Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Impact of sprouting pretreatment on physicochemical properties and in vitro digestibility of buckwheat milk
Tunç, Merve Tuğçe; Yılmaz, Fırat; Akdoğan, Arda; Atalar, İlyas; Odabaş, Halil İbrahim
BACKGROUND: Buckwheat is a strategic raw material for plant-based milk production due to its gluten-free nature and rich bioactive profile. However, antinutritional factors and starch structure limit the nutritional quality and technological properties of such beverages. This study aims to investigate the effects of sprouting pretreatment (0, 24, 48, and 72 h) on the physicochemical properties, rheological behavior, phytic acid content, and in vitro protein/phenolics digestibility of buckwheat milk. RESULTS: As the sprouting duration increased, the viscosity of buckwheat milk decreased from 31.42 to 15.42 mPa s (at 72 h) due to the enzymatic hydrolysis of starch and proteins. Rheological analysis revealed that all samples exhibited weak gel behavior. Color analysis showed a decrease in lightness (L*) while redness (a*) and yellowness (b*) values significantly increased with sprouting. The results showed that sprouting significantly reduced phytic acid content, reaching its minimum at 72 h. The highest in vitro protein digestibility was observed at 24 h of sprouting, after which a relative decline occurred due to the formation of protein–polyphenol complexes and metabolic amino acid utilization. Furthermore, total phenolic content, flavonoid content, and antioxidant capacities measured after in vitro digestion were substantially higher in sprouted samples, especially at 48 and 72 h, than in the control. CONCLUSION: The results indicate that a sprouting duration of 48 h represents an optimal balance for the physical stability and nutritional enhancement of buckwheat milk. At this stage, significant increases in bioaccessible phenolics were achieved while maintaining a stable colloidal structure.
- MakaleYalnız künye2026Germination as a Pre-isolation Modification Method for Common Buckwheat Protein Isolate
Gülbahar, Esma; Tunç, Merve Tuğçe; Akdoğan, Arda; Baltacı, Cemalettin; Sarıcaoğlu, Furkan Türker; Parlak, Mahmut Ekrem; Aydın, Engin; Odabaş, Halil İbrahim
This study investigated germination as a pre-isolation modification method to enhance the techno-functional and nutritional properties of common buckwheat (Fagopyrum esculentum Moench) protein. Germination was conducted at two different temperatures (20 and 30 °C) for 24, 48, and 72 h, and isolated proteins were analyzed for their chemical, structural, and functional properties. Results showed that the highest protein yield was achieved at 30 °C for 24 h, though durations exceeding 48 h reduced purity. SDS-PAGE and FTIR analyses confirmed that endogenous protease activity degraded high-molecular-weight proteins and increasing random coil proportions, indicating partial unfolding. SEM imaging revealed that germination transformed the dense protein surface into a porous morphology. Increasing germination time and temperature led to decreased lightness (L*) and hue angle, along with moderate increases in redness (a*), indicating notable changes in the visual appearance of the protein isolates. DSC results showed a decrease in thermal stability (Td) due to structural changes. In addition, germination significantly improved solubility, emulsifying activity, foaming capacity, and water/oil absorption, particularly at the 24 h of germination. Most notably, germination at 30 °C for 24 h increased in vitro protein digestibility from 75.67 to 82.19%. The results show that the germination is a promising approach to enhance the functionality and digestibility of buckwheat protein for potential application in food industry.
- MakaleYalnız künye2026Freeze–ohmic thawing: A novel pretreatment strategy for cold-pressed black cumin oil production
Tunç, Merve Tuğçe
Cold pressing is one of the most preferred techniques for producing high-quality vegetable oils; however, its relatively low extraction efficiency remains a major limitation. Although ohmic thawing has been investigated as a rapid thawing technique for frozen foods, its application as a pretreatment prior to cold-press oil extraction has not yet been reported. Therefore, this study investigated, for the first time, the potential of freeze–thawing (FT) and freeze-ohmic thawing (FOT) as pretreatment strategies to enhance the recovery and preserve the quality of cold-pressed black cumin oil. FT and FOT pretreatments were applied for one, two, and three cycles before cold pressing, and the extracted oils were comparatively evaluated in terms of oil recovery, physicochemical properties, antioxidant characteristics, FTIR, aroma profile, and fatty acid composition. Both FT and FOT significantly improved oil recovery compared with the untreated control. While FT2 increased the extraction yield to 51.68 ± 2.21%, FOT2 achieved the highest extraction yield (63.11 ± 1.50%), corresponding to a 41% increase over the control. FTIR analysis confirmed the preservation of the characteristic functional groups of black cumin oil following both pretreatments. Thymoquinone was largely preserved, with only a slight reduction in FT2. Likewise, the fatty acid profile remained stable, with no significant differences (p > 0.05) among treatments. These findings demonstrate, for the first time, that freeze-ohmic thawing can be successfully employed as a pretreatment prior to cold pressing, substantially improving black cumin oil recovery while preserving its physicochemical, structural, and compositional quality.
