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Xavier F Malcata - One of the best experts on this subject based on the ideXlab platform.
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incorporation of probiotic bacteria in Whey Cheese decreasing the risk of microbial contamination
Journal of Food Protection, 2011Co-Authors: Raquel A Madureira, Manuela Pintado, A. Gomes, Xavier F MalcataAbstract:For dairy products that are consumed fresh, contamination by spoilage microorganisms and pathogens from the environment is a major concern. Contamination has been associated with a number of outbreaks of foodborne illnesses; however, consistent data pertaining to the microbial safety of Whey Cheeses specifically have not been reported. Hence, the goals of this research effort were (i) to manufacture a probiotic Whey Cheese with Bifidobacterium animalis and Lactobacillus casei and (ii) to assess the antimicrobial activity of these probiotics against a set of foodborne pathogens (Listeria innocua, Salmonella Enteritidis, and Staphylococcus aureus) and food spoilage microorganisms (Pseudomonas aeruginosa and Escherichia coli). Three ranges of these microbial contaminants were used for inoculation of Cheeses: 103 to 104, 104 to 106, and 106 to108 CFU/g. Inoculation in plain culture medium served as a control. The inhibition produced by the probiotics was calculated, and the major effect was found to be bacter...
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technological optimization of manufacture of probiotic Whey Cheese matrices
Journal of Food Science, 2011Co-Authors: Ana Raquel Madureira, Manuela Pintado, A. Gomes, Teresa R S Brandao, Xavier F MalcataAbstract:: In attempts to optimize their manufacture, Whey Cheese matrices obtained via thermal processing of Whey (leading to protein precipitation) and inoculated with probiotic cultures were tested. A central composite, face-centered design was followed, so a total of 16 experiments were run using fractional addition of bovine milk to feedstock Whey, homogenization time, and storage time of Whey Cheese as processing parameters. Probiotic Whey Cheese matrices were inoculated with Lactobacillus casei LAFTI®L26 at 10% (v/v), whereas control Whey Cheese matrices were added with skim milk previously acidified with lactic acid to the same level. All Whey Cheeses were stored at 7 °C up to 14 d. Chemical and sensory analyses were carried out for all samples, as well as rheological characterization by oscillatory viscometry and textural profiling. As expected, differences were found between control and probiotic matrices: fractional addition of milk and storage time were the factors accounting for the most important effects. Estimation of the best operating parameters was via response surface analysis: milk addition at a rate of 10% to 15% (v/v), and homogenization for 5 min led to the best probiotic Whey Cheeses in terms of texture and organoleptic properties, whereas the best time for consumption was found to be by 9 d of storage following manufacture.
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protective effect of Whey Cheese matrix on probiotic strains exposed to simulated gastrointestinal conditions
Food Research International, 2011Co-Authors: Raquel A Madureira, Manuela Pintado, A. Gomes, Xavier F Malcata, Manuela AmorimAbstract:Abstract A probiotic Whey Cheese added with Lactobacillus casei LAFTI®L26, Lactobacillus acidophilus LAFTI®L10 or Bifidobacterium animalis Bo was subject in vitro to sequential conditions that parallel the four major steps of digestion: mouth (artificial saliva), oesophagus–stomach (artificial gastric juice), duodenum (artificial intestinal juice) and ileum; its manufacture followed the traditional Cheesemaking protocol of Portuguese Requeijao. MRS broth was inoculated in parallel as reference medium, to ascertain the protective effect of the Whey Cheese matrix itself upon those strains in every digestion step. Mouth conditions had an almost negligible effect upon all three strains, whereas oesophagus–stomach, duodenum and ileum conditions decreased the viable numbers of L. casei and L. acidophilus; in both systems, B. animalis suffered only slight decreases in viable numbers; and L. casei and L. acidophilus behaved likewise in MRS exposed to duodenum and ileum conditions. Whey Cheese matrices thus appeared to protect the aforementioned three strains during transit throughout the simulated gastrointestinal system, so they are promising carriers of those probiotic bacteria.
