The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform
Pierre Galzy - One of the best experts on this subject based on the ideXlab platform.
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Isolation and partial characterization of an esterase (EC 3.1.1.1) from a Debaryomyces hansenii strain
Netherlands milk and dairy journal, 1995Co-Authors: Xavier Besancon, Robert Ratomahenina, Pierre GalzyAbstract:Esterase extracted from a strain of Debaryomyces hansenii isolated from the surface of Roquefort Cheese was purified 224-fold by ion-exchange chromatography on a Q Sepharose Fast Flow column and gel filtration on a Sephacryl HR S200 column. It was identified as a monomeric enzyme of 80 kDa. Tributyrin and ethyl butyrate were hydrolysed with maximum activity at pH 8 and 35°C. Activity on tributyrin was tested in the presence of several metal ions and chemical effectors. The esterase hydrolysed the methyl and ethyl esters of short-chain fatty acids (C2 to C5) very well and esters of longer-chain fatty acids (C6 to C14) moderatly. Aliphatic and aromatic acetate esters were also hydrolysed.
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characteristics of micrococci from the surface of Roquefort Cheese
Journal of Applied Microbiology, 1994Co-Authors: Delphine Vivier, Robert Ratomahenina, Pierre GalzyAbstract:Five different Micrococcus spp. were isolated from the surface of Roquefort Cheese: M. roseus, M. sedentarius, M. lylae, M. luteus and M. varians. During culture on synthetic medium these bacteria produced acetic acid as the main volatile fatty acid and propanol as the main alcohol. On a complex medium these isolates synthesized additional volatile fatty acids. Studies were made of the effect of pH, of water activity adjusted with sodium chloride or sorbitol, and of temperature on growth rates. All five isolates were inhibited at a pH lower than 5.5 and grew at temperatures from 4 o to 44 o C; they were halotolerant and multiplied at NaCl concentrations up to 20%, corresponding to a water activity of 0.884
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study of surface yeast flora of Roquefort Cheese
International Journal of Food Microbiology, 1992Co-Authors: Xavier Besancon, J P Reverbel, Marie Rivemale, C Smet, C Chabalier, Robert Ratomahenina, Pierre GalzyAbstract:Abstract The change in yeast flora on the surface of two batches of Roquefort Cheese was monitored over a period of 6 months. 401 isolates were determined and their technological properties were investigated. The main species isolated were: Debaryomyces hansenii and its non sporulating form Candida famata, Kluyreromyces lactis and its non sporulating form Candida sphaerica and Candida species. The species Debaryomyces hansenii inoculated on the surface of the Cheese in one of the batches just before the salting phase was abundant throughout the ripening phases but never exceeded 50% of the yeast count. About 80% of the isolates of each species were resistant to 15% (w/v) of sodium chloride. Most of the species were able to assimilate lactose and lactic acid. 50–90% of the isolates of each species were able to hydrolyze rapeseed oil and glycerol tributyrate. Ten isolates among 401 hydrolyzed gelatin. Most of them were able to assimilate cadaverine, histamine, putrescine and tyramine.
K Shetty - One of the best experts on this subject based on the ideXlab platform.
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Inhibitory potential of herb, fruit, and fungal-enriched Cheese against key enzymes linked to type 2 diabetes and hypertension
Innovative Food Science and Emerging Technologies, 2007Co-Authors: Evlampios Apostolidis, Y. I. Kwon, K ShettyAbstract:Abstract In the current study, three different types of Cheese, cheddar, feta, and Roquefort, were screened to determine the variations in phenolic-linked antioxidant activity and the potential to inhibit key enzymes relevant to type 2 diabetes and related hypertension. The Cheese samples were assayed for total phenolic content, related antioxidant activity, and inhibition of α-glucosidase, pancreatic α-amylase inhibitory activity, and the angiotensin-converting enzyme (ACE)-I inhibitory activity. The three fungal-enriched Roquefort Cheese samples had the highest total phenolic content. The phenolic content in the herb Cheese was slightly but not significantly higher compared to plain Cheese. Roquefort Cheese samples had the highest antioxidant-linked DPPH (free radical) scavenging activity and as expected DPPH radical scavenging activity was higher in the herb Cheese compared to plain Cheese. All samples had some α-glucosidase and α-amylase inhibitory activities, with cranberry-enriched Cheese having the highest activities. However, no correlation to soluble phenolic content was observed. All the Cheese samples had very high anti-ACE-I inhibitory activity, indicating no correlation to phenolic content and activity was even high in 10× diluted samples. The highest ACE-I inhibitory activity was observed in plain and herb-enriched cheddar Cheese as well as cranberry-enriched Cheese. These studies indicate that cranberry-enriched Cheese had the best potential for inhibition of α-glucosidase and α-amylase relevant for type 2 diabetes management, whereas any Cheese product had potential for ACE-I inhibition linked to hypertension management, indicating likely the role of other factors such as peptides from Cheese fermentation. Industrial relevance This research is focused on screening of different types of commercial plain, herbal, fruit, and fungal-enriched to provide a strong biochemical rationale for further design of functional Cheese products for anti-type 2 diabetic and relevant hypertension management. A better understanding of these functional attributes provides a strong biochemical rationale for design in vivo and clinical studies from which right design of functional food can be established.