- MakaleAçık Erişim2025Sumak ekşisi üretiminde ohmik ısıtma destekli evaporasyonun kullanımı: Kalite parametreleri ve proses koşulları üzerindeki etkileri
Baltaci, Cemalettin; Odabaş, Halil İbrahim; Tunç, Merve Tuğçe
Bu çalışma ile ohmik ısıtma destekli evaporasyonun sumak şurubu üretimi üzerindeki etkilerinin incelenmesi amaçlanmıştır. Bu amaçla hem geleneksel evaporasyon hem de ohmik ısıtma destekli evaporasyon yöntemleri kullanılmıştır. Ohmik ısıtma destekli evaporasyon işleminde 20 V/cm (188 V) ve 25 V/cm (235 V) olmak üzere iki farklı voltaj gradyanı uygulanmıştır. Çalışmada, örneklerin fizikokimyasal parametreleri, HMF (5-hidroksimetilfurfural) miktarları, antioksidan özellikleri, reolojik karakteristikleri ve uygulanan metotların enerji tüketimi ile diğer proses parametreleri incelenmiştir. Ohmik ısıtma destekli ve geleneksel evaporasyon yöntemleriyle üretilen sumak şurupları arasında antioksidan özellikleri veya HMF miktarları açısından önemli bir farklılık bulunmamıştır. Ancak enerji verimliliği açısından incelendiğinde, ohmik ısıtma destekli evaporasyon işlemi sırasında enerji tüketiminin (20 ve 25 V/cm için sırasıyla 121,93±5,98 ve 95,00±3,08 kj), geleneksel yönteme göre (1331,00±101,82 kj) yaklaşık on bir kat daha düşük olduğu hesaplanmıştır. Elde edilen sonuçlar incelendiğinde, ohmik ısıtma destekli evaporasyon ile üretilen sumak ekşilerinin kalite özelliklerini korunurken, enerji tüketimini, CO₂ emisyonlarını ve proses parametrelerinin önemli ölçüde azaldığını göstermiştir.
- MakaleAçık Erişim2024Bioethanol Production from Mulberry Molasses Waste with Ohmic-Assisted Hydrodistillation
Tunç, Merve Tuğçe; Genç, Berna; Karataş, Şeyda Merve
In this study, the fermentation process of bioethanol production conditions were optimized by response surface methodology. Mulberry molasses production waste was used as the only carbon source for yeast fermentation to produce bioethanol. Hydrodistillation (HD) and ohmic-assisted hydrodistillation (OAHD) methods were employed to concentrate the bioethanol. Fermentation time (48–168 h), waste matter rate (5–45%) and pH (5–7) were selected as independent variables. Alcohol concentration was treated as the response. Optimum fermentation conditions were determined as 96.894 h fermentation time, 45% waste ratio and pH 7. At these optimum conditions, alcohol concentration was determined as 3.77 ± 0.33%. While the distillate obtained in the HD method contained 22.50 ± 1.89% alcohol, it showed 27.72 ± 0.24% in the OAHD method. The energy consumption values for OAHD and HD was 2.92 ± 0.51 and 53.24 ± 1.74 Wh/mL bioethanol, respectively. Results of study showed that the OAHD could be a cost-effective and green method to distillation of bioethanol from mulberry molasses waste.
- MakaleAçık Erişim2024Rheological properties of pestil enriched wheat, potato and corn flour using simplex lattice mixture design
Yuksel, Ferhat; Yavuz, Busra; Tunç, Merve Tuğçe
In this study, pestil was made using various concentrations of wheat, corn, and potato flours and the ideal flour combination amounts were determined using the simplex lattice mixture design technique. The apparent viscosity, G' (elastic modulus), G'' (viscous modulus), and tan δ (G''/G') analyses were determined. In all samples, it is seen that viscosity reduces while shear rate increases. This type of behaviour is pseudoplastic behaviour. While the highest apparent viscosity was observed in the 13th sample (12 g/100 g potato flour), the lowest was seen in the 11th sample (12 g/100 g wheat flour). In all samples, the elastic modulus (G') was higher than the viscous modulus (G''). The ANOVA table shows that linear data have a significant (p<0.05) effect on apparent viscosity, G', G'', and tan δ values. In general, formulations using potato flour show higher apparent viscosity values. Also, it is observed that the tan δ, G', G'' and apparent viscosity values increase with the addition of potato flour.
