Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Non-Alcoholic Beer Production Using Ohmic Heating-Assisted Vacuum Distillation Method
Akdoğan, Arda; Baltacı, Cemalettin
In this study, non-alcoholic beer was produced with an ohmic heating-assisted vacuum distillation system (ODVD) and vacuum rotary distillation (VDD). The processes were conducted at three vacuum pressure levels (100, 150, and 200 mbar). Corresponding operating temperatures were 50, 58, and 67°C for the VDD system, while the ODVD system operated at in-situ-ohmic heating without an external heating medium. In ODVD, three voltage gradients (15, 20, and 25 V/cm) were applied. The two systems were compared in terms of processing time, energy efficiency, aroma profile, antioxidant capacity (ABTS, DPPH, TAC, FRAP), total phenolic (TPC) and total flavonoid content (TFC), vicinal diketone (VDK), pH, color, and bitterness value. The ODVD system showed significantly shorter processing times and energy efficiency than VDD. While the pH values of dealcoholized beer increased slightly compared to the original beer, color and bitterness values were higher in VDD samples. Aroma compounds such as ethyl acetate, isoamyl acetate, and ethyl caproate were lost during both processes. Overall, the findings demonstrate that ODVD is a promising and energy-efficient alternative for the production of non-alcoholic beer, with comparable product quality to VDD.
- 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.
- MakaleAçık Erişim2026Evaluation of Physicochemical Properties, Phytochemical Composition, Antioxidant Activity, Mineral Content, and Sensory Characteristics of Crackers Fortified with Olive Pomace
Altay, Kadriye; Akdoğan, Arda; Erdoğan, Selma Lubabe; Koç, Gülşah Çalışkan
Olive pomace (OP), a by-product of olive oil production, is a rich source of various bioactive compounds. OP can be used as a value-added product for the development of functional food. The research aimed to produce functional crackers incorporating different levels of OP powder (ranging from 0% to 20%). Subsequent analysis involved evaluating the physicochemical and phytochemical compositions, antioxidant activity, mineral content, and sensory characteristics of all samples. In light of the findings, the samples containing OP powder are rich in phytochemicals (total phenolic and flavonoid contents), with higher antioxidant activities (total antioxidant content, DPPH radical scavenging activity, ABTS radical scavenging activity, and ferric reducing power), as well as a high amount of minerals compared to the control sample (P<0.05). Moreover, as the concentration of OP increased, there was a decline in the moisture content, water activity, and color values of the crackers. Conversely, the ash, fat, total flavonoid, total phenolic, and mineral contents, as well as antioxidant activity and hardness values, exhibited an increase. Sensory analyses revealed that the addition of 10% OP powder produced highly acceptable crackers compared to the higher concentration of OP (15 and 20%). Overall results indicated that functional crackers can be produced by the addition of powder and a maximum of 10% OP powder fortification is recommended for consumer acceptability.
- MakaleYalnız künye2025Enrichment of Tarhana with Olive Leaf Powder: Evaluation of Physical, Functional, Powder, and Sensory Properties
Koc, Gulsah Caliskan; Altay, Kadriye; Erdoğan, Lubabe; Akdoğan, Arda; Gülden, Emin
Olive leaves are a by-product of olive cultivation and remain underutilized despite their significant potential as a rich source of health-promoting and functional components. Similarly, tarhana, a fermented food product, is known for its valuable nutritional properties. This study aimed to combine these two beneficial products by examining the effect of different concentrations of dried olive leaf powder (0, 2.5, 5, 7.5, and 10% by weight) on the physical, functional, powder, and sensory properties of tarhana samples. Results showed that moisture content of the tarhana samples were below 10% (wet basis, wb). The ash content (2.17-2.71%, wb) and water holding capacity (32.50-59.00%) of samples increased significantly with the addition of olive leaf powder (p<0.05). The pH value of the doughs was found to be around 5.5 and decreased during the fermentation. The wettability and solubility times of all samples were found to be less than 25 seconds and 16 seconds, respectively. All tarhana samples exhibited high flowability and low stickiness properties. Formulations containing up to 7.5% olive leaf powder were well-received by consumers.
