Graciela Savoy - Academia.edu (original) (raw)

Papers by Graciela Savoy

Research paper thumbnail of Profesora Doctora Aída Pesce de Ruíz Holgado (1926-2012)

Research paper thumbnail of Development of gluten-free breads started with chia and flaxseed sourdoughs fermented by selected lactic acid bacteria

Research paper thumbnail of Draft Genome Sequence of Lactobacillus delbrueckii subsp. bulgaricus CRL871, a Folate-Producing Strain Isolated from a Northwestern Argentinian Yogurt

Genome Announcements, 2015

Research paper thumbnail of Milk fermented with selected strains of lactic acid bacteria is able to improve folate status of deficient rodents and also prevent folate deficiency

Journal of Functional Foods, 2015

ABSTRACT Folate deficiencies are common in many parts of the world. The use of folate producing f... more ABSTRACT Folate deficiencies are common in many parts of the world. The use of folate producing food grade microorganisms has been proposed as a more natural alternative to fortification with the chemical folic acid. The aim of this study was to evaluate the effectiveness of a novel fermented milk elaborated with adequately selected folate producing lactic acid bacteria. This product was tested using both a rodent depletion–repletion model and a complete deficient model. The folate bio-enriched fermented milk was able to increase plasma folate concentrations and decrease homocysteine levels. This is the first report demonstrating that a naturally folate bio-enriched fermented milk, elaborated with folate-producing starter cultures, not only is effective to improve folate status but can also prevent folate deficiency. Consumers also would obviously benefit from this type of product because they could increase their folate intakes while consuming foods that form part of their normal diets.

Research paper thumbnail of Ingestion of milk fermented by genetically modified Lactococcus lactis improves the riboflavin status of deficient rats

Journal of dairy science, 2005

Riboflavin deficiency is common in many parts of the world, particularly in developing countries.... more Riboflavin deficiency is common in many parts of the world, particularly in developing countries. The use of riboflavin-producing strains in the production of dairy products such as fermented milks, yogurts, and cheeses is feasible and economically attractive because it would decrease the costs involved during conventional vitamin fortification and satisfy consumer demands for healthier foods. The present study was conducted to assess in a rat bioassay the response of administration of milk fermented by modified Lactococcus lactis on the riboflavin status of deficient rats. Rats were fed a riboflavin-deficient diet during 21 d after which this same diet was supplemented with milk fermented by Lactoccus lactis pNZGBAH, a strain that overproduces riboflavin during fermentation. The novel fermented product, with increased levels of riboflavin, was able to eliminate most physiological manifestations of ariboflavinosis, such as stunted growth, elevated erythrocyte glutathione reductase a...

Research paper thumbnail of Isolation and identification of anaerobic contaminants from a machine for producing processed cheese

Revista Argentina de microbiología, 1982

Some bacteria of the genus Clostridium can contaminate milk. These bacteria can cause "the l... more Some bacteria of the genus Clostridium can contaminate milk. These bacteria can cause "the late gas" or "late blowing" defect in the cheese if this is made with milk containing such contaminants. In this study, six samples from a processed cheese contaminated in a manufacturing machine were analysed. Out of 60 strains studied, 30 were classified as Clostridium tyrobutyricum, 20 as Clostridium butyricum, and 10 as Desulfotomaculum ruminis.

Research paper thumbnail of Use of SDS-PAGE of cell-wall proteins for rapid differentiation of Lactobacillus delbrueckii subsp. lactis and Lactobacillus helveticus

Biotechnology Letters, 2000

Cell-wall protein profiles of different strains of Lactobacillus helveticus and L. delbrueckii su... more Cell-wall protein profiles of different strains of Lactobacillus helveticus and L. delbrueckii subsp. lactis isolated from regional cheeses were studied by SDS-PAGE. The patterns were highly reproducible and the presence of numerous bands with molecular weight ranging from 14 to 160 kDa allowed L. delbrueckii subsp. lactis to be differentiated from L. helveticus. The method is a reliable and rapid way to identify thermophilic

Research paper thumbnail of Characterisation of a cell-envelope proteinase from Lactobacillus helveticus

