Sürdürülebilir Kalkınma Amaçları
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- MakaleYalnız künye2026Scopus SJRQ2Microwave-assisted extraction of pectin from persimmon: physicochemical properties, structural characterization and greenness assessment
Yılmaz, Özlem; Kutlu, Naciye; Kamiloğlu, Aybike; Elbir Abca, Tuğba
In this study, the microwave-assisted extraction (MAE) of pectin from persimmon was optimized using a Box-Behnken experimental design, with pH, extraction time, and liquid-to-solid ratio as independent variables. The optimization results obtained through response surface methodology indicated optimum conditions of pH 1.78, extraction time of 8 min, and a liquid-to-solid ratio of 125 mL/g, corresponding to a predicted pectin yield of 4.28%. In the validation experiment, the actual pectin yield was determined to be 3.79 ± 0.04%, confirming a good agreement with the model predictions. The degree of esterification, methoxyl content, galacturonic acid and ash contents, water- and oil-holding capacities, antioxidant activity, rheological behavior, and structural properties (FT-IR, DSC, and 1H NMR) of the samples obtained under optimal MAE and conventional extraction conditions were compared. Based on the degree of esterification, both samples were classified as high-methoxyl, with galacturonic acid contents of 41% and 42% for the MAE and conventionally extracted samples, respectively; both values were below the ≥ 65% level specified for commercial food-grade pectin. The ash content was higher in the MAE sample (7.22%) than in the conventionally extracted sample (1.56%). MAE resulted in a pectin-rich complex with a relatively low galacturonic acid content and higher antioxidant activity than the conventionally extracted sample. Furthermore, the MAE sample exhibited higher water-holding capacity but lower oil-binding capacity than the conventionally extracted sample. Rheological analysis showed that the MAE sample exhibited higher apparent viscosity and shear stress than the conventionally extracted sample. FT-IR analysis revealed more pronounced absorption bands in the MAE sample, suggesting structural differences. DSC analysis revealed differences in the thermal behavior of the MAE and conventionally extracted samples. Additionally, 1H NMR analysis supported the presence of characteristic pectic structural features in both samples. The greenness assessment of the method was assessed using the Greenness Evaluation Metric for Analytical Methods (GEMAM), which yielded an overall score of 7.482, indicating a high level of environmental acceptability. Overall, MAE can be considered an efficient and sustainable approach for obtaining a pectin-rich complex with antioxidant activity from persimmon.
- MakaleAçık Erişim2022Scopus SJRQ3A comparative characterization study between fungal and bacterial eumelanin pigments
Bayram, Sinan
Melanins are the most common and the most enigmatic natural pigments in the nature that found in many different taxa group such as bacteria, yeasts, fungi, insects, plants, reptiles, birds and mammals. These biological macromolecules are highly complex cross-linked, heterogeneous biopolymers and composed of polymerized phenolic and/or indolic compounds. Recently, interest in these ubiquitous biopolymers has been increasing considerably in many different areas such as medicine, pharmacology, cosmetics, organic electronic and optoelectronics because of their versatile properties. In this study, four different extracellular eumelanin pigments (two bacterial eumelanins and two fungal eumelanins) were characterized by different spectrometric techniques such as FT-IR, XRD, NMR and UV-vis. In XRD analyzes, purified fungal and bacterial eumelanin pigments were characterized by giving a wide peak at about 22o with an angle of 2θ. Furthermore, in the 1 H NMR spectra of these biopolymers, it was observed that all pigments have signals in both aromatic and aliphatic regions. In addition to these analyzes, nanostructures of these biopolymers were characterized using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Finally, eumelanin pigment producer microorganisms were molecularly characterized. 16 S rDNA and 18 S rDNA sequence analysis results of these microorganisms (Streptomyces fulvissimus MPPS4, Streptomyces xiamenensis MPPS6, Aspergillus niger MPPF16 and Aspergillus terreus MPPF25) were deposited in NCBI GenBank® database with accession number MT825594, MT973972, MW652652 and MW652653 respectively.
AtıfScopus16WoS13OpenAlex14
İncele - MakaleAçık Erişim2021Scopus SJRQ2Production, purification, and characterization of Streptomyces sp. strain MPPS2 extracellular pyomelanin pigment
Bayram, Sinan
Melanins are natural pigments widely distributed in nature from bacteria to humans. These complex, negatively charged, amorphous, high molecular mass natural biopolymers have many different bioactive properties such as antimicrobial, antiviral, antioxidant, liver protective effects, etc. In this study, some chemical and physical properties of the purified extracellular pyomelanin pigment were investigated via XRD (X-ray diffraction), FT-IR (Fourier transform infrared), and 1H NMR (Nuclear magnetic resonance). Additionally, the melanin pigment producer Streptomyces sp. strain MPPS2 was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) and 16S rDNA sequence analysis. 16S rDNA nucleotide sequence analysis result was deposited in NCBI GenBank® under accession number MT825616.
AtıfScopus28WoS22OpenAlex27İncele