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Inhibitory potential of herb, fruit, and fungal-enriched Cheese against key enzymes linked to type 2 diabetes and hypertension
Innovative Food Science and Emerging Technologies, 2007Co-Authors: Evlampios Apostolidis, Y. I. Kwon, K ShettyAbstract:In the current study, three different types of Cheese, cheddar, feta, and Roquefort, were screened to determine the variations in phenolic-linked antioxidant activity and the potential to inhibit key enzymes relevant to type 2 diabetes and related hypertension. The Cheese samples were assayed for total phenolic content, related antioxidant activity, and inhibition of α-glucosidase, pancreatic α-amylase inhibitory activity, and the angiotensin-converting enzyme (ACE)-I inhibitory activity. The three fungal-enriched Roquefort Cheese samples had the highest total phenolic content. The phenolic content in the herb Cheese was slightly but not significantly higher compared to plain Cheese. Roquefort Cheese samples had the highest antioxidant-linked DPPH (free radical) scavenging activity and as expected DPPH radical scavenging activity was higher in the herb Cheese compared to plain Cheese. All samples had some α-glucosidase and α-amylase inhibitory activities, with cranberry-enriched Cheese having the highest activities. However, no correlation to soluble phenolic content was observed. All the Cheese samples had very high anti-ACE-I inhibitory activity, indicating no correlation to phenolic content and activity was even high in 10× diluted samples. The highest ACE-I inhibitory activity was observed in plain and herb-enriched cheddar Cheese as well as cranberry-enriched Cheese. These studies indicate that cranberry-enriched Cheese had the best potential for inhibition of α-glucosidase and α-amylase relevant for type 2 diabetes management, whereas any Cheese product had potential for ACE-I inhibition linked to hypertension management, indicating likely the role of other factors such as peptides from Cheese fermentation. Industrial relevance: This research is focused on screening of different types of commercial plain, herbal, fruit, and fungal-enriched to provide a strong biochemical rationale for further design of functional Cheese products for anti-type 2 diabetic and relevant hypertension management. A better understanding of these functional attributes provides a strong biochemical rationale for design in vivo and clinical studies from which right design of functional food can be established. © 2006 Elsevier Ltd. All rights reserved.
Evlampios Apostolidis - One of the best experts on this subject based on the ideXlab platform.