Biotechnology Letters, 1999

The cell-envelope proteinase from Lactobacillus helveticus CRL 1062 was detected in the cell memb... more The cell-envelope proteinase from Lactobacillus helveticus CRL 1062 was detected in the cell membrane fraction. The enzyme remained associated with the cells even after treatment with lysozyme and was not released from washed cells in absence of calcium. The proteinase was maximally active at pH 6.5–7.0 and 42?°C and hydrolysed a- and ß-caseins at different rates. Activity was inhibited (98%) by

Research paper thumbnail of Chemical composition and microbial evaluation of Argentinean Corrientes cheese

Research paper thumbnail of Evaluation of Minimal Nutritional Requirements of Lactic Acid Bacteria Used in Functional Foods

Environmental Microbiology, 2004

ABSTRACT The lactic acid bacteria (LAB) are important industrial microorganisms because of their ... more ABSTRACT The lactic acid bacteria (LAB) are important industrial microorganisms because of their role in food fermentation, especially dairy products. In addition, it has been showed that LAB exhibit a range of physiological and therapeutic effects in consumers of these foods, including immune stimulation, pathogen exclusion, production of bioactive peptides, and others (1). Foods containing such bacteria are considered “functional foods,” foods that promote health beyond providing basic nutrition.

Research paper thumbnail of Differentiation of Lactobacilli Strains by Electrophoretic Protein Profiles

Food Microbiology Protocols, 2000

ABSTRACT Lactic acid bacteria (LAB) comprise a diverse group of Gram-positive, non-spore-forming ... more ABSTRACT Lactic acid bacteria (LAB) comprise a diverse group of Gram-positive, non-spore-forming microorganisms (1). Fermentable carbohydrates are used as energy sources and are degraded to lactate (homofermentatives) or to lactate and additional products such as acetate, ethanol, carbon dioxide, formate, or succinate (heterofermentatives). Lactobacilli species are widely used in food technology. The manufacture of high-quality products requieres close attention to characterization, differentiation, and maintenance of lactobacilli starter culture strains. The species identification of LAB depends mainly on physiological and biochemical criteria. These conventional methods are time-comsuming and difficult and the results are often ambiguous. Therefore, for microbiological quality control, it is necessary to develop more reliable and quicker identification methods. The electrophoretic separation of cellular proteins is a sensitive technique, applied in bacterial systematics, that mainly provides information on the similarity of strains within the same species or subspecies. The present chapter deals with the most common technique of polyacrylamide gel electrophoresis (PAGE) in the presence of denaturing agents (sodium dodecyl sulfate [SDS]) of whole and wall-cell-associated proteins extracts for strain typing of lactobacilli. These methods will be useful for culture maintenance by giving each particular strain a fingerprint.

Research paper thumbnail of Lactococcus lactis is capable of improving the riboflavin status in deficient rats

British Journal of Nutrition, 2005

Lactococcus lactis is a commonly used starter strain that can be converted from a vitamin B2 cons... more Lactococcus lactis is a commonly used starter strain that can be converted from a vitamin B2 consumer into a vitamin B2 ‘factory’ by over-expressing its riboflavin biosynthesis genes. The present study was conducted to assess in a rat bioassay the response of riboflavin produced by GM or native lactic acid bacteria (LAB). The riboflavin-producing strains were able to eliminate most physiological manifestations of ariboflavinosis such as stunted growth, elevated erythrocyte glutathione reductase activation coefficient values and hepatomegalia that were observed using a riboflavin depletion–repletion model. Riboflavin status and growth rates were greatly improved when the depleted rats were fed with cultures of L. lactis that overproduced this vitamin whereas the native strain did not show the same effect. The present study is the first animal trial with food containing living bacteria that were engineered to overproduce riboflavin. These results pave the way for analysing the effect ...

