The Experts below are selected from a list of 138 Experts worldwide ranked by ideXlab platform
Victoria Ferragut - One of the best experts on this subject based on the ideXlab platform.
-
Flavour profiles and survival of starter cultures of yoghurt produced from high-pressure Homogenized Milk
International Dairy Journal, 2009Co-Authors: Mar Serra, Antonio J. Trujillo, Buenventura Guamis, Victoria FerragutAbstract:Abstract Volatile carbonyl compounds, organic acids and yoghurt bacteria counts were investigated in yoghurts made from ultra-high pressure Homogenized Milk. Yoghurts were manufactured from Milk treated using ultra-high pressure homogenization at 200 or 300 MPa and at 30 °C or 40 °C, and compared with those produced from heat-treated Milk with 3% added skim Milk powder. To study the evolution of these parameters, samples were analysed after days 1, 14 and 28 of storage. Yoghurts from Milk heat-treated or treated at 300 MPa had very similar profiles of organic acids and volatile compounds, as well as similar bacterial counts of both starter cultures. In comparison, yoghurts from Milk treated at 200 MPa at either 30 °C or 40 °C gave different profiles, together with a sharp decrease in counts of lactobacilli. During storage, only slight differences in flavour compounds and yoghurt bacteria counts were detected, except in those samples from Milk treated at 200 MPa.
-
Heat damage evaluation in ultra-high pressure Homogenized Milk
Food Hydrocolloids, 2009Co-Authors: J. Pereda, Victoria Ferragut, J.m. Quevedo, Buenaventura Guamis, Antonio J. TrujilloAbstract:Abstract The evaluation of heat damage in ultra-high pressure Homogenized (UHPH)-treated samples has been studied by analyzing different thermal indicators such as compounds that absorb at 340 nm, hydroxymethylfurfural, free sulphydryl content, furosine, lactulose and whey protein denaturation. Milk was treated at 200 and 300 MPa with inlet temperature of 30 and 40 °C and was compared to high-pasteurized Milk (PA; 90 °C, 15 s) and to commercial UHT, in bottle-sterilized and pasteurized Milks. UHPH samples were differentiated from PA Milk, basically by the determination of absorbance at 340 nm and β-Lactoglobulin denaturation. Both parameters indicated a reduced thermal effect in UHPH samples over PA Milk. Comparison of UHPH samples with UHT and sterilized Milks showed an increase of all heating indicators when severe heat process was applied. Overall, in spite of the increase of temperature during UHPH treatments, heat damage was lower compared to PA Milk, suggesting the potential of this technology as an alternative to pasteurization.
-
proteolysis of yogurts made from ultra high pressure Homogenized Milk during cold storage
Journal of Dairy Science, 2009Co-Authors: Mar Serra, Antonio J. Trujillo, Buenventura Guamis, Victoria FerragutAbstract:Abstract Proteolysis was investigated in yogurts made from Milk that was ultra-high-pressure Homogenized at 200 or 300 MPa and at 30 or 40°C and compared with those produced from heat-treated Milk containing 3% skim Milk powder. To evaluate changes in the protein fraction, samples were analyzed at d 1, 7, 14, 21, and 28 of storage for residual caseins, peptides, and total free amino acids. Results showed that yogurts from heat-treated Milk and 300 MPa-treated Milk presented similar levels of residual caseins, as well as similar profiles of soluble peptides and total free amino acids. On the contrary, greater amounts of hydrophobic peptides were detected in yogurts made from 200 MPa-treated Milk at both 30 and 40°C, especially at the end of storage. In all treatments studied, caseins were hydrolyzed and hydrophobic peptides were increased during storage, as reflected by the increase in soluble nitrogen at the end of the storage.
