Browsing by Author "Korkmaz, Aziz"

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Citation - WoS: 1
Citation - Scopus: 1
Volatile profile, textural and sensory properties of Diyarbakır Örgü cheese produced from sheep and cow milk of different ripening time
(Mljekarstvo, 2023) Hatipoğlu, Abdulkerim; Korkmaz, Aziz; Çelik, Şerafettin
Diyarbakır Örgü (knitted) cheese (DOC) is a semi-fat, hard, and a pasta-filata type cheese. The objective of this study was to evaluate volatile organic compounds (VOC), and textural and sensory properties of DOC during the 120-day maturation period. For this purpose, a total of 5 different cheeses were produced as 100 % sheep’s milk (C1), 100 % cow’s milk (C2), 90 % sheep’s milk + 10 % cow’s milk (C3), 80 % sheep’s milk + 20 % cow’s milk (C4), and 70 % sheep’s milk + 30 % cow’s milk (C5). Volatile compounds increased, both qualitatively and quantitatively, along with the increase of the percentage of sheep milk used in the cheese production increased. At the beginning of ripening, the total amount of VOC in the DOC obtained from sheep’s milk was 3.27-fold greater than that of the produced cow’s milk, while this ratio increased to 4.57 at the end of ripening. The total VOC contents of all the DOC reduced along the ripening and decreased by 53.37, 64.92, 15.53, 51.81, and 64.84 % for C1, C2, C3, C4, and C5, respectively. As the amount of cow’s milk used in DOC production increased, the values of all textural properties (hardness, adhesiveness, springiness, cohesiveness, gumminess, and chewiness) of the cheese increased too. On the other hand, these values decreased with the maturation (p<0.05). The rates of decrease in hardness (N), adhesiveness (N.s), springiness (cm), cohesiveness, gumminess (N), and chewiness (mJ) values of the cheese groups with the storage were C1>C3>C2>C4>C5, C4>C1>C5>C2>C3, C2>C1>C3>C4>C5, C3>C2>C1>C5>C4, C1>C4>C3>C2>C5 and C3>C4>C1>C5>C2, respectively. In terms of sensory properties (colour, texture and, taste-aroma) of the cheese mature C2, mature C1 and 30-day ripened C1 cheese samples were preferred more, respectively.
Citation - WoS: 34
Citation - Scopus: 34
The effects of production methods on the color characteristics, capsaicinoid content and antioxidant capacity of pepper spices (C. annuum L.)
(Elsevier, 2021) Korkmaz, Aziz; atasoy, Ahmet Ferit; Hayaloğlu, Ali adnan
The effects of production methods for red pepper flakes (RPF) and traditional (TRI) and industrial (INI) isot spices were evaluated with respect to the carotenoid and capsaicinoid contents, extractable color (ASTA color), surface color parameters, nonenzymatic browning (NEB), and the DPPH free radical-scavenging capacity of fresh red Capsicum (FRC). The measured characteristics were significantly affected by the processing methods used. RPF exhibited the highest antioxidant activity and best color quality in terms of carotenoid content, which was the highest; ASTA value; surface color intensity; and NEB, which was the lowest. In contrast, INI-processing methods resulted in poor color quality, causing the maximum increase in NEB. The concentration of capsaicinoid increased at the end of TRI processing, whereas it decreased in the two other methods. These results suggest that the traditional production method for isots prevents excessive destruction of their color attributes and contributes to the desirable characteristic browning.
