The essential oils (EOs) constituents have trade importance due to their bioactivities. In this research, the essential oil of the roots of Chrysopogon zizanioides (L.) Roberty cultivated in Giresun was obtained by hydrodistillation. Then, the chemical composition and biological activities of Chrysopogon zizanioides root essential oil (CEO) were studied. Thirty compounds were identified by gas chromatography-mass spectrometry (GC-MS) and the major compounds were determined as isobutyl-angelate (11.15%), α-muurolene (10.56%), α-cedrene (8.42%), α-patchoulene (8.10%), and ethylene brassylate (7.49%). The antimicrobial effect of CEO was investigated against pathogenic bacteria and fungus. Minimal inhibition concentration (MIC) was determined 31.25 μg/mL against C. albicans and between 62.5 and 125 μg/mL against the rest of the microorganisms. According to the antioxidant assays, the total phenolic content of CEO was found to be 13.70 ± 2.10 μg/mL gallic acid equivalent (GAE) and 24.67 ± 3.79 μg/mL catechin equivalent (CE). Ferric reducing/antioxidant power (FRAP) of CEO was found to be 356.44 ± 2.34 μM Trolox equivalent antioxidant capacity (TEAC). 2,2-diphenyl-1-picrylhydrazyl (DPPH•) was determined as IC₅₀ to be 7.124 ± 0.076 μg/mL. According to the obtained results, CEO has significant antimicrobial and antioxidant activities. This study is the first report determining the chemical composition, antimicrobial and antioxidant activities of essential oil obtained from vetiver grown in the Black Sea Region of Turkey.

This paper includes the results of the first study about the phenolic characteristics and antimicrobial analyses of Geranium ibericum subsp. jubatum species found in Turkey . In the present work, the phenolic contents of different parts of the G. ibericum (flower, root, leaf) were determined with high-performance liquid chromatography (HPLC)–DAD (diode-array detector) and liquid chromatography (LC)–MS/MS (mass spectrometry). The following phenolic compounds were investigated: catechin, protocatechuic acid, gallic acid, ellagic acid, chlorogenic acid, 4-hydroxybenzaldehyde, p -coumaric acid, rutin, naringenin, kaempferol . Based on the results obtained, the roots and flowers of the plant are found to be very rich in ellagic acid (3473.57 µg g-1 dry plant) and catechin (2228.76 µg g-1 dry plant). The amount of chlorogenic acid (54.570 µg g-1 dry plant) is also high in the roots. The amounts of protocatechuic acid (122.5 µg g-1 dry plant) and gallic acid (725.34 µg g-1 dry plant) are high in the leaves. In addition, the total extract of G. ibericum obtained from leaf, flower, and root was tested against 6 gram-negative bacteria and Candida albicans . The G. ibericum extract was nearly as effective as commercial antibiotics at some concentrations (500-750 µg µL-1) for Acinetobacter baumannii , Klebsiella pneumonia , Proteus mirabilis , and Bacillus cereus .

Thermostable xylanases contribute to enhancing dough properties and bread quality in industrial baking. This study aimed to identify a high-yield thermophilic xylanase producer, optimize its heterologous expression, and evaluate its functional role in baking applications. Screening of 19 Anoxybacillus species identified A. bogrovensis as the highest xylanase producer. The xyn gene was cloned and expressed in Escherichia coli BL21, and the recombinant enzyme (iAboXYN) was purified using heat treatment, ion-exchange, and hydrophobic interaction chromatography. Biochemical characterization confirmed high thermal and pH stability, with over 50 % activity retained up to 80 °C and moderate stability observed at 90 °C, along with broad pH adaptability (5.0-8.5) and metal ion resistance. The enzyme's functional role in dough processing was assessed using a direct dose-response analysis, demonstrating improvements in dough stability, elasticity, and hydration efficiency while reducing mixing time and water absorption. Application in bread formulations led to enhanced loaf volume, improved crumb structure, and better texture, with sensory evaluation confirming superior quality. Preference ranking tests further validated the improved consumer perception of iAboXYN-treated bread. These findings establish iAboXYN as a functional biocatalyst for enzyme-assisted baking, offering a scalable approach to optimizing dough properties and improving bread quality.

Hazelnut has become an important commercial product in recent years due to its worldwide applications in the pharmaceutical industry as well as in the confectionery and food industry. In addition, hazelnut shell is a waste material obtained after hazelnut harvest and mainly used as heating sources. However, its bioproducts are essentially a very important phytochemical source. In this study, the composition of phenolic compounds, carotenoids, tocopherols and fatty acids of different bioproducts of hazelnut plant were investigated. The highest phenolic compound content (2630.84 µg/g), and lutein amount (73.05 µg/g) were determined in green leafy cover. The major fatty acids were found to be as oleic acid (81.493%), linoleic acid (7.778%) and palmitic acid (6.408%), respectively. Total tocopherol concentration of hazelnut kernel was determined as 364.1 µg/g. In the present study, the antibacterial activity of hazelnut bioproducts was determined using eight pathogenic bacteria. They showed strong antimicrobial activity against the Gram (+) and Gram (-) bacteria which might be attributed to the rich phytochemical composition of hazelnut bioproducts. This work comprehensively summarized the chemical composition of hazelnut bioproducts and their antibacterial activity potential grown in Giresun-Türkiye region which had an important place in the global market.