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Inhibitory potential of herb, fruit, and fungal-enriched Cheese against key enzymes linked to type 2 diabetes and hypertension
Innovative Food Science and Emerging Technologies, 2007Co-Authors: Evlampios Apostolidis, Y. I. Kwon, K ShettyAbstract:Abstract In the current study, three different types of Cheese, cheddar, feta, and Roquefort, were screened to determine the variations in phenolic-linked antioxidant activity and the potential to inhibit key enzymes relevant to type 2 diabetes and related hypertension. The Cheese samples were assayed for total phenolic content, related antioxidant activity, and inhibition of α-glucosidase, pancreatic α-amylase inhibitory activity, and the angiotensin-converting enzyme (ACE)-I inhibitory activity. The three fungal-enriched Roquefort Cheese samples had the highest total phenolic content. The phenolic content in the herb Cheese was slightly but not significantly higher compared to plain Cheese. Roquefort Cheese samples had the highest antioxidant-linked DPPH (free radical) scavenging activity and as expected DPPH radical scavenging activity was higher in the herb Cheese compared to plain Cheese. All samples had some α-glucosidase and α-amylase inhibitory activities, with cranberry-enriched Cheese having the highest activities. However, no correlation to soluble phenolic content was observed. All the Cheese samples had very high anti-ACE-I inhibitory activity, indicating no correlation to phenolic content and activity was even high in 10× diluted samples. The highest ACE-I inhibitory activity was observed in plain and herb-enriched cheddar Cheese as well as cranberry-enriched Cheese. These studies indicate that cranberry-enriched Cheese had the best potential for inhibition of α-glucosidase and α-amylase relevant for type 2 diabetes management, whereas any Cheese product had potential for ACE-I inhibition linked to hypertension management, indicating likely the role of other factors such as peptides from Cheese fermentation. Industrial relevance This research is focused on screening of different types of commercial plain, herbal, fruit, and fungal-enriched to provide a strong biochemical rationale for further design of functional Cheese products for anti-type 2 diabetic and relevant hypertension management. A better understanding of these functional attributes provides a strong biochemical rationale for design in vivo and clinical studies from which right design of functional food can be established.
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Inhibitory potential of herb, fruit, and fungal-enriched Cheese against key enzymes linked to type 2 diabetes and hypertension
Innovative Food Science and Emerging Technologies, 2007Co-Authors: Evlampios Apostolidis, Y. I. Kwon, K ShettyAbstract:In the current study, three different types of Cheese, cheddar, feta, and Roquefort, were screened to determine the variations in phenolic-linked antioxidant activity and the potential to inhibit key enzymes relevant to type 2 diabetes and related hypertension. The Cheese samples were assayed for total phenolic content, related antioxidant activity, and inhibition of α-glucosidase, pancreatic α-amylase inhibitory activity, and the angiotensin-converting enzyme (ACE)-I inhibitory activity. The three fungal-enriched Roquefort Cheese samples had the highest total phenolic content. The phenolic content in the herb Cheese was slightly but not significantly higher compared to plain Cheese. Roquefort Cheese samples had the highest antioxidant-linked DPPH (free radical) scavenging activity and as expected DPPH radical scavenging activity was higher in the herb Cheese compared to plain Cheese. All samples had some α-glucosidase and α-amylase inhibitory activities, with cranberry-enriched Cheese having the highest activities. However, no correlation to soluble phenolic content was observed. All the Cheese samples had very high anti-ACE-I inhibitory activity, indicating no correlation to phenolic content and activity was even high in 10× diluted samples. The highest ACE-I inhibitory activity was observed in plain and herb-enriched cheddar Cheese as well as cranberry-enriched Cheese. These studies indicate that cranberry-enriched Cheese had the best potential for inhibition of α-glucosidase and α-amylase relevant for type 2 diabetes management, whereas any Cheese product had potential for ACE-I inhibition linked to hypertension management, indicating likely the role of other factors such as peptides from Cheese fermentation. Industrial relevance: This research is focused on screening of different types of commercial plain, herbal, fruit, and fungal-enriched to provide a strong biochemical rationale for further design of functional Cheese products for anti-type 2 diabetic and relevant hypertension management. A better understanding of these functional attributes provides a strong biochemical rationale for design in vivo and clinical studies from which right design of functional food can be established. © 2006 Elsevier Ltd. All rights reserved.
Michel Bakalowicz - One of the best experts on this subject based on the ideXlab platform.
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The protection of a karst water resource from the example of the Larzac karst plateau (south of France): a matter of regulations or a matter of process knowledge?