- MakaleAçık Erişim2024Characterization of Water-Soluble Extracellular Polysaccharide from Aeribacillus pallidus IM17
Genc, Berna; Tunç, Merve Tuğçe; Adiguzel, Ahmet
The production of the extracellular polysaccharide from the thermophilic bacterium Aeribacillus pallidus was carried out in the study. The polysaccharide was isolated and characterized by means of GC–MS, FT-IR, DSC, and XRD analyses. The rheological, foaming, and emulsifying properties of the polysaccharide were determined. Using a sucrose-rich medium, 27.1 mg dried EPS/100 mL was obtained with 94% carbohydrate and 1.5% protein. The monosaccharide profile of water-soluble EPS-IM17 was composed of rhamnose, arabinose, xylose, mannose, glucose, and galactose. The foaming capacity and stability of EPS-IM17 were 26.67% (± 4.71) and 40.01% (± 4.95), respectively, and the foaming stability was not affected by time. The emulsification index of EPS-IM17 was 64.54 (± 8.71) and decreased to 38.47 (± 10.44) after 24 h. EPS-IM17 had a crystalline structure. Solutions at different concentrations (10, 20, 40 mgmL-1) showed pseudoplastic behavior. In conclusion, this report could be a lead study for the use of Aeribacillus pallidus extracellular polysaccharide for different applications.
- MakaleAçık Erişim2024Enterococcus durans SL70, a Novel Exopolysaccharide Producer from Traditional Sourdough Fermentation of Einkorn (Triticum monococcum L. ssp. monococcum)
Genc, Berna; Karatas, Seyda Merve; Tunç, Merve Tuğçe
Research background. Given the potential of microbial exopolysaccharides from lactic acid bacteria in various industrial processes, alternative sources for the isolation of lactic acid bacteria are highly topical. In this study, we used a traditional sourdough from einkorn (Triticum monococcum L. ssp. monococcum) as a source of lactic acid bacteria for the isolation, identification and determination of exopolysaccharide producers. Experimental approach. The sourdough was prepared from einkorn according to the traditional method. Lactic acid bacteria were isolated and purified using the single colony technique on MRS and M17 media. The isolates were characterised using matrix-assisted laser desorption ionization-time of flight mass (MALDI-TOF) spectrometry. All isolates were analysed for extracellular polysaccharide production and one isolate was selected for purification and characterisation of its polysaccharide. Results and conclusions. The isolates were identified as Lactobacillus plantarum, L. paraplantarum, L. brevis, Pediococcus pentosaceus, Enterococcus faecium and E. durans. The production of exopolysaccharides by all lactic acid bacteria was evaluated and it was found that all strains (except one) were capable of producing exopolysaccharides. One polysaccharide (EPS-SL70) was purified from the isolates of E. durans SL70. This anionic heteropolysaccharide had, in addition to the carbohydrate backbone, a protein structure that did not contain nucleic acid. The carbohydrate backbone consisted of mannose, glucose, rhamnose, arabinose, xylose and galactose. Novelty and scientific contribution. The microbial flora of traditional einkorn sourdough has been identified in this study and represents the first report on the exopolysaccharide production by lactic acid bacteria in traditional einkorn sourdough. Additionally, Enterococcus durans from einkorn sourdough was identified as a new exopolysaccharide producer.
- MakaleYalnız künye2021Single-step recovery of pectin and essential oil from lemon waste by ohmic heating assisted extraction/hydrodistillation: A multi-response optimization study
Tunç, Merve Tuğçe; Odabaş, Halil İbrahim
The main products obtained from citrus wastes are pectin and essential oil. In this work, ohmic heating assisted extraction/hydrodistillation (OHAE/H) was applied for the simultaneous recovery of pectin and essential oil from lemon waste. Optimum OHAE/H conditions to maximize the yield of pectin and essential oil were determined with response surface methodology. Three independent variables, namely liquid to solid ratio (w:v), extraction/hydrodistillation time (min) and voltage gradient (V/cm) were varied to obtain maximum pectin and essential oil yield. Optimum OHAE/H conditions were determined as 8.7:1 liquid to solid ratio, 58.4 min extraction/hydrodistillation time and 14.2 V/cm voltage gradient. The predicted pectin and essential oil yields at optimum conditions were 16.58 and 3.62 g/100 g lemon waste, respectively. Data analysis showed that all of the independent variables significantly affected the pectin and essential oil yield. In the verification study, close agreement was found between predicted and experimental values. Conventional heating extraction/hydrodistillation (CHE/H) were conducted to evaluate the effectivity of OHAE/H. With OHAE/H process, the yields of the pectin and essential oil were significantly increased when compared to CHE/H. Limonene concentration of the essential oil produced with OHAE/H was higher than the essential oil produced by CHE/H. Results demonstrate that the single-step OHAE/H could be an effective method for simultaneous extraction and hydrodistillation of pectin and essential oils.
