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E. Anifantakis - One of the best experts on this subject based on the ideXlab platform.

  • Evolution of lipolysis during the ripening of traditional Feta Cheese
    Food Chemistry, 2005
    Co-Authors: Aikaterini Georgala, T. Massouras, I. Kandarakis, Ekaterini Moschopoulou, Anastasios Aktypis, Evaggelia Zoidou, E. Anifantakis
    Abstract:

    Abstract Lipolysis was studied during ripening of traditional Feta Cheese produced in two small dairies, A and B. The Cheeses were made from a thermized mixture of ewes’/goats’ milk by using yoghurt as starter and artisanal rennet from lambs’ and kids’ abomasa (Cheese A) or mixed artisanal rennet with calf rennet (Cheese B). The acid degree value and the free fatty acids (FFA) contents in both Cheeses increased sharply up to 18 d (pre-ripening period at 15 °C) and continued to increase throughout ripening. In both mature Cheeses, acetic acid was found at high levels (13–18% of the total FFAs). However, except for this, all FFA contents differed significantly ( P P In organoleptic evaluation, Cheese A had a piquant taste that was attributed to its high content of butyric acid and showed a significantly ( P

  • evolution of microbial populations during traditional Feta Cheese manufacture and ripening
    International Journal of Food Microbiology, 2003
    Co-Authors: Eugenia Manolopoulou, I. Kandarakis, Ekaterini Moschopoulou, Anastasios Aktypis, Evaggelia Zoidou, P. Sarantinopoulos, E. Anifantakis
    Abstract:

    Abstract In three different dairies (A, B and C) located in Peloponess region (Southern Greece), traditional Feta Cheese trials took place February to March using mixtures of sheep's and goat's milk. Only small variations in the evolution of microbial groups were observed during the whole ripening period. The main groups, such as thermophilic cocci, mesophilic lactococci, thermophilic lactobacilli, nonstarter lactic acid bacteria (NSLAB), presumptive Leuconostoc, enterococci and micrococci, reached their highest levels during the first 16 days, and then declined approximately 1–2 log units until the end of ripening. The remaining groups investigated, comprising yeasts, coliforms and Escherichia coli, were highest at day 4. The yeasts remained constant, while coliforms and E. coli decreased sharply and were not detectable after 120 days of ripening. A number of 146 isolates (dairy A) taken from all stages of the manufacturing and ripening process were purified and studied. Lactobacillus plantarum (58/146) and isolates of related species Lactobacillus pentosus and Lactobacillus paraplantarum (16/146) were the most common microorganisms found during Cheese ripening. Streptococcus thermophilus (23/146) and Lactobacillus delbrueckii subsp. bulgaricus (20/146) were detected in high levels up to 20 days, and then gradually reduced. Enterococcus faecium (29/146) was found in all manufacturing and ripening stages.

  • Nitrogenous fractions during the manufacture of whey protein concentrates from Feta Cheese whey
    Food Chemistry, 2003
    Co-Authors: Golfo Moatsou, I. Kandarakis, A. Hatzinaki, E. Anifantakis
    Abstract:

    Abstract Samples taken from different manufacturing stages of Feta Cheese whey protein concentrates (WPCs), with 65 and 35% total protein content, were analyzed by chemical methods and by reversed-phase HPLC and by size-exclusion chromatography. Mean total protein content of Feta Cheese whey was 1.37%. 22% of total nitrogen (TN) was non-protein N (NPN) and 12% was proteose–peptone N (PPN). The mean native N (NN), NPN and PPN percentages of WPC 65 and 35%, were 63 and 71%, 10 and 14%, 0.08 and 0.08%, respectively. According to reversed-phase HPLC data, the percentages of β -Lg and α -La and their ratio were high; 56.5 and 59% of native proteins of whey and of WPC powders, respectively, were β -Lg. The respective α -La percentages were 13.1 and 14.1% and the respective caseino-macropeptide (CMP) percentages were 12.9 and 15.3%. Apart from ultrafiltration, the most critical stage for nitrogenous fraction composition was the evaporation process before spray drying.

