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Apricot nectar processing by pulsed electric fields
(Taylor & Francis Inc, 2013) Evrendilek, Gülsün Akdemir; Altuntaş Julide; Sangun, Mustafa Kemal; Zhang, Howard Q.
Application of pulsed electric fields to process apricot nectar by determining the pH,. Brix, total acidity, conductivity, color, non-enzymatic browning index, concentration of mineral ions, and retention of ascorbic acid and beta carotene as well as inactivation of Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, Pseudomonas syringae subs. syringae, Erwinia carotowora, Penicillum expansum, and Botrytis cinerea was explored in this study. Processing of apricot nectar did not cause a significant difference in measured attributes (p > 0.05). However, inactivation of all microorganisms was significantly increased with increased electric field strength and treatment time (p <= 0.05). Microbial inactivation data fit both the Weibull distribution and log-logistic model.
Assessing edible composite film polymer from potato industry effluent under high hydrostatic pressure and its antimicrobial properties
(Wiley, 2022) Evrendilek, Gülsün Akdemir; Bulut, Nurullah; Uzuner, Sibel
Development of edible film from potato industry effluent having antimicrobial properties against Salmonella enteritidis and Escherichia coli O157:H7 by addition of Citrus sinensis volatile oil (VO), and changes of its textural properties under high hydrostatic pressure (HHP) are investigated. The optimum operational conditions are determined as 500 MPa pressure, 36.97 mu L VO, and 15 min processing time with the minimum force value of 372.33 x g. Textural properties are also modeled through empirical modeling, best fit Box-Behnken design, and artificial neuron network. Inhibition zones for Salmonella enteritidis and E. coli O157:H7 at the optimum HHP conditions are 1.50 +/- 0.11 and 2.18 +/- 0.07 cm, respectively. Textural properties of force and elongation at break of the HHP-processed films range from 2.27 +/- 0.52 to 5.23 +/- 0.38 N, and from 8.57 +/- 1.31 to 13.36 +/- 1.36 mm, respectively. Thermal transition of the edible film is observed at 87.42 degrees C for 7.36 min. Addition of C. sinensis VO improves the antimicrobial properties, whereas HHP improves the textural properties of the film. It is suggested that the developed film has potential to be used as an edible food packaging material.
Assessing impacts of pulsed electric fields on quality attributes and furfural and hydroxymethylfurfural formations in apple juice
(Wiley, 2017) Evrendilek, Gülsün Akdemir; Çelik, Perihan; Ağçam, Erdal; Akyıldız, Asiye
Effects of pulsed electric fields (PEF) processing on physical properties, bioactive compounds, and formations of furfural and hydroxylmethylfurfural (HMF) were determined for apple juice. A central composite design to determine the optimal number and order of experimental runs and the best-fit multiple nonlinear regression (BF-MNLR) models to quantify and predict rates of change in the response variables as a function of the PEF processing were used. No significant difference was detected between the control and PEF-treated apple juice in terms of physical properties, organic acids, and polyphenols of (-)-epicatechin, caffeic acid, p-coumaric acid, ferrulic acid, quercetin, and gallic acid. The highest predictive power ( Rpred2) belonged to a* (88%), (+)-catechin (90.7%), and HMF (93.8%). Except for chlorogenic acid, no significant decrease was detected in the initial concentrations of the bioactive compounds. PEF processing provided retention of quality attributes and bioactive compounds without significant formation of furfural and HMF. Practical applicationsHeat processing causes degradation of bioactive compounds, changes in physical properties, and formation of undesirable compounds in apple juice; however, PEF processing provided the preservation of most bioactive compounds without significant changes in physical properties. Thus, findings in this study revealed that PEF processing is a viable option for fruit juice industry, especially, for apple juice pasteurization.
