Time filter

Source Type

Erkan N.,Istanbul University | Alpas H.,Middle East Technical University | Uretener G.,Istanbul University | Selcuk A.,TUBITAK - Marmara Research Center | Buzrul S.,Tutun Ve Alkol PiyasasI Duzenleme Kurumu TAPDK
Archiv fur Lebensmittelhygiene | Year: 2010

Changes in the physicochemical quality of rainbow trout's High pressure (HP)treated at 220, 250 and 330 MPa, 7, 15 and 25 °C for 5 and 10 min were investigated. HP-treated rainbow trout's showed significantly increased L* value relative to untreated rainbow trout's. Little changes in colour (a* value) were observed, compared to untreated rainbow trout's, which did not showed b* values. From tests of chemical properties, HP-treated rainbow trout's did not showed or showed significantly decreased thiobarbituric acid (TBA) and trimethylamine nitrogen (TMA-N) with increasing treatment pressure compared to controls. HP-treated rainbow trout samples showed significantly increased or decreased free amino acids (P < 0.05) relative to untreated trout samples. The results obtained from this study showed that the quality of HP-treated rainbow trout is best preserved at 220 MPa, 7-15-25 °C for 5-10 min and 250 MPa, 7-15 °C for 5 min. © M. & H. Schaper GmbH & Co. Source

Erkan N.,Istanbul University | Uretener G.,Istanbul University | Alpas H.,Middle East Technical University | Selcuk A.,TUBITAK - Marmara Research Center | And 2 more authors.
Innovative Food Science and Emerging Technologies | Year: 2011

Cold smoked salmon were HP treated at 220, 250 and 330 MPa, at 3, 7, 15 and 25 °C for 5 and 10 min. The influences of such treatments on some quality parameters (the changes of colour, TBA and TMA values) were studied. These parameters were determined for cold smoked salmon suitable combinations (at 220-250 MPa, 3 °C for 5 min, at 330 MPa, 15 °C for 5 min and at 250 MPa, 25 °C for 10 min). In the second stage the shelf life of cold smoked salmon HP treated at 250 MPa, 3 °C for 5 min and at 250 MPa, 25 °C for 10 min and stored at 2 °C was investigated by measurement of sensory, chemical and microbiological analyses. Based on the sensory and microbiological results, the control samples were acceptable only up to 6 weeks, compared to 8 weeks in HP treatment cold smoked salmon samples, extending the shelf-life by 2 weeks. Industrial relevance: Little information exists on the effects on physical and biochemical characteristics and shelf life of HP-treated cold smoked samples, compared to other preserved methods. This paper illustrates the changes induced in cold smoked salmon flesh by pressurization at different conditions. HP treatment significantly changed the sensory, chemical and microbiological properties of cold smoked salmons, and in combination with adequate chilled storage, can improve the shelf-life and safety of cold smoked salmons. © 2010 Elsevier Ltd. All rights reserved. Source

Karaca B.,Ankara University | Buzrul S.,Tutun Ve Alkol PiyasasI Duzenleme Kurumu TAPDK | Tato V.,Ankara University | Akcelik N.,Ankara University | Akcelik M.,Ankara University
Journal of Food Safety | Year: 2013

Biofilm formations of 25 Salmonella strains belonging to 19 serotypes were monitored with respect to time at a constant temperature. Two (DMC8 and DMC73) out of 25 strains had low biofilm formation ability and were not included in the modeling study. One (SL1344) strain had awkward biofilm formation which could not be described by a mathematical model, whereas biofilm formation of three strains (DMC33, DMC85 and DMC93) could be described by an exponential model. The modified Gompertz equation with high adjusted determination coefficient (R2 adj) and low mean square error values produced reasonable fits for the biofilm formation of 19 Salmonella strains. It was also possible to predict the biofilm formation of these strains at two different time values by use of the modified Gompertz equation. Although more studies should be carried out to evaluate different mathematical models under both iso- and nonisothermal conditions, this study reveals that describing and predicting the biofilm formation could be possible. Practical Application: Many Salmonella strains are capable of adhering and forming biofilm on certain surfaces. Biofilm formed in food processing environments may lead to food spoilage or transmission of diseases. Therefore, it is of vital importance to understand the formation of biofilm on different surfaces. It could be possible to describe and predict the biofilm formation with respect to time by using common modeling techniques. © 2013 Wiley Periodicals, Inc. Source

Pilavtepe-Celik M.,Kocaeli University | Buzrul S.,Tutun Ve Alkol PiyasasI Duzenleme Kurumu TAPDK | Alpas H.,Middle East Technical University | Largeteau A.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Demazeau G.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux
Journal fur Verbraucherschutz und Lebensmittelsicherheit | Year: 2011

Escherichia coli cells in peptone water were pressurized at 300 MPa at ambient temperature with no holding time (pulse series) and with a total holding duration of 300 s for single- (300 s × 1 pulse) and multi-pulsed (150 s × 2 pulses, 100 s × 3 pulses, 75 s × 4 pulses, 60 s × 5 pulses, 50 s × 6 pulses and 30 s × 10 pulses) high hydrostatic pressure (HHP) treatments. Multi-pulsed HHP treatment with no holding time indicated that as the pulse number increased the number of inactivated and injured cells also increased. Holding time had significant effect on the inactivation of E. coli. There was low inactivation difference between single- and multi-pulsed HHP treatments with holding time. Escherichia coli cells showed at least 1.6 log10 more reduction on selective medium than the non-selective medium indicating that more than 95 % of the survivors severely injured for both single- and multi-pulsed treatments with holding time. Although the inactivation difference was low between single- and multi-pulsed HHP treatments, storage at 4 °C revealed that there was less recovery from injury for multi-pulsed HHP treatment. © 2010 Springer Basel AG. Source

Buzrul S.,Tutun Ve Alkol PiyasasI Duzenleme Kurumu TAPDK
Innovative Food Science and Emerging Technologies | Year: 2012

High hydrostatic pressure (HHP) technology has become a reality in the food industry. Commercial use of HHP has been accepted in many countries and it is possible to find and buy products treated by HHP such as meat products, sea foods and fruit juices. Nevertheless, no HHP-treated beer and wine are introduced in the market throughout the world although rice wine is one of the earliest HHP-treated commercial products that appeared on the Japanese market. This contribution compiles the studies about HHP on beer and wine: in addition to microbial destruction, it has been reported that HHP improves some organoleptic properties of beer and wine without detrimental effects on important quality characteristics, such as color, pH and turbidity. Although more studies should be carried out on the sensory properties and consumer attitudes to HHP-treated beer and wine, HHP could be an alternative to the existing stabilization methods used in beer and wine industries. Industrial Relevance: Studies have shown that HHP treatment not only inactivates the undesirable microorganisms but also improves the organoleptic properties of beer and wine. The pressure levels used to treat beer and wine were similar to the commercial applications used in fruit juice industry i.e.; 400-600 MPa. Therefore, HHP has a huge potential to eliminate the negative effect of heat on the aroma and flavor beer and also to reduce the SO2 levels used in wine. © 2011 Elsevier Ltd. Source

Discover hidden collaborations