  • Evolution of proteolysis during the ripening of traditional Feta Cheese
    Le Lait, 2002
    Co-Authors: Golfo Moatsou, T. Massouras, I. Kandarakis, E. Anifantakis
    Abstract:

    Four Cheesemaking trials were conducted in three different traditional Feta Cheese plants. The characteristics of the Cheesemaking process had to do with: the heat treatment of the Cheese milk, the use of yoghourt as a starter, the use of traditional rennet from kids' and lambs' abomasa, and the packaging in wooden barrels without brine addition. At 60 d (minimum ripening period according to Greek Codex Alimentarius), the percentage of water soluble nitrogen (WSN) varied from 15.88% to 19.58% of total nitrogen (TN) and 73.4%-79.9% of the WSN was nitrogen soluble in 12% TCA. At the same age, 13.3-23.6% of WSN was nitrogen soluble in 5% PTA. The quantitative and qualitative changes of the middle area of the RP-HPLC profiles (A220) indicated the evolution of nitrogenous fractions during the ripening and the effect of each Cheese plant technology on them. Most of the qual- itative and quantitative changes occured during the pre-ripening period (18 d). In general, the rate of proteolysis was similar to that of the industrially made Feta. However, the percentages of low molecu- lar weight fractions were higher. Feta Cheese / proteolysis

  • effect of draining temperature on the biochemical characteristics of Feta Cheese
    Food Chemistry, 2001
    Co-Authors: I. Kandarakis, Golfo Moatsou, Aikaterini Georgala, Stelios Kaminarides, E. Anifantakis
    Abstract:

    Two different draining temperatures, 15 and 21°C were applied to five Feta Cheese curds made with different starters, containing mesophilic or thermophilic strains or mixtures of them. After 20 h of draining, the pH of curds made with thermophilic starters ranged from 5.28 to 5.49. The draining temperature significantly affected (P<0.05) the pH and the total solids of the Cheeses. The inclusion of whey proteins in the Cheese curd due to the insufficient draining of Cheeses at 15°C, resulted in higher water-soluble nitrogen (WSN), as % of total nitrogen content. Free amino acid contents were significantly affected (P<0.05) by the draining temperature and by the presence of thermophilic lactobacilli in the starter mixture. Draining temperature also significantly affected (P<0.05) residual αs- and β-casein and the RP-HPLC profiles of the WSN. The C2:0 to C8:0 free fatty acids, hardness (kg) and fracturability (kg), as well as the total organoleptic scores, were significantly (P<0.05) higher in Feta drained at 21°C.

Mohammad Safari - One of the best experts on this subject based on the ideXlab platform.

  • PROFILE OF FATTY ACIDS, MICROSTRUCTURE AND PHYSICO-CHEMICAL PROPERTIES OF ULTRAFILTERED Feta Cheese
    2009
    Co-Authors: Karami Mostafa, Karamatollah Rezaei, M.r. Ehsani, Ebrahimzadeh Mousavi, Mohammad Safari
    Abstract:

    Changes in the fatty acid (FA) composition of Iranian UF (Ultrafiltered)-Feta Cheese during ripening (3, 20, 40 and 60 days) were studied. With an increase in the ripening period, due to the conversion of FA to secondary metabolites, the percentages of C4:0-C12:0 decreased significantly (P

  • Microstructural properties of fat during the accelerated ripening of ultrafiltered-Feta Cheese
    Food Chemistry, 2009
    Co-Authors: Mostafa Karami, Mohammad Reza Ehsani, Karamatollah Rezaei, Seyed Mohammad Mousavi, Mohammad Safari
    Abstract:

    Abstract A commercial pregastric lipase was used to accelerate lipolysis of Iranian ultrafiltered-Feta (UF-Feta) Cheese. Scanning electron microscopy images showed that with an increase in lipase levels from 2.0 to 6.0 g 100 kg−1 of retentate, disruption of fat globules increased significantly. On day 3 of ripening and enzyme level of 2.0 g 100 kg−1 of retentate, individual fat globules and fat aggregates were clearly observed on the Cheese samples. An increase in the lipase level or ripening period resulted in an increase in the rate of disappearance of fat globules. After 20 days of ripening, no apparent fat globules were observed and fewer fingerprints and voids of free fat were detected, compared to when no enzyme was used.