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incorporation and survival of probiotic bacteria in Whey Cheese matrices
Journal of Food Science, 2006Co-Authors: Ana Raquel Madureira, Manuela Pintado, A. Gomes, Maria S Giao, Cristina A Freitas, Xavier F MalcataAbstract:ABSTRACT: The viabilities of probiotic strains of Lactobacillus acidophilus, Lactobacillus paracasei, Bifidobacterium animalis, and Lactobacillus brevis were studied following incorporation in a Whey Cheese matrix. Experimental production of plain, as well as sugar-added or salt-added Whey Cheeses, was based on the traditional manufacture protocol of Requeijao, a Portuguese Whey Cheese that essentially results from protein denaturation via heating of Whey at about 85°C. After inoculation, the experimental Whey Cheeses were incubated at 7°C for 28 d. Our results have shown that all strains considered were able to maintain (or even increase) their initial viable numbers; L. paracasei ssp. paracasei strain LCS-1 and L. acidophilus strain Ki exhibited the highest cell viability in plain Requeijao by the end of the storage period—an increase of ca. 2 log cycles in their viable numbers was actually recorded. Among the parameters studied, bacterial species and matrix nature had the most important effect upon viable counts, whereas time of storage was the least important.
E. P.l. De Santis - One of the best experts on this subject based on the ideXlab platform.
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Use of Carnobacterium spp protective culture in MAP packed Ricotta fresca Cheese to control Pseudomonas spp
Food Microbiology, 2018Co-Authors: Carlo Spanu, A. M. Mocci, E. P.l. De Santis, Fabrizio Piras, G. Nieddu, Christian ScaranoAbstract:Ricotta fresca is a Whey Cheese susceptible of secondary contamination, mainly from Pseudomonas spp. The extension of the shelf life of refrigerated ricotta fresca could be obtained using protective cultures inhibiting the growth of this spoilage microorganism. A commercial biopreservative, Lyofast CNBAL, comprising Carnobacterium spp was tested against Pseudomonas spp. The surface of ricotta fresca samples were inoculated either with Pseudomonas spp or Pseudomonas and Carnobacterium spp. Samples were MAP packed, stored at 4 °C and analyzed the day of the inoculum and 7, 14 and 21 days after the contamination. Microbiological analyses included total bacterial count, mesophilic lactic acid bacteria, Enterobacteriaceae, Pseudomonas spp, Listeria monocytogenes, moulds and yeasts. Pseudomonas mean initial contamination level was comparable in blank and artificially inoculated samples, respectively with values of 2.15 ± 0.21 and 2.34 ± 0.26 log cfu g−1. Carnobacterium spp. significantly reduced the growth of Pseudomonas spp respectively of 1.28 log and 0.83 log after 14 and 21 days of refrigerated storage. Intrinsic properties and physico-chemical composition were also investigated. Limited variation of pH was observed in samples inoculated with the protective cultures, indicating low acidification properties of Carnobacterium spp. Instead, no significant differences were observed for aW, moisture, fat and proteins during storage and between inoculated and control samples.
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evaluation of a post lethality treatment against listeria monocytogenes on ricotta salata Cheese
Food Control, 2013Co-Authors: Carlo Spanu, C Scarano, Vincenzo Spanu, S Virdis, Carlo Pala, E. P.l. De SantisAbstract:As a control measure for Listeria monocytogenes contamination a post-lethality heat treatment was applied in vacuum packaged Ricotta salata, a traditional Whey Cheese obtained from sheep’s milk. In Ricotta salata L. monocytogenes usually occurs as post-process contamination and its concentration can increase during storage at refrigeration temperature. Ricotta salata wheels were challenged spraying the rind with a L. monocytogenes suspension, obtaining a contamination level of ca. 106 cfu g−1. In order to take into account strains differences in growth, the inoculum contained a mixture of the reference strain NCTC 10887 (serovar 1/2b) and two wild type (serovar 1/2a) strains. 87 artificially contaminated Ricotta wheels were randomly selected and subjected to water bath heat treatment at 85 °C for 90 min, while 21 served as negative controls. Samples were stored at refrigeration temperatures until analysis. L. monocytogenes, background microflora and physico-chemical properties were assessed 6 h, 2, 4, 6 and 12 months after the artificial contamination. Pulsed filed gel electrophoresis was conducted to distinguish between the inoculated and recovered strains. L. monocytogenes cells were below the limit for the enumeration method in samples submitted to the lethal treatment. Heat treatment was effective to achieve a 6 log10 reduction of L. monocytogenes cells.