Assessment of the freshness changes in lessepsian Lizardfish (Saurida lessepsianus, n. sp.) during storage in ice
(M H Schaper Gmbh Co Kg, 2018) Öksüz, Abdullah; Özyılmaz, Ayşe; Evrendilek, Gülsün Akdemir
Freshness changes in lessepsian lizardfish (Saurida lessepsianus, n. sp.) was investigated during ice storage of 18 days through chemical, microbiological, and sensory analyses. In contrast to K and related values, proposed Fr-i value decreased with the loss of freshness. Average K value was 6 % prime freshness soon after the catch, and reached to 30 % in limit of acceptability on 15th day. TVB-N value increased from 16.9 mg TVB-N 100 g(-1) to 32 mg TVB-N 100 g(-1) in spoiled fish on the 18th day. Initial pH value of the flesh was by beginning 6.46 and increased to 7.5 on the 18th day. Total microbial load was by beginning day 3.45 log cfu g(-1) and had a very slow increase until the 5th day (4.49 log cfu g(-1)), and it reached 7.02 log cfu g(-1) at the end of the storage period. The results of sensory scores agreed with those of chemical and microbiological analyses.
Change regime of aroma active compounds in response to pulsed electric field treatment time, sour cherry juice apricot and peach nectars, and physical and sensory properties
(Elsevier Sci Ltd, 2016) Evrendilek, Gülsün Akdemir
Regime (direction, amount, rate, and pattern) of change in aroma active compounds was quantified as a function of four pulsed electric field (PEF) treatment times, three fruits, and 10 physical and eight sensory properties using the best-fit multiple linear regression (MLR) models. The PEF treatment times did not deteriorate 94% of the sensory properties and 70% of the physical properties and significantly change 57% of a total of 73 aroma active compounds detected for sour cherry juice, and apricot and peach nectars. The best performing MLR models belonged to 1-methyl-4-prop-1-en-2-ylcyclohexene as a function of fruit type, treatment time, and titratable acidity (= 49 mg/L; R-adj(2) = 95.7%;R-cv(2) = 94.9%) and to 2-[(2S,5S)-5-ethenyl-5-methyloxolan-2-yl]propan-2-ol as a function of fruit type, and treatment time (SE = 157 mg/L; R-adj(2) = 98.2%; R-cv(2) = 98.0%), respectively (n = 48; p < 0.001). Industrial relevance: Pulsed electric field (PEF) is one of the leading nonthermal food technologies especiallyfor processing of high acid low viscosity foods with satisfactory quality and microbial inactivation. It was shown in this study that PEF with different treatment times can successfully be applied in the pasteurization of sour cherry juice, and apricot and peach nectars with minimum loss of aroma active compounds and sensory and physical properties. Both PEF processing conditions and results can be used as a guide to determine PEF processing parameters for industrial scale processing of juices/nectars. (C) 2015 Elsevier Ltd. All rights reserved.
Characterisation and fate of grayanatoxins in mad honey produced from Rhododendron ponticum nectar
(Elsevier Sci Ltd, 2014) Kurtoğlu, Arzum Bahar; Yavuz, Recep; Evrendilek, Gülsün Akdemir
Mad honey from Rhododendron ponticum nectar is produced in a large quantity in the western Black Sea region of Turkey and causes poisoning due to consumption of grayanatoxins (GTX I and III). There are a few studies about characterisation of GTXs in mad honey produced from R. ponticum. This study quantified basic properties including concentrations of GTX I and GTX III in mad honey samples collected in three consecutive years. Although the chemical composition of mad honey varied annually depending on the production year, mean GTX I and GTX III contents were estimated at 20.4 +/- 1.69 and 8.20 +/- 1.93 mg/kg, respectively. The concentrations of GTXs did not change significantly during storage of 6 months. (C) 2014 Elsevier Ltd. All rights reserved.