Research paper thumbnail of Supplementation with engineered Lactococcus lactis improves the folate status in deficient rats

Research paper thumbnail of Soymilk fermented with Lactobacillus rhamnosus CRL981 ameliorates hyperglycemia, lipid profiles and increases antioxidant enzyme activities in diabetic mice

Journal of Functional Foods, 2013

ABSTRACT Interest in soybeans and soy-based products has grown significantly in the last decades ... more ABSTRACT Interest in soybeans and soy-based products has grown significantly in the last decades due to their reported nutritional and health-promoting effects. In soybean and non-fermented soy foods, isoflavones are predominantly found as glucosides, which must be hydrolyzed in order to exert their documented beneficial effects. The objective of this study was to evaluate the effect of soymilk fermented with Lactobacillus rhamnosus CRL981, a strain that can completely hydrolyze glucoside isoflavones due to its high beta-glucosidase activity. Using a diabetes animal model induced with streptozotocin, it was shown that the fermented soymilk was able to significantly decrease glucose levels, total cholesterol concentrations, triacylglycerols and increase antioxidant enzyme activities compared to animals that received unfermented soymilk. This study clearly shows that the adequate selection of starter cultures could be used to develop novel soy based products intended for the prevention or adjuvant treatment of diseases such as diabetes.

Research paper thumbnail of Enhancement of the antioxidant capacity of soymilk by fermentation with Lactobacillus rhamnosus

Journal of Functional Foods, 2012

ABSTRACT

Research paper thumbnail of A Novel Functional Soy-based Food Fermented by Lactic Acid Bacteria: Effect of Heat Treatment

Journal of Food Science, 2004

Research paper thumbnail of Application of Conductimetry for Evaluation of Lactic Starter Cultures in Soymilk

Journal of Food Science, 2002

Research paper thumbnail of UDP-galactose 4-epimerase: a key enzyme in exopolysaccharide formation by Lactobacillus casei CRL 87 in controlled pH batch cultures

Journal of Applied Microbiology, 2003

Research paper thumbnail of Release of the Cell-Envelope-Associated Proteinase of Lactobacillus delbrueckii Subspecies lactis CRL 581 Is Dependent upon pH and Temperature

Journal of Agricultural and Food Chemistry, 2009

Research paper thumbnail of Bioactive action of β-glucosidase enzyme of Bifidobacterium longum upon isoflavone glucosides present in soymilk

International Journal of Food Science & Technology, 2013

ABSTRACT

Research paper thumbnail of Profesora Doctora Aída Pesce de Ruíz Holgado (1926-2012)

Research paper thumbnail of Development of gluten-free breads started with chia and flaxseed sourdoughs fermented by selected lactic acid bacteria

Research paper thumbnail of Draft Genome Sequence of Lactobacillus delbrueckii subsp. bulgaricus CRL871, a Folate-Producing Strain Isolated from a Northwestern Argentinian Yogurt

Genome Announcements, 2015

Research paper thumbnail of Milk fermented with selected strains of lactic acid bacteria is able to improve folate status of deficient rodents and also prevent folate deficiency

Journal of Functional Foods, 2015

ABSTRACT Folate deficiencies are common in many parts of the world. The use of folate producing f... more ABSTRACT Folate deficiencies are common in many parts of the world. The use of folate producing food grade microorganisms has been proposed as a more natural alternative to fortification with the chemical folic acid. The aim of this study was to evaluate the effectiveness of a novel fermented milk elaborated with adequately selected folate producing lactic acid bacteria. This product was tested using both a rodent depletion–repletion model and a complete deficient model. The folate bio-enriched fermented milk was able to increase plasma folate concentrations and decrease homocysteine levels. This is the first report demonstrating that a naturally folate bio-enriched fermented milk, elaborated with folate-producing starter cultures, not only is effective to improve folate status but can also prevent folate deficiency. Consumers also would obviously benefit from this type of product because they could increase their folate intakes while consuming foods that form part of their normal diets.