  • Changes in the rheological properties of Iranian UF-Feta Cheese during ripening
    Food Chemistry, 2009
    Co-Authors: M. Karami, Mohammad Reza Ehsani, Karamatollah Rezaei, Seyed Mohammad Mousavi, Mohammad Safari
    Abstract:

    Abstract The frequency sweep test was used to evaluate storage modulus (G′), loss modulus (G′′) and loss tangent [tan (δ)] of Iranian UF-Feta Cheese during ripening period (3, 20, 40 and 60 days). With development of ripening, storage and loss moduli increased at varying rates. The rate of increase in G′ was greater than that in G′′ resulting in a reduction in tan (δ). That is, storage modulus was dominant to loss modulus and as a result the elasticity nature was greater than the viscous nature of Cheese samples. Due to the disruption of fat globules and proteolysis, protein matrix rearranged and formed a more compact texture containing aggregates of casein. Ripening did not influence the pH level and also the concentrations of dry matter, fat, salt, and total nitrogen in dry matter. However, water soluble nitrogen increased significantly (P

  • Microstructural changes in fat during the ripening of Iranian ultrafiltered Feta Cheese.
    Journal of dairy science, 2008
    Co-Authors: Mostafa Karami, M. Reza Ehsani, M. Ebrahimzadeh Mousavi, Karamatollah Rezaei, Mohammad Safari
    Abstract:

    In this study, fat globules in Iranian ultrafiltered Feta Cheese (3 to 60 d) were directly observed during the ripening period by scanning electron microscopy. According to images of ultrafiltered Feta Cheese samples obtained by scanning electron microscopy, individual fat globules and aggregates of fat were easily distinguishable on d 3 and had completely disappeared within 20 d of storage. On d 20, only the fingerprints of the fat globules and pools of free fat in the casein matrix remained. After 40 d of ripening, the texture was homogeneous and no fat globules or fat voids were detected. Chemical analysis of Cheese samples showed that with an increase in the ripening period, the contents of dry matter and fat decreased significantly, whereas the pH values and salt content did not indicate any significant changes.

Evanthia Litopoulou-tzanetaki - One of the best experts on this subject based on the ideXlab platform.

  • Assessment of microbial diversity of the dominant microbiota in fresh and mature PDO Feta Cheese made at three mountainous areas of Greece
    LWT - Food Science and Technology, 2016
    Co-Authors: Despina Bozoudi, Sandra Torriani, Antonios Zdragas, Evanthia Litopoulou-tzanetaki
    Abstract:

    The aim of the present study was to assess the dynamics and the diversity of dominant microbiota in fresh and mature traditional Feta Cheese produced in three mountainous areas and for that purpose a combined approach of culture-independent examination with conventional genotypic typing of the predominant NSLAB microbiota were applied. The microbial communities were monitored by PCR-DGGE on seven fresh and nine mature Feta Cheese samples made by three artisanal producers. DGGE profiles suggested variability in the microbial composition of Cheeses within the production area and distinctive differences in band profile of NSLAB in Cheeses between the areas. PCR-DGGE analysis showed that Lactococcus spp. were the most widespread bacteria, Streptococcus macedonicus was detected often and, among lactobacilli, Lactobacillus plantarum prevailed. The diversity of NSLAB isolates from fresh and mature Cheeses was assessed by RAPD-PCR and PFGE. Typing data indicated intraspecies genetic heterogeneity and specificity to the production area. Our results point to the conclusion that the manufacturing environment influence the dynamic and the diversity of microbial groups developed in the Cheese and possibly the Cheese flavour. In addition, the traditional Feta Cheese may be a source of different NSLAB genotypes to make Cheese with sensorial peculiarities appropriate for each area.