Chemical composition and antibacterial activity of essential oils of bitter fennel (Foeniculum vulgare Mill. var. vulgare) and dill (Anethum graveolens L.) against the growth of food-borne and seed-borne pathogenic bacteria
(Chiriotti Editori, 2009) Soylu, Soner; Soylu, Emine Mine; Evrendilek, Gülsün Akdemir
In the present study, the chemical composition and antibacterial activity of essential oils of bitter fennel (Foeniculum vulgare Mill. var. vulgare) and dill (Anethum graveolens L.) were investigated against food-borne and seed-borne pathogenic bacteria. The chemical composition of bitter fennel and dill essential oils was analyzed by gas chromatography-mass spectroscopy. The major compounds found in the essential oils of bitter fennel and dill were estragole (37.6%) and limonene (33.1%), respectively. These essential oils have antibacterial activity against food-borne as well as seed-borne pathogenic bacteria. Fennel essential oil had the highest antibacterial activity against the food-borne bacterial pathogen Staphylococus aureus, while dill essential oil had the highest antibacterial activity against seed-borne pathogenic Clavibacter michiganensis subsp. michiganensis. Amongst all the bacterial species tested, the plant pathogenic agent Pseudomonas syringae pv. tomato had the greatest resistance to both essential oils. Considering the significant level of bacterial growth inhibition of seed-borne and food-borne pathogens, essential oils or their components could be promising seed disinfectants or food additives in appropriate products.
Comparison of phenolic compounds of orange juice processed by pulsed electric fields (PEF) and conventional thermal pasteurisation
(Elsevier Sci Ltd, 2014) Ağçam, Erdal; Akyıldız, Asiye; Evrendilek, Gülsün Akdemir
Processing of orange juice by pulsed electric fields (PEF) and thermal pasteurisation was carried out to compare changes in total phenolic concentration, hydroxybenzoic acid, hydroxycinnamic acids, flavonols, flavones and flavonones before and after being stored at 4 degrees C for 180 days. Changes in the initial total phenolic concentration of the samples varied depending on the applied electric field intensity and thermal pasteurisation. Hesperidin and chlorogenic acids were detected as the most abounded flavonoid and phenolic acids in the orange juice, respectively. Except for syringic acid and neoeriocitrin, the concentration of the phenolic compounds indentified in the orange juice samples enhanced after the PEF or thermal pasteurisation. The samples treated with PEF had more stable flavonoids and phenolic acids than those treated with the thermal pasteurisation. The PEF-treated samples had higher sensory scores than the heat-treated samples. (C) 2013 Elsevier Ltd. All rights reserved.
Configuring pulsed electric fields to treat seeds: an innovative method of seed disinfection
(Ista-Int Seed Testing Assoc, 2017) Evrendilek, Gülsün Akdemir; Tanasov, Igor
This study presents the design and testing of a bench-scale pulsed electric field (PEF) system to process different seeds to reduce the total number of mesophilic aerobic bacteria (TMAB) and fungi (TF). The PEF system was configured to treat seeds at 50 and 200 Hz frequency with 12 kV cm(-1) electric fields strength. PEF treatment was effective in reducing TMAB and TF in the seeds with reduction ranging from 0.22 +/- 0.06 log cfu mL(-1) for cabbage to 2.81 +/- 0.69 log cfu mL(-1) for lettuce for TMAB and from 0.49 +/- 0.10 log cfu mL(-1) for garden rocket to 2.85 +/- 0.8 log cfu mL(-1) for wheat for TF. No significant difference was observed between the control and PEF groups of wheat seeds in terms of germination. It was concluded that the PEF treatment was a promising alternative to reduce initial TMAB and TF values of seeds without an adverse affect on seed germination.
