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Öğe Ammonia-responsive thermoplastic starch films incorporated with gallic acid-cobalt metal-organic frameworks (GA/Co-MOF) for real-time tracking of shrimp freshness(Elsevier, 2026) Yilmaz, Mustafa Tahsin; Parlak, Mahmut Ekrem; Uzuner, Kubra; Yildiz, Zehra Irem; Dundar, Ayse Neslihan; Sahin, Oya Irmak; Saricaoglu, Furkan TurkerDeveloping ammonia-responsive biopolymer-based smart films with strong mechanical properties and reliable visual freshness indicators is a significant research focus. Integrating cobalt-based metal-organic frameworks (CoMOF) into a polymer matrix is a contemporary method for manufacturing intelligent packaging materials, primarily due to their rapid responsiveness to ammonia. This study successfully synthesized an ammonia-sensitive Co-MOF by using gallic acid as the ligand (GA/Co-MOF) and integrated them into a thermoplastic starch (TPS) matrix, creating high-performance, multifunctional TPS-based intelligent active composite films (TPS/Co-MOF). FTIR analysis indicates that cobalt exhibits a strong affinity for the carboxy and hydroxy groups of gallic acid, leading to the formation of spherical aggregates, which have diameters of between 600 and 1000 nm, as visualized using SEM. A thorough analysis assessed the impact of GA/Co-MOF on the films' physicochemical, water barrier, and morphological properties, as well as their color, optical, UV-blocking, and material characteristics (thermal, crystallographic, molecular, and mechanical) and ammonia-responsive performances. The GA/Co-MOF nanofillers were uniformly dispersed in the TPS matrix, significantly enhancing tensile strength (from 4.35 to 5.29 MPa), elongation at break (from 122.97 to 153.7 %), puncture force (from 612.78 to 1069.96 g), puncture deformation (from 3.78 to 4.87 mm), water resistance, and UV-blocking abilities. Additionally, the films exhibited improved thermal stability, toughness, elasticity, and ammonia-sensitive discoloration properties. Notably, the TPS/Co-MOF films enabled effective real-time visual monitoring of shrimp freshness, with a faster color response time than existing nanocomposite films, making them promising for active and intelligent food packaging. These findings highlight the significant potential of TPS/Co-MOF films to meet the demands of safe packaging solutions with superior mechanical performance and freshness monitoring.Öğe Application of high-pressure homogenization-assisted pH-shift to enhance techno-functional and interfacial properties of lentil protein isolate(Elsevier Sci Ltd, 2024) Parlak, Mahmut Ekrem; Saricaoglu, Furkan Tuerker; Yilmaz, Mustafa TahsinHigh-pressure homogenization (HPH) is a promising physical non-thermal approach to improve protein technofunctionality. This study aims to examine the effects of HPH on the lentil proteins through the perspective of the interfacial adsorption mechanism. The impact of HPH treatment on lentil protein isolate (LPI) at varying pressure levels (0-150 MPa) was determined using several analytical techniques, including SDS-PAGE, FTIR, solubility, and techno-functional properties (foaming and emulsifying properties), alongside analyses of interfacial tension and interfacial shear rheology at the o/w and a/w interfaces for two pH values (2.0 and 4.5). Results reveal that HPH treatment up to 100 MPa effectively unfolds lentil proteins by disrupting disulfide-bonded subunits into lower molecular weight fractions and unfolding highly-ordered secondary structures into random coils. LPI's capacity to produce emulsions and foams was found to be enhanced concurrently with these physicochemical changes, particularly at pressures up to 50 MPa. The findings aligned with the interfacial tension and shear rheology analyses, which show that proteins can form interfacial viscoelastic films on both o/w and a/w interfaces. Furthermore, the interfacial behavior of LPI and the effect of HPH on the interfacial behavior were found to be pH-dependent. The lower interfacial tension and the higher interfacial viscoelastic moduli (G ' and G '') were recorded at 50 MPa and 0 MPa at pH 2.0 and 4.5, respectively. These results stated that the effects of the HPH on the technofunctionality of LPI can be further enlightened by investigating the interfacial adsorption kinetics.