  • Protease, peptidase and esterase activities by lactobacilli and yeast isolates from Feta Cheese brine.
    Journal of applied microbiology, 2003
    Co-Authors: T. Bintsis, Evanthia Litopoulou-tzanetaki, A. Vafopoulou-mastrojiannaki, Richard K. Robinson
    Abstract:

    Aims: The study of peptidase, esterase and caseinolytic activity of Lactobacillus paracasei subsp. paracasei, Debaryomyces hansenii and Sacchromyces cerevisiae isolates from Feta Cheese brine. Methods and Results: Cell-free extracts from four strains of Lact. paracasei subsp. paracasei, four strains of D. hansenii and three strains of S. cerevisiae, isolated from Feta Cheese brine were tested for their proteolytic and esterase enzyme activities. Lactobacillus paracasei subsp. paracasei strains had intracellular aminopeptidase, dipeptidyl aminopeptidase, dipeptidase, endopeptidase and carboxypeptidase activities. Esterases were detected in three of four strains of lactobacilli and their activities were smaller with higher molecular weight fatty acids. The strains of yeasts did not exhibit endopeptidase as well as dipeptidase activities except on Pro-Leu. Their intracellular proteolytic activity was higher than that of lactobacilli. Esterases from yeasts preferentially degraded short chain fatty acids. Lactobacilli degraded preferentially β-casein. Caseinolytic activity of yeasts was higher than that of lactobacilli. Conclusions: The results suggest that Lact. paracasei subsp. paracasei and yeasts may contribute to the development of flavour in Feta Cheese. Significance and impact of the Study: Selected strains could be used as adjunct starters to make high quality Feta Cheese.

  • Assimilation of Cholesterol by Yeast Strains Isolated from Infant Feces and Feta Cheese
    Journal of dairy science, 2003
    Co-Authors: Evangelos Psomas, Evanthia Litopoulou-tzanetaki, Dimitrios J. Fletouris, Nikolaos Tzanetakis
    Abstract:

    Eight yeast strains isolated from infant feces and the traditional Greek Feta Cheese, selected for their probiotic properties, were tested along with a commercially available strain of Saccharomyces boulardii for their ability to remove cholesterol from a growth medium (yeast extract glucose peptone broth) supplemented with 0.3% Oxgall. The amount of cholesterol removed during 72 h of growth at 37°C revealed significant variations among the yeast strains examined. Two isolates from infant feces, namely Saccharomyces cerevisiae KK1 and Isaatchenkia orientalis KK5.Y.1 and one isolate from Feta Cheese, namely S. cerevisiae 832, along with the commercial strain S. boulardii, were able to remove cholesterol from the growth medium after 48 h of incubation at 37°C. However, Saccharomyces strains proved to be able to remove cholesterol even after 24 h of growth at 37°C. The cholesterol removed from the growth medium was not metabolically degraded but was rather assimilated into the yeast cells. The ability to assimilate cholesterol in vitro and to tolerate low pH levels, gastric juice, and bile indicate that S. cerevisiae 832, and especially S. cerevisiae KK1 and I. orientalis KK5.Y.1 (being more bile and gastric juice tolerant because of their human origin) may be promising candidate strains for use as probiotics.

  • Microbiology of brines used to mature Feta Cheese.
    International Journal of Dairy Technology, 2000
    Co-Authors: Thomas Bintsis, Evanthia Litopoulou-tzanetaki, R. Davies, Richard K. Robinson
    Abstract:

    The microfloras of brines from two commercial factories manufacturing traditional Feta Cheese were examined over a period of 60 days, which is the normal maturation time for Greek Feta. Non-starter lactic acid bacteria were the dominant group, and Lactobacillus paracasei ssp. paracasei and Lactobacillus plantarum were the principal species identified. A number of strains of Debaryomyces hansenii were isolated from the brines, and both the yeasts and the lactobacilli possessed enzymes capable of degrading fat or protein. It is suggested that these microfloras play an important role in the maturation of Feta Cheese. No recognized pathogens were isolated from the brines of' either factory.