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listeria monocytogenes growth potential in ricotta salata Cheese
International Dairy Journal, 2012Co-Authors: Carlo Spanu, C Scarano, Vincenzo Spanu, C Penna, S Virdis, E. P.l. De SantisAbstract:Abstract Growth potential of Listeria monocytogenes was assessed in Ricotta salata, a traditional sheep’s Whey Cheese. 36 Ricotta salata wheels were inoculated with a mixture of three L. monocytogenes strains obtaining an inoculum level of approximately 102 cfu g−1. Samples were analyzed for the detection and enumeration of L. monocytogenes after 6 h, and after 2, 4 and 6 months. Growth potential (log10 cfu g−1) was 4.87, 6.90 and 6.20 at 2, 4 and 6 months, respectively. The greater relative rate of increase in L. monocytogenes levels was obtained in the first 2 months after inoculation. Ricotta salata supports the growth of L. monocytogenes to levels that may represent a serious risk to public health even during storage at refrigeration temperatures. Further research is needed to assess the effectiveness of post-lethality treatments to reduce the initial level of contamination or of competitive microflora to limit the extent of pathogen growth.
Athanasios A. Koutinas - One of the best experts on this subject based on the ideXlab platform.
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effect of freeze dried kefir culture on proteolysis in feta type and Whey Cheeses
Food Chemistry, 2010Co-Authors: Dimitra Dimitrellou, Athanasios A. Koutinas, Panagiotis Kandylis, Athanasios Mallouchos, Michalis Komaitis, Yiannis KourkoutasAbstract:Abstract The effect of freeze–dried kefir culture on the proteolysis of feta-type and Whey-Cheese was investigated. All nitrogen fractions increased during ripening. Although no significant differences were observed in total nitrogen (TN), the levels of water-soluble nitrogen (WSN), pH 4.4-soluble nitrogen (SN), 12% trichloroacetic acid-soluble nitrogen (TCA-SN) and phosphotungstic acid-soluble nitrogen (PTA-SN) were significantly higher in Cheeses produced by freeze–dried kefir culture during the later stages of ripening. Content of total free amino acids (FAA) was significantly affected by freeze–dried kefir starter culture and it was continuously increased in kefir-Cheese while, in rennet-Cheese it was increased up to 30 days of ripening and then slightly decreased. On the other hand, FAA content continuously decreased in kefir-Whey-Cheese whereas it increased in Whey-Cheese. The Cheese samples produced by freeze–dried kefir as starter culture were characterised as high-quality products during the preliminary sensory evaluation and they were accepted by the panel. Overall, the use of freeze–dried kefir suggested acceleration of Cheese ripening and resulted in improved sensory characteristics.
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Whey Cheese production using freeze dried kefir culture as a starter
Journal of Applied Microbiology, 2007Co-Authors: Dimitra Dimitrellou, Yiannis Kourkoutas, Ibrahim M Banat, Roger Marchant, Athanasios A. KoutinasAbstract:Aims: The aim of the present study was to evaluate the use of a freeze-dried kefir culture in the production of a novel type of Whey-Cheese similar to traditional Greek Myzithra-Cheese, to achieve improvement of the quality characteristics of the final product and the extension of shelf-life. Methods and Results: The use of kefir culture as a starter led to increased lactic acid concentrations and decreased pH values in the final product compared with Whey-Cheese without starter culture. The effect of the starter culture on production of aroma-related compounds responsible for Cheese flavour was also studied using the solid phase microextraction gas chromatography/mass spectrometry technique. Spoilage in unsalted kefir-Whey-Cheese was observed on the thirteenth and the twentieth day of preservation at 10 and 5 degrees C, respectively, while the corresponding times for unsalted Whey-Cheese preservation were 11 and 14 days. Conclusions: The Cheeses produced were characterized as high-quality products during the preliminary sensory evaluation. An indication of increased preservation time was attributed to the freeze-dried kefir culture, which also seemed to suppress growth of pathogens. Significance and Impact of the Study: The results suggested the use of kefir culture as a means to extend the shelf-life of dairy products with reduced or no salt content.
Yiannis Kourkoutas - One of the best experts on this subject based on the ideXlab platform.
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effect of freeze dried kefir culture on proteolysis in feta type and Whey Cheeses
Food Chemistry, 2010Co-Authors: Dimitra Dimitrellou, Athanasios A. Koutinas, Panagiotis Kandylis, Athanasios Mallouchos, Michalis Komaitis, Yiannis KourkoutasAbstract:Abstract The effect of freeze–dried kefir culture on the proteolysis of feta-type and Whey-Cheese was investigated. All nitrogen fractions increased during ripening. Although no significant differences were observed in total nitrogen (TN), the levels of water-soluble nitrogen (WSN), pH 4.4-soluble nitrogen (SN), 12% trichloroacetic acid-soluble nitrogen (TCA-SN) and phosphotungstic acid-soluble nitrogen (PTA-SN) were significantly higher in Cheeses produced by freeze–dried kefir culture during the later stages of ripening. Content of total free amino acids (FAA) was significantly affected by freeze–dried kefir starter culture and it was continuously increased in kefir-Cheese while, in rennet-Cheese it was increased up to 30 days of ripening and then slightly decreased. On the other hand, FAA content continuously decreased in kefir-Whey-Cheese whereas it increased in Whey-Cheese. The Cheese samples produced by freeze–dried kefir as starter culture were characterised as high-quality products during the preliminary sensory evaluation and they were accepted by the panel. Overall, the use of freeze–dried kefir suggested acceleration of Cheese ripening and resulted in improved sensory characteristics.