-
Characterization of volatile compounds in ultra-high-pressure Homogenized Milk
International Dairy Journal, 2008Co-Authors: J. Pereda, Victoria Ferragut, J.m. Quevedo, Buenaventura Guamis, D.p. Jaramillo, Antonio J. TrujilloAbstract:Abstract The effect of ultra-high-pressure homogenization (UHPH) on the volatile profile of Milk was studied and compared with thermal treatments. Milk was treated at 200 and 300 MPa with inlet temperatures of 30 and 40 °C. UHPH-treated Milk samples were compared with high-pasteurized Milk (PA; 90 °C, 15 s) and to commercial UHT, in-bottle sterilized and pasteurized Milk types. Volatiles were extracted by solid phase micro-extraction and were identified by gas chromatography/mass spectrometry. Volatile profiles showed that UHPH-treated Milk at 200 MPa produced fewer carbonyl compounds than PA and 300 MPa Milk samples but there was a high level of hexanoic acid, related to rancid flavors. Milk treated at 300 MPa showed higher aldehyde content compared to PA Milk, but lower compared with commercial Milk samples (UHT, in-bottle sterilized and pasteurized). No differences were detected in relation to dimethyl sulfide. Heat treatment resulted in an increase in aldehydes and methyl ketones with increased severity of treatment. UHPH technology induced an increase in aldehydes alone.
Antonio J. Trujillo - One of the best experts on this subject based on the ideXlab platform.
-
Flavour profiles and survival of starter cultures of yoghurt produced from high-pressure Homogenized Milk
International Dairy Journal, 2009Co-Authors: Mar Serra, Antonio J. Trujillo, Buenventura Guamis, Victoria FerragutAbstract:Abstract Volatile carbonyl compounds, organic acids and yoghurt bacteria counts were investigated in yoghurts made from ultra-high pressure Homogenized Milk. Yoghurts were manufactured from Milk treated using ultra-high pressure homogenization at 200 or 300 MPa and at 30 °C or 40 °C, and compared with those produced from heat-treated Milk with 3% added skim Milk powder. To study the evolution of these parameters, samples were analysed after days 1, 14 and 28 of storage. Yoghurts from Milk heat-treated or treated at 300 MPa had very similar profiles of organic acids and volatile compounds, as well as similar bacterial counts of both starter cultures. In comparison, yoghurts from Milk treated at 200 MPa at either 30 °C or 40 °C gave different profiles, together with a sharp decrease in counts of lactobacilli. During storage, only slight differences in flavour compounds and yoghurt bacteria counts were detected, except in those samples from Milk treated at 200 MPa.
-
Heat damage evaluation in ultra-high pressure Homogenized Milk
Food Hydrocolloids, 2009Co-Authors: J. Pereda, Victoria Ferragut, J.m. Quevedo, Buenaventura Guamis, Antonio J. TrujilloAbstract:Abstract The evaluation of heat damage in ultra-high pressure Homogenized (UHPH)-treated samples has been studied by analyzing different thermal indicators such as compounds that absorb at 340 nm, hydroxymethylfurfural, free sulphydryl content, furosine, lactulose and whey protein denaturation. Milk was treated at 200 and 300 MPa with inlet temperature of 30 and 40 °C and was compared to high-pasteurized Milk (PA; 90 °C, 15 s) and to commercial UHT, in bottle-sterilized and pasteurized Milks. UHPH samples were differentiated from PA Milk, basically by the determination of absorbance at 340 nm and β-Lactoglobulin denaturation. Both parameters indicated a reduced thermal effect in UHPH samples over PA Milk. Comparison of UHPH samples with UHT and sterilized Milks showed an increase of all heating indicators when severe heat process was applied. Overall, in spite of the increase of temperature during UHPH treatments, heat damage was lower compared to PA Milk, suggesting the potential of this technology as an alternative to pasteurization.
