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Öğe Determination of physical and chemical properties of oleogels prepared with olive oil and olive-based emulsifier(Wiley, 2021) Erinc, Hakan; Okur, IlhamiThis study aimed to investigate the use of olive-based emulsifier (OBE), as an oleogelator, in the production of olive oil oleogels and to determine some physical and chemical properties of oleogels. For this purpose, olive oil was mixed with a different ratio of OBE (0.5%-10% wt/wt), and analyses of minimum gelation concentration, gelation time, oil-binding capacity, and stability of oleogels were undertaken. In addition, free fatty acid, peroxide value, color analysis, and textural properties of oleogels were investigated during the storage period (90 days). According to the results, the minimum gelation concentration of OBE was found as 4%. The gelation time decreased with increased OBE content, and it was found 5 min 42 s at 10% concentration. Furthermore, oil-binding capacity and stability increased in parallel to OBE concentration. According to rheological analysis, oleogels have elastic-dominant behavior, and gel point (T-g) of the oleogels was founded around 40 degrees C. In color analysis, greenery, yellowness, and brightness decreased with increasing OBE concentration, resulting in opaque oleogels. Free fatty acid and peroxide value analyses demonstrated the suitability of the produced oleogels for storage. In brief, oleogels containing OBE can be successfully used in the food industry with their favorable physical, chemical, and textural properties. Practical applications Oleogelation has been actively explored as an emerging technology geared towards the development of healthier lipid-based food products to modify lifestyle and prevent diet-induced diseases such as obesity and cardiovascular diseases. Olive-based emulsifier (OBE) is food grade plant material, low cost and, white flake at 70 degrees C, so it can be used in foods like margarine. It consists of sorbitan olivate and cetearyl olivate derived from olive oil. Hence, the objective of this study is to evaluate the textural, rheological and structural properties of oleogels prepared with OBE.Öğe Evaluation of the Effect of Different Extraction Techniques on Sour Cherry Pomace Phenolic Content and Antioxidant Activity and Determination of Phenolic Compounds by FTIR and HPLC(Springer, 2019) Okur, Ilhami; Baltacioglu, Cem; Agcam, Erdal; Baltacioglu, Hande; Alpas, HamiSour cherry pomace derived from mashed cherries that maintains the color and beneficial properties of the cherries (Prunus cerasus L.). In this study, microwave-assisted extraction (MAE) (900 W for 30, 60 and 90 s.), high hydrostatic pressure (HHP) (400 and 500 MPa for 1, 5 and 10 min at 20 degrees C) and ultrasonic-assisted extraction (UAE) (for 5,10 and 15 min with a power of 100%) was used as novel processes. Total phenolic content (TPC), morphological changes, antioxidant activity (AA) and structural changes of cherry pomace were measured by the Folin-Ciocalteu assay, high performance liquid chromatography (HPLC), DPPH-scavenging activity, scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). According to the results, all novel technologies (MAE-HHP-UAE) increase PC and AA with respect to conventional solvent extraction method (50 degrees C and 30 min) (CSE). Among novel technologies, MAE (90 s) had highest TPC (275.31 +/- 4.26 GAE/100 g FW) and also had highest antioxidant activity (89.9 +/- 0.22%). The lowest TPC and AA values were 108.36 +/- 3.99 mg gallic acid equivalent (GAE)/100 g fresh weight (FW) and 71.30 +/- 1.21% in CSE, respectively. According to FTIR results, there are no significant structural changes in samples when different extraction techniques were applied. Individual phenolics were quantified by using HPLC for different extraction techniques. GraphicÖğe High hydrostatic pressure assisted extraction of pectin from sugar beet pulp(Wiley, 2021) Kaya, Burcu; Okur, Ilhami; Alpas, Hami; Oztop, Mecit HalilThis study aimed to investigate the effect of high hydrostatic pressure assisted extraction (HHPE) (250, 350 and 450 MPa at 40 degrees C for 5 min with/without acid addition) of pectin from sugar beet pulp and compare its properties with pectin obtained from conventional extraction (CE). Degree of esterification (DE), galacturonic acid (Gal-A) content, Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) relaxometry experiments were performed on the obtained pectin powder. HHPE (12.23 +/- 0.13%) doubled extraction yield compared to CE (6.43 +/- 0.07%). Also, HHPE and acid addition were found to have a synergetic effect on the extraction. HHPE resulted in degradations in the polymer structure and reduced Gal-A content and DE. Pectin extracted with both methods was classified as low methoxyl pectin (LMP). According to the NMR Relaxometry results, HHPE decreased water holding capacity (WHC). In brief, HHP was shown to increase the pectin extraction yield and no changes in viscosity were observed at the concentrations studied (2 g/L).