Öğe Characterization of biodegradable bi-layer films from thermoplastic starch and poly-l-lactic acid(Wiley, 2024) Parlak, Mahmut Ekrem; Uzuner, Kubra; Ozdemir, Sebahat; Kirac Demirel, Fatma Tuba; Dundar, Ayse Neslihan; Sahin, Oya Irmak; Saricaoglu, Furkan TurkerThis study aimed to enhance the oxygen barrier properties of polylactic acid (PLA) film, a biodegradable packaging material with high oxygen permeability (OP). Bi-layer films were produced by coating thermoplastic starch (TPS) onto PLA films in various ratios while maintaining constant film thickness. The mechanical, optical, barrier, thermal, hydrophobicity, moisture sorption, and microstructural properties of the films were analyzed. Increasing the TPS ratio elevated moisture content (MC), water uptake, solubility, and opacity while enhancing UV barrier properties. TPS coating reduced tensile and burst strength but increased the burst deformation of the bi-layer films. Bi-layer film production resulted in a water vapor permeability increase of 59.26%-94.44% compared with neat PLA while decreasing OP by 2.52%-29.66%. The equilibrium moisture content (EMC) rose with higher TPS ratios, displaying type II isotherms. FTIR analysis indicated no chemical interactions between PLA and TPS. Increasing the TPS ratio decreased PLA crystallinity, supporting the mechanical and barrier properties of the bi-layer films. Neat and bi-layer films exhibited smooth, homogeneous surfaces, with a visible interface in the cross-section of the bi-layer films. In conclusion, TPS shows promise as an alternative to improve oxygen barrier properties in PLA films without adversely affecting other properties.Öğe Characterization of cakes produced with different legume aquafaba(Elsevier, 2025) Konal, Gozde; Dundar, Ayse Neslihan; Sahin, Oya Irmak; Parlak, Mahmut Ekrem; Saricaoglu, Furkan TurkerThis study investigates the potential of aquafaba, derived from various legumes including white chickpeas, black chickpeas, white beans, and red beans, as an egg substitute in cake production. Aquafaba samples were analyzed for physicochemical properties and functional characteristics at different pH levels. The results revealed that the foam and emulsion properties of all aquafaba samples at pH 3 were superior to those obtained at other pH values. Specifically, at pH 3, foam capacity values were approximately 238.74 f 28.54%, 231.25 f 26.52%, 237.50 f 17.68%, and 112.50 f 17.68% for aquafaba derived from white chickpeas, black chickpeas, white beans, and red beans, respectively. Aquafaba derived from white chickpeas demonstrated the highest foam stability at pH 3 (92.43 f 0.61%), followed by black chickpeas (86.96 f 3.30%). Similarly, emulsion capacity at pH 3 was highest for aquafaba derived from white chickpeas (41.14 f 11.73%), followed by black chickpeas (65.33 f 26.28%), white beans (28.94 f 37.69%), and red beans (49.65 f 9.57%). Emulsion stability was measured as 100% for aquafaba derived from white chickpeas, black chickpeas, and white beans at pH 3, with slightly lower values observed for aquafaba from red beans. Furthermore, aquafaba derived from different legumes exhibited varying protein contents at pH 3, ranging from 17.75 f 0.05% to 19.20 f 0.09%. Cake production with aquafaba as an egg substitute was conducted at pH 3, with analyses including moisture, ash, protein, fat, color, texture, specific volume, weight loss, and sensory evaluation. Results indicate the potential of aquafaba as a versatile egg substitute in cake formulations, with promising foam and emulsion properties, protein content, and sensory attributes.Öğe Drying kinetics and change in bioactive compounds of edible flowers: Prunus domestica(Wiley, 2023) Dundar, Ayse Neslihan; Sahin, Oya Irmak; Parlak, Mahmut Ekrem; Saricaoglu, Furkan TurkerThe aim of the study is to reveal the effect of different drying methods (hot-air drying [HAD] and freeze-drying [FD]) on flowers of Prunus domestica-white, pink, and red, methanolic extracts and their effects on polyphenolic compounds. Drying kinetics, phytochemical and antioxidant activity were investigated, and compared with each other and also with fresh samples. The modeling of the terms of Fick's diffusion equation were used to estimate the coefficients of diffusion. Drying kinetics from HAD and FD were analyzed mathematically, and obtained data was statistically analyzed to obtain best fit among all available models. The total phenolic content (TPC) of plum blossom extracts (PBEs) varied between 185.16 and 279.73 mg GAE per g dry weight sample. TPC levels increased in red and white PBE samples subjected to the FD process. However, in contrast, the TPC values of the pink PBE were in a decreasing trend with the drying process. CUPRAC levels were highest in the PBE of red flowers (1.04 mmol TE g(-1)). ABTS (65 mu mol TE g(-1)) and