Citation - WoS: 26
Citation - Scopus: 25
Characterization and Comparison of Extra Virgin Olive Oils of Turkish Olive Cultivars
(Molecules, 2023) Korkmaz, Aziz
Extra virgin olive oils (EVOOs) obtained from five Turkish olive cultivars widely produced in the Aegean and Marmara regions were investigated based on their total antioxidant capacity (TAC), total phenolic content (TPC), pigment contents, fatty acid (FA) profiles, phenolic compounds (PC), volatile compounds (VC), and sensory properties. The results showed that all properties of EVOO samples were significantly affected by the olive cultivar used. The pigment contents in Ayvalık (9.90 mg·kg−1) and Uslu (9.00 mg·kg−1) oils were higher than the others (p < 0.05). The greatest values for oleic acid (74.13%) and TPC (350.6 mg·kg−1) were observed in Gemlik and Domat oils, respectively (p < 0.05). Edincik oil showed the maximum hydroxytyrosol content (48.022 mg·kg−1) and TAC value (515.36 mg TE·kg−1) (p < 0.05). The Edincik, Domat, and Uslu oils were significantly not different for the total content of C6 compounds derived by lipoxygenase, which are the main volatiles responsible for the typical aroma of EVOOs (p > 0.05). Domat oil also exhibited the highest scores for bitterness and pungency perceptions (p < 0.05). The fruitiness scores of the oil samples (except for Ayvalık oil) were close to each other, even if they were statistically different (p < 0.05). Principal component analysis (PCA) indicated that the Ayvalık oil was separated from the others due to its poor-quality characteristics. As a result, it can be stated that Domat olive oil has better quality than the others
Zeytin Yaprağı Özütünün Tereyağı, Ayçiçek Yağı ve Patates Cipsinde Lipit Oksidasyonu Üzerindeki Etkileri
(2024) Korkmaz, Aziz; Atasoy, Ahmet Ferit; Gaser, Sevim
Lipit oksidasyonu, yemeklik yağlarda duyusal kalite kusurlarına neden olmakla birlikte tüketici sağlığı açısından da risk oluşturan bir bozulma tipidir. Bu çalışmada, zeytin yaprağından elde edilen bir özüt (ZYÖ) ile sentetik bir antioksidan olan bütillenmiş hidroksitoluenin (BHT) tereyağı, ayçiçek yağı ve patates cipsindeki antioksidan özellikleri karşılaştırılmıştır. Bu amaçla, her iki antioksidan farklı konsantrasyonlarda (50, 100, 200 ppm) tereyağına ve ayçiçek yağına ilave edilmiş, bunlardan ayçiçek yağı kızartma yöntemiyle (170±5°C) patetes cipsi üretiminde kullanılırken tereyağı ise herhangi bir ısıl işleme tabi tutulmamıştır. Hızlandırılmış raf ömrü testinden sonra oksidasyon parametreleri olarak örneklerin tiyobarbitürik asit (TBA) içerikleri ve peroksit sayıları (PS) belirlenmiştir. Ayrıca, 2,2-difenil-1-pikrilhidrazil (DPPH) radikali giderme aktivitesine dayalı olarak ZYÖ ile BHT’nin toplam antioksidan kapasitleri (TAK) de karşılaştırılmıştır. ZYÖ ilave edilmiş tereyağı, ısıl işlem görmüş ayçiçek yağı ve patates cipsinin oksidasyon göstergeleri herhangi bir antioksidan bileşen eklenmemiş örneklerinkine (kontrol) nazaran önemli oranda düşük bulunmuştur (P<0.05). 50, 100 ve 200 ppm kosantrasyonlarında BHT eklenmiş tereyağlarında, aynı konsantrasyonlarda ZYÖ ilave edilmiş örneklere göre sırasıyla %48,92, %47,76 ve %50,97 oranında daha düşük miktarlarda TBA oluşmuştur. Benzer oranlar, tereğının PS değerleri için de saptanmıştır. Ayçiçek yağı örneklerinde ise ZYÖ eklenmiş örneklerin TBA değerleri BHT eklenmiş örneklerin ve kontrol örneğinin TBA değerlerine göre daha düşük bulunmuştur (P<0.05). Ancak, 100 ve 200 ppm’lik konsantrasyonlarda BHT ve ZYÖ kullanımı bu yağın PS düzeyi için anlamlı bir fark oluşturmamıştır (P>0.05). ZYÖ eklenmiş patates cipslerinin TBA içerikleri BHT’li örneklerinkine göre önemli düzeyde daha düşük bulunmuştur (P<0.05). TAK bakımından ise ZYÖ (79,12 mg TE (troloks eşdeğeri) g-1) BHT’ye (67,39 mg TE g-1) nazaran daha yüksek değer sergilemiştir (P<0.05). Çalışmanın sonuçları, doğal bir antioksidan olarak ZYÖ’nun lipit oksidasyonlarının önlenmesinde BHT’ye alternatif olabileceğini göstermiştir.