Dairy microbiology and biochemistry recent developments preface
(Crc Press-Taylor & Francis Group, 2015) Özer, Barbaros Hamdi; Evrendilek, Gülsün Akdemir
Design and effectiveness of pulsed electric fields towards seed disinfection
(Wiley, 2019) Evrendilek, Gülsün Akdemir; Karataş, Berna; Uzuner, Sibel; Tanasov, Igor
BACKGROUNDSeeds harbor different microorganisms on their surfaces that degrade seed quality, thus causing an economic loss. Even though different approaches are available for the disinfection of seed surfaces, there is a need to develop environmentally friendly and sustainable technologies. A bench-scale pulsed electric field (PEF) unit was designed to inactivate microflora of eight seeds after which the resultant vigor of the treated seeds was determined. RESULTSSignificant reductions were obtained in endogenous natural and inoculated pathogenic (Alternaria brassica and Xanthomonas campestris pv. campestris, Drechslera graminea and Fusarium graminearum) microflora of seeds. The survival ratios of total aerobic mesophilic bacteria and of total mold and yeast decreased significantly for winter wheat and barley, parsley, onion, lettuce, tomato, and garden rocket with the PEF treatments of 240 and 960J. A significant increase in germination ratio was observed for winter wheat and barley, lettuce, and tomato with 960J. Germination energy increased for parsley with 240J and for winter wheat and barley, lettuce, tomato, and garden rocket with 960J. A better root development and seedling were found for winter barley. CONCLUSIONPEFs are a viable option to both disinfect seed surfaces and improve seed vigor. (c) 2019 Society of Chemical Industry
Edible Film Production from Effluents of Potato Industry Incorporated with Origanum onites Volatile Oils and Changes Its Textural Behaviors under High Hydrostatic Pressure
(2021) Evrendilek, Gülsün Akdemir; Bulut, Nurullah; Uzuner, Sibel
Development and characterization of edible film incorporated with Origanum onites volatile oil from the effluents of potato industry, determination of changes on its textural properties of force and elongation at break (EAB) under high hydrostatic pressure (HHP) in addition to its antimicrobial effect against Escherichia coli O157:H7 and Salmonella Enteritis were prompted. The optimum operational conditions under HHP for maximum force and EAB were achieved with 350 MPa pressure, 8 min operational time, and addition of 45 ?L O. onites volatile oil concentration (VOC). Inhibition zones for S. Enteritis and E. coli O157:H7 at the optimum conditions were 1.7 ± 0.109 and 2.386 ± 0.07 cm, respectively. Textural properties of force and EAB of the HHP-processed films ranged from 2.27 ± 0.52 to 5.23 ± 0.79 N, and from 7.47 ± 1.68 to 15.71 ± 0.65 mm, respectively. Thermal transition of the edible film was observed at 86.77°C for 7.19 min. The microscopic observation of the film surfaces shoowed homogenous and translucent structure. The improved textural properties with HHP and VOC revealed that it carries a potential to be used as a food packaging material.
Effect of pulsed electric fields on germination tube elongation and spore germination of botrytis cinerea inoculated into sour cherry juice, apricot and peach nectars
(Chiriotti Editori, 2009) Evrendilek, Gülsün Akdemir; Tok, F. M.; Soylu, Emine Mine; Soylu, Soner
Inactivation of Botrytis cinerea inoculated into sour cherry juice, apricot and peach nectars was determined by pulsed electric fields (PEF) based on the measurement of germination tube elongation, spore germination rate and light and scanning electron (SEM) mi-croscopic observations. With increasing electric field strength and processing time, germination tube elongation and spore germination were completely inhibited (P <= 0.05). Microscopic observations revealed considerable morphological alterations such as cytoplasmic coagulation, vacuolations, hyphal shriveling and protoplast leakage. PEF processing of juice/nectars was very effective to inactivate B. cinerea. This method could be used to prevent product loss in fruit juice/nectars due to B. cinerea contamination.
Effect of pulsed electric fields on physical, chemical, and microbiological properties of formulated carrot juice
(Sage Publications Ltd, 2009) Akın, E.; Evrendilek, Gülsün Akdemir
The objective of this study was to process a developed carrot juice-based beverage by pulsed electric fields (PEF) and determination of its physical, chemical, and microbiological properties before and after PEF processing. Results revealed that PEF processing did not cause any significant change in pH, titratable acidity (TA), degrees Brix, conductivity, color (L*, a*, and b*), nonenzymatic browning index (NBI), metal ion, and vitamin C concentration (p>0.05). There was a significant reduction on the total aerobic mesophilic bacteria, total mold and yeast, total enterobactericeae and Escherichia coli O157:H7 counts resulting with 4.30 +/- 0.26, 3.4 2 +/- 0.40, 4.46 +/- 0.36, and 3.57 +/- 0.32 log cfu/mL, respectively (p <= 0.01). PEF processing could be successfully used to process a carrot juice based beverage with significant amount of microbial reduction.