DPPH (47.50 mu mol TE g(-1)) levels were highest in PBE of pink flowers. ABTS values of only red-colored samples increased after HAD and FD, while antioxidant activity results decreased in all other samples. Compared to HAD, FD negatively affected quercetin and its derivative content, on the other hand positively affected the cyanidin contents. It can be concluded that different drying methods would be effective for different polyphenolic compounds depending on the pigment type of flowers. Practical applications Edible flowers have been used for their therapeutic purposes traditionally, and nowadays they gain a renewed interest as rich sources of bioactive compounds for both the food and culinary science. As a new tool for functional food development, the focus of edible flowers research is how to preserve the bioactive content. Drying is known to be the best way to avoid the perishability of edible flowers. The present work has been carried out for comparing two drying methods (HAD, FD) in terms of the bioactive changes and kinetic parameters. Our results showed that the quality attributes of Prunus flowers, rich in bioactive compounds and pigments, either preserve or enhance by FD. Mathematical modeling of drying affected by the pigment types, which is determined Jena&Das model for white flowers while Page model was the most appropriate to describe drying kinetics of red and pink flowers. It can be concluded that freeze drying can be effectively used in the dehydration of Prunus flowers and further studies can be promoted as a functional additive.Öğe Effect of pH and ionic strength on functional, structural, and interfacial rheological properties of aquafaba(Elsevier B.V., 2025) Parlak, Mahmut Ekrem; Ozmen, Duygu; Toker, Omer Said; Inan, Mehmet; Sarıcaoğlu, Furkan TurkerThis study explored the nuanced influence of pH and ionic strength on aquafaba and investigated its viability as a plant-based alternative in food formulation. Functional assessments, including foaming capacity (FC), foam stability (FS), emulsifying activity index (EAI), and emulsifying stability index (ESI), underscore the critical role of pH. FC and FS peaked at pH 4, whereas EAI was highest at pH 5, highlighting the significant impact of protein net charge on aquafaba functionality. However, although increasing the ionic strength decreased the absolute zeta potential, the foaming and emulsifying properties differed. Rheological analysis confirmed non-Newtonian shear-thinning behavior, which shifted toward Newtonian-like behavior near the isoelectric point. The increasing ionic strength significantly increased the ?-helix content by decreasing the ?-structure content, which increased the adsorption rate of aquafaba at the air/water (A/W) interface. The pH-dependent adsorption rates highlight the importance of the net surface charge of the adsorbed molecules. The interfacial shear rheology results showed that while the foaming properties of aquafaba are dominated by the adsorption rate, the emulsifying properties are mainly dominated by the interactions between adsorbed molecules rather than the adsorption rate at the oil/water (O/W) interface. In summary, this study provides comprehensive insights into the intricate interplay between pH and ionic strength in aquafaba, which is crucial for the formulation of sustainable plant-based alternatives in the food industry. © 2025 Elsevier B.V.Öğe Effects of high hydrostatic pressure treatment on structural, techno-functional and rheological properties of sesame protein isolate(Elsevier Sci Ltd, 2025) Gul, Osman; Gul, Latife Betul; Parlak, Mahmut Ekrem; Saricaoglu, Furkan Turker; Atalar, Ilyas; Tornuk, FatihIn this study, the modification of sesame protein isolate extracted from sesame cake with high hydrostatic pressure (HHP) was carried out. For this purpose, protein dispersions (4 %) were subjected to HHP treatment (up to 600 MPa) and the structural, techno-functional and rheological properties of the sesame protein were determined. Considering the control sample, it was determined that the HHP caused changes in the SDS-PAGE band intensities. The solubility of sesame proteins increased from 54.28 % to 80.12 % with HHP treatment up to 400 MPa and obtained a minimum (11.06 mu m) and maximum (36.96 mV) values in particle size and absolute zeta potential, respectively. The FTIR results indicated that HHP treatment increased beta-sheets, reduced alpha-helix and beta-turn structure. The free-SH group and surface hydrophobicity (H-0) for control were determined as 4.15 mu mol/g protein and 25.47, respectively, and