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https://hdl.handle.net/11147/6754
Title: | Effects of Ultraviolet Light Emitting Diodes (leds) on Microbial and Enzyme Inactivation of Apple Juice | Authors: | Pelvan Akgün, Merve Ünlütürk, Sevcan |
Keywords: | Bacterial inactivation Enzyme inactivation Polyphenoloxidase Escherichia coli Cloudy apple juice |
Publisher: | Elsevier Ltd. | Source: | Pelvan Akgün, M., and Ünlütürk, S. (2017). Effects of ultraviolet light emitting diodes (LEDs) on microbial and enzyme inactivation of apple juice. International Journal of Food Microbiology, 260, 65-74. doi:10.1016/j.ijfoodmicro.2017.08.007 | Abstract: | In 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. | URI: | http://doi.org/10.1016/j.ijfoodmicro.2017.08.007 http://hdl.handle.net/11147/6754 |
ISSN: | 0168-1605 |
Appears in Collections: | Food Engineering / Gıda Mühendisliği PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection |
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