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Whey Cheese production using freeze dried kefir culture as a starter
Journal of Applied Microbiology, 2007Co-Authors: Dimitra Dimitrellou, Yiannis Kourkoutas, Ibrahim M Banat, Roger Marchant, Athanasios A. KoutinasAbstract:Aims: The aim of the present study was to evaluate the use of a freeze-dried kefir culture in the production of a novel type of Whey-Cheese similar to traditional Greek Myzithra-Cheese, to achieve improvement of the quality characteristics of the final product and the extension of shelf-life. Methods and Results: The use of kefir culture as a starter led to increased lactic acid concentrations and decreased pH values in the final product compared with Whey-Cheese without starter culture. The effect of the starter culture on production of aroma-related compounds responsible for Cheese flavour was also studied using the solid phase microextraction gas chromatography/mass spectrometry technique. Spoilage in unsalted kefir-Whey-Cheese was observed on the thirteenth and the twentieth day of preservation at 10 and 5 degrees C, respectively, while the corresponding times for unsalted Whey-Cheese preservation were 11 and 14 days. Conclusions: The Cheeses produced were characterized as high-quality products during the preliminary sensory evaluation. An indication of increased preservation time was attributed to the freeze-dried kefir culture, which also seemed to suppress growth of pathogens. Significance and Impact of the Study: The results suggested the use of kefir culture as a means to extend the shelf-life of dairy products with reduced or no salt content.
A. Gomes - One of the best experts on this subject based on the ideXlab platform.
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bioactivity of probiotic Whey Cheese characterization of the content of peptides and organic acids
Journal of the Science of Food and Agriculture, 2013Co-Authors: Ana Raquel Madureira, F. X. Malcata, A. Gomes, Jose Soares, Maria M Amorim, Tânia G Tavares, Maria Manuela PintadoAbstract:BACKGROUND: Probiotic Whey Cheeses have been produced for several years. It is recognized that several bacterium-mediated metabolic activities contribute differently to the final sensory and nutritional profiles of dairy products. Hence the metabolic activity of probiotic strains in a Whey Cheese and their contribution to the bioactivity of such matrices were investigated here, including in particular Bifidobacteriumanimalis, Lactobacillusacidophilus and Lactobacilluscasei. RESULTS: Both L. casei and B. animalis produce lactic and acetic acids, whereas L. acidophilus produce mainly lactic acid; these metabolites may be considered bioprotection factors. Water-soluble extracts (WSE) obtained from these Cheese matrices were subjected to ultrafiltration through a 3 kDa cut-off membrane, and the eluted peptides were resolved by high-performance liquid chromatography. Different qualitative and quantitative profiles were obtained, depending on the strain. WSE were further assayed for their ability to inhibit angiotensin-converting enzyme; the <3 kDa fraction exhibited higher activities in the case of L.casei and B.animalis than the control and L.acidophilus. CONCLUSION: Whey Cheeses with higher nutritional value were those inoculated withL.casei. c � 2012 Society of Chemical Industry
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incorporation of probiotic bacteria in Whey Cheese decreasing the risk of microbial contamination
Journal of Food Protection, 2011Co-Authors: Raquel A Madureira, Manuela Pintado, A. Gomes, Xavier F MalcataAbstract:For dairy products that are consumed fresh, contamination by spoilage microorganisms and pathogens from the environment is a major concern. Contamination has been associated with a number of outbreaks of foodborne illnesses; however, consistent data pertaining to the microbial safety of Whey Cheeses specifically have not been reported. Hence, the goals of this research effort were (i) to manufacture a probiotic Whey Cheese with Bifidobacterium animalis and Lactobacillus casei and (ii) to assess the antimicrobial activity of these probiotics against a set of foodborne pathogens (Listeria innocua, Salmonella Enteritidis, and Staphylococcus aureus) and food spoilage microorganisms (Pseudomonas aeruginosa and Escherichia coli). Three ranges of these microbial contaminants were used for inoculation of Cheeses: 103 to 104, 104 to 106, and 106 to108 CFU/g. Inoculation in plain culture medium served as a control. The inhibition produced by the probiotics was calculated, and the major effect was found to be bacter...