the highest free-SH group (8.21 mu mol/g) and surface hydrophobicity (41.14) were recorded for the protein samples treated at 400 MPa (P < 0.05). Similarly, the maximum WHC and OHC, foam capacity and ESI index of sesame protein were obtained by applying 400 MPa pressure. The samples treated with 0.1 MPa and 600 MPa pressure exhibited shear-thinning behavior, while the others exhibited Newtonian-type behavior. The highest viscosity was determined in the samples subjected to 200 MPa pressure. HHP treated samples were more elastic than control sample and gel formation temperature decreased with increasing pressure. Overall, HHP could constitute an important technological approach for improving the techno-functional properties of sesame protein as a functional ingredient in food system.Öğe Ekşi Hamurlardan İzole Edilen FODMAPs Azaltıcı Laktobasil Suşları Kullanılarak Fonksiyonel Ekmek Üretimi(2023) Dundar, Ayse Neslihan; Bağcı, Ufuk; Togay, Sıne Ozmen; Parlak, Mahmut Ekrem; Sökmen, Özenİrritabl bağırsak sendromu (İBS), en yaygın görülen gastrointestinal hastalıklardan biridir. Bu hastalıkların en önemli nedeni diyetle alınan fermente edilebilir laktoz, glikoz, fruktooligosakkaritler, galaktooligosakkaritler, sorbitol, mannitol gibi bileşenlerden oluşan oligosakkaritler, disakkaritler, monosakkaritler ve polioller (FODMAPs)?dir. Buğday, çavdar, arpa ve bunların ilavesi ile üretilen ekmeklerde bulunan başlıca FODMAPs karbonhidratları fruktanlardır. Ekşi hamur fermentasyonu, fruktan miktarını azaltarak İBS hastaları için uygun ekmek üretimine olanak sağlar. Bu çalışmada Marmara bölgesinde yaz ve kış mevsimleri olmak üzere 11 şehirden toplanan ticari maya karıştırılmamış toplam 66 ekşi hamur örneklerinden elde edilen FODMAPs azaltıcı laktobasil izolatları ile düşük FODMAPs içerikli fonksiyonel ekmek üretimi ve ekmeklerin fizikokimyasal, mikrobiyolojik, reolojik ve duyusal değerlendirmesi yapılmıştır. Hamurlarda yapılan FODMAPs analizi sonucunda ticari ekmek mayası ile üretilen kontrol örneği en yüksek değere sahip olup, ekşi hamur örnekleri ile arasındaki fark istatistiksel olarak önemli bulunmuştur. Düşük FODMAPs içerikli ekşi hamur örneklerinden izole edilen Bursa-1Y, Balıkesir-1Y-1, Edirne-1K-2 veTekirdağ-3K-2 izolatlarında FODMAPs degradasyon özelliği tespit edilmiş ancak izolatların ekstraselüler fruktanaz enzimini kodlayan fruA ve fosE genlerini taşımadığı görülmüştür. Elde edilen izolatların Lactiplantibacillus plantarum ve Lentilactobacillus parabuchneri olduğu tespit edilmiştir. Çalışma kapsamında FODMAPs azaltıcı laktobasil izolatları ile üretilen ekmek örnekleri incelendiğinde ise ticari ekmek mayası ile üretilen kontrol ekmeğinin fruktan miktarı 2200 ppm?dir. Bursa-1Y, Balıkesir-1Y-1, Edirne-1K-2 ve Tekirdağ-3K-2 laktobasil izolatı ile üretilen ekmeklerin sırasıyla fruktan miktarları 1490 ppm, 1640 ppm, 1930 ppm ve 1470 ppm düzeylerinde bulunmuştur. FODMAPs miktarı ticari ekmek mayası ile üretilen kontrol ekmeğinin 6066 ppm, Bursa-1Y, Balıkesir-1Y-1, Edirne-1K-2 ve Tekirdağ-3K-2 laktobasil izolatı ile üretilen ekmeklerin sırasıyla FODMAPs miktarı 4298 ppm, 6430 ppm, 5250 ppm ve 5507 ppm düzeylerinde bulunmuştur. Duyusal olarak tüm ekmeklerin beğenildiği tespit edilmiştir. Sonuç olarak, çalışma kapsamında değerlendirilen ve ekmek üretiminde kullanım uygunluğu karakterize edilen ekşi hamur kaynaklı laktobasil izolatları ile üretilen ekmeklerde FODMAPs miktarlarının kontrol ekmeğine göre önemli ölçüde azaldığı belirlenmiş ve bu izolatların kullanılmasıyla İBS hastalarının tüketimine uygun fonksiyonel ekmek üretiminin mümkün olabildiği görülmüştür.Öğe Explainable AI unlocks temperature-driven oscillatory viscoelastic transitions in sesame protein isolate during integrated heating-cooling cycles(Elsevier Sci Ltd, 2025) Yilmaz, Mustafa Tahsin; Alkabaa, Abdulaziz S.; Saricaoglu, Furkan Turker; Milyani, Ahmad H.; Gul, Osman; Parlak, Mahmut Ekrem; Hassanein, Wael S.The temperature-dependent viscoelastic behavior of sesame protein isolate (SePI) gels was investigated across integrated heating-cooling cycles (25-95 degrees C) under oscillatory rheometry (10 % strain, 0.1 Hz). Experiments were performed across a range of treatment conditions, including pressure levels of 0, 50, and 100 MPa and ionic concentrations (IC) of 0-200 mM. Empirical results showed that storage modulus (G ') consistently exceeded loss modulus (G ''), particularly during cooling, indicating elastic-dominant gelation. Application of pressure and ionic concentration (IC) treatments enhanced viscoelastic recovery, yet condition-specific