-
proteolysis of yogurts made from ultra high pressure Homogenized Milk during cold storage
Journal of Dairy Science, 2009Co-Authors: Mar Serra, Antonio J. Trujillo, Buenventura Guamis, Victoria FerragutAbstract:Abstract Proteolysis was investigated in yogurts made from Milk that was ultra-high-pressure Homogenized at 200 or 300 MPa and at 30 or 40°C and compared with those produced from heat-treated Milk containing 3% skim Milk powder. To evaluate changes in the protein fraction, samples were analyzed at d 1, 7, 14, 21, and 28 of storage for residual caseins, peptides, and total free amino acids. Results showed that yogurts from heat-treated Milk and 300 MPa-treated Milk presented similar levels of residual caseins, as well as similar profiles of soluble peptides and total free amino acids. On the contrary, greater amounts of hydrophobic peptides were detected in yogurts made from 200 MPa-treated Milk at both 30 and 40°C, especially at the end of storage. In all treatments studied, caseins were hydrolyzed and hydrophobic peptides were increased during storage, as reflected by the increase in soluble nitrogen at the end of the storage.
-
Characterization of volatile compounds in ultra-high-pressure Homogenized Milk
International Dairy Journal, 2008Co-Authors: J. Pereda, Victoria Ferragut, J.m. Quevedo, Buenaventura Guamis, D.p. Jaramillo, Antonio J. TrujilloAbstract:Abstract The effect of ultra-high-pressure homogenization (UHPH) on the volatile profile of Milk was studied and compared with thermal treatments. Milk was treated at 200 and 300 MPa with inlet temperatures of 30 and 40 °C. UHPH-treated Milk samples were compared with high-pasteurized Milk (PA; 90 °C, 15 s) and to commercial UHT, in-bottle sterilized and pasteurized Milk types. Volatiles were extracted by solid phase micro-extraction and were identified by gas chromatography/mass spectrometry. Volatile profiles showed that UHPH-treated Milk at 200 MPa produced fewer carbonyl compounds than PA and 300 MPa Milk samples but there was a high level of hexanoic acid, related to rancid flavors. Milk treated at 300 MPa showed higher aldehyde content compared to PA Milk, but lower compared with commercial Milk samples (UHT, in-bottle sterilized and pasteurized). No differences were detected in relation to dimethyl sulfide. Heat treatment resulted in an increase in aldehydes and methyl ketones with increased severity of treatment. UHPH technology induced an increase in aldehydes alone.
Isabelle Crenon - One of the best experts on this subject based on the ideXlab platform.
-
Effect of the size and interface composition of Milk fat globules on their in vitro digestion by the human pancreatic lipase: Native versus Homogenized Milk fat globules
Food Hydrocolloids, 2012Co-Authors: Amélie Berton, Stéphanie Rouvellac, Christelle Lopez, Benoit Robert, Florence Rousseau, Isabelle CrenonAbstract:Although the bioavailability of dietary lipids is of primary importance in human nutrition and health, the mechanisms involved in lipid digestion are not fully understood and are of growing interest. The objective of this study was to determine the effect of the size of Milk fat globules and of the composition of their interface on the activity of the human pancreatic lipase (PL). Native Milk fat globules of various sizes covered by their biological membrane (MFGM) and Homogenized fat globules of various sizes covered by Milk proteins were prepared from whole Milk and underwent lipolysis by the human PL with colipase and bile salts. A lag phase preceding the hydrolysis of Milk TAG occurred with all native Milk fat globules samples but not with Homogenized Milk samples. The kinetic parameters of human PL were determined by measuring the enzyme activity either after the lag phase for native Milk fat globules samples or immediately after the addition of the enzyme for Homogenized Milk samples. The catalytic efficiency of human PL is 4.6-fold higher on small (1.8 μm) than large (6.7 μm) native Milk fat globules, related to a 3.6-fold larger available surface. Despite the 25-fold larger available surface, Milk TAG from Homogenized Milk are only 2-fold better hydrolyzed compared to native Milk fat globules, as a possible result of a less favourable interface covered by Milk proteins. The potential mechanisms involved in native vs. Homogenized Milk fat globules digestion by the human PL are discussed. Our study highlights the crucial role of the MFGM in the efficient digestion of Milk fat globules and brings new insight for the design of dairy products and infant formulas.