- MakaleAçık Erişim2024Validation Study on Spectrophotometric Measurement of Ethanol from Beer and Non-Alcoholic Beer Samples Distilled by Micro Steam Distillation Method
Baltaci, Cemalettin; Akdoğan, Arda
In this study, a new spectrophotometric method based on the oxidation of sodium dichromate was proposed for the determination of ethanol percentage (v/v) in beer and non-alcoholic beer after distillation with the micro water vapor method, and the method was validated with various parameters. The Harmonized Guidelines for Single-Laboratory Validation of Methods of Analysis were used to validate the analytical method we provided. The following aspects of the method were assessed: precision, recovery, linearity, measuring range, limit of detection (LOD), limit of quantification (LOQ), method detection limit (MDL), and measurement uncertainty. The LOD, LOQ, and MDL values obtained for ethanol were 0.04%, 0.05%, and 0.15%, respectively. The relative standard deviation (RSD) values were less than 2.36% and 4.12% for both repeatability and within-laboratory reproducibility, respectively. Recovery percentages of analytes added to the sample at certain levels were determined to be quantitative between 97% and 102%. These findings fulfill the minimal performance standards outlined in AOAC Official Methods of Analysis Appendix F: Guidelines for Standard Method Performance Requirements. In conclusion, the method validated with various parameters in this study has proven to be effectively usable for the routine analysis of ethanol in beer and non-alcoholic beer. This developed analysis method stands out as an innovative approach in terms of collecting ethanol from beers with the help of micro-distillation water vapor and measuring the color resulting from oxidation.
- MakaleAçık Erişim2024Production and Enrichment of Erucic Acid Methyl Ester Analytical Standards from Natural Oils for Food Control Analysis
Karabaş, Yağmur; Gül, Abdulkadir; Karpuz, Ömer; Akdoğan, Arda; Baltacı, Cemalettin
Foods high in erucic acid (EA), a fatty acid considered a natural toxin, can pose various health risks. Studies have reported that people exposed to high levels of EA are more likely to experience cardiovascular disease, are susceptible to myocardial adiposity, and have increased rates of diabetes. Therefore, in 2019, the European Commission (EC) declared that the maximum EA content in vegetable oils should be no more than 2%. These regulations require EA analysis in import and export food samples. A methyl ester of EA (EAME) standard is required to analyze EA content. In many countries, this analytical standard is not available and is being imported. This study endeavored to economically produce the EAME standard, which is in high demand due to mandated analysis, using natural oils. Initially, the fatty acid amounts in the food samples were analyzed by the gas chromatography–mass spectrometry/flame ionization detection (GC-MS/FID) method. The analyses revealed that mustard seed oil had the lowest EA content, while yellow mustard seed oil had the maximum EA content. The esterification was conducted on the samples containing both high and low EA, resulting in an efficiency of approximately 80%. The crystallization process was subsequently repeated to increase the EA quantity until the highest EAME content was obtained. By this process, 14 different concentrations of EAME ranging from 2.33 to 55.66% were produced. These results demonstrate the first successful production of EAME standards from natural oils that can be used in validation and internal quality control studies for food control analysis.
- MakaleAçık Erişim2024Physicochemical Properties, Antioxidant Capacity and Sensory Acceptability of Instant Rosehip Teas Prepared by Spray-Drying and Freeze-Drying Methods
Baltaci, Cemalettin; Bostanci, Dilara Erkmen; Altintaş, Rahime; Dalkiran, Yusuf; Akdoğan, Arda; Okan, Onur T.
