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Öğe Corn processing by pulsed electric fields with respect to microbial inactivation and improvement of seed vigour(Elsevier Sci Ltd, 2024) Evrendilek, Gulsun Akdemir; Atmaca, Bahar; Uzuner, SibelPulsed electric field (PEF) treatment of corn grains to improve seed vigour and inactivation of endogenous microflora by energies ranging from 1.20 to 28.8 J were applied to determine effectiveness of applied energies on germination rate (GR), normal seedling rate (NSR), electrical conductivity (EC), ability to germinate under salt (100- and 200 mM salt) and cold (at 10 degrees C for 7 days and at 25 degrees C for 5 days) stresses. Moreover, the effect of PEF treatments was further investigated for the inactivation of total aerobic mesophilic bacteria (TAMB), total mold and yeast (TMY), and inactivation rate (%) of Aspergillus parasiticus. Increased energy provided 11.10 % increase in GR, 21.22 % increase in NSR, 95.50 % increase in germination at 10 degrees C for 7 days. Germination under stress conditions revealed 32.53 %, 68.35 %, and 76 % increase in germination at 25 degrees C for 5 days, under 100 mM- and 200 mM NaCI salt stresses. Inactivation on the mean initial TAMB and TMY were approximately 9.25 and 7.93 log, respectively, with 63.33 +/- 0.22 % reduction in A. parasiticus culture. PEF treated corn seedlings had stronger and taller body formation with stronger roots. The most optimal processing parameters were detected as 300 Hz, 28.80 J, and 19.78 sec. PEF treatment carries a high potential to improve corn vigour with inactivation of surface microflora.Öğe Development of pulsed electric fields treatment unit to treat wheat grains: Improvement of seed vigour and stress tolerance(Elsevier B.V., 2021) Akdemir Evrendilek, Gulsun; Atmaca, Bahar; Bulut, Nurullah; Uzuner, SibelPulsed electric field (PEF) treatment may pose a potential to be an alternative to chemical use for seed surface disinfection and seed vigour improvement. In order to test effectiveness of PEF treatment, a new pilot-scale PEF treatment unit was designed and used to treat wheat grains with the energy range of 1.07–17.28 J. Compared to the control samples, all PEF treatments significantly increased germination and seedling rates by 10 and 28%, respectively. Electrical conductivity was significantly affected by the delayed measurement time rather than PEF treatment. PEF-treated seed samples had significantly higher tolerance to cold and salt stresses. Endogenous microflora of total aerobic mesophilic bacteria and total mold and yeast were significantly reduced by the applied energy. Salt stress on day 8 (100 mM NaCI) exhibited the highest predictive power of 98.43% in modellıng studies. The multi-objective optimization of the 19 responses pointed to 161.8 Hz, 6.1 J, and 19.5 s as the optimal settings (D = 0.52). It was concluded that PEF processing of the wheat seeds improved vigor, promote cold and salt stress tolerance, and inactivated surface microflora. © 2021Öğe High-pressure processing of traditional hardaliye drink: Effect on quality and shelf-life extension(MDPI, 2023) Atmaca, Bahar; Demiray, Merve; Evrendilek, Gülsün Akdemir; Bulut, Nurullah; Uzuner, SibelHardaliye, as one of the oldest and lesser known traditional beverages, is produced using red grape pomace from wine production. This drink production is achieved through lactic acid fermentation, with the addition of sour cherry leaves and mustard seeds-either heat-treated, grinded, or whole-in various concentrations. Hardaliye has a very short shelf life; thus, efforts have recently been made to process hardaliye with novel processing technologies in order to achieve shelf-life extension. Therefore, the high-hydrostatic-pressure (HHP) processing of hardaliye was performed to determine its impact on important properties, including in microbial inactivation and shelf-life extension, with respect to a Box-Behnken experimental design. Maximum log reductions of 5.38 & PLUSMN; 