Research paper thumbnail of Ingestion of milk fermented by genetically modified Lactococcus lactis improves the riboflavin status of deficient rats

Journal of dairy science, 2005

Riboflavin deficiency is common in many parts of the world, particularly in developing countries.... more Riboflavin deficiency is common in many parts of the world, particularly in developing countries. The use of riboflavin-producing strains in the production of dairy products such as fermented milks, yogurts, and cheeses is feasible and economically attractive because it would decrease the costs involved during conventional vitamin fortification and satisfy consumer demands for healthier foods. The present study was conducted to assess in a rat bioassay the response of administration of milk fermented by modified Lactococcus lactis on the riboflavin status of deficient rats. Rats were fed a riboflavin-deficient diet during 21 d after which this same diet was supplemented with milk fermented by Lactoccus lactis pNZGBAH, a strain that overproduces riboflavin during fermentation. The novel fermented product, with increased levels of riboflavin, was able to eliminate most physiological manifestations of ariboflavinosis, such as stunted growth, elevated erythrocyte glutathione reductase a...

Research paper thumbnail of Isolation and identification of anaerobic contaminants from a machine for producing processed cheese

Revista Argentina de microbiología, 1982

Some bacteria of the genus Clostridium can contaminate milk. These bacteria can cause "the l... more Some bacteria of the genus Clostridium can contaminate milk. These bacteria can cause "the late gas" or "late blowing" defect in the cheese if this is made with milk containing such contaminants. In this study, six samples from a processed cheese contaminated in a manufacturing machine were analysed. Out of 60 strains studied, 30 were classified as Clostridium tyrobutyricum, 20 as Clostridium butyricum, and 10 as Desulfotomaculum ruminis.

Research paper thumbnail of Use of SDS-PAGE of cell-wall proteins for rapid differentiation of Lactobacillus delbrueckii subsp. lactis and Lactobacillus helveticus

Biotechnology Letters, 2000

Cell-wall protein profiles of different strains of Lactobacillus helveticus and L. delbrueckii su... more Cell-wall protein profiles of different strains of Lactobacillus helveticus and L. delbrueckii subsp. lactis isolated from regional cheeses were studied by SDS-PAGE. The patterns were highly reproducible and the presence of numerous bands with molecular weight ranging from 14 to 160 kDa allowed L. delbrueckii subsp. lactis to be differentiated from L. helveticus. The method is a reliable and rapid way to identify thermophilic

Research paper thumbnail of Characterisation of a cell-envelope proteinase from Lactobacillus helveticus

Biotechnology Letters, 1999

The cell-envelope proteinase from Lactobacillus helveticus CRL 1062 was detected in the cell memb... more The cell-envelope proteinase from Lactobacillus helveticus CRL 1062 was detected in the cell membrane fraction. The enzyme remained associated with the cells even after treatment with lysozyme and was not released from washed cells in absence of calcium. The proteinase was maximally active at pH 6.5–7.0 and 42?°C and hydrolysed a- and ß-caseins at different rates. Activity was inhibited (98%) by

Research paper thumbnail of Chemical composition and microbial evaluation of Argentinean Corrientes cheese

Research paper thumbnail of Evaluation of Minimal Nutritional Requirements of Lactic Acid Bacteria Used in Functional Foods

Environmental Microbiology, 2004

ABSTRACT The lactic acid bacteria (LAB) are important industrial microorganisms because of their ... more ABSTRACT The lactic acid bacteria (LAB) are important industrial microorganisms because of their role in food fermentation, especially dairy products. In addition, it has been showed that LAB exhibit a range of physiological and therapeutic effects in consumers of these foods, including immune stimulation, pathogen exclusion, production of bioactive peptides, and others (1). Foods containing such bacteria are considered “functional foods,” foods that promote health beyond providing basic nutrition.

Research paper thumbnail of Differentiation of Lactobacilli Strains by Electrophoretic Protein Profiles

Food Microbiology Protocols, 2000

ABSTRACT Lactic acid bacteria (LAB) comprise a diverse group of Gram-positive, non-spore-forming ... more ABSTRACT Lactic acid bacteria (LAB) comprise a diverse group of Gram-positive, non-spore-forming microorganisms (1). Fermentable carbohydrates are used as energy sources and are degraded to lactate (homofermentatives) or to lactate and additional products such as acetate, ethanol, carbon dioxide, formate, or succinate (heterofermentatives). Lactobacilli species are widely used in food technology. The manufacture of high-quality products requieres close attention to characterization, differentiation, and maintenance of lactobacilli starter culture strains. The species identification of LAB depends mainly on physiological and biochemical criteria. These conventional methods are time-comsuming and difficult and the results are often ambiguous. Therefore, for microbiological quality control, it is necessary to develop more reliable and quicker identification methods. The electrophoretic separation of cellular proteins is a sensitive technique, applied in bacterial systematics, that mainly provides information on the similarity of strains within the same species or subspecies. The present chapter deals with the most common technique of polyacrylamide gel electrophoresis (PAGE) in the presence of denaturing agents (sodium dodecyl sulfate [SDS]) of whole and wall-cell-associated proteins extracts for strain typing of lactobacilli. These methods will be useful for culture maintenance by giving each particular strain a fingerprint.