In this study, the physicochemical properties, antioxidant capacity, sensory properties, and phenolic and mineral profiles of instant rosehip teas prepared using spray-drying (SD) and freeze-drying (FD) were compared. The yield of instant tea produced using FD and SD was 23.75 and 21.25 g/100 g, respectively. The total color difference between the FD and SD tea was 50.74, with the SD sample exhibiting higher redness and yellowness. The FD tea was richer in ascorbic acid than SD tea (67.2 and 59.4 mg/100 g dry weight, DW, respectively). The mineral content ranged from 0.20 mg/kg DW (copper) to 2,837 mg/kg DW (potassium) in SD tea, and from 0.31 mg/kg DW (copper) to 3,083 mg/kg DW (potassium) in FD samples. The total phenolic content was 1,315 and 1,495 mg GAE/100 g DW of SD and FD samples, respectively. The antioxidant capacity of instant rosehip teas was determined as total antioxidant capacity, ferric reducing antioxidant power and DPPH radical scavenging activity. In all these assays, FD tea was found to have a higher antioxidant capacity. In the phenolic profile determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique, protocatechuic acid dominated in instant rosehip teas prepared using both methods. The main flavonoids identified were quercetin, quercitrin, hyperoside and luteolin 7-glucoside. Following the sensory analysis, the panelists have generally preferred the FD tea in terms of aroma and flavor, while opting for the SD tea in terms of appearance and color. In conclusion, although freeze-drying allowed obtaining a product with a higher antioxidant capacity and antioxidant content than spray-drying, both drying methods may be considered suitable for the production of instant rosehip teas and ensure obtaining a functional food product.
- MakaleAçık Erişim2023Zeytin pirinasının mikrodalga kurutulmasında ultrases ön işleminin ürünün bazı fiziksel ve kimyasal özellikleri üzerine etkisi
Koc, Gulsah Caliskan; Altay, Kadriye; Akdoğan, Arda
Bu çalışmada, mikrodalga kurutma öncesi zeytin pirinasına uygulanan ultrases ön işleminin kurutulmuş pirinanın fizikokimyasal kompozisyonu (nem, su aktivitesi ve renk), toz ürün özellikleri üzerine biyoaktif bileşenleri (toplam flavonoid, fenolik madde içeriği), antioksidan aktivitesi ve mineral madde içeriği özelliklerine etkisinin araştırılması hedeflenmiştir. Bu amaç doğrultusunda, pirina örneklerine 10 dakika ultrases ön işlemi uygulanmış ve örnekler 460W güçte 8 dakika süre ile mikrodalga fırında kurutulmuştur. Kurutma sonrası örneklerin nem içerikleri %5 (yaş bazda)’in altına düşmüştür. Ultrases ön işleminin kurutulmuş pirinanın b*, kroma ve esmerleşme indeksi değerlerini azalttığı gözlenmiştir. Toz formdaki kurutulmuş pirina örneklerinin iyi akabilirlik ve düşük yapışkanlık özelliğinde olduğu belirlenmiştir. Ultrases ön işleminin pirinaların flavonoid ve fenolik madde miktarı ve antioksidan aktivite özelliklerini azalttığı tespit edilmiştir. Ultrases ön işleminin örneklerin demir, nikel, alüminyum, mangan, kurşun ve potasyum içeriklerinde artış meydana getirdiği sonucuna varılmıştır.
- MakaleYalnız künye2022Production of grape pekmez by Ohmic heating-assisted vacuum evaporation
Tunç, Merve Tuçe; Akdoğan, Arda; Baltacı, Cemalettin; Kaya, Zeliha; Odabaş, Halil İbrahim
Pekmez is a concentrated syrup-like food conventionally produced by vacuum evaporation process from sugar-rich fruits. In this study, the applicability of grape pekmez production by ohmic heating assisted vacuum evaporation (ΩVE) method was investigated. Conventional vacuum evaporation (CVE) and ΩVE methods were compared in terms of physicochemical properties, HMF (5-hydroxymethylfurfural) contents, rheological properties, and energy consumptions. ΩVE was run at four different voltage gradients (17.5, 20, 22.5, and 25 V/cm). Total process times for grape pekmez production were determined as 57, 28.5, 32, 39, and 50 minutes for CVE, ΩVE (25 V/cm), ΩVE (22.5 V/cm), ΩVE (20 V/cm) and ΩVE (17.5 V/cm), respectively. Energy consumption of CVE method was higher than ΩVE method for all voltage gradients. Energy efficiency increased as the voltage gradient increased. There was no significant difference between CVE and ΩVE methods for HMF contents. The results show that the ΩVE method could be an alternative to the CVE process for grape pekmez production.