-
Individual and combined action of pancreatic lipase and pancreatic lipase‐related proteins 1 and 2 on native versus Homogenized Milk fat globules
Molecular nutrition & food research, 2009Co-Authors: Amélie Berton, Stéphanie Rouvellac, Corinne Sebban-kreuzer, Christelle Lopez, Isabelle CrenonAbstract:Pancreatic lipase (PL) and pancreatic lipase-related proteins 1 and 2 (PLRP1 and PLRP2) display different functional properties, despite close structures. The aim of the study was to compare the kinetic properties of recombinant human PLRP1, PLRP2, and PL on a physiological substrate: the Milk fat under native and Homogenized structures. No lipolytic activity is measured for PLRP1. PLRP2 hydrolyses Milk fat with a lower catalytic efficiency than that of PL. PLRP2 activity, higher on Homogenized than on native Milk fat, is differently influenced by fatty acids (FA) and colipase depending on a proteolytic cleavage in the lid domain. FA enhance the activity on both Milks. A colipase positive effect on the non-proteolyzed PLRP2 is observed on Homogenized Milk and with FA on native Milk fat. Bile salts are necessary. An original observation is a synergic effect between PL and PLRP2 on the two Milks. An inhibitory effect of PLRP1 on PL activity is also demonstrated. The combined action of pancreatic lipases on Milk fat digestion proposes PLRPs as modulators of PL. Our study supports the hypothesis of a major role of PLRP2 in fat digestion in newborns and brings new insights to understand the physiological role of PLRPs.
-
Individual and combined action of pancreatic lipase and pancreatic lipase-related proteins 1 and 2 on native versus Homogenized Milk fat globules
Molecular Nutrition and Food Research, 2009Co-Authors: Amélie Berton, Stéphanie Rouvellac, Corinne Sebban-kreuzer, Christelle Lopez, Isabelle CrenonAbstract:Pancreatic lipase (PL) and pancreatic lipase-related proteins 1 and 2 (PLRP1 and PLRP2) display different functional properties, despite close structures. The aim of the study was to compare the kinetic properties of recombinant human PLRP1, PLRP2, and PL on a physiological substrate: the Milk fat under native and Homogenized structures. No lipolytic activity is measured for PLRP1. PLRP2 hydrolyses Milk fat with a lower catalytic efficiency than that of PL. PLRP2 activity, higher on Homogenized than on native Milk fat, is differently influenced by fatty acids (FA) and colipase depending on a proteolytic cleavage in the lid domain. FA enhance the activity on both Milks. A colipase positive effect on the non-proteolyzed PLRP2 is observed on Homogenized Milk and with FA on native Milk fat. Bile salts are necessary. An original observation is a synergic effect between PL and PLRP2 on the two Milks. An inhibitory effect of PLRP1 on PL activity is also demonstrated. The combined action of pancreatic lipases on Milk fat digestion proposes PLRPs as modulators of PL. Our study supports the hypothesis of a major role of PLRP2 in fat digestion in newborns and brings new insights to understand the physiological role of PLRPs.
Mar Serra - One of the best experts on this subject based on the ideXlab platform.
-
Flavour profiles and survival of starter cultures of yoghurt produced from high-pressure Homogenized Milk
International Dairy Journal, 2009Co-Authors: Mar Serra, Antonio J. Trujillo, Buenventura Guamis, Victoria FerragutAbstract:Abstract Volatile carbonyl compounds, organic acids and yoghurt bacteria counts were investigated in yoghurts made from ultra-high pressure Homogenized Milk. Yoghurts were manufactured from Milk treated using ultra-high pressure homogenization at 200 or 300 MPa and at 30 °C or 40 °C, and compared with those produced from heat-treated Milk with 3% added skim Milk powder. To study the evolution of these parameters, samples were analysed after days 1, 14 and 28 of storage. Yoghurts from Milk heat-treated or treated at 300 MPa had very similar profiles of organic acids and volatile compounds, as well as similar bacterial counts of both starter cultures. In comparison, yoghurts from Milk treated at 200 MPa at either 30 °C or 40 °C gave different profiles, together with a sharp decrease in counts of lactobacilli. During storage, only slight differences in flavour compounds and yoghurt bacteria counts were detected, except in those samples from Milk treated at 200 MPa.