- MakaleYalnız künye2021Optimization of ohmic heating assisted hydrodistillation of cinnamon and bay leaf essential oil
Tunç, Merve Tuğçe; Koca, İlkay
In this work, optimum ohmic heating assisted hydrodistillation (OAHD) conditions for extraction of cinnamon (CEO) and bay leaf (BEO) essential oil were determined by response surface methodology (RSM). OAHD were compared with conventional hydrodistillation (HD). Hydrodistillation time (30–120 min), mass of sample (20–40 g) and voltage gradient (7.5–12.5 V/cm), were varied to maximize essential oil (EO) yield and minimize energy consumption. Optimized OAHD conditions were determined as 119.90 min, 8.83 V/cm and 40 g, and 120 min, 8.53 V/cm and 40 g for CEO and BEO, respectively. EO yields of cinnamon and bay leaves at optimum conditions were found 3.98 ± 0.25% and 1.36 ± 0.14%, respectively. Energy consumptions were found 0.42 ± 0.02 and 0.86 ± 0.09 kWh/g EO for CEO and BEO, respectively. EO yield of OAHD was found to be higher when compared with HD methods for both plant materials. Energy consumptions and emitted CO2 values of OAHD method were significantly (p < 0.05) lower than HD methods. Cinnamaldehyde (CEO) and eucalyptol (BEO) contents of essential oils extracted with OAHD were higher when compared with HD methods. Antioxidant activities of essential oils extracted with different methods were not significantly different. CEO and BEO formed inhibition zones against all tested microorganism strains. Practical Applications: Essential oils of cinnamon bark and bay leaf are commonly used for food and pharmaceutical industries and, have important economic value. Conventional hydrodistillation method to extraction essential oils is time consuming, requires more energy and has more CO2 emission rates. Ohmic heating assisted hydrodistillation as a novel technology, is a promising method to extraction of essential oils from different plant materials with lower process times and energy consumption when compared with conventional hydrodistillation. Ohmic heating assisted hydrodistillation method can developed with regard to scale up as a green technology to essential oil production. This work provides a knowledge about the effects of different OAHD process variables on essential oil yield and energy consumption for cinnamon bark and bay leaf essential oils. It is expected that the outcomes of this study will be useful for the designing of large scale ohmic heating assisted hydrodistillation units.
- MakaleYalnız künye2019Ohmic heating assisted hydrodistillation of clove essential oil
Tunç, Merve Tuğçe; Koca, İlkay
Ohmic heating assisted hydrodistillation is a novel green technology for the extraction of essential oils. In this study, clove bud essential oils (CEO) were extracted by ohmic heating assisted hydrodistillation (OAHD) and compared with conventional hydrodistillation (HD) process, in terms of extraction yield, energy consumption and chemical properties. Ohmic heating assisted hydrodistillation process conditions were optimized by response surface methodology. Voltage gradient (7.5–12.5 V/cm, A), process time (30–120 minutes, B) and mass of clove bud (20–40 g, C) were varied in order to maximize CEO yield and to minimize energy consumption. Optimized extraction conditions were determined as, 12.5 V/cm voltage gradient, 97.967 min for process time and 40 g of mass of clove bud. Yield of CEO and energy consumption were found 13.18 ± 1.50% and 0.214 ± 0.030 kW h/g CEO at optimum extraction conditions, respectively. Under optimum conditions, both OAHD and HD methods were used for CEO extraction. Yields of CEO obtained by OAHD, HD-D (distilled water) and HD-S (salted water) were 13.18 ± 1.50, 8.23 ± 0.35 and 7.88 ± 0.60 respectively. Energy consumptions of OAHD and HD methods were not significantly different (P > 0.05). The main chemical component of CEO was eugenol and the yield of eugenol (g/100 g clove bud) was found higher with OAHD (6.95±0.6) method than HD-D (5.16 ± 0.20) and HD-S (5.13 ± 0.28). Antioxidant and antimicrobial properties of CEOs were investigated by FRAP, DPPH and disk diffusion method. Antioxidant properties of CEOs obtained by different extraction methods were not significantly different (P > 0.05) according to FRAP and DPPH analysis. Although inhibition zones of CEOs extracted with different methods were not significantly different (P > 0.05) for gram positive bacteria's, CEO obtained by OAHD and HD-D have significantly higher (P < 0.05) inhibition zones for K. pneumonia and E. coli, respectively. The results of this study showed that OAHD method is applicable for CEO production.