- MakaleYalnız künye2021Mineral content, fatty acid composition, and volatile compounds of gluten-free tarhana formulated with different cereal and pulse flours
Çalışkan Koç, Gülşah; Tekgül, Yeliz; Erten, Edibe Seda; Akdoğan, Arda
Abstract: This research was intended to determine the effect of different cereal and pulse flours and commercial gluten-free flour on the mineral content, fatty acid composition, and volatile compounds of the gluten-free tarhana (cereal-based fermented dry soup). In order to produce the gluten-free tarhana, white bean (BF), chickpea (CF), commercial gluten-free (GWF), yellow lentil (LF), and rice (RF) flours were used. The Mg, K, Al, and Mn contents of tarhanas obtained using different pulse and cereal flours were found to be quite high compared to tarhanas produced with commercial GWF. The utilization of different cereal and pulse flours in the tarhana formulation resulted in an increase in the percentage (30.37–51.47%) of the total polyunsaturated fatty acid (TPUFA). The highest (452.4 µg/g) and the lowest (241.17 µg/g) total concentration of all compounds were detected in BF and GWF, respectively. The highest number (21) of compounds belonged to terpenes and terpenoids, followed by acids, hydrocarbons, alcohols, aldehydes, esters, ketones, and alkanes. Practical Application: This study shows that cereal and pulse flours can be used to produce acceptable tarhana with improved nutritional quality in terms of mineral and fatty acid contents. The results of the current study may be useful and applicable to food manufacturers producing gluten-free products for celiac patients.
- MakaleAçık Erişim2021Determination of the effect of wheat germ on the mineral and fatty acid composition and aroma compounds of tarhana: A traditional fermented cereal food
Tekgül, Yeliz; Çalışkan Koç, Gülşah; Erten, Edibe Seda; Akdoğan, Arda
In this study, to supply to the trend toward natural and functional foods that do not include synthetic products, the wheat germ which exists as waste in nature was added to tarhana formulation in order to increase the nutritional content of tarhana. Wheat germ supplemented tarhana samples met the recommended dietary allowances of iron. A total of 63 compounds were detected and quantitated in all samples. Terpenes and terpenoids were observed as the dominant compound group. The addition of wheat germ to tarhana dough resulted in an increase in the number of volatile compounds. The most abundant odor-active compounds were acetic acid and 2-acetylpyyrole.The mineral (Mg, K, Zn, Mn), fatty acid (undecaenoic, linoleic, gondoic acid, and α-linolenic), oil, acid (propanoic and hexanoic), alcohol (linalool, benzyl, phenylethyl), aldehyde ((E)-2-heptenal, nonanal, 5-methyl-2-phenyl-2-hexenal), ketone (3-Octen-2-one), terpene (junipene, citronellol, trans-Carveol) contents of tarhana samples can be increased by addition of the wheat germ. Practical applications: The wheat germ which exists as waste in nature and contains a high amount of essential amino acids, proteins, fatty acids, minerals, dietary fiber, vitamins, etc. Wheat germ can be added to cereal-based food formulation such as tarhana in order to supply to the trend toward natural and functional foods that do not include synthetic products. Tarhana (basically made from yogurt, wheat flour, herbs, tomato, pepper, onion, etc.) which is a traditional fermented dry Turkish soup is rich in vitamins, minerals, and proteins. Wheat germ based-fermented products such as Tarhana may be considered promising new functional foods due to its probiotic effects in order to expand the market due to the increasing trend toward functional foods.