Citation - WoS: 63
Citation - Scopus: 71
Changes in volatile compounds, sugars and organic acids of different spices of peppers (Capsicum annuum L.) during storage
(FOOD CHEMISTRY, 2020) Korkmaz, Aziz; Atasoy, Ahmet Ferit; Hayaloglu, Ali Adnan
Changes in sugars, organic acids and volatile compounds (VC) of red pepper flakes (RPF), traditional (TRI), and industrial (INI) isot peppers were evaluated during one year storage at the room condition. The changes in the flavor components were significantly affected by the production methods and storage time. Glucose content decreased gradually along storage and reduced by about 21.23, 47.22 and 56.65% for TRI, INI and RPF, respectively. However, fructose decreased significantly only in RPF (11.29%). Citric and succinic acids exhibited slight changes, but malic acid showed an increasing trend, especially in RPF (4-fold). Most of the VC in all samples decreased or disappeared after storage. The major quantitative losses in these compounds were found in TRI during the first 3 months as 81.76%. The storage was found to be caused deterioration flavor properties in red pepper spices and revealed the importance of appropriate storage conditions.
Citation - WoS: 19
Citation - Scopus: 19
Evaluation of fatty acids, free fatty acids and textural properties of butter and sadeyag (anhydrous butter fat) produced from ovine and bovine cream and yoghurt
(ScienceDirect, 2022) Karakuş, Mehmet Şükrü; Yıldız Akgül, Filiz; Korkmaz, Aziz; Atasoy, Ahmet Ferit
Fatty acids (FAs), free fatty acids (FFAs) and textural characteristics were determined in butter and sadeyag (anhydrous butter fat) manufactured from ovine and bovine cream and yoghurt. The samples made from cream and yoghurt had similar FA and FFA profiles and textural properties. Ovine milk fat products had higher short- and medium-chain saturated fatty acid (SFA) content, while samples made with bovine milk fat had higher long-chain SFA content. Ovine milk fat samples contained higher levels of capric, myristic, stearic and oleic acids and lower levels of butyric and caproic acids than bovine milk samples. Bovine milk fat products had firmer and poorer spreadability, and lower adhesiveness than ovine milk fat products. Polyunsaturated fatty acid (PUFA) content of butter was higher than that of sadeyag. Sadeyag was firmer and less spreadable than butter. Textural characteristics of the milk fat products depended on the FA composition of the samples.
Citation - WoS: 34
Citation - Scopus: 34
The effects of production methods on the color characteristics, capsaicinoid content and antioxidant capacity of pepper spices (C. annuum L.)
(Food Chemistry, 2021) Korkmaz, Aziz; Atasoy, Ahmet Ferit; Hayaloglu, Ali Adnan
The effects of production methods for red pepper flakes (RPF) and traditional (TRI) and industrial (INI) isot spices were evaluated with respect to the carotenoid and capsaicinoid contents, extractable color (ASTA color), surface color parameters, nonenzymatic browning (NEB), and the DPPH free radical-scavenging capacity of fresh red Capsicum (FRC). The measured characteristics were significantly affected by the processing methods used. RPF exhibited the highest antioxidant activity and best color quality in terms of carotenoid content, which was the highest; ASTA value; surface color intensity; and NEB, which was the lowest. In contrast, INI-processing methods resulted in poor color quality, causing the maximum increase in NEB. The concentration of capsaicinoid increased at the end of TRI processing, whereas it decreased in the two other methods. These results suggest that the traditional production method for isots prevents excessive destruction of their color attributes and contributes to the desirable characteristic browning.