0.6, 5.10 & PLUSMN; 0.0, 5.05 & PLUSMN; 0.2, and 4.21 & PLUSMN; 0.0 with HHP were obtained for Brettanomyces bruxellensis, total mesophilic aerobic bacteria, Lactobacillus brevis, and total mold and yeast, respectively. The processing parameters of 490 MPa and 29 & DEG;C for 15 min were found as the optimal conditions, with the response variables of an optical density at 520 nm and the inactivation of L. brevis. The samples processed at the optimal conditions were stored at both 4 and 22 & DEG;C for 228 d. While the non-treated control samples at 4 and 22 & DEG;C were spoiled at 15 and 3 d, the HHP-treated samples were spoiled after 228 and 108 d at 4 and 22 & DEG;C, respectively.Öğe Pilot ölçekli atımlı elektrik alanı sistem prosesinin salatalık, buğday ve mısır tohumlarının kalite özellikleri ile tohum gücü üzerine etkisi(Bolu Abant İzzet Baysal Üniversitesi, 2020) Atmaca, Bahar; Evrendilek, Gülsün AkdemirTohum kalitesi mahsul üretimi için çok önemlidir. Tohum kalitesini artırmak için ise en yaygın kullanılan yöntemlerden biri kimyasal uygulamalarıdır. Kimyasal uygulamalar çoğu zaman tohumlara zarar vermekte ve tohumun çimlenme kabiliyetini azaltmaktadır. Bu nedenle, tohum dezenfeksiyonu ve kalite kaybının önlenmesi amacıyla ekonomik, çevreye zarar vermeyen ve insan sağlığı üzerinde olumsuz etkileri olmayan pratik ve çevre dostu teknolojilere ihtiyaç vardır. Bu amaçla bu tezde mısır ve buğday daneleri ile salatalık tohumlarına 100-300 Hz frekanslarda, 1-8 döngü sayısında atımlı elektrik alan uygulanarak tohumların mikrobiyolojik ve tohum kalite kriterleri üzerine etkisi incelenmiştir. Mısır tohumlarına uygulanan 6.00, 2.82, 22.56, 18.00 ve 28.80 J atımlı elektrik alanı (AEA) uygulamalardan sonra toplam aerobik mezofilik bakteri (TAMB) tamamen inaktive edilmiştir. Toplam maya ve küf (TMK) sayısında en iyi inaktivasyon ise 28.80 J enerji uygulamasıyla gerçekleşmiş ve yaklaşık 1 log kob/g azalma sağlanmıştır. Buğday danesi ve salatalık tohumlarında ise en iyi TAMB ve TMK inaktivasyonları 17.28 J AEA uygulaması ile gerçekleşmiş ve sırasıyla buğday danelerinde 0.97 ve 1.15 log kob/g, salatalık tohumlarında ise 3.22 ve 1.31 log kob/g azalma sağlanmıştır. Buğday daneleri ile salatalık tohumlarının yüzeyine 105-106 kob/g seviyesinde inoküle edilen Aspergillus parasiticus sayısında ise en iyi azalmalar sırasıyla 3.21 J ve 10.88 J AEA uygulamasından sonra 0.96 log kob/g ve 1.27 log kob/g olarak tespit edilmiştir. Mısır tohumlarında en iyi A. parasiticus inaktivasyonu 1.15 log kob/g olarak 25.44 J AEA uygulamasında görülmüştür. Tohumların elektriksel iletkenlikleri incelendiğinde tüm tohumlarda AEA uygulamasından ziyade ölçüm süresinin iletkenlik artışında önemli olduğu ve 24 saat sonunda ölçülen elektriksel iletkenlik değerlerinin 4 ve 8 saat sonunda ölçülen değerlerden önemli ölçüde yüksek olduğu görülmüştür. AEA uygulamalarının tohum kalite kriterlerine etkisi incelendiğinde ise tohumların ve danelerin çimlenme kabiliyetinin arttığı tohumların soğuk ve tuzluluk streslerine karşı daha dayanıklı hale geldiği görülmüştür. Dolayısıyla elde edilen veriler AEA teknolojisinin tohum yüzey dezenfeksiyonu ve tohum kalitesini artırmak amacıyla kullanılabileceğini göstermektedir.Öğe Potential of pulsed electric field to control Aspergillus parasiticus, aflatoxin and mutagenicity levels: Sesame seed quality(Wiley, 2020) Bulut, Nurullah; Atmaca, Bahar; Evrendilek, Gülsün Akdemir; Uzuner, SibelSeed processing technologies are essential for seed safety and functionality through protection of physicochemical quality, pathogen inactivation, aflatoxin detoxification and alleviation of mutagenicity. Design of a pilot-scale unit of pulsed electric fields (PEF) to treat sesame seeds with respect to quality parameters,Aspergillus parasiticusinactivation and aflatoxin reduction as well as alleviation of aflatoxin mutagenicity were prompted in this study. PEF energy ranged from 0.97 to 17.28 J achieved maximum reductions of peroxide value and acidity number of 67.4 and 85.7%, respectively, and did not change colorL*,a*,b* and hue values. A 60% reduction ofA. parasiticuscounts occurred at the maximum PEF energy. Aflatoxins G1, G2, B1, and B2 contents decreased by 94.7, 92.7, 86.9, and 98.7%, respectively. Except for the samples treated by 2.16 J with 100 mu g/plate and by 6.80 J with 10 mu g/plate, PEF treatment provided elimination of aflatoxin mutagenity. It is concluded that PEF treatment can be used to treat sesame seeds with preservation of physicochemical properties, inactivation ofA. parasiticusand decomposition of aflatoxins with reduced mutagenicity.