Food Engineering / Gıda Mühendisliği
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Article Citation - Scopus: 11Chemical Composition and Biological Activities of Cypriot Propolis(Taylor and Francis Ltd., 2022) Nalbantsoy, A.; Sarıkahya, N.B.; Özverel, C.S.; Barlas, A.B.; Kırcı, D.; Akgün, İ.H.; Yalçın, Tansel; Düven, GamzePropolis compositions are highly variable, depending on the geographic region and the season of collection. In this study, propolis samples from seven different regions of Cyprus were studied for the first time by means of chemical content and biological activities. Secondary metabolite composition was determined by LC-HRMS. While the major flavonoids found were isosakuranetin, naringenin, rhamnocitrin, diosmetin, chrysin and acacetin, interestingly verbascoside, a phenylethanoid glycoside, and chlorogenic acid were identified as the major compounds in the ethanol-water extracts. α-Pinene was detected as the major compound of propolis extracts according to the volatile compositions via GC-MS. Karaoglanoglu and Tirmen extracts, presenting different chemical profiles, exerted enormous cytotoxic activity by MTT assay (IC50: 2.36–11.56 µg/mL; 1.44–9.33 µg/mL, respectively). The highest iNOS inhibition potential was detected in the Karpaz extract (IC50:2.6 µg/mL) in LPS induced RAW 264.7 cells whereas the Guzelyurt sample demonstrated remarkable antioxidant (88.82 ± 0.10%) and antimicrobial activities (with a MIC value of 31.2 μg/mL against S. aureus, S. epidermidis, E. faecium, and E. faecalis). © 2021 International Bee Research Association.Article Citation - WoS: 2Citation - Scopus: 2Enhanced Reducing Sugar Production and Extraction for Chlorella Vulgaris in Mixotrophic Cultivation Using High Hydrostatic Pressure Processing and Ultrasound(Taylor & Francis, 2023) Uzuner, Sibel; Kurhan, Şebnem; Akdemir Evrendilek, GülsünAlthough extraction of polysaccharides to convert reducing sugars (RS) from microalgae by acid or alkali pretreatments and enzymatic hydrolysis has been extensively studied, few reports exploring the use of high hydrostatic pressure processing (HHP) and ultrasonication (US) as emerging technologies for the extraction of sugars from microalgae biomass exist. Thus, the present study was conducted to determine the effects of mixotrophic growth and stress conditions (NaNO3 and CO2 concentration and light intensity) on RS and protein accumulation in the unicellular green alga Chlorella vulgaris in addition to optimization of the effectiveness of the sequential applications of HHP and US with dilute acid as well as simultaneous enzymatic saccharification on the production of RS from microalga cells. High light intensity, high CO2 concentration and limited nitrogen concentration promoted RS production. The maximum protein content (0.0683 mg g(-1)) was achieved at 0.3 g l(-1) NaNO3 concentration, 7000 mu mol photons m(-2) s(-1) and 6 l min(-1) CO2 concentration. The highest RS content of C. vulgaris after 48 h enzymatic saccharification (583.86 +/- 13.23 mg g(-1)) was obtained at 1% (w/w) acid concentration and 80% amplitude for 30 min with 79.4% RS yield. Combined US-assisted dilute acid pretreatment and enzymatic hydrolysis were also found to be more effective than HHP assisted dilute acid pretreatment and enzymatic saccharification. Therefore, microalgal biomass can be considered a suitable renewable feedstock used in fermentation. Highlights center dot The cultivation period of Chlorella vulgaris was reduced from 25 days to 14 days using mixotrophic growing conditions.center dot Mixotrophic conditions enhanced reducing sugar productivity.center dot Novel extraction techniques enhanced the extraction of reducing sugar from microalgae.Article Enhanced Production of 3-Phenyllactic Acid From Novel Non-Axenic Coculture: Adaptive Evolution and Statistical Fermentation Studies(Springer Heidelberg, 2024) Meruvu, HarithaThis research pivots around screening of idoneous lactic acid bacteria (LAB) from cow milk and subjecting them to adaptive evolution experiments to aid superior growth/robustness necessary for 3-phenyllactic acid (3-PLA) production. Conventional and statistical fermentation studies were conducted at batch scale using a non-axenic coculture of three novel LAB strains: Lactiplantibacillus plantarum str. nov. plantharim, Lactobacillus