Effect of various forms of non-thermal treatment of the quality and safety in carrots
(Elsevier Science Bv, 2019) Evrendilek, Gülsün Akdemir; Özdemir, Pınar
Fresh carrots were processed using ozone, ultrasonication, alkaline ionized water, and high pressure processing (HPP) as well as quantifying their effects on 28 food quality and safety responses. Out of the four treatments, HPP at 350 and 450 MPa for 5 min achieved the highest reductions by 5.8, 5.7, 6.3, 4.7 and 5.7 log cfu mL(-1) in total mesophilic aerobic bacteria, total mold and yeast, total coliform, Escherichia coli O157:H7, and Salmonella Enteritidis, respectively. No downgrading changes as a function of the treatments were observed in pH, degrees Brix, titratable acidity, conductivity, color values, total antioxidant capacity, organic acids, phenolic compounds, and alpha and beta carotenes. The most pronounced textural changes occurred with HPP. Joint optimization of 25 food quality and safety responses pointed to ozone (8.2 g m(-3)) and HPP (450 MPa) for 5 min as the most effective treatments, respectively.
Effects of ozonation, alkaline ionized water, and their combination on surface disinfection and shelf life extension of tomatoes
(Wiley, 2020) Evrendilek, Gülsün Akdemir; Kanar Uzun, Kübra
The study aimed at the surface disinfection and shelf life extension of cherry tomatoes using ozone (1O(3); 17.2 g/m(3)ozone for 4 min and 2O(3); 17.2 g/m(3)ozone for 12 min), alkaline ionized water (1AEW; pH 10 for 20 min and 2AEW; pH 8.5 for 20 min), and their eight combinations. No significant difference was detected inL*,a*,b*, chroma, hue, and browning index; and titratable acidity, chroma, hue, total antioxidant capacity, and total phenolic and lycopene contents. All the treatments significantly reduced total aerobic mesophilic bacteria, mold and yeast counts and inoculatedSalmonella enteritidis,Listeria monocytogenes,andBotrytis cinerea. 1AEW + 2O(3)led to a shelf life of 7 weeks, whereas the other treatments and control groups had a shelf life of 5 and 3 weeks, respectively. The joint optimization pointed to 2O(3) + 1AEW, 2O(3) + 2AEW, and 2AEW + 1O(3)as the optimal treatments. Practical applications The fungal and bacterial growths on the tomato surfaces shorten their shelf life. The extension of their shelf life with no adverse effects on their physical, chemical, and bioactive properties with proper disinfection technologies is of great importance. Surface disinfection through the ozone, alkaline ionized water, and their dual combinations extended the shelf life up to 7 weeks without adversely affecting the important quality parameters. The shelf life extension greatly reduces both product and economic losses.
Effects of PEF and heat pasteurization on PME activity in orange juice with regard to a new inactivation kinetic model
(Elsevier Sci Ltd, 2014) Ağçam, Erdal; Akyıldız, Asiye; Evrendilek, Gülsün Akdemir
The inactivation kinetics of pectin methyl esterase (PME) during the shelf life (4 C-180 days) of freshly squeezed orange juice samples processed by both pulsed electric fields (PEF) and heat pasteurization (HP) was evaluated in the study. The PME inactivation level after the PEF (25.26 kV/cm-1206.2 mu s) and HP (90 degrees C-20 s) treatments were 93.8% and 95.2%, respectively. The PME activity of PEF-processed samples decreased or did not change, while that of HP samples increased during storage (p < 0.01). A kinetic model was developed expressing PME inactivation as a function of the PEF treatment conditions, and this enabled the estimation of the reaction rate constant (587.8-2375.4 s(-1)), and the time required for a 90% reduction (D-e, 3917.7-969.5 s). Quantification of the increase in PEF energy to ensure a ten-fold reduction in D-e (z(e), 63.7 J), activation electric fields (-921.2 kV cm(-1) mol(-1)), and electrical activation energy (12.9 kJ mol(-1)) was also carried out. Consequently, PEF processing was very effective for the inactivation of PME and for providing stability of orange juice during storage. (C) 2014 Published by Elsevier Ltd.
Effects of pulsed electric field processing on the quality and microbial inactivation of sour cherry juice
(Wiley, 2010) Altuntaş, Jülide; Evrendilek, Gülsün Akdemir; Sangün, Mustafa Kemal; Zhang, Howard Q.