Öğe Prediction of Aspergillus parasiticus inhibition and aflatoxin mitigation in red pepper flakes treated by pulsed electric field treatment using machine learning and neural networks(Elseiver, 2022) Evrendilek, Gülsün Akdemir; Bulut, Nurullah; Atmaca, Bahar; Uzuner, SibelPresence of aflatoxins in agricultural products is a worldwide problem. Because of their high heat stability and resistance to most of the food processing technologies, aflatoxin degradation is still a big challenge. Thus, effi-cacy of pulsed electric fields (PEF) by energies ranging from 0.97 to 17.28 J was tested to determine changes in quality properties in red pepper flakes, mitigation of aflatoxins, inactivation of aflatoxin producing Aspergillus parasiticus, reduction in aflatoxin mutagenity, and modelling of A. parasiticus inactivation in addition to aflatoxin mitigation. Maximum inactivation rate of 64.37 % with 17.28 J was encountered on the mean initial A. parasiticus count. A 99.88, 99.47, 97.75, and 99.58 % reductions were obtained on the mean initial AfG1, AfG2, AfB1, and AfB2 concentrations. PEF treated samples by 0.97, 1.36, 5.76, and 17.28 J at 1 mu g/plate, 0.97, 1.92, 7.78, 10.80 J at 10 mu g/plate, and 0.97, 1.92, 2.92, 4.08, 5.76, 4.86, 6.80, 9.60, 10.80, and 10.89 J at 100 mu g/plate were not mutagenic. Modelling with gradient boosting regression tree (GBRT), random forest regression (RFR), and artificial neural network (ANN) provided the lowest RMSE and highest R2 value for GBRT model for the predicted inactivation of A. parasiticus, whereas ANN model provided the lowest RMSE and highest R2 for predicted mitigation of AfG1, AfB1, and AfB2. PEF treatment possess a viable alternative for aflatoxin degradation with reduced mutagenity and without adverse effect on quality properties of red pepper flakes.Öğe Synergistic effect of coupling ozonation/adsorption system for toxic dye efficient removal: chemometric optimization by Box-Behnken response surface methodology(Desalination Publ, 2023) Benjelloun, Mohammed; Miyah, Youssef; Evrendilek, Gulsun Akdemir; Lalami, Abdelhakim El Ouali; Demir, Irem; Atmaca, Bahar; Ssouni, SalmaThis work aims to optimize the ozonation/adsorption coupling system as an advanced technique for the removal of the dye crystal violet (CV) in the presence of new innovative material based on the Capparis spinosa L waste (CSLW). Data from operational parameters such as adsorbent dose (X1), CV concentration (X2), and oxygen flow rate (X3) were used to optimize the dye removal rate (Y) by the Box-Behnken design (BBD) response surface methodology. Under the ideal conditions of X1 (2 g center dot L-1), X2 (100 mg center dot L-1), and X3 (4 L center dot min-1), the rate Y exceeded 99.75%. The complete removal of the CV dye by the ozonation/adsorption coupling results from the selective interactions between the surface groups of the CSLW material, the ozone, and the various charges present in the solution. The coupling mechanism indicates that ozonation partially degrades the CV dye and the adsorption process significantly increases the percentage of removal due to the different adsorbent-adsorbate interactions. Due to the low power consumption of the oxygenator and ozonator and the lack of CSLW cost, the treatment of CV by the ozonation/adsorption coupling could cost about $1.8518 L-1. Thus, this process could be generalized through an industrial pilot-scale application.