-
proteolysis of yogurts made from ultra high pressure Homogenized Milk during cold storage
Journal of Dairy Science, 2009Co-Authors: Mar Serra, Antonio J. Trujillo, Buenventura Guamis, Victoria FerragutAbstract:Abstract Proteolysis was investigated in yogurts made from Milk that was ultra-high-pressure Homogenized at 200 or 300 MPa and at 30 or 40°C and compared with those produced from heat-treated Milk containing 3% skim Milk powder. To evaluate changes in the protein fraction, samples were analyzed at d 1, 7, 14, 21, and 28 of storage for residual caseins, peptides, and total free amino acids. Results showed that yogurts from heat-treated Milk and 300 MPa-treated Milk presented similar levels of residual caseins, as well as similar profiles of soluble peptides and total free amino acids. On the contrary, greater amounts of hydrophobic peptides were detected in yogurts made from 200 MPa-treated Milk at both 30 and 40°C, especially at the end of storage. In all treatments studied, caseins were hydrolyzed and hydrophobic peptides were increased during storage, as reflected by the increase in soluble nitrogen at the end of the storage.
J. Pereda - One of the best experts on this subject based on the ideXlab platform.
-
Heat damage evaluation in ultra-high pressure Homogenized Milk
Food Hydrocolloids, 2009Co-Authors: J. Pereda, Victoria Ferragut, J.m. Quevedo, Buenaventura Guamis, Antonio J. TrujilloAbstract:Abstract The evaluation of heat damage in ultra-high pressure Homogenized (UHPH)-treated samples has been studied by analyzing different thermal indicators such as compounds that absorb at 340 nm, hydroxymethylfurfural, free sulphydryl content, furosine, lactulose and whey protein denaturation. Milk was treated at 200 and 300 MPa with inlet temperature of 30 and 40 °C and was compared to high-pasteurized Milk (PA; 90 °C, 15 s) and to commercial UHT, in bottle-sterilized and pasteurized Milks. UHPH samples were differentiated from PA Milk, basically by the determination of absorbance at 340 nm and β-Lactoglobulin denaturation. Both parameters indicated a reduced thermal effect in UHPH samples over PA Milk. Comparison of UHPH samples with UHT and sterilized Milks showed an increase of all heating indicators when severe heat process was applied. Overall, in spite of the increase of temperature during UHPH treatments, heat damage was lower compared to PA Milk, suggesting the potential of this technology as an alternative to pasteurization.
-
Characterization of volatile compounds in ultra-high-pressure Homogenized Milk
International Dairy Journal, 2008Co-Authors: J. Pereda, Victoria Ferragut, J.m. Quevedo, Buenaventura Guamis, D.p. Jaramillo, Antonio J. TrujilloAbstract:Abstract The effect of ultra-high-pressure homogenization (UHPH) on the volatile profile of Milk was studied and compared with thermal treatments. Milk was treated at 200 and 300 MPa with inlet temperatures of 30 and 40 °C. UHPH-treated Milk samples were compared with high-pasteurized Milk (PA; 90 °C, 15 s) and to commercial UHT, in-bottle sterilized and pasteurized Milk types. Volatiles were extracted by solid phase micro-extraction and were identified by gas chromatography/mass spectrometry. Volatile profiles showed that UHPH-treated Milk at 200 MPa produced fewer carbonyl compounds than PA and 300 MPa Milk samples but there was a high level of hexanoic acid, related to rancid flavors. Milk treated at 300 MPa showed higher aldehyde content compared to PA Milk, but lower compared with commercial Milk samples (UHT, in-bottle sterilized and pasteurized). No differences were detected in relation to dimethyl sulfide. Heat treatment resulted in an increase in aldehydes and methyl ketones with increased severity of treatment. UHPH technology induced an increase in aldehydes alone.