Self-Control as a Key Mediator and Moderator of the Relationship Between Psychological Distress and Food Addiction in a Large Community Sample of Adults
(Academic Press Ltd- Elsevier Science Ltd, 2026) Ceylan, Jiyan Aslan; Korkmaz, Aziz; Hatipoglu, Abdulkerim; Akcali, Caglar; Coskunsu, Sedat
Objective: This study investigated the extent to which psychological distress (depression, anxiety, and stress) predicts food addiction (FA) symptoms and examined whether self-control operates as both a mediator and a moderator in these associations. Method: A total of 4234 adults (40.7 % male) participated in a large-scale, community-based, cross-sectional survey conducted in T & uuml;rkiye. FA symptoms were measured via the Yale Food Addiction Scale (YFAS), self-control was assessed via the Brief Self-Control Scale (BSCS), and psychological distress was evaluated via the Depression Anxiety Stress Scales (DASS-21). Statistical analyses were conducted in SPSS, with significance defined at p < 0.05. Results: Overall, 35.1 % of the participants met the criteria for FA, with no significant sex difference (p = 0.19). Logistic regression analyses revealed that greater anxiety (OR = 1.078, p < 0.01) and stress (OR = 1.109, p < 0.01) were significant predictors of increased risk for FA, whereas greater self-control emerged as a protective factor (OR = 0.952, p < 0.01). Mediation analyses confirmed that self-control partially accounted for the effects of psychological distress on FA symptoms, with significant indirect effects observed for stress (beta = 0.025), anxiety (beta = 0.029), and depression (beta = 0.032). Moderation analysis revealed that self-control attenuated the effect of depression on FA symptoms (interaction term: B = 0.002, p < 0.01), although no moderating effects were found for anxiety or stress. Conclusions: This study highlights self-control as both a mechanism through which psychological distress contributes to food addiction and a protective factor that reduces its impact. Enhancing self-control may help mitigate addiction-related eating behaviors.
Citation - WoS: 5
Citation - Scopus: 5
The effects of different concentration methods on the chemical composition, functional and sensory attributes of molasses produced from grape (Vitis vinifera L.) juice
(SpringerLink, 2023) Korkmaz, Aziz
The efects of concentration by outdoor (OCM) and vacuum (VCM) and traditional (TCM) methods for the production of molasses from fresh grape juice (FGJ) were evaluated concerning volatile compounds, sugars, organic acids, hydroxymethylfurfural (HMF), total phenolic (TPC), total favonoid (TFC) contents, and antioxidant capacity (TAC), and sensory properties. Compared to FGJ, its molasses had lower TPC, TFC, TAC, and total organic acids and total sugars (except for the OCM) in total soluble solids (TSS). Additionally, the most of (60.7%) volatile compounds in FGJ disappeared with the production of the molasses. Moreover, all investigated features were signifcantly infuenced by the concentration method used. The TCMconcentration method markedly increased the amounts of both HMF (~ 180- and 50-fold greater than of the OCM and TCM, respectively) and total volatile furans (~20- and 3.6-fold greater than that of OCM and TCM, respectively). Additionally, this method presented the best antioxidant properties in terms of greater TPC, TFC, and TAC, whereas both TPC and TFC in the molasses produced by the OCM-method were not signifcantly diferent from those they obtained by the VCM-method. The principal component analysis (PCA) based on the chemical characteristics revealed close similarity between the OCM and VCM, even though the OCM had higher contents for sugars and organic acids. According to the sensory evaluation, there were no signifcant diferences between the scores of favor and overall acceptability for the TCM and OCM. In conclusion, an adapted the OCM-concentrating method to industrial-type can be proposed to produce high-quality molasses.
Chemical Evaluation of Arbequina Extra Virgin Olive Oil with in Silico Analysis of Its Key Phenolic Compounds Targeting LDL Metabolism
(Nature Portfolio, 2025) Korkmaz, Aziz; Unsal, Velid; Yildiz, Resit; Oner, Erkan; Atasoy, Ahmet Ferit
The chemical properties of extra virgin olive oil (EVOO) from Arbequina variety grown in T & uuml;rkiye were evaluated, and its major phenolic compounds (PC) (oleocanthal, oleacein, luteolin and tyrosol) were compared with drugs (bempedoic acid and ezetimibe) involved in LDL metabolism through in silico analyses. The fatty acids composition (FA), PC and volatile organic compound (VC) profiles of EVOO obtained from Arbequina olive were evaluated via chromatographic methods (GC-FID, HPLC). The quality parameters, including total phenolic content (TPC), pigment content, peroxide value (PV), free fatty acid levels (FFA) and absorption coefficients, were determined via spectrophotometric methods. ADMET profiles, density functional theory (DFT), molecular docking, and the biological targets and activities of oleocanthal, oleacein, luteolin, tyrosol, bempedoic acid and ezetimibe were calculated and compared. Oleocanthal, oleacein, and luteolin completely passed the rules of Lipinski, Ghose, Veber, Egan, and Muegge, whereas only luteolin met the optimum ranges of all the criteria on the radar map. All 4 PC strongly inhibited OATP1B1 and OATP1B3, whereas oleocanthal, oleacein, and luteolin inhibited CYP3A4. Additionally, luteolin, oleocanthal and ezetimibe had individual inhibitory effects on CYP1A2, CYP2C9 and CYP2D6, respectively. Oleacein had the best binding affinity for LDLR, whereas luteolin had the best binding affinity for PCSK9 and ACLY. Oleacein was biologically effective against pathogens such as Leishmania species, but showed high reactivity with a low energy gap and high malleability. In conclusion, oleacein, oleocanthal and luteolin have potential therapeutic functions in LDL metabolism, which plays a role in atherosclerosis. However, experimental and clinical studies are needed for more evidence.
