Beslenme ve Diyetetik Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12514/223

Browse

Now showing 1 - 5 of 5

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.
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.
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.
Electrochemical Behavior of Pt Nano-Particles Dispersed on Cu/Ni Electrode in Alkaline Environment
(Pergamon-elsevier Science Ltd, 2024) Doslu, Serap Toprak; Doner, Ali
The development of a low-cost Pt-based electrocatalyst for industrial water splitting is important. In this study, to prepare cost-efficient Pt-based electrocatalyst for hydrogen evolution, Cu electrode is deposited with nickel (Cu/ Ni) and this surface is modified with Pt nanoparticles by electrodeposition method (Cu/Ni-Pt). The surface properties of the produced electrocatalysts are studied via X-ray diffraction (XRD), scanning electron spectroscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Characterizations demonstrated that the coating is homogeneous and compact. Hydrogen evolution and corrosion behaviors of prepared electrode (Cu/Ni-Pt) are examined in 1.0 M KOH solution using cyclic voltammetry (CV) and cathodic and anodic current-potential curves, electrochemical impedance spectroscopy (EIS). Tafel slope is determined to be 133 mV dec(-1) on Cu/Ni-Pt. Very high exchange current density (5.65 mA cm(-2)) and very low charge transfer resistance (0.91 Omega cm(2) at 1.05 V vs RHE) are measured again on this electrocatalyst. High activity is due to intrinsic activity of Pt and synergistic interaction of Pt and Ni. Besides, Cu/Ni-Pt exhibits so stable structure over 4 h without any current densities decay as well as showing good corrosion performance after long-term immersion times and these properties make it possible electrocatalyst with high corrosion resistant and activity in the water electrolysis systems.
Experimental and theoretical study on hydrogen production by using Ag nanoparticle-decorated graphite/Ni cathode
(International Journal of Energy Research, 2021) Yıldız, Reşit; Doğru Mert, Başak; Karazehir, Tolga; Gurdal, Yeliz; Toprak Döşlü, Serap; Yıldız, Reşit
In this study, graphite (G) electrode was coated with nickel and decorated with silver nanoparticles (G/Ni/Ag) with the help of galvanostatic method, and electrodes were used as a cathode in alkaline water electrolysis system. The characterization was achieved using X-ray diffraction and field emission scanning electron microscopy. Hydrogen evolution performance of electrodes was investigated via cyclic voltammetry, chronoamperometry, cathodic polarization curves, and electrochemical impedance measurements. Electrochemical results showed that hydrogen production efficiency significantly increased and charge transfer resistance decreased via G/Ni/Ag. The electrochemical water splitting performance of G/Ni/Ag, was established in a joint experimental and computational effort. Water and proton adsorption on Ag-decorated Ni surface were investigated using density functional theory. Electronic structure calculations identified the role of Ag adatom and Ni surface on water and proton adsorptions. From the computational studies, O in water was more reliable to adsorb at the bridge position of the Ag and Ni atoms, leading improved orbital overlap between H and Ni atoms and maximized chemical and physical interactions between the H2O molecules. Therefore, the Ag-decorated Ni(111) surface provides preferable adsorption site for the O atom in water and direct interactions between water Hs and available surface Ni atoms promote water dissociation.

Browse

Browsing Beslenme ve Diyetetik Bölümü Koleksiyonu by WoS Q "Q1"