Öğe Improving the physical properties of fish gelatin by high hydrostatic pressure (HHP) and ultrasonication (US)(Wiley, 2020) Sezer, Purlen; Okur, Ilhami; Oztop, Mecit Halil; Alpas, HamiIn this study, it was aimed to improve the physical properties of fish gelatin by using high hydrostatic pressure (HHP) and ultrasonication (US). Gelatin solutions were exposed to different pressures and ultrasonication separately and gelled afterwards. The physicochemical measurements based on gel strength, turbidity and rheology experiments showed that HHP treatment on fish and bovine gelatin stabilized the gelatin network by organising the structure and reducing the free volume. Both processing methods (HHP and US) increased the gel strength significantly (P < 0.05) compared with non-treated samples. Fourier-transform infrared spectroscopy (FTIR) results indicated that conformations of amino acids changed after the treatments. Furthermore, US treatment was shown to destroy the gelatin network, change the gelation mechanism and decreased the degree of aggregation. Both treatments improved the gel characteristics as gel strength, gelling and melting temperatures of the fish gelatin. At the end, the best combination for fish gelatin among HHP and US treatments was found as 400 MPa-10 degrees C-15 min pressurisation.Öğe Improving the Recovery of Phenolic Compounds from Spent Coffee Grounds (SCG) by Environmentally Friendly Extraction Techniques(Mdpi, 2021) Okur, Ilhami; Soyler, Betul; Sezer, Purlen; Oztop, Mecit Halil; Alpas, HamiThe aim of this study was to investigate and compare the effects of different extraction techniques (high hydrostatic pressure-assisted extraction (HHPE), ultrasound-assisted extraction (UAE), and classical solvent extraction (CSE)) on phenolic compounds from spent coffee grounds (SCG). Different HHPE parameters (300, 400 and 500 MPa at 25 degrees C for 5, 10 and 15 min) and UAE parameters (40%, 50%, and 60% amplitude at 25 degrees C for 5, 10 and 15 min) were used. These techniques were compared with CSE (at 50 degrees C for 30 min) according to total phenolic content (TPC), antioxidant activity (AA), high-performance liquid chromatography (HPLC), scanning electron microscopy (SEM), and infrared (IR) spectroscopy. The results showed that eco-friendly techniques increased the TPC and AA compared to CSE and morphological changes were verified by SEM results. Furthermore, chlorogenic and caffeic acid were also quantified by using HPLC. Chlorogenic acid was found as the main phenolic compound in spent coffee grounds (SCG). The highest chlorogenic acid was detected as 85.0 +/- 0.6 mg/kg FW with UAE at 60% amplitude for 15 min. In brief, for the extraction of phenolic compounds from waste SCG eco-friendly techniques such as HHPE and/or UAE were more convenient than CSE.Öğe Nuclear Magnetic Resonance (NMR) study of Palm Kernel Stearin: Effects of cooling rate on crystallization behaviour(Elsevier, 2022) Okur, Ilhami; Ozel, Baris; Ucbas, Derya; Grunin, Leonid; Okur, Purlen Sezer; Alpas, Hami; Ide, SemraIn this study, effects of different cooling rates (0.5,3.3,4.7 and 6.9 degrees C/min) on the crystallization behavior of palm-kernel-stearin (PKS) were studied by low-field NMR relaxometry. According to results, solid fat content (SFC), longitudinal relaxation time (T1), second moment (M2) and degree of crystallinity (%) of the samples increased with increase in cooling rate from 0.5 to 6.9 degrees C/min. In contrast, transverse relaxation time (T2) demonstrated an opposite behavior with respect to T1 and decreased when the cooling rate increased. Additionally, effects of cooling rate on the changes of polymorph structures were detected by X-ray measurements. Degree of crystallinity showed high Pearson correlation values (alpha <= 0.05) with SFC (r = 0.771) and T1(r = 0.932). Changes in the crystal polymorphs could also be explained by NMR parameters to some extent as can be observed by the strong correlation between the 13 crystal content and T2 (r = 0.927). At the highest cooling rate, 13 ' crystals were the dominant polymorphic form and constituted 75(%) of the total crystals present. Results of this study suggested that NMR relaxometry could be used as a complementary tool to interpret the crystallization behavior of PKS.Öğe Optimization of microwave-assisted extraction of phenolic compounds from tomato: Characterization by FTIR and HPLC and comparison with conventional solvent extraction(Elsevier, 2021) Baltacioglu, Hande; Baltacioglu, Cem; Okur, Ilhami; Tanrivermis, Arif; Yalic, MuharremIn the extraction of phenolic compounds from tomato, Microwave-Assisted Extraction (MAE) was used as a novel technