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Öğe Determination of biofilm formation capacity of Metschnikowia reukaufii strain(Refik Saydam National Public Health Agency (RSNPHA), 2024) Büyüksırt Bedir, TubaObjective: Biofilm is a community of microorganisms attached to biotic or abiotic surfaces. Microorganisms that form biofilms cause much more serious medical and industrial problems than their planktonic forms. In this sense, the ability of microorganisms to form biofilms must be known and precautions must be taken. The aim of this study is to create stress in the Metschnikowia reukaufii MN622824 strain, whose inhibitory substance production increases under stress conditions, by trying different environmental conditions and to determine its effect on biofilm formation. In addition, to observe its effect on biofilm formation on stainless steel (SS) surfaces, which are frequently used in food machines. Methods: Biofilm formation was compared with the tube method and the microtitration plate method. For this purpose, 5 different media compositions containing 5% glucose, 10% glucose, 5% NaCl, 10% NaCl, containing no glucose and NaCl (sodium chloride), and 3 different incubation periods consisting of 3, 5 and 7 days were tested. Additionally, scanning electron microscopy imaging was performed to examine the adhesion of biofilm to stainless steel coupons. Results: In the tube method, the highest biofilm formation was observed after three days of incubation in tubes with 5% glucose added. No biofilm was formed in the tubes that were kept for seven days or 10% NaCl was added. In the microtitration plate method the strong biofilm formation (1.3022) was obtained after three days of incubation in a medium containing 5% glucose. In the control group without glucose and NaCl, moderate biofilm formation were observed on the 3rd day (0.7385) and the 5th day (0.6882). Biofilm formation was evaluated as absent or weak in media containing 10% glucose or NaCl. As glucose and NaCl concentrations increased, biofilm formation decreased. Reticular bond structure showing biofilm formation were imaged with a scanning electron microscope in the control group on days 3–5–7, 5% NaCl and 5% glucose concentration on the 3rd day, and 5% glucose concentration on the 5th day. Conclusion: Biofilm formation in food factories poses a significant health problem. It was observed that increasing NaCl, glucose concentration and incubation time negatively affected the biofilm formation of the Metschnikowia reukaufii strain. Biofilm formation decreases or disappears in yeasts exposed to stress conditions. It is thought that the data obtained will help in biofilm control. © (2024), (Refik Saydam National Public Health Agency (RSNPHA)). All rights reserved.Öğe Health benefits and risks of fermented foods—the PIMENTO initiative(FRONTIERS MEDIA SA, 2024) Todorovic, Smilja; Akpınar, Aslı; Assunção, Ricardo; Güzel, MustafaWorldwide, fermented foods (FF) are recognized as healthy and safe. Despite the rapid increase of research papers, there is a lack of systematic evaluation of the health benefits and risks of FF. The COST Action CA20128 "Promoting innovation of fermented foods" (PIMENTO) aims to provide a comprehensive assessment on the available evidence by compiling a set of 16 reviews. Seven reviews will cover clinical and biological endpoints associated with major health indicators across several organ systems, including the cardiovascular, gastrointestinal, neurological, immune, and skeletal systems. Nine reviews will address broader biological questions associated with FF including bioactive compounds and vitamin production, nutrient bioavailability and bioaccessibility, the role of FF in healthy diets and personalized nutrition, food safety, regulatory practices, and finally, the health properties of novel and ethnic FF. For each outcome assessed in the reviews, an innovative approach will be adopted based on EFSA's published guidance for health claim submissions. In particular, each review will be composed of three parts: (1) a systematic review of available human studies; (2) a non-systematic review of the mechanism of action related to the clinical endpoints measured by the human studies identified in part 1; and (3) a non-systematic review of the characterization of the FF investigated in the human studies identified in part 1. The evidence and research gaps derived from the reviews will be summarized and published in the form of a strategic road map that will pave the way for future research on FF.Öğe Experimental modeling and optimization of pullulan production by Aureobasidium pullulans AZ?6(SPRINGER, 2024) Müjdeci, Gamze Nur; Bozdemir, Melek Tijen; Özbaş, Zekiye YeşimAbstract The objective of this study was to optimize the fermentation parameters by using response surface methodology for increasing pullulan production of Aureobasidium pullulans AZ-6 in synthetic fermentation medium. The optimum conditions were determined as follows: the initial sucrose concentration (X1): 100 g/L; the initial peptone concentration (X2): 11.31 g/L; the initial pH (X3): 6.48; and the temperature (X4): 24.2 °C. In the optimum conditions, the maximum exopolysaccharide (EPS) concentration (Y1), the maximum pullulan concentration (Y2), the specifc growth rate (Y3), the maximum specifc pullulan formation rate (Y4), and the pullulan yield (Y5) were expected to be obtained as 37.078 and 35.372 g/L, 0.062 h?1, 0.021 [g pullulan/(g mo.h)], and 53.681%, respectively. The observed values of Y1, Y2, Y3, Y4, and Y5 were 36.950 g/L, 35.470 g/L, 0.064 h?1, 0.036 [g pullulan/(g mo.sa)], and 54.480%, respectively, as a result of validation experiments. EPS samples were characterized by Fourier-transform infrared spectroscopy and scanning electron microscope analyses. The optimization process caused more than a 50% increase in EPS and pullulan concentrations. This study showed that the color-variant A. pullulans AZ-6 strain could become a signifcant industrial strain if it is explored further in the future to produce pullulan on a larger scale.Öğe Impact of germination pre-treatments on buckwheat and Quinoa: Mitigation of anti-nutrient content and enhancement of antioxidant properties(ELSEVIER, 2024) Altıkardeş, Ebrar; Güzel, NihalThis study evaluated the effects of pre-germination treatments on the nutritional and anti-nutritional values of buckwheat and quinoa during germination. Pre-germination method was effective on the chemical composition and phenolic profile of buckwheat and quinoa samples (p < 0.05). During the germination, color changes were notable, particularly in the alkali-treated samples. The decrease in tannin content reached the highest rate in germinated buckwheat (83 %) and quinoa (20 %) by alkali treatment. The highest antioxidant and total phenolic content were measured in germinated pseudocereals treated by ultrasound. However, the lowest phytic acid content was determined after germination in the quinoa sample treated by ultrasound. Rutin was the major flavonoid in buckwheat while quercetin, galangin, ellagic, syringic, and p-coumaric acids were only synthesized after 72 h of germination. Catechin and epicatechin were decreased only in the alkali-treated buckwheat sample. Controlled germination processes can enhance the antioxidant activity and development of functional foods from whole grains.Öğe Germination: A Powerful Way to Improve the Nutritional, Functional, and Molecular Properties of White- and Red-Colored Sorghum Grains(MDPI, 2024) Kayışoğlu, Çağla; Altıkardeş, Ebrar; Güzel, Nihal; Uzel, SeçilAbstract: This study explored the effects of the germination of red and white sorghum grains (Sorghum bicolor [Moench (L.)]) for up to seven days on various properties of the grain. Germination enriched sorghum’s nutritional and sensory qualities while mitigating existing anti-nutritional factors. The study employed Fourier-transformed infrared spectroscopy (FT-IR) and scanning electron microscopy techniques to support its findings. Germination increased protein and lipid content but decreased starch content. White sorghum grains showed elevated calcium and magnesium but decreased iron, potassium, and zinc. Red sorghum grains showed a consistent decrease in mineral content during germination. Germination also increased fiber and lignin values in both sorghum varieties. The results of the FT-IR analysis demonstrate that germination induced significant changes in the molecular structure of white sorghum samples after 24 h, whereas this transformation was observed in red sorghum samples at four days. Total phenolic content (TPC) in red sorghum ranged from 136.64 ± 3.76 mg GAE/100 g to 379.5 ± 6.92 mg GAE/100 g. After 72 h of germination, the germinated seeds showed a threefold increase in TPC when compared to ungerminated seeds. Similarly, the TPC of white sorghum significantly increased (p < 0.05) from 52.84 ± 3.31 mg GAE/100 g to 151.76 mg GAE/100 g. Overall, during the 7-day germination period, all parameters showed an increase, and the germination process positively impacted the functional properties that contributed to the health benefits of white and red sorghum samples.Öğe Effect of Foam-mat Drying on Bioactive, Powder and Thermal Properties of Carrot Juice Powders(ACAD BRASILEIRA DE CIENCIAS, 2023) Çakmak, Hülya; Özyurt, Vasfiye HazalAbstract: Foam-mat drying is a promising method due to involvement of proteins as foaming agent which acts like a wall material wrapping around bioactives and retards their degradation. In this study, powder properties of foam-mat dried carrot juice powders including 15% egg albumen (EA) and 15% egg albumen+ 10% whey protein isolate (WPI) during 90 days of storage at room conditions were evaluated by means of physical,chemical, thermal (DSC and TGA) and microstructural (SEM) analyses. The powder flow properties (wettability, hygroscopicity, degree of caking, Carr index and Hausner ratio) have been significantly affected from the moisture uptake during storage; however, powder flow properties of 15% EA+ 10% WPI powders were found to be better than 15% EA powders as it was also confirmed by particle diameter distributions that remained the same before and after the storage period. Besides, the total antioxidant, phenolic and carotenoid contents of 15% EA+ 10% WPI carrot powder was found comparably higher than 15% EA powders due to possible encapsulating mechanism of whey proteins. In addition to delaying of physical and chemical deteriorations in powders with WPI incorporation, thermal stability of the foam-mat dried carrot juice powders was also improved in 15% A+ 10% WPI powderÖğe Determination of 355 Pesticides in Lemon and Lemon Juice by LC-MS/MS and GC-MS/MS(MDPI, 2023) Aslantaş, Şule; Gölge, Özgür; González-Curbelo, Miguel Ángel; Kabak, BülentAbstract: While pesticides have become a primary tool in modern agriculture, these compounds remain a high priority on the list of consumer concerns regarding food safety. The use of pesticides in the production and post-harvesting of lemon fruits is widely used to ensure agricultural yield and fruit quality. Therefore, monitoring studies on citrus fruits to enforce regulatory compliance and ensure food safety is in great demand. The aim of this study was to monitor multi-class pesticide residues in lemon fruits commercialized in Turkey. The transmission of residues that existed on the outer surface of the fruit into its juice was also studied. Whole fruits and lemon juice samples were prepared using the quick, easy, cheap, effective, rugged and safe (QuEChERS) methodology prior to analysis. For the screening and quantification of 355 pesticide residues, liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS) were used. The analytical method has been shown to have a sufficiently low limit of quantification with respect to current maximum residue limits (MRLs) for all target analytes. The obtained recovery and precision parameters fulfilled the requirements in DG SANTE guidelines. The in-house validated analytical method was then applied for the determination of 355 pesticide substances in 100 whole fruit samples and their juices. Sixteen different residues were detected in 43% of lemon fruits, whereas 57 lemon samples were pesticide-free. The MRLs exceedances were recorded in 29 lemon samples. The most frequently detected (17%) pesticide in lemon fruits was chlorpyrifos-methyl, with a range of 0.013–0.098 mg kg?1 . A lower frequency was detected for metamitron (10%, 0.027–0.118 mg kg?1 ), buprofezin (9%, 0.023–0.076 mg kg?1 ), pyriproxyfen (9%, 0.021–0.102 mg kg?1 ) and malathion (7%, 0.100–0.482 mg kg?1 ) in whole fruits. However, none of the pesticide residues were detected in lemon juice samples. These results showed that target analytes are unable to penetrate the lemon exocarp and/or endocarp. Keywords: food safÖğe Quantification of 363 Pesticides in Leafy Vegetables (Dill, Rocket and Parsley) in the Turkey Market by Using QuEChERS with LC-MS/MS and GC-MS/MS(MDPI, 2023) Deveci, Bilge; Gölge, Özgür; Kabak, BülentAbstract: Contamination of agricultural products with pesticide residues is a growing concern due to their adverse health effects and increasing worldwide usage of pesticides. In 2021 a total of 200 samples of green leafy vegetables, including 80 dill, 80 rocket and 40 parsley, purchased from greengrocer shops, markets and bazaars in Corum Province, Turkey, were monitored for pesticide residues. In green leafy vegetables, 363 pesticides were analyzed using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation, followed by liquid chromatography coupled to mass spectrometry (LC-MS/MS) for 311 residues and gas chromatography coupled to mass spectrometry (GC-MS/MS) for 52 residues. The method was in-house validated at two fortification levels, and satisfactory recoveries and precisions were achieved for all residues. No quantifiable residues were found in 35% of the samples, whereas 43 residues belonging to 24 different chemical classes were detected in 130 green leafy vegetables. Among the green leafy vegetables, the highest occurrence frequency was recorded in the rocket, followed by dill and parsley. In 46% of the green leafy vegetables, the residue levels exceeded European Union Maximum Residue Levels (EU MRLs). The most frequently detected pesticides were pendimethalin (22.5%), diuron (38.7%) and pymetrozine (52.5%) in dill, rocket and parsley, respectivelyÖğe Optimization of Cellulosic Fiber Extraction from Parsley Stalks and Utilization as Filler in Composite Biobased Films(MDPI, 2022) Çakmak, Hülya; Dekker, MatthijsAbstract: Food waste is an abundant source of cellulose which can be extracted via mild alkali treatment. The extraction conditions of cellulose fibers can be optimized for reduced chemical and energy use and optimal functionality. This study focused on the optimization of alkali extraction of lignocellulosic fiber from parsley stalks by building an experimental design with the response surface method with alkali concentration (2, 6, and 10%, w/v), fiber:alkali ratio (0.02, 0.035, and 0.05; w/v) and extraction temperature (40, 70, and 100 ?C) as independent variables, in order to evaluate the effects of extraction conditions on fiber yield and composition of parsley stalks extract (PSE). Following the optimization, PSE and untreated fibers (PF) were incorporated as filler into gum Arabic–sodium alginate-based films, and film properties such as water vapor permeability, optical and thermal properties, Fourier transform infrared spectra and surface morphology of the films were analyzed for evaluating the compatibility of these fillers with the composite film matrix. The optimal extraction conditions were determined as 2% alkali, sample:alkali ratio of 0.0276 and extraction temperature of 40 ?C. PSE extracted at optimal conditions was added to the composite films, and water vapor permeability and optical properties were improved by up to 10% PSE compared to films with PF.Öğe Effects of Moisture Contents and Storage Temperatures on the Physical, Chemical and Microbiological Qualities of Non-Sulfitted Dried Apricots(ANKARA UNIV, FAC AGR, 2022) Güzel, Nihal; Tağı, Şeref; Özkan, MehmetThis study was conducted to determine the changes in the physicochemical and microbiological qualities of the non-sulfited sun dried apricots (NSDAs) at three different moisture contents (MCs, 13.7, 23.5 and 27.0%) and at four different storage temperatures (4, 10, 20, and 30 degrees C) for 12 months in bulk and packaged samples. NSDAs were subjected to physical (moisture, water activity, pH and reflectance colour values), chemical (browning formation, beta-carotene, and acidity), and microbial (counts for total aerobic mesophilic and psycrofilic bacteria, yeast and mould, xerofilic mould and yeast, osmophilic yeast, lactic acid bacteria, Enterobacteriaceae, Staphylococcus-Micrococcus spp.) analyses at one-month time intervals. Results indicated that while the fastest brown colour formation occurred in the samples containing 23.5% MC and stored at 30 degrees C, the browning decelerated below 10 degrees C. No significant change was observed in beta-carotene contents of NSDAs during storage (P>0.05). After rehydration, osmophilic yeast count of NSDAs increased by 2.5 log colony-forming units (cfu/g). Significant reductions were observed in the microbial loads of the samples at 23.5 and 27.0% MCs with the decreasing water activity (P<0.05) during storage and increasing storage temperatures. However, yeast and mould counts exceeded 5.0 log cfu/g of the samples containing 27.0% MC after 2-months storage at 20 degrees C. Overall, we suggest that MC and storage temperature for NSDAs should be below 23.5% and 20 degrees C to achieve high microbial and physicochemical qualities for a year, respectively.Öğe A Rapid Detection of Whole Wheat Gluten Quality by a Novel Chemometric Technique - GlutoPeak(MDPI, 2022) Türksoy, Seçil; Onar, DemetThe study aims to accurately detect gluten quality of whole wheat flour without a refining process by measuring gluten aggregation properties with a novel and non-destructive chemometric technique called GlutoPeak, coupled with principal component analyses (PCA) and hierarchical cluster analyses (HCA). For this purpose, whole wheat flour samples from 125 common bread wheat cultivars were analyzed for protein content (PC), wet gluten content (WGC), and Zeleny sedimentation value (SV). The correlations of GlutoPeak indices (peak maximum time, PMT; maximum torque, MT; torque 15 s before MT, AM; torque 15 s after MT) with other conventional wheat quality parameters were evaluated. Results indicated that MT had high correlations with WGC (r = 0.627, p < 0.05) and PC (r = 0.589, p < 0.05) while PC (r = 0.511, p < 0.05) and WGC (r = 0.566, p < 0.05) values had moderate correlations with the GlutoPeak PM index. Considering the effect of regions, the MT and PM GlutoPeak indices are powerful parameters to discriminate whole wheat flour samples by their gluten strengths. In conclusion, the GlutoPeak test can be a powerful and reliable tool for prediction of refined and unrefined wheat quality without being time-consumingÖğe Doğal Mayaların Yaygın Patojenler Üzerindeki İnhibitör Etkileri(2020) Büyüksırıt Bedir, Tuba; Kuleaşan, HakanMayalar, bazı bakteri ve maya türleri üzerinde inhibitör etki göstermektedir. Bu mayaların, gıdalarda bozulma etmeni ve patojen mikroorganizmaların biyokontrolünde kullanılma olanakları araştırılmaktadır. Bu amaçla, mayaların elde edilebilmesi için çok sayıda doğal materyal ve fermente gıdadan izolasyon yapılmıştır. Ön taramalar sonucunda farklı 110 maya suşu izole edilerek saflaştırılmıştır. Elde edilen izolatların Escherichia coli, Micrococcus luteus ve Candida albicans üzerindeki inhibitör etkileri test edilmiştir. İzolatlardan 8 tanesi M. luteus, 2 tanesi E. coli ve 4 tanesi C. albicans üzerinde inhibitör etki göstermiştir. Bunlar üzerinde inhibitör etki gösteren suşlara Staphylococcus aureus, Listeria monocytogenes, Saccharomyces cerevisiae, Pseudomonas aeruginosa, E. coli O157 ve O157:H7, Bacillus subtilis, Salmonella enterica subsp. Typhimurium üzerinde de inhibisyon testleri uygulanmıştır. İnhibitör etkinin farklı patojenler üzerinde farklı derecelerde olduğu gözlenmiştir. Patojenlere karşı en fazla katil özellik gösteren izolatlar tanımlanmış ve bu izolatların Metschnikowia pulcherrima, Metschnikowia reukaufii ve Saccharomyces cerevisiae oldukları belirlenmiştir.Öğe Çorum Yöresi Ballarının Bazı Kimyasal Kalite Parametrelerinin Değerlendirilmesi(2020) Güzel, Nihal; Bahçeci, Kazım SavaşBu araştırma, Çorum yöresi ballarının bazı kalite parametrelerinin belirlenmesi amacıyla gerçekleştirilmiş olup temin edilen 47 bal örneğinde pH, çözünür kuru madde, nem, serbest asitlik, HMF, kül, elektriksel iletkenlik, diastaz sayısı, şeker oranı gibi pek çok kalite parametresi değerlendirilmiştir. Ortalama değerler göz önüne alındığında pH 3.83 (3.55-4.20), çözünür kuru madde 81.5°Bx (76.8-83.8), nem %16.9 (14.5-21.7), serbest asitlik 32.2 meq/kg (21.1-47.8), HMF 3.5 mg/kg (0.3-36.5), kül %0.18 (0.02-1.58), elektriksel iletkenlik 350 µS/cm (205-674), diastaz sayısı 16.4 (0.1-32.2), glukoz %30.4 (26.0-34.3), fruktoz %35.3 (31.5-39.1), sukroz %0.34 (<0.05-4.64), glukoz ve fruktoz toplamı %65.8 (57.5-73.4) ve fruktozun glukoza oranı ise 1.16 (1.03- 1.24) şeklinde sonuçlar elde edilmiştir. Bu veriler, genel olarak bal örneklerinin Türk Gıda Kodeksi Bal Tebliği’nde belirtilen yasal limitlere uygunluğunu ortaya koymaktadır. Bununla birlikte bir örnek nem ile glukoz ve fruktoz toplamı, üç örnek ise diastaz sayısı bakımından söz konusu mevzuata uymamaktadır.Öğe 3D Food Printing With Improved Functional Properties: A Review(2020) Çakmak, Hülya; Gümüş, Cansu EkinIn food industry, 3D printing gives the opportunity to fabricate a 3D food structure using layer-by-layer deposition of the food material that may not be possible using conventional food production techniques. 3D food printing technology has been used to develop foods with different shapes or textures. Also, different food materials can be printed in different layers for creating functional food with a complete nutritional balance. The novel and appealing textures with 3D printing are launched for elderly people having swallowing difficulties (dysphagia) or children and athletes who have different energy and nutrition requirements. Moreover, 3D food printing technology has a great potential to reduce food waste by making use of discarded food parts such as meat scraps, and damaged fruits and vegetables. However, there are some obstacles regarding the building of a 3D structure, as well as retaining the designed geometry in the post-deposition period. The composition and properties of food materials and processing parameters are effective on the characteristics of the final 3D printed foods. This review focuses on the recent developments on 3D food printing process according to different food categories, and pre or post processing parameters.Öğe Evaluation Of Foam-Mat Drying Behaviour Of Crab Apple (Malus Floribunda) Fruit Juice And Powder Quality(2020) Çakmak, HülyaMalus floribunda (MF) is an ornamental plant and the fruits with its red flesh have potential to be used as natural food colorant. In this study, the effects of faba bean protein concentrate (FB) and maltodextrin (MD) levels on MF juice foam stability was evaluated. In addition, the effects of drying conditions (temperature/power) on drying kinetics and powder quality (powder flow properties, colour, and anthocyanin content) were determined. The foam stability was significantly dependent on the FB level (P <0.05), but MD addition didn’t have any significant effect (P >0.05). Drying period was reduced with foam?mat drying compared to control, and the average Carr index values were found between 17.3-26.0%, while the Hausner ratios were between 1.21-1.35. The redness and lightness values of foam-mat dried powders were comparably higher than the control and MD-added sample at every drying condition (P <0.05), although the anthocyanin content decreased with increasing drying temperatures.