeate Fermentations using L. casei , supplemented with yeast extract, whey protein hydrolysate, and malt combing nuts (MCN). There is an emphasis on investigating how little supplement needs to be added while still achieving high lactose conversion and lactic acid yield in a reasonable Fermentation time. This was around 0.4% w/w for yeast extract, 5% for the hydrolysate (10% whey protein solution) and 5% for MCN. At these levels of supplement addition, the majority of the supplement is actually not utilised and just contributes to a major increase in the concentration of impurities at the end of the Fermentation with a corresponding increase in separation cost, in addition to raw material cost. The ash content of regular whey permeate is another significant source of impurities that need to be separated to produce high purity lactic acid. Fermentations were performed to investigate the effect of low ash content on Fermentation performance. Fermentations performed in supplemented demineralised whey permeate, with at least 70% ash reduction, showed no negative effect on Fermentation performance, however Fermentations conducted in a supplemented lactose solution did show a slowdown in Fermentation performance. This is most likely due to mineral deficiency which should not pose a problem as minerals are usually micronutrients, and addition of very small amounts are required to restore Fermentation performance.
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Malt combing nuts as a nutrient supplement to whey permeate for producing lactic by Fermentation with Lactobacillus casei
Process Biochemistry, 2002Co-Authors: Tatjana Pauli, J.j. FitzpatrickAbstract:Malt combing nuts (MCN) is a low value byproduct from the malting industry. It provides a cheap source of nitrogen and vitamins and has potential for being applied as a nutrient supplement in Fermentations to produce lactic acid. This work investigates the supplementation of whey permeate with MCN to produce lactic acid by Fermentation with Lactobacillus casei, and compares it with Fermentations supplemented with yeast extract (YE). The results showed that MCN can be applied successfully as a nutrient supplement to produce lactic acid by Fermentation, achieving complete sugar conversion and lactic acid yield similar to YE supplementation. 5% w/v MCN addition was required to achieve a Fermentation time of around 55 h in whey permeate containing lactose at a concentration of 55 g/l. This was similar to Fermentations with 0.3% w/v YE supplementation. The major advantage of using MCN is that its raw material cost for supplementing a Fermentation is many times lower than YE for a comparable Fermentation. However, on the other hand, the results showed that the levels of impurities remaining after Fermentation are a lot higher. MCN adds much more ash to the Fermentation and there is a lot more unused nitrogen remaining at the end of the Fermentation. This is undesirable for the production of high purity lactic acid as it leads to increased separation costs. © 2002 Elsevier Science Ltd. All rights reserved.
J.j. Fitzpatrick - One of the best experts on this subject based on the ideXlab platform.
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impurity and cost considerations for nutrient supplementation of whey permeate Fermentations to produce lactic acid for biodegradable plastics
International Dairy Journal, 2003Co-Authors: J.j. Fitzpatrick, C Murphy, F M Mota, Tatjana PauliAbstract:Abstract A potential application for whey permeate is to ferment it to lactic acid for use in the manufacture of biodegradable plastics. High purity lactic acid is required, thus the separation of impurities after Fermentation is a major process cost. For batch Fermentations, whey permeate requires nutrient supplementation, which can add to impurity levels at the end of Fermentation. This work presents the results of whey permeate Fermentations using L. casei , supplemented with yeast extract, whey protein hydrolysate, and malt combing nuts (MCN). There is an emphasis on investigating how little supplement needs to be added while still achieving high lactose conversion and lactic acid yield in a reasonable Fermentation time. This was around 0.4% w/w for yeast extract, 5% for the hydrolysate (10% whey protein solution) and 5% for MCN. At these levels of supplement addition, the majority of the supplement is actually not utilised and just contributes to a major increase in the concentration of impurities at the end of the Fermentation with a corresponding increase in separation cost, in addition to raw material cost. The ash content of regular whey permeate is another significant source of impurities that need to be separated to produce high purity lactic acid. Fermentations were performed to investigate the effect of low ash content on Fermentation performance. Fermentations performed in supplemented demineralised whey permeate, with at least 70% ash reduction, showed no negative effect on Fermentation performance, however Fermentations conducted in a supplemented lactose solution did show a slowdown in Fermentation performance. This is most likely due to mineral deficiency which should not pose a problem as minerals are usually micronutrients, and addition of very small amounts are required to restore Fermentation performance.
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Malt combing nuts as a nutrient supplement to whey permeate for producing lactic by Fermentation with Lactobacillus casei
Process Biochemistry, 2002Co-Authors: Tatjana Pauli, J.j. FitzpatrickAbstract:Malt combing nuts (MCN) is a low value byproduct from the malting industry. It provides a cheap source of nitrogen and vitamins and has potential for being applied as a nutrient supplement in Fermentations to produce lactic acid. This work investigates the supplementation of whey permeate with MCN to produce lactic acid by Fermentation with Lactobacillus casei, and compares it with Fermentations supplemented with yeast extract (YE). The results showed that MCN can be applied successfully as a nutrient supplement to produce lactic acid by Fermentation, achieving complete sugar conversion and lactic acid yield similar to YE supplementation. 5% w/v MCN addition was required to achieve a Fermentation time of around 55 h in whey permeate containing lactose at a concentration of 55 g/l. This was similar to Fermentations with 0.3% w/v YE supplementation. The major advantage of using MCN is that its raw material cost for supplementing a Fermentation is many times lower than YE for a comparable Fermentation. However, on the other hand, the results showed that the levels of impurities remaining after Fermentation are a lot higher. MCN adds much more ash to the Fermentation and there is a lot more unused nitrogen remaining at the end of the Fermentation. This is undesirable for the production of high purity lactic acid as it leads to increased separation costs. © 2002 Elsevier Science Ltd. All rights reserved.
H P Fleming - One of the best experts on this subject based on the ideXlab platform.
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use of rapd pcr as a method to follow the progress of starter cultures in sauerkraut Fermentation
International Journal of Food Microbiology, 2004Co-Authors: V. Plengvidhya, Frederick Breidt, H P FlemingAbstract:Abstract DNA fingerprinting methods were used to follow the progress of unmarked starter cultures in laboratory sauerkraut Fermentations (1.2 and 13 l). Random prime PCR (RAPD-PCR) was used for strain-specific identification of Leuconostoc mesenteroides cultures. A comparative analysis of RAPD banding patterns for Fermentation isolates and starter cultures was carried out using both genetically marked and unmarked cultures. While some variation in the RAPD patterns was observed, the results showed that the starter cultures dominated the Fermentation during early heterofermentative stage for up to 5 days after the start of Fermentation. Results from marked and unmarked starter cultures were confirmed by intergenic transcribed spacer (ITS)-PCR, and strain identify was confirmed by pulse field gel electrophoresis (PFGE) patterns. The results demonstrate the utility of RAPD to follow the progression of unmarked starter cultures of L. mesenteroides in sauerkraut Fermentations.
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Isolation and characterization of bacteriophages from fermenting sauerkrautt
Applied and Environmental Microbiology, 2002Co-Authors: S.s. Yoon, R. Barrangou-poueys, Frederick Breidt, Todd R Klaenhammer, H P FlemingAbstract:This paper presents the first report of bacteriophage isolated from commercial vegetable Fermentations. Nine phages were isolated from two 90-ton commercial sauerkraut Fermentations. These phages were active against Fermentation isolates and selected Leuconostoc mesenteroides and Lactobacillus plantarum strains, including a starter culture. Phages were characterized as members of the Siphoviridae and Myoviridae families. All Leuconostoc phages reported previously, primarily of dairy origin, belonged to the Siphoviridae family.