Research paper thumbnail of Lactococcus lactis is capable of improving the riboflavin status in deficient rats

British Journal of Nutrition, 2005

Lactococcus lactis is a commonly used starter strain that can be converted from a vitamin B2 cons... more Lactococcus lactis is a commonly used starter strain that can be converted from a vitamin B2 consumer into a vitamin B2 ‘factory’ by over-expressing its riboflavin biosynthesis genes. The present study was conducted to assess in a rat bioassay the response of riboflavin produced by GM or native lactic acid bacteria (LAB). The riboflavin-producing strains were able to eliminate most physiological manifestations of ariboflavinosis such as stunted growth, elevated erythrocyte glutathione reductase activation coefficient values and hepatomegalia that were observed using a riboflavin depletion–repletion model. Riboflavin status and growth rates were greatly improved when the depleted rats were fed with cultures of L. lactis that overproduced this vitamin whereas the native strain did not show the same effect. The present study is the first animal trial with food containing living bacteria that were engineered to overproduce riboflavin. These results pave the way for analysing the effect ...

Research paper thumbnail of Supplementation with engineered Lactococcus lactis improves the folate status in deficient rats

Research paper thumbnail of Soymilk fermented with Lactobacillus rhamnosus CRL981 ameliorates hyperglycemia, lipid profiles and increases antioxidant enzyme activities in diabetic mice

Journal of Functional Foods, 2013

ABSTRACT Interest in soybeans and soy-based products has grown significantly in the last decades ... more ABSTRACT Interest in soybeans and soy-based products has grown significantly in the last decades due to their reported nutritional and health-promoting effects. In soybean and non-fermented soy foods, isoflavones are predominantly found as glucosides, which must be hydrolyzed in order to exert their documented beneficial effects. The objective of this study was to evaluate the effect of soymilk fermented with Lactobacillus rhamnosus CRL981, a strain that can completely hydrolyze glucoside isoflavones due to its high beta-glucosidase activity. Using a diabetes animal model induced with streptozotocin, it was shown that the fermented soymilk was able to significantly decrease glucose levels, total cholesterol concentrations, triacylglycerols and increase antioxidant enzyme activities compared to animals that received unfermented soymilk. This study clearly shows that the adequate selection of starter cultures could be used to develop novel soy based products intended for the prevention or adjuvant treatment of diseases such as diabetes.

Research paper thumbnail of Enhancement of the antioxidant capacity of soymilk by fermentation with Lactobacillus rhamnosus

Journal of Functional Foods, 2012

ABSTRACT

Research paper thumbnail of A Novel Functional Soy-based Food Fermented by Lactic Acid Bacteria: Effect of Heat Treatment

Journal of Food Science, 2004

Research paper thumbnail of Application of Conductimetry for Evaluation of Lactic Starter Cultures in Soymilk

Journal of Food Science, 2002

Research paper thumbnail of UDP-galactose 4-epimerase: a key enzyme in exopolysaccharide formation by Lactobacillus casei CRL 87 in controlled pH batch cultures

Journal of Applied Microbiology, 2003

Research paper thumbnail of Release of the Cell-Envelope-Associated Proteinase of Lactobacillus delbrueckii Subspecies lactis CRL 581 Is Dependent upon pH and Temperature

Journal of Agricultural and Food Chemistry, 2009

Research paper thumbnail of Bioactive action of β-glucosidase enzyme of Bifidobacterium longum upon isoflavone glucosides present in soymilk

International Journal of Food Science & Technology, 2013

ABSTRACT