nonlinear trends in G ' and G '' responses-particularly across temperature cycles-and associated hysteresis effects remained difficult to isolate from aggregated empirical trends alone. To address these limitations, stacking ensemble mimicry models were developed and explainable AI (XAI) methods, including SHAP values, partial dependence plots (PDPs), and variance-based sensitivity indices (VBSIs), were employed. The XGBMeta-Stacker and LGBMMeta-Stacker models predicted G ' and G '' with high accuracy, achieving R2 values above 0.94 for both training and testing sets. Despite variability and outliers in the temperature sweep dataset, both ensemble models showed strong predictive alignment with actual values, highlighting the robustness of the stacking strategy in complex rheological modeling. XAI analyses uncovered temperature-driven oscillatory viscoelastic transitions-repeated patterns unlikely to be captured when heating and cooling cycles are examined separately, particularly between 25 and 75 degrees C-highlighting the necessity of integrated cycle analysis to reveal such behavior and enabling quantitative ranking of temperature, pressure, and IC influences across the domain. Temperature emerged as the dominant driver of G ' and G '' transitions, while pressure exerted stronger effects on viscous behavior under high-intensity conditions. Integrated interpretation of SHAP, PDP, and VBSI analyses revealed condition-dependent feature dynamics and interaction effects, offering mechanistic insights inaccessible through traditional methods alone.Öğe Gelatin extraction from chicken skin by conventional and Ohmic heating methods and comparison with commercial halal gelatins(Elsevier Sci Ltd, 2024) Isik, Cigdem; Parlak, Mahmut Ekrem; Demirel, Fatma Tuba Kirac; Odabas, Halil Ibrahim; Dagdelen, Adnan Fatih; Yilmaz, Mustafa Tahsin; Saricaoglu, Furkan TurkerGelatin extraction from chicken skins using ohmic heating (OH) is a promising application in the food industry. In this study, the effects of OH parameters (electric field (5, 10, 15, and 20 V/cm) and extraction time (1, 3, and 5 h)) on the extraction yield, physicochemical, functional, rheological, thermal, and microstructural properties of chicken skin gelatin were investigated, as well as comparison with conventional extraction and commercial halal gelatins. Chicken skin gelatins obtained with OH-assisted extraction showed higher ash content resulting in more turbidity than commercial gelatins. OH parameters significantly increased the gelatin yield, and 1 h of OH treatment revealed the highest gel strength amongst the electric field applications, conventional extracted, and bovine gelatin. The melting and gelation temperatures of chicken skin gelatins were higher than bovine gelatin and OH treatment increased the thermal stability. The amino acid composition significantly changed with OH treatment, and total imino acid content, relating to the gelation properties, increased. Functional properties, water and oil binding, emulsifying, and foaming, of chicken skin gelatin were significantly higher than commercial gelatins, and OH treatment significantly increased these properties. Overall, OH extraction of gelatin from chicken skins could be a better option for less extraction time, higher extraction yield, better functionality, and higher thermal stability compared to conventional extraction. It was concluded that chicken skin gelatins extracted using OH have properties that can be an alternative to commercial gelatins, but further purification processes are required.Öğe Impact of drying techniques on the physicochemical, structural, thermal, techno-functional, rheological properties, and in vitro digestibility of sesame protein isolate(Elsevier, 2025) Gul, Osman; Akgun, Abdullah; Karaman, Safa; Parlak, Mahmut Ekrem; Saricaoglu, Furkan Turker; Simsek, SenaySesame protein isolate (SPI) is emerging as a valuable plant-based protein with promising nutritional and functional properties. This study examined the influence of three drying techniques-hot air drying (OD), spray drying (SD), and freeze-drying (FD)-on the physicochemical, structural, thermal, techno-functional, rheological properties, and in vitro digestibility of SPI. While proximate composition remained unchanged, notable variations were observed in particle size, zeta potential, FTIR spectra, free sulfhydryl (-SH) groups, and surface hydrophobicity (H0), reflecting conformational modifications. OD-PI exhibited the highest denaturation temperature (81.83 degrees C) and lowest enthalpy (28.86 J/g). SD-PI demonstrated superior functional traits, including emulsion capacity (29.91 %), stability (64.83 min), foaming capacity (127.78 %), stability (47.78 %), waterholding capacity (1.81 %), and rheology, attributed to its small particle size (4.51 mu m) and high solubility (72.62 %). FD-PI showed the greatest -SH and H0 values. Importantly, SD-PI displayed enhanced digestibility, establishing spray drying as the most effective method for producing high-quality SPI for food applications.Öğe Influence of pH and ionic strength on the bulk and interfacial rheology and technofunctional properties of hazelnut meal protein isolate(Elsevier, 2023) Gul, Osman; Gul, Latife Betul; Baskinci, Tugba; Parlak, Mahmut Ekrem; Saricaoglu, Furkan TurkerThe functional, bulk, and interfacial shear rheological properties of hazelnut protein isolate were studied at different pH values between 3.0 and 8.0 and ionic strength levels between 0.0 and 1.0 M. The results showed that pH significantly affected protein solubility, emulsion properties, water and oil holding capacities, foam stability, surface hydrophobicity, and free-SH groups. The highest surface hydrophobicity, free-SH groups, and better functional properties were observed at pH 8.0. Protein solubility also increased with increasing ionic strength up to 0.6 M. The emulsion and foam stability of hazelnut protein isolate showed similar changes with protein solubility. The flow behavior of hazelnut protein suspensions was found to be shear thinning with the highest consistency index at pH 3.0 and the lowest at pH 6.0, however, the ionic strength did not significantly affect the consistency coefficient but did cause a significant change in the flow behavior index, with the lowest value observed at 0.6 M. The best gel structure in hazelnut proteins was observed at pH 3.0 and 4.0. The addition of ions at 0.4 and 0.6 M concentrations resulted in an improved viscoelastic character. The hazelnut protein isolate was also found to form solid-like viscoelastic layers at both air-water and oil-water interfaces, with the interfacial adsorption behavior affected by both pH and ionic strength. Overall, these results suggest that pH and ionic strength have significant effects on the functional and rheological properties of hazelnut protein isolate, which may have the potential as an auxiliary substance in food systems.Öğe Mechanism for Improving Acid-Induced Hazelnut Protein Gels Through High-Pressure Homogenization: Effect on Structural, Rheological and Gelling Properties(Mdpi, 2025) Gul, Osman; Akgun, Abdullah; Maribao, Iannie P.; Parlak, Mahmut Ekrem; Saricaoglu, Furkan Turker; Simsek, SenayThis study aimed to investigate the effects of high-pressure homogenization (HPH) (0, 25, 50, 100, and 150 MPa) pretreatment on the structural, rheological, and gelling properties of alkaline-extracted hazelnut protein isolate gels induced by glucono-delta-lactone (GDL). Homogenization pretreatment shortened the time required to obtain the maximum G ' value (12.65 Pa) from 32 to 28 min in the control sample. The particle size of protein isolates decreased with increasing pressure, resulting in lower particle size aggregates after gelation and in a denser gel structure with increasing gel hardness (from 1.52 g to 2.06 g) and WHC (from 31.95% to 48.36%). FT-IR spectroscopy revealed that HPH pretreatment and gelling time changed the secondary structure of the protein, promoting the formation of hazelnut protein gels. Hazelnut gel pretreated at 150 MPa exhibited the highest apparent viscosity and G ' value, indicating a more elastic and stronger gel network structure. The gel intermolecular force results showed that the contribution of hydrophobic interactions to gel formation was significant, and the chemical bond content of the gels increased with the increase in pressure up to 100 MPa. The physical stability of the gels was also improved by HPH pretreatment. Although the best WHC and physical stability were observed in the 100 MPa-pretreated gel sample, the hazelnut protein isolate pretreated at 150 MPa exhibited the best gel performance. Overall, HPH pretreatment has the potential to enhance hazelnut protein gel properties for industrial food applications.