PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Citation - WoS: 81Citation - Scopus: 115Effects of Ultraviolet Light Emitting Diodes (leds) on Microbial and Enzyme Inactivation of Apple Juice(Elsevier Ltd., 2017) Pelvan Akgün, Merve; Ünlütürk, Sevcan; Ünlütürk, Sevcan; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIn this study, the effects of Ultraviolet light-emitting diodes (UV-LEDs) on the inactivation of E. coli K12 (ATCC 25253), an indicator organism of E. coli O157:H7, and polyphneoloxidase (PPO) in cloudy apple juice (CAJ) were investigated. The clear (AJ) and cloudy apple juice were exposed to UV rays for 40 min by using a UV device composed of four UV-LEDs with peak emissions at 254 and 280 nm and coupled emissions as follows: 254/365, 254/405, 280/365, 280/405 and 254/280/365/405 nm. UV-LEDs at 254 nm achieved 1.6 ± 0.1 log10 CFU/mL inactivation of E. coli K12 at UV dose of 707.2 mJ/cm2. The highest inactivation of E. coli K12 (2.0 ± 0.1 log10 CFU/mL and 2.0 ± 0.4 log10 CFU/mL) was achieved when the cloudy apple juice was treated with both 280 nm and 280/365 nm UV-LEDs. For clear apple juice the highest inactivation 4.4 log10 CFU/mL obtained for E. coli K12 was achieved using 4 lamps emitting light at 280 nm for 40 min exposure time. For the same treatment time, the experiments using a combination of lamps emitting light at 280 and 365 nm (2lamp/2lamp) were resulted in 3.9 ± 0.2 log10 CFU/mL reductions. UV-A and UV-C rays in combination showed a better inactivation effect on PPO than UV-C rays used separately. Residual activity of PPO in CAJ was reduced to 32.58% when treated with UV-LED in combination of UV-C (280 nm) and UV-A (365 nm) rays. Additionally, the total color change (ΔE) of CAJ subjected to combined UV-LED irradiation at 280/365 nm was the lowest compared to other studied processing conditions. This study provides key implications for the future application of UV-LEDs to fruit juice pasteurization.Article Citation - WoS: 76Citation - Scopus: 89Uv-C Light Inactivation and Modeling Kinetics of Alicyclobacillus Acidoterrestris Spores in White Grape and Apple Juices(Elsevier Ltd., 2013) Baysal, Ayşe Handan; Molva, Çelenk; Molva, Çelenk; Ünlütürk, Sevcan; Ünlütürk, Sevcan; Baysal, Ayşe Handan; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIn the present study, the effect of short wave ultraviolet light (UV-C) on the inactivation of Alicyclobacillus acidoterrestris DSM 3922 spores in commercial pasteurized white grape and apple juices was investigated. The inactivation of A. acidoterrestris spores in juices was examined by evaluating the effects of UV light intensity (1.31, 0.71 and 0.38mW/cm2) and exposure time (0, 3, 5, 7, 10, 12 and 15min) at constant depth (0.15cm). The best reduction (5.5-log) was achieved in grape juice when the UV intensity was 1.31mW/cm2. The maximum inactivation was approximately 2-log CFU/mL in apple juice under the same conditions. The results showed that first-order kinetics were not suitable for the estimation of spore inactivation in grape juice treated with UV-light. Since tailing was observed in the survival curves, the log-linear plus tail and Weibull models were compared. The results showed that the log-linear plus tail model was satisfactorily fitted to estimate the reductions. As a non-thermal technology, UV-C treatment could be an alternative to thermal treatment for grape juices or combined with other preservation methods for the pasteurization of apple juice.Article Citation - WoS: 87Citation - Scopus: 99Modeling Inactivation Kinetics of Liquid Egg White Exposed To Uv-C Irradiation(Elsevier Ltd., 2010) Ünlütürk, Sevcan; Atılgan, Mehmet Reşat; Ünlütürk, Sevcan; Ünlütürk, Mehmet S.; Baysal, Ayşe Handan; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe efficiency of UV-C irradiation as a non-thermal pasteurization process for liquid egg white (LEW) was investigated. LEW inoculated with Escherichia coli K-12 (ATCC 25253), pathogenic strain of Escherichia coli O157:H7 (NCTC12900) and Listeria innocua (NRRL B33314) were treated with UV light using a bench top collimated beam apparatus. Inoculated LEW samples were exposed to UV-C irradiation of known UV intensity of 1.314mW/cm2 and sample depth of 0.153cm for 0, 3 5, 7, 10, 13, 17 and 20min. The populations of E. coli K-12, E. coli O157:H7 and L. innocua were reduced after 20min of exposure by 0.896, 1.403 and 0.960logCFU respectively. Additionally, the inactivation data obtained for each strain suspended in LEW was correlated by using Weibull (2 parameter), Log-Linear (1 parameter), Hom (2 parameter) and modified Chick Watson (2 parameter) models. The inactivation kinetics of E. coli K-12, E. coli O157:H7 and L. innocua were best described by modified Chick Watson model with the smallest root mean squared error (RMSE) (R2≥0.92). © 2010 Elsevier B.V.