Engineering Geology, 2002Co-Authors: Valérie Plagnes, Michel BakalowiczAbstract:Abstract Wide karst plateaus extend in limestone and dolostone of the Grands Causses area north of Montpellier. They are surrounded with a hard rock basement that feeds important rivers, such as the Tarn River and its tributaries, crossing the plateaus in deep gorges. The Larzac plateau, the most southern of them, makes the bond with the Mediterranean region, traversed by one of the main national roads, presently doubled with a speedway under construction from Clermont-Ferrand to Montpellier and Spain. The karst water resource, through several springs, is used for the water supply of the Millau area (30,000 people). It also recharges surface rivers, mainly during the summer and fall low stage, in a region well known for water recreation activities, fish farming and, above all, sheep farming and Roquefort Cheese production. The fundamental question is, “Should the karst and its water resource be fully protected by strict regulations, for example considering the plateau in the same way as a nature reservation, or may we foresee a land management plan of the plateau based upon the knowledge of its hydrogeological functioning and of its karst structure?” Support decisions concerning about a 500-km 2 area were developed from detailed hydrogeological studies, including natural and artificial tracing, landscape analysis, risk inventory and mapping. Recommendations were proposed to local and regional decision-makers in order to define what are the preference shares in terms of water resource protection and water quality restoration. Following such an approach is not easy for hydrogeologists and for decision-makers. In non-karstic regions, protection zones currently extend over small areas of few square kilometers, which is easily under the control of a small municipality. In the present example, the main water supplies are two springs with recharge areas of 100 and 110 km 2 , respectively. Concerning several municipalities, some of them are used as water supply, others for pollution risks and land management projects. The recent French Water Act, which considers water as a common heritage, allows management of water and the terrain in which it flows in a common way, by all users, in the same area. The regulation tools seem very well suited to karst region management. However, time is necessary for educating users and decision-makers, with the help of karst environment scientists, to work together in a frame other than the usual municipal limits.
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The protection of a karst water resource from the example of the Larzac karst plateau (South of France): A matter of regulations or a matter of process knowledge?
Engineering Geology, 2002Co-Authors: Valérie Plagnes, Michel BakalowiczAbstract:Wide karst plateaus extend in limestone and dolostone of the Grands Causses area north of Montpellier. They are surrounded with a hard rock basement that feeds important rivers, such as the Tarn River and its tributaries, crossing the plateaus in deep gorges. The Larzac plateau, the most southern of them, makes the bond with the Mediterranean region, traversed by one of the main national roads, presently doubled with a speedway under construction from Clermont-Ferrand to Montpellier and Spain. The karst water resource, through several springs, is used for the water supply of the Millau area (30,000 people). It also recharges surface rivers, mainly during the summer and fall low stage, in a region well known for water recreation activities, fish farming and, above all, sheep farming and Roquefort Cheese production. The fundamental question is, "Should the karst and its water resource be fully protected by strict regulations, for example considering the plateau in the same way as a nature reservation, or may we foresee a land management plan of the plateau based upon the knowledge of its hydrogeological functioning and of its karst structure?" Support decisions concerning about a 500-km2area were developed from detailed hydrogeological studies, including natural and artificial tracing, landscape analysis, risk inventory and mapping. Recommendations were proposed to local and regional decision-makers in order to define what are the preference shares in terms of water resource protection and water quality restoration. Following such an approach is not easy for hydrogeologists and for decision-makers. In non-karstic regions, protection zones currently extend over small areas of few square kilometers, which is easily under the control of a small municipality. In the present example, the main water supplies are two springs with recharge areas of 100 and 110 km2, respectively. Concerning several municipalities, some of them are used as water supply, others for pollution risks and land management projects. The recent French Water Act, which considers water as a common heritage, allows management of water and the terrain in which it flows in a common way, by all users, in the same area. The regulation tools seem very well suited to karst region management. However, time is necessary for educating users and decision-makers, with the help of karst environment scientists, to work together in a frame other than the usual municipal limits. © 2002 Elsevier Science B.V. All rights reserved.