Öğe Natural colorant incorporated biopolymers-based pH-sensing films for indicating the food product quality and safety(Elsevier Ltd, 2024) Parlak, Mahmut Ekrem; Irmak Sahin, Oya; Dundar, Ayşe Neslihan; Sarıcaoğlu, Furkan Turker; Smaoui, Slim; Gökşen, Gülden; Koirala, PankajThe current synthetic plastic-based packaging creates environmental hazards that impact climate change. Hence, the topic of the current research in food packaging is biodegradable packaging and its development. In addition, new smart packaging solutions are being developed to monitor the quality of packaged foods, with dual functions as food preservation and quality indicators. In the creation of intelligent and active food packaging, many natural colorants have been employed effectively as pH indicators and active substances, respectively. This review provides an overview of biodegradable polymers and natural colorants that are being extensively studied for pH-indicating packaging. A comprehensive discussion has been provided on the current status of the development of intelligent packaging systems for food, different incorporation techniques, and technical challenges in the development of such green packaging. Finally, the food industry and environmental protection might be revolutionized by pH-sensing biodegradable packaging enabling real-time detection of food product quality and safety. © 2023 Elsevier LtdÖğe Ohmic Heating (OH)-Assisted Extraction of Bovine Hide Gelatin: Functional and Physicochemical Comparison With Halal Commercial Gelatins(Wiley, 2026) Demirel, Fatma Tuba Kirac; Isik, Cigdem Akdemir; Parlak, Mahmut Ekrem; Odabas, Halil Ibrahim; Dagdelen, Adnan Fatih; Saricaoglu, Furkan TurkerConventional gelatin extraction from high-collagen tissues requires prolonged thermal processing (8-10 h), resulting in high energy consumption and potential degradation of functional properties. To address this limitation, this study investigated ohmic heating (OH) as an alternative extraction method for bovine hide gelatin. Gelatin was extracted using voltage gradients of 5-20 V/cm for 1-5 h and compared with both conventional extraction parameters and commercial halal gelatins. OH markedly reduced the extraction time to 1-5 h while maintaining a maximum temperature of 70 degrees C, resulting in significantly improved extraction efficiency and higher dry matter and protein contents (p < 0.05). Although gel strength (122.12-176.81 g) was lower than that of commercial bovine gelatin (242.44 g), all OH-treated samples except those extracted at 20 V/cm formed stable gels. SDS-PAGE and compositional analyses indicated that OH induced partial degradation of high-molecular-weight fractions, consistent with the observed gel strength trends. The amino acid profiles, dominated by glycine, proline, and hydroxyproline, and the viscoelastic behavior (G ' > G '') were comparable to commercial references. Thermal analyses further revealed sharper melting transitions and higher Delta H values, suggesting improved thermal stability. Microstructural changes in pore size and distribution supported the observed functional differences. Overall, OH-assisted extraction provides an efficient, energy-saving, and thermally controlled approach to gelatin production. To our knowledge, this is the first study to demonstrate the applicability of ohmic heating for extracting gelatin from bovine hide, underscoring its potential as a sustainable alternative to conventional processing methods.Öğe Shear-thinning dynamics and viscoelasticity of a novel Eremurus spectabilis glucomannan: Structural insights and implications for food/ pharmaceutical applications(Elsevier, 2025) Hoseinpour, Zahra; Niazmand, Razieh; Parlak, Mahmut Ekrem; Heydari-Majd, Mojtaba; Saricaoglu, Furkan TurkerThis study aimed to isolate, purify, and characterize the principal water-soluble polysaccharide (ESRP) from E. spectabilis roots and evaluate its structural, thermal, emulsifying, and rheological properties. ESRP exhibited notable in vitro phenolic content and DPPH radical scavenging abilities. Thermal analysis via DSC revealed superior thermal stability, while FT-IR analysis indicated the presence of beta-pyranose configuration in its main polysaccharide backbone. GC-MS and analyse revealed a composition of D-glucose (42.77 %), D-mannose (52.82 %), and D-galactose (4.43 %) and presence of degree of O-acetyl groups with a molecular weight of 19.1 kDa. The Zeta potential was negative (-20.97 mV), indicating an anionic nature of ESRP. The aqueous ESRP solutions showed shear thinning behaviour, with viscosity dependent on concentration and temperature. ESRP solutions exhibited pseudo-plastic properties, with lower moduli values compared to inulin. Overall, these findings suggest that ESRP, as a shear-thinning substance, has potential as a novel stabilizer or thickener in various industrial applications.