Citation - WoS: 7
Citation - Scopus: 9
Evaluation of Extra Virgin Olive Oil Compounds Using Computational Methods: in Vitro, Admet, Dft, Molecular Docking and Human Gene Network Analysis Study
(Bmc, 2025) Unsal, Velid; Yildiz, Resit; Korkmaz, Aziz; Mert, Basak Dogru; Caliskan, Cemile Gunbegi; Oner, Erkan
This study investigates the phenolic compounds (PC), volatile compounds (VC), and fatty acids (FA) of extra virgin olive oil (EVOO) derived from the Turkish olive variety "Sar & imath; Ulak", along with ADMET, DFT, molecular docking, and gene network analyses of significant molecules identified within the EVOO. Chromatographic methods (GC-FID, HPLC) were employed to characterize FA, PC, and VC profiles, while quality parameters, antioxidant activities (TAC, ABTS, DPPH) were assessed via spectrophotometry. The analysis revealed a complex composition of 40 volatile compounds, with estragole, 7-hydroxyheptene-1, and 3-methoxycinnamaldehyde as the primary components. Hydroxytyrosol, tyrosol, oleuropein, apigenin, ferulic acid, and vanillic acid emerged as main phenolic constituents, with hydroxytyrosol and apigenin exhibiting high bioavailability. Molecular docking highlighted oleuropein and pinoresinol as compounds with strong binding affinities, though only hydroxytyrosol, apigenin, and pinoresinol fully met Lipinski and other drug-likeness criteria. DFT analysis showed that oleuropein and pinoresinol have notable dipole moments, reflecting polar and asymmetrical structures. KEGG enrichment analysis further linked key molecules like oleuropein and apigenin with pathways related to lipid metabolism and atherosclerosis, underscoring their potential bioactivity and relevance in health-related applications.
Citation - WoS: 2
Citation - Scopus: 3
Volatile Compounds, Bioactive Properties and Chlorophylls Contents in Dried Spearmint (Mentha Spicata L.) as Affected by Different Drying Methods
(Galenos Publ House, 2023) Korkmaz, Aziz; Arslan, Erhan; Kosan, Meltem
This study presents a comparison of the quality characteristics of spearmint (Mentha spicata L.) dried by a photovoltaic thermal dryer (PVT), the shade dried spearmint (SDS), and an oven dried spearmint (ODS). The obtained samples were evaluated with respect to volatile compounds (VC), total phenolic content (TPC) and flavonoid content (TFC), antioxidant capacity (AC) and chlorophylls (Chl) contents. PDS had the highest amount of TPC, TFC and AC, while SDS and ODS did not differ significantly from each other in terms of these features. SDS exhibited the highest Chl a and Chl b contents, whereas ODS showed the lowest. The composition of VC in the dried spearmints was significantly affected by the drying methods used. The total amount of terpenoids, especially carvone, responsible for spearmint's characteristic aroma in SDS was higher than those of the others, while the concentrations of most VC were lowest in ODS. According to the results, the PVT can be recommended for drying spearmint.
A Study on Changes in Some Physicochemical Properties, Volatile Compounds, Sugar, and Organic Acid Contents of Grape Juice During Molasses Production
(2023) Korkmaz, Aziz
The changes in some physicochemical properties, sugar, organic acid and volatile compound contents in fresh Verdani grape (Vitis vinifera L.) juice (FGJ) were evaluated in the production of its traditional molasses (pekmez). After the production, the total soluble solid (TSS), titratable acidity (TA), glucose, fructose, malic, citric and succinic acid concentrations were increased (P