delbrueckki str. nov. delharim, and Pediococcus pentasaceous str. nov. pentharim. Statistically optimized fermentation using Box Behnken technique resulted in 1225 mg/L 3-PLA production using the growth medium: cheese whey-MRS medium mixture (5:2 ratio), phenylalanine (2.69% w/v), and glucose (9.6% w/v). Statistical optimization of fermentation parameters resulted in a substantial increase (17 times higher) compared to the non-optimized fermentation conditions (72 mg/L). Monad growth kinetics of the cow milk whey (CMW) coculture were calculated and estimated as: mu(max)=0.336 h(-1), K-s=11.64 mg/mL, Y-x/s=0.835 mg/g, Y-P/S=1.66 mg/g, Y-X/P=0.112 mg/mg. The purified 3-PLA (1.93 mg/mL) showed antimicrobial activity with pathogenic bacteria like Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, with a minimum inhibitory concentration of 12 mg/mL.Review Citation - WoS: 25Citation - Scopus: 27Bacillus Cereus: a Review of “fried Rice Syndrome” Causative Agents(Academic Press, 2023) Leong, Sui Sien; King, Jie Hung; Korel, Figen“Fried rice syndrome” originated from the first exposure to a fried rice dish contaminated with Bacillus cereus. This review compiles available data on the prevalence of B. cereus outbreak cases that occurred between 1984 and 2019. The outcome of B. cereus illness varies dramatically depending on the pathogenic strain encounter and the host's immune system. B. cereus causes a self-limiting, diarrheal illness caused by heat-resistant enterotoxin proteins, and an emetic illness caused by the deadly toxin named cereulide. The toxins together with their extrinsic factors are discussed. The possibility of more contamination of B. cereus in protein-rich food has also been shown. Therefore, the aim of this review is to summarize the available data, focusing mainly on B. cereus physiology as the causative agent for “fried rice syndrome.” This review emphasizes the prevalence of B. cereus in starchy food contamination and outbreak cases reported, the virulence of both enterotoxins and emetic toxins produced, and the possibility of contaminated in protein-rich food. The impact of emetic or enterotoxin-producing B. cereus on public health cannot be neglected. Thus, it is essential to constantly monitor for B. cereus contamination during food handling and hygiene practices for food product preparation. © 2023 Elsevier LtdArticle Citation - WoS: 6Citation - Scopus: 6Organosolv Pretreatment of Corncob for Enzymatic Hydrolysis of Xylan(Springer, 2023) Büyükkileci, Ali Oğuz; Temelli, NuranXylan is a renewable polysaccharide, readily available in agricultural and forestry residues. It can be hydrolyzed to produce xylooligosaccharides (XOS) with prebiotic activity and xylose, a precursor for several industrial chemicals. Enzymatic hydrolysis of xylan in the lignocellulosic biomass to obtain xylose and XOS requires a pretreatment to facilitate xylanase activity. In this study, organosolv was evaluated for the delignification of corncob while retaining xylan in the pretreated biomass. The treatment at 170 °C for 1 h with 70% ethanol provided 50% lignin removal and 81% xylan recovery. Increasing temperatures and decreasing ethanol fractions decreased the pH and the xylan recovery. Loss of xylan in the organosolv at 190 °C and in the liquid hot water treatment could be prevented by the addition of 100 mM MgO, without compromising lignin removal. Pretreated corncob was suspended in citrate buffer and hydrolyzed by commercial xylanases. Accellerase XY (250 U/ml) at pH 5.5 and 55 °C and Econase XT (0.6 U/ml) at pH 6.0 and 70 °C provided around 65% xylan digestibility and generated xylose (9.8 g/l) and XOS (10.9 g/l), respectively. This approach could decrease xylan loss and degradation in the pretreatment step and yield clear hydrolysates composed of essentially xylose or XOS. Lignocellulosic biorefineries can benefit from the efficient utilization of xylan, increasing sustainability. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Article Citation - WoS: 7Citation - Scopus: 11Chemical Composition and Biological Activities of Cypriot Propolis(Taylor and Francis Ltd., 2021) Nalbantsoy, Ayşe; Sarıkahya, Nazlı Böke; Özverel, Cenk Serhan; Barlas, Ayşe Berçin; Kırcı, Damla; Akgün, İsmail Hakkı; Yalçın, Tansel; Güven, Gamze; Kışla, Duygu; Demirci, Betül; Topçu, Gülaçtı; Gören, Ahmet CeyhanPropolis compositions are highly variable, depending on the geographic region and the season of collection. In this study, propolis samples from seven different regions of Cyprus were studied for the first time by means of chemical content and biological activities. Secondary metabolite composition was determined by LC-HRMS. While the major flavonoids found were isosakuranetin, naringenin, rhamnocitrin, diosmetin, chrysin and acacetin, interestingly verbascoside, a phenylethanoid glycoside, and chlorogenic acid were identified as the major compounds in the ethanol-water extracts. alpha-Pinene was detected as the major compound of propolis extracts according to the volatile compositions via GC-MS. Karaoglanoglu and Tirmen extracts, presenting different chemical profiles, exerted enormous cytotoxic activity by MTT assay (IC50: 2.36-11.56 mu g/mL; 1.44-9.33 mu g/mL, respectively). The highest iNOS inhibition potential was detected in the Karpaz extract (IC50:2.6 mu g/mL) in LPS induced RAW 264.7 cells whereas the Guzelyurt sample demonstrated remarkable antioxidant (88.82 +/- 0.10%) and antimicrobial activities (with a MIC value of 31.2 mu g/mL against S. aureus, S. epidermidis, E. faecium, and E. faecalis).Article Citation - WoS: 17Citation - Scopus: 18Incorporation of Organic Acids Turns Classically Brittle Zein Films Into Flexible Antimicrobial Packaging Materials(Wiley, 2021) Sözbilen, Gözde Seval; Çavdaroğlu, Elif; Yemenicioğlu, AhmetThis study aimed to turn classically brittle zein films into flexible antimicrobial ones by the use of lactic (LA), malic (MA) and tartaric acids (TA). The most effective plasticizer was LA (400% elongation at break [EB] at 4%), while MA (189% EB at 4.5%) and TA (68% EB at 5%) showed moderate and limited plasticizing effects, respectively. The LA- and MA-loaded films maintained their flexibility during 30-day storage at 4 degrees C or 25 degrees C. Fourier transform infrared (FTIR) analysis suggested that the plasticization of LA and MA could be related to secondary structural changes in zein such as increased alpha-helix and random coils (mainly by MA) and spaced/modified intermolecular (only by LA) and intramolecular (mainly by MA) beta-sheets. Atomic force and scanning electron microscopy showed that LA and MA gave more homogenous and smoother films than TA. Films with LA showed the highest water vapour permeability followed by those of control, MA- and TA-loaded films. Films with 3%-4% LA or MA formed clear zones on Listeria innocua and Klebsiella pneumonia, but only films with LA formed clear zones on Escherichia coli. All OA-loaded films gave unclear zones on Staphylococcus aureus in disc-diffusion tests, but this bacterium was inactivated rapidly in antimicrobial tests based on surface inoculation tests. LA is the best OA to develop flexible antimicrobial films from zein, an industrial by-product that films could not have been utilized as a widespread packaging material due to their brittleness.Article Citation - WoS: 13Citation - Scopus: 14Uv-Vis Spectroscopy for the Estimation of Variety and Chemical Parameters of Olive Oils(Springer, 2021) Jolayemi, Olusola Samuel; Tokatlı, Figen; Özen, BanuOlive oils produced in different years from different varieties were studied with UV-Vis spectroscopy for classification and prediction. Multivariate models were created with second derivative spectral data, and tested with external validation sets. For varietal classification, orthogonal partial least square discriminant analysis resolved oil samples into various classes with correct classification rate more than 89% for validation set (n = 20). A sample of fresh and stored oils were also classified with a correct classification rate more than 90% for validation set (n = 20). In the predictions of chemical parameters (70 for calibration, 30 for validation), the combination of UV-Vis spectroscopy with orthogonal partial least square regression models showed potential for simultaneous quantification of chlorophylls (0.6-5.6 mg/kg; R-val(2) , 0.79; RPD, 1.97); carotenoids (0.6-3.3 mg/kg; R-val(2), 0.80; RPD, 2.38); ratio of mono to polyunsaturated fatty acids (3.6-8.8; R-val(2) , 0.77; RPD, 1.90), oleuropein derivatives (1.2-62.3 mg/kg; R-val(2) , 0.66; RPD, 1.77), and total phenol content (62.2-505 