  • Heterogeneity of Lactobacillus plantarum isolates from Feta Cheese throughout ripening
    Journal of applied microbiology, 2000
    Co-Authors: V. Xanthopoulos, Nikolaos Tzanetakis, Magdalini Hatzikamari, T. Adamidis, E. Tsakalidou, Evanthia Litopoulou-tzanetaki
    Abstract:

    Thirty-two Lactobacillus plantarum strains isolated from Feta Cheese throughout ripening were studied for their phenotypic characteristics, protein profile of cell-free extracts, enzyme profiles, plasmid profiles, proteolytic and acidifying abilities and ability to grow at low pH and in the presence of bile. Results showed that some biotechnologically important characteristics, such as acidifying and proteolytic activities, can differ between strains. In addition, different plasmid profiles suggest the presence of different Lact. plantarum strains in Feta Cheese throughout ripening. The results suggest the possibility of choosing strains with specific biotechnologically interesting properties.

Osman Erkmen - One of the best experts on this subject based on the ideXlab platform.

  • Predictive modeling of Yersinia enterocolitica inactivation in Turkish Feta Cheese during storage
    Journal of Food Engineering, 2001
    Co-Authors: Hüseyin Bozkurt, Osman Erkmen
    Abstract:

    Several nonlinear models (Gompertz, Logistic-1, Logistic-2, Richards, Stannard and Schnute models) were compared to describe Yersinia enterocolitica and aerobic bacteria inactivation in Turkish Feta Cheese during the storage period. They were compared statistically by using the F-test. The Gompertz model was decided as a sufficient model, which describes the inactivation of both Y. enterocolitica and aerobic bacteria. The biological parameters were calculated from the modified Gompertz model. The effect of starter culture (Streptococcus cremoris), salt (150 or 200 g/l) and initial inoculum level of Y. enterocolitica on the phase of disappearance (λ) and the rate of reduction (μ) of Y. enterocolitica and aerobic bacteria were determined. Addition of starter culture had a significant (P 0.10) effect on both λ and μ of microorganisms.

  • Survival of virulent Yersinia enterocolitica during the manufacture and storage of Turkish Feta Cheese.
    International journal of food microbiology, 1996
    Co-Authors: Osman Erkmen
    Abstract:

    Abstract The ability of virulent Y. enterocolitica (serotype 0:3) to grow and survive during the manufacture and storage of Turkish Feta Cheese was studied. Pasteurized whole cow's milk inoculated with different amounts of Y. enterocolitica was used to make Cheese. Y. enterocolitica was examined during the manufacture and ripening period of Feta Cheeses with particular reference to (a) different inoculation levels of Y. enterocolitica, (b) the addition of starter culture, (c) salt concentration and {d) storage time. Cheeses were also examined periodically for total solids, moisture and salt contents, pH values, and aerobic plate count. Selected Y. enterocolitica colonies were confirmed biochemically. An increase in the number of Y. enterocolitica was observed during manufacture. Following salting and throughout the storage period, the numbers of Y. enterocolitica decreased at a rate which depended on salt concentration, starter activity, and storage time.

Nikolaos Tzanetakis - One of the best experts on this subject based on the ideXlab platform.