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technological optimization of manufacture of probiotic Whey Cheese matrices
Journal of Food Science, 2011Co-Authors: Ana Raquel Madureira, Manuela Pintado, A. Gomes, Teresa R S Brandao, Xavier F MalcataAbstract:: In attempts to optimize their manufacture, Whey Cheese matrices obtained via thermal processing of Whey (leading to protein precipitation) and inoculated with probiotic cultures were tested. A central composite, face-centered design was followed, so a total of 16 experiments were run using fractional addition of bovine milk to feedstock Whey, homogenization time, and storage time of Whey Cheese as processing parameters. Probiotic Whey Cheese matrices were inoculated with Lactobacillus casei LAFTI®L26 at 10% (v/v), whereas control Whey Cheese matrices were added with skim milk previously acidified with lactic acid to the same level. All Whey Cheeses were stored at 7 °C up to 14 d. Chemical and sensory analyses were carried out for all samples, as well as rheological characterization by oscillatory viscometry and textural profiling. As expected, differences were found between control and probiotic matrices: fractional addition of milk and storage time were the factors accounting for the most important effects. Estimation of the best operating parameters was via response surface analysis: milk addition at a rate of 10% to 15% (v/v), and homogenization for 5 min led to the best probiotic Whey Cheeses in terms of texture and organoleptic properties, whereas the best time for consumption was found to be by 9 d of storage following manufacture.
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protective effect of Whey Cheese matrix on probiotic strains exposed to simulated gastrointestinal conditions
Food Research International, 2011Co-Authors: Raquel A Madureira, Manuela Pintado, A. Gomes, Xavier F Malcata, Manuela AmorimAbstract:Abstract A probiotic Whey Cheese added with Lactobacillus casei LAFTI®L26, Lactobacillus acidophilus LAFTI®L10 or Bifidobacterium animalis Bo was subject in vitro to sequential conditions that parallel the four major steps of digestion: mouth (artificial saliva), oesophagus–stomach (artificial gastric juice), duodenum (artificial intestinal juice) and ileum; its manufacture followed the traditional Cheesemaking protocol of Portuguese Requeijao. MRS broth was inoculated in parallel as reference medium, to ascertain the protective effect of the Whey Cheese matrix itself upon those strains in every digestion step. Mouth conditions had an almost negligible effect upon all three strains, whereas oesophagus–stomach, duodenum and ileum conditions decreased the viable numbers of L. casei and L. acidophilus; in both systems, B. animalis suffered only slight decreases in viable numbers; and L. casei and L. acidophilus behaved likewise in MRS exposed to duodenum and ileum conditions. Whey Cheese matrices thus appeared to protect the aforementioned three strains during transit throughout the simulated gastrointestinal system, so they are promising carriers of those probiotic bacteria.
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sweet Whey Cheese matrices inoculated with the probiotic strain lactobacillus paracasei lafti l26
Dairy Science & Technology, 2008Co-Authors: Ana Raquel Madureira, Manuela Pintado, A. Gomes, Jose Soares, Ana C. Freitas, F. X. MalcataAbstract:Consumption of dairy products containing viable probiotic strains has increased dramatically in recent years, owing to general health claims associated therewith. This trend has boosted diversification of the portfolio of said products, including Whey Cheese matrices. However, taking into account the relatively poor organoleptic and textural features of these matrices, improvement is in order via incorporation of selected additives, provided that viability of the strains is duly assayed. Lactobacillus paracasei LAFTI® L26 was accordingly incorporated into Whey protein solid matrices, in the presence of several additives aimed at enhancing their organoleptic appeal and textural performance. These matrices were produced from a combination of either ovine or bovine Whey (or a mixture thereof) with ovine milk, and were inoculated at 10% (v/v) with the probiotic strain. Sugar, sugar and aloe vera, sugar and chocolate, and sugar and jam were further added, and the resulting products were then stored at 7 °C for 21 d. In general, viable cell numbers remained high in all experimental matrices throughout storage. Despite the observed low extents of breakdown, proteolytic activities by the end of storage were higher in matrices containing jam. Furthermore, L. paracasei partially converted lactose into lactic acid in these matrices. Additives enhanced the organoleptic features of Whey Cheeses, and produced different textural patterns. The higher sensory scores were attained by matrices containing sugar: sugar and aloe vera received the best scores by 3 d of storage, but these scores decreased as storage time elapsed.