Öğe Viscoelastic characterization and extrusion performance of a novel ink for metal direct ink writing(Emerald Group Publishing Ltd, 2025) Ercan, Necati; Saray, Onur; Parlak, Mahmut EkremPurposeThis study aims to improve the extrudability and stability of polyvinyl alcohol-polyethylene glycol (PVA-PEG)-based water-soluble binders by modifying their composition with carboxymethyl cellulose (CMC). The primary objective is to determine the optimal CMC concentration that enhances critical solid loading capacity, suppresses binder segregation and phase separation and promotes stable and consistent extrusion. Furthermore, this work seeks to establish quantitative relationships between the rheological properties and extrudability of inks to be used in Direct Ink Writing.Design/methodology/approachA comprehensive analysis of the physical, rheological and mechanical behavior of CMC-modified binders was conducted. Rheological characterization involved the assessment of zero-shear viscosity, extrusion viscosity, yield stress, storage modulus, loss modulus and phase angle. An innovative extrusion testing setup was developed to simulate Solvent Cast Direct Ink Writing (SC-DIW) process conditions, enabling real-time detection of flow instabilities such as clogging and phase separation. The optimum solid loading range was determined based on extrusion force profiles. In addition, three-point bending tests were performed on green parts to evaluate mechanical strength and validate interlayer cohesion after extrusion.FindingsThe results show a CMC concentration of 1.5 Wt.% improves the stability of the PVA-PEG binder, preventing phase decomposition and separation and ensuring stable flow. The critical powder loading ratio for the binder with 1.5 Wt.% CMC was determined to be within the range of 85-87.5 wt. Moreover, an optimal balance of extrudability and post-extrusion green part strength can be achieved using a binder containing 1.5 Wt.% CMC. In addition, a successful extrusion process can be achieved using CMC-modified binders when G ', tau y, mu ex and mu 0 are lower than 3 x 105 Pa, 820 Pa, 100 Pa.s and 50,000 Pa.s., with alpha values ranging from 0.5 to 0.6.Originality/valueThis research introduces a novel strategy for stabilizing PVA-PEG-based binders by integrating CMC to suppress phase decomposition and separation and improve extrudability in SC-DIW processes. This study provides, for the first time, a predictive framework linking rheological thresholds to extrusion performance through a custom-designed extrusion simulation test. Findings of this study are expected to significantly advance the design of high-solid-loading inks for extrusion-based metal additive manufacturing.Öğe Zein-Curcumin Composite Edible Films for Intelligent Packaging: A Natural pH-Sensing Indicator to Monitor Sea Bream Freshness(Mdpi, 2025) Demirtas, Burcu; Keser, Beyza; Tural, Serpil; Gul, Latife Betul; Yilmaz, Ilay; Parlak, Mahmut Ekrem; Saricaoglu, Furkan TurkerThis study developed and characterized zein-based edible films enriched with curcumin as natural pH-sensitive indicators for monitoring fish freshness. Colorimetric films were prepared with different curcumin concentrations (1-7% wt) and evaluated for physicochemical, mechanical, optical, and antioxidant properties. Increasing curcumin content reduced water vapor permeability (0.085-0.110 gmm/m(2)hkPa), lowered water contact angles (<90 degrees), and enhanced hydrophilicity. Films exhibited high brightness, with decreased a* and increased b* values, while light transmission decreased, improving UV barrier properties. Colorimetric response (Delta E*) across pH 3-10 was more pronounced at higher curcumin levels, confirming pH-sensitivity. Antioxidant activity significantly increased with curcumin loading (up to 24.18 mol Trolox/g). Mechanical analysis revealed decreased tensile strength but improved elongation at break, bursting strength, and deformation, supported by SEM images showing more homogeneous, micro-porous structures at 7% curcumin. Zein films containing 7% (wt) curcumin (Z/CR7) were applied to gilthead sea bream (Sparus aurata) fillets stored at 4 degrees C for 13 days. Results showed lower TBARS and TVB-N values in Z/CR7 compared to the control, indicating delayed lipid oxidation and spoilage. Colorimetric changes in the films corresponded with fish freshness deterioration, providing a clear visual indicator. Microbiological results supported chemical findings, though antimicrobial effects were limited. Curcumin-enriched zein films demonstrated strong potential as intelligent, biodegradable packaging for real-time monitoring of seafood quality.