Pulsed electric fields (PEF) processing of sour cherry juice with the measurement of pH, boolean OR Brix, titratable acidity, conductivity, colour (L*, a* and b*), nonenzymatic browning index, metal ion concentration, total ascorbic acid and total antocyanin content as well as microbial inactivation were searched in the study. Applied PEF treatment parameters did not cause any significant difference on measured properties of sour cherry juice (P > 0.05). On the other hand, inactivation of Escherichia coli O157:H7, Staphylococcus aureus, Listeria monocytogenes, Erwinia carotowora, Pseudomonas syringae subs. syringae, Botrytis cinerea and Penicillum expansum significantly increased with increased electric field strength and treatment time (P < 0.05). It was revealed that PEF is a viable option to process sour cherry juice with significant amount of microbial inactivation and without adversely affecting important physical and quality parameters.
Effects of pulsed electric fields on sour cherry juice properties and formations of furfural and hydroxymethylfurfural
(WALTER DE GRUYTER GMBH, 2021) Evrendilek, Gülsün Akdemir; Ağçam, Erdal; Akyıldız, Asiye
Impacts of pulsed electric fields (PEF) on physicochemical properties, bioactive compounds, and furfural and hydroxymethylfurfural (HMF) formations were quantified for sour cherry juice (SCJ). pH, titratable acidity (TA), total soluble solids (TSS), a*, b*, chroma, and total monomeric anthocyanin content (TMAC) were not significantly affected by 0-0.0341 J/L. The initial total antioxidant capacity (TAC) significantly rose with all the PEF treatments but initial citric, malic, fumaric, oxalic, succinic (-)-epicatechin, ferrulic, gallic, luteolin, p-coumaric, and o-coumaric acids, Cy-3-sop, and Cy-3-glu did not significantly degrade with no formations of furfural and HMF. The best-fit regression models explained 60.1, 39.7, and 36.3% of variation in TAC, TMAC, and TSS, respectively. Frequency exerted a greater impact than did electric field strength (EFS) on TA, pH, TSS, total color difference (TCD), hue, chroma, TMAC, TAC, sinapic, oxalic, quinic and tartaric acids, Cy-3-glu-rut, and furfural formation. 350.9 mu s, 6.78 kV/cm, and 98 Hz were pointed as optimal settings.
Empirical prediction and validation of antibacterial inhibitory effects of various plant essential oils on common pathogenic bacteria
(Elsevier, 2015) Evrendilek, Gülsün Akdemir
In this study, fractional compound composition, antioxidant capacity, and phenolic substance content of 14 plant essential oils-anise (Pimpinella anisum), bay leaves (Laurus nobilis), cinnamon bark (Cinnamomum verum), clove (Eugenia caryophyllata), fennel (Foeniculum vulgare), hop (Humulus lupulus), Istanbul-oregano (Origanum vulgare subsp. hirtum), Izmir oregano (Origanum onites), mint (Mentha piperita), myrtus (Myrtus communis), orange peel (Citrus sinensis), sage (Salvia officinalis), thyme (Thymbra spicata), and Turkish oregano (Origanum minutiflorum) were related to inhibition of 10 bacteria through multiple linear or non-linear (M(N)LR) models four Gram-positive bacteria of Listeria innocua, coagulase-negative staphylococci, Staphylococcus aureus, and Bacillus subtilis, and six Gram-negative bacteria of Yersinia enterocolitica, Salmonella Enteritidis, Salmonella Typhimurium, Proteus mirabilis, Escherichia coli O157:H7, and Klebsiella oxytoca. A total of 65 compounds with different antioxidant capacity, phenolic substance content and antibacterial properties were detected with 14 plant essential oils. The best-fit M(N)LR models indicated that relative to anise essential oil, the essential oils of oreganos, cinnamon, and thyme had consistently high inhibitory effects, while orange peel essential oil had consistently a low inhibitory effect. Regression analysis indicated that beta-bisabolene (Turkish and Istanbul oreganos), and terpinolene (thyme) were found to be the most inhibitory compounds regardless of the bacteria type tested. (C) 2015 Elsevier B.V. All rights reserved.

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