Öğe Çorum Yöresi Ballarının Fenolik Madde İçerikleri İle Renk Ve Antioksidan Kapasiteleri Arasındaki İlişki(2019) Güzel, Nihal; Bahçeci, Kazım SavaşBu çalışmanın amacı Çorum yöresi ballarının toplam fenolik madde ve flavonoid içerikleri ile renk ve antioksidan kapasiteleri arasındaki ilişkilerin değerlendirilmesidir. Bu amaçla 47 bal örneğinin toplam fenolik içerikleri Folin-Ciocalteu yöntemi, flavonoid içeriği ise alüminyum klorür yöntemiyle analiz edilmiştir. Antioksidan kapasitesinin belirlenmesi için iki farklı yöntem (ABTS, DPPH) kullanılmış ve antioksidan kapasitenin ABTS yöntemi için 0.466-1.353 mM TEAC, DPPH yöntemi için 0.170-0.605 mM TEAC aralığında değiştiği belirlenmiştir. Toplam fenolik ve toplam flavonoid içerikleri sırasıyla 243-546 mg GAE/kg ve 30.8-87.0 mg CE/kg aralığında değişmektedir. Bal örneklerinin CIE renk parametreleri olan L*, a* ve b* değerleri sırasıyla 32.02-41.48, 0.20-6.82 ve 10.76-20.58 aralığında belirlenmiştir. Pfund değerleri 1.0- 111.2 aralığında olup bal örneklerinin çoğu beyaz ile açık amber arasında renge sahiptir. Örneklerin fenolik madde içerikleri ile renk değerleri ve antioksidan kapasiteleri arasında güçlü korelasyonlar olduğu gözlenmiştir.Öğe Effects of Water Soluble Materials on Water-in-oil Primary Food Emulsion Stability(2019) Çakmak, Hülya; Kumcuoğlu, Seher; Tavman, ŞebnemWater-in-oil (w/o) primary food emulsions are often used for encapsulation of bioactive food ingredients or preparing multiple emulsions, however there is a lack of study about evaluation of stability of these emulsions by adding food materials in the dispersed phase. In this study, water-in-olive oil emulsions were prepared with using different dispersed phases; maltodextrin (MD), whey protein isolate (WPI) and maltodextrin+whey protein isolate (MD+WPI) mixture (1:1 w/w) solutions were used at different rates to determine the effects of dissolved material on physical, chemical, rheological and thermal properties of the emulsions. The kinetic stability of emulsions were significantly improved with increasing rates of soluble materials (p<0.05), however the improvement was much clearer in emulsions with MD and WPI. The electrical conductivity of emulsions gradually decreased with the increasing amounts of soluble materials and the lowest conductivity was observed for the emulsion with 16% MD+WPI. Newtonian flow behaviour was observed for all of the emulsions, and the viscosity decreased with increasing amounts of dissolved material. The freezing and melting profiles of emulsions were found different than pure olive oil. The average freezing peak temperatures as well as the freezing and melting enthalpies of emulsions were higher than olive oil, but there was no clear difference observed depending on the amount or type of dissolved material. Average d43 values were found changing between 0.855-2.793 ?m and the lowest polydispersity was obtained when MD+WPI mixtures were used as the dispersed phase at 16% level.Öğe A natural approach, the use of killer toxin produced by Metschnikowia pulcherrima in fresh ground beef patties for shelf life extention(Elsevier, 2021) Büyüksırıt Bedir, Tuba; Kuleasan, HakanA novel killer toxin produced by yeast Metschnikowia pulcherrima was purified and added into ready to cook meatballs to enhance their microbial safety and extension of their shelf life. The agent was added into ready to cook meatballs at two different concentrations (1%-K1 and 2%-K2). The results of those two groups were compared to the control group (K0) lacking the killer toxin. Physical, chemical and microbiological analyses were carried out in meat dough and all analyses were repeated at two day intervals during 10 day-storage at +4 ?C. Addition of inhibitor compound in meat dough decreased the numbers of total aerobic mesophillic bacteria, yeast and molds and lactic acid bacteria. Staphylococci/Micrococci, coliform bacteria and total psychrotrophic bacterial counts of the samples were determined as well. Results showed that all indicators of microbial deterioration were found to be higher in K1 group than K2 group, revealing that there was an inverse correlation between the concentration of killer toxin and the number of microorganisms causing spoilage. In addition to 1 log decrease in the number of microorganisms in toxin added groups, the high TBARS values of the control group also showed the effectiveness of the toxin. Toxic effect analysis results showed that the killer toxin had no toxic effect on L929 mouse fibroblast cells after 24h exposure.