  • Assimilation of Cholesterol by Yeast Strains Isolated from Infant Feces and Feta Cheese
    Journal of dairy science, 2003
    Co-Authors: Evangelos Psomas, Evanthia Litopoulou-tzanetaki, Dimitrios J. Fletouris, Nikolaos Tzanetakis
    Abstract:

    Eight yeast strains isolated from infant feces and the traditional Greek Feta Cheese, selected for their probiotic properties, were tested along with a commercially available strain of Saccharomyces boulardii for their ability to remove cholesterol from a growth medium (yeast extract glucose peptone broth) supplemented with 0.3% Oxgall. The amount of cholesterol removed during 72 h of growth at 37°C revealed significant variations among the yeast strains examined. Two isolates from infant feces, namely Saccharomyces cerevisiae KK1 and Isaatchenkia orientalis KK5.Y.1 and one isolate from Feta Cheese, namely S. cerevisiae 832, along with the commercial strain S. boulardii, were able to remove cholesterol from the growth medium after 48 h of incubation at 37°C. However, Saccharomyces strains proved to be able to remove cholesterol even after 24 h of growth at 37°C. The cholesterol removed from the growth medium was not metabolically degraded but was rather assimilated into the yeast cells. The ability to assimilate cholesterol in vitro and to tolerate low pH levels, gastric juice, and bile indicate that S. cerevisiae 832, and especially S. cerevisiae KK1 and I. orientalis KK5.Y.1 (being more bile and gastric juice tolerant because of their human origin) may be promising candidate strains for use as probiotics.

  • some probiotic properties of yeast isolates from infant faeces and Feta Cheese
    International Journal of Food Microbiology, 2001
    Co-Authors: Evangelos Psomas, E Litopouloutzanetaki, Christian Andrighetto, Angiolella Lombardi, Nikolaos Tzanetakis
    Abstract:

    Abstract Yeast isolates from infant faeces and Feta Cheese were characterized to species level by phenotypic criteria, Randomly Amplified Polymorphic DNA (RAPD)-PCR and mitochondrial DNA (mt-DNA) restriction analysis. Results suggested that there is a good agreement between phenotypic characterization of yeasts and RAPD-PCR at species level; in addition, RAPD-PCR as well as mt-DNA restriction analysis provided good discrimination at strain level. Some technological and probiotic properties of selected strains were also investigated. The test strains exhibited lipolytic and proteolytic activities. They also tolerated low pH and survived satisfactory in gastric juice in vitro as well as in the presence of bile. In general, the isolates from faeces were more resistant to low pH and bile than those from Feta Cheese. Selected strains could be used as starter supplements for industrial fermentations.

  • Heterogeneity of Lactobacillus plantarum isolates from Feta Cheese throughout ripening
    Journal of applied microbiology, 2000
    Co-Authors: V. Xanthopoulos, Nikolaos Tzanetakis, Magdalini Hatzikamari, T. Adamidis, E. Tsakalidou, Evanthia Litopoulou-tzanetaki
    Abstract:

    Thirty-two Lactobacillus plantarum strains isolated from Feta Cheese throughout ripening were studied for their phenotypic characteristics, protein profile of cell-free extracts, enzyme profiles, plasmid profiles, proteolytic and acidifying abilities and ability to grow at low pH and in the presence of bile. Results showed that some biotechnologically important characteristics, such as acidifying and proteolytic activities, can differ between strains. In addition, different plasmid profiles suggest the presence of different Lact. plantarum strains in Feta Cheese throughout ripening. The results suggest the possibility of choosing strains with specific biotechnologically interesting properties.

  • Effect of the type of lactic starter on microbiologicalchemical and sensory characteristics of Feta Cheese
    Food Microbiology, 1993
    Co-Authors: Evanthia Litopoulou-tzanetaki, Nikolaos Tzanetakis, A. Vafopoulou-mastrojiannaki
    Abstract:

    The influence of the type of lactic starter inoculation on chemical and microbiologicalcharacteristics of Feta Cheese was investigated. Yoghurt (Y) and starters, (A) Lactococcus lactis subsp. lactis + Lactobacillus casei + Leuconostoc cremoris (6:2:2). (B) L. lactis subsp. lactis + L. casei + Enterococcus durans (6:2:2). (C) L. lactic subsp. lactis + L. casei + E. durans + Leuc. ceremoris (6:2:1:1), were examined. Inoculation with starters B and/or C had a significant (P