mg/kg; R-val(2) , 0.67; RPD, 1.74), although showed poor to moderate results for the quantification of free fatty acid (0.3-5.4%; R-val(2), 0.67; RPD, 1.64); monounsaturated fatty acids (66-76.5%; R-val(2) , 0.71; RPD, 1.67); polyunsaturated fatty acids (8.6-18.2%; R-val(2) , 0.73; RPD, 1.65). The models were unable to estimate oxidative stability, saturated fatty acids, and individual phenolics such as hydroxytyrosol, pinoresinol, luteolin, total phenolic acids (R-val(2) , 0.26-0.64; RPD, 0.60-1.52). Results showed the capacities of UV-Vis spectroscopy for classification of olive oils, and prediction of total pigments and phenol content and ratio of mono to polyunsaturated fatty acids.Article Citation - WoS: 37Citation - Scopus: 37A Novel First-Line Treatment Alternative for Noncomplicated Idiopathic Granulomatous Mastitis: Combined Intralesional Steroid Injection With Topical Steroid Administration(S. Karger AG, 2021) Toktaş, Osman; Konca, Can; Trabulus, Didem Can; Soyder, Aykut; Köksal, Hande; Karanlık, Hasan; Kamalı Polat, Ayfer; Özbaş, Serdar Mustafa; Yormaz, Serdar; Sezgin, Efe; Soran, AtillaBackground: Idiopathic granulomatous mastitis (IGM) is a rare form of nonlactational mastitis. Due to the small number of case series and consequently inadequate prospective studies, there is still no consensus on the optimal treatment of IGM. In this study, we aimed to compare the efficacy of intralesional steroid injection with concomitant topical steroids to systemic steroid therapy only in the treatment of noncomplicated IGM. Methods: Between June 2015 and April 2018, the patients' data was prospectively collected and analyzed retrospectively. The study included a total of 78 female patients diagnosed with IGM. Patients were divided into 2 groups: the local steroid treatment group (intralesional steroid injection with topical steroid administration; group 1, n = 46) and the peroral systemic steroid treatment group (group 2, n = 32). Response to the therapy, side effects, recurrence, the need for surgical treatment, and complication rates were compared. Results: Forty-three patients (93.5%) in group 1 achieved a partial or complete response compared to 23 patients (71.9%) in group 2 after 3 months; this difference was significant (p = 0.012). The recurrence rates were significantly lower in group 1 (8.7%) compared to group 2 (46.9%; p = 0.001), and the need for surgical treatment was significantly less in group 1 (2.2%) than in group 2 (9.4%; p = 0.001). While the complication rates were similar between groups, a higher rate of systemic side effects was observed in group 2. Conclusion: Based on the results of our study, combined steroid injection and topical steroid treatment in IGM is as effective as systemic steroid treatment. We suggest that this combination therapy of topical steroids and local steroid injection should be used as first-line therapy in patients with noncomplicated IGM. © 2020 S. Karger AG, Basel. Copyright: All rights reserved.Article Citation - WoS: 19Citation - Scopus: 21Physicochemical and Antimicrobial Properties of Oleoresin Capsicum Nanoemulsions Formulated With Lecithin and Sucrose Monopalmitate(Humana Press, 2019) Akbaş, Elif; Söyler, U. Betül; Öztop, Mecit HalilOleoresin capsicum (OC) is an extract of chili pepper containing the active agent capsaicin. In this study, OC-loaded nanoemulsions were prepared by microfluidization and stabilized with sucrose monopalmitate (SMP) and lecithin. The difference in size and distribution of droplets determined the nanoemulsion behavior mainly due to the interaction of emulsifiers between oil and aqueous phase. The hydrophilic interaction between SMP and aqueous phase and the hydrophobic interaction between lecithin and oil phase were monitored with NMR relaxometry. OC nanoemulsion fabricated with SMP showed the best transparency with smallest droplet size (around 34nm) and stable with glycerol after 28days at ambient storage. Lecithin containing nanoemulsions showed improved bioactivity as showing antioxidant (0.82mg DPPH/L) and antimicrobial (3.40 log for Escherichia coli and 4.37 log for Staphylococcus aureus) activity. Finally, results have important implications to determine the appropriate formulation conditions for OC with food-grade surfactants to be used in pharmaceuticals and food industry.