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The protection of karst water resources: the example of the Larzac karst plateau (south of France)
Environmental Geology, 2001Co-Authors: Valérie Plagnes, Michel BakalowiczAbstract:Wide karst plateaus extend in the carbonate rocks of the Grands Causses area, north of Montpellier (south of France). They are surrounded by a hard rock base that feeds important rivers, such as the Tarn River and tributaries, and crosses the plateaus creating deep gorges. The Larzac plateau, the most southern, makes a link with the Mediterranean region. It is traversed by one of the main national roads and another main road under construction from Clermont-Ferrand to Montpellier and Spain. The karst water resource of the plateau, from springs, is used as a water supply for the Millau area (30,000 inhabitants); but it also recharges surface rivers, mainly during the summer and fall when the water level is low, in a region that is well known for water recreation activities, for fish farming and, above all, for sheep farming and Roquefort Cheese production. The fundamental question was should the karst and its water resource be fully protected by strict regulations (for example as a nature reservation) in land-use management of the plateau based upon the knowledge of its hydrogeological functioning and its karst structure? Decisions, concerning the ∼500-km^2 area were elaborated from detailed hydrogeological studies, which included natural and artificial tracing, analysis of karst aquifer functioning, landscape analysis, and risk assessment and mapping. Recommendations were proposed to local and regional decision makers to define what were the preferences in terms of water resource protection and water quality restoration. Following such an approach in a karst area is not easy for hydrogeologists or for decision makers. In non-karstic regions, protection zones currently extend over small areas of a few square kilometers, which can be easily placed under the control of a small municipality. In the present example, the main water supplies are two springs that recharge areas that extend respectively over 100 and 110 km^2. Included are several municipalities, some of which use them for their water supply, whereas others are concerned with pollution risks and land management projects. The recent French Water Act, which considers water as a common heritage, allows for general management by all the users, and it deals with the water and the terrain in which it flows. The regulation tools seem very well suited to karst region management. However, time is needed to educate users and decision makers, and with the help of karst scientists, to work together in a framework that is larger than the usual municipal limits.
Robert Ratomahenina - One of the best experts on this subject based on the ideXlab platform.
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Isolation and partial characterization of an esterase (EC 3.1.1.1) from a Debaryomyces hansenii strain
Netherlands milk and dairy journal, 1995Co-Authors: Xavier Besancon, Robert Ratomahenina, Pierre GalzyAbstract:Esterase extracted from a strain of Debaryomyces hansenii isolated from the surface of Roquefort Cheese was purified 224-fold by ion-exchange chromatography on a Q Sepharose Fast Flow column and gel filtration on a Sephacryl HR S200 column. It was identified as a monomeric enzyme of 80 kDa. Tributyrin and ethyl butyrate were hydrolysed with maximum activity at pH 8 and 35°C. Activity on tributyrin was tested in the presence of several metal ions and chemical effectors. The esterase hydrolysed the methyl and ethyl esters of short-chain fatty acids (C2 to C5) very well and esters of longer-chain fatty acids (C6 to C14) moderatly. Aliphatic and aromatic acetate esters were also hydrolysed.
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characteristics of micrococci from the surface of Roquefort Cheese
Journal of Applied Microbiology, 1994Co-Authors: Delphine Vivier, Robert Ratomahenina, Pierre GalzyAbstract:Five different Micrococcus spp. were isolated from the surface of Roquefort Cheese: M. roseus, M. sedentarius, M. lylae, M. luteus and M. varians. During culture on synthetic medium these bacteria produced acetic acid as the main volatile fatty acid and propanol as the main alcohol. On a complex medium these isolates synthesized additional volatile fatty acids. Studies were made of the effect of pH, of water activity adjusted with sodium chloride or sorbitol, and of temperature on growth rates. All five isolates were inhibited at a pH lower than 5.5 and grew at temperatures from 4 o to 44 o C; they were halotolerant and multiplied at NaCl concentrations up to 20%, corresponding to a water activity of 0.884
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study of surface yeast flora of Roquefort Cheese
International Journal of Food Microbiology, 1992Co-Authors: Xavier Besancon, J P Reverbel, Marie Rivemale, C Smet, C Chabalier, Robert Ratomahenina, Pierre GalzyAbstract:Abstract The change in yeast flora on the surface of two batches of Roquefort Cheese was monitored over a period of 6 months. 401 isolates were determined and their technological properties were investigated. The main species isolated were: Debaryomyces hansenii and its non sporulating form Candida famata, Kluyreromyces lactis and its non sporulating form Candida sphaerica and Candida species. The species Debaryomyces hansenii inoculated on the surface of the Cheese in one of the batches just before the salting phase was abundant throughout the ripening phases but never exceeded 50% of the yeast count. About 80% of the isolates of each species were resistant to 15% (w/v) of sodium chloride. Most of the species were able to assimilate lactose and lactic acid. 50–90% of the isolates of each species were able to hydrolyze rapeseed oil and glycerol tributyrate. Ten isolates among 401 hydrolyzed gelatin. Most of them were able to assimilate cadaverine, histamine, putrescine and tyramine.