Öğe Determination of the effects of flaxseed (Linum usitatissimum L.) sprouts powder on the gluten-free cupcake quality(Wiley, 2021) Çakmak, Hülya; Mama, Merve; Yılmaz, Şeyma MeryemIn this study, germinated flaxseed sprouts powder (FSP) as plant-based gum alternative was produced and the effectiveness in gluten-free cupcake formulation at different levels was evaluated. The cupcake quality with FSP was compared with xanthan gum including cupcakes and the commercial gluten-free flour by analyzing the proximate composition, bake loss, specific volume, porosity, crumb, and crust color. Besides, results of texture profile analysis and SEM images were discussed based on the gum source used. Xanthan gum (XG) and FSP addition significantly increased the specific volume compared to the control (p < .05). Also, increasing the amount of XG or FSP resulted in higher specific volume and porosity, but the effect of FSP was more pronounced. The lowest hardness was observed for the 2% FSP, while the highest was obtained for 2% XG (p < .05). The number of air holes visible in SEM images was higher in cupcakes with FSP compared to 2% XG. Practical applications Gluten-free products are essential for individuals having celiac disease or gluten-related disorders since they need to follow a strict gluten-free diet. But because of gluten absence in the formulations especially for bakery products, gluten-free product formulations are developed by trial and error tests. Especially gums, emulsifiers, and other stabilizers are required for giving a better texture and improving other sensorial properties of final product. Commercial gums like xanthan gum, guar gum, or gum Arabic are used individually or as a mixture and they are readily available on the market. However, gluten-free product consumers always demand for new ingredients and product formulations, and plant-based ingredients particularly attracts more attention because of their compatibility with diets for special needs.Öğe Solid-Liquid Extraction by Manothermosonication: Recapturing the Value of Pomegranate Peels and Nanocomplexation of Extracts with Pea Protein(Amer Chemical Soc, 2020) Güzel, Nihal; Kahraman, Ozan; Feng, HaoManothermosonication (MTS) is a treatment that combines ultrasonication with mild temperature and pressure. MTS extraction was evaluated for recapturing bioactive compounds of pomegranate peel waste. The influence of extraction time (0.5-3 min), temperature (25-50 degrees C), and pressure (100-500 kPa) on the yield of total phenolic content (TPC) and antioxidant activity (AOA) was assessed. Pea protein isolates (PPIs) and PPI-modified starch (PPIS) were used to form nanocomplexes with the phenolic extract (PE). Lyophilized peels were extracted with an ethanol/water (30%, v/v) mixture, at a peel:solvent ratio of 1:50. MTS extraction reduced the extraction time by 40 times compared with conventional extraction (35 degrees C and 60 min) for achieving the same amount of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The samples treated under 500 kPa for 3 min had the highest TPC (1007 pmol GA/g DW) and AOA (1.57 mmol TE/g DW). Nanocomplexes produced from PPI-PE and PPI-S-PE had similar encapsulation efficiency (-73%). The mean diameters of freeze-dried PPI-PE complexes were 54.5 +/- 19.7 nm, as determined by ImageJ, while that of PPI-PE in emulsion was 111.3 +/- 6.4 nm measured by dynamic light scattering (DLS). MTS is shown to be a green and efficient alternative to improve the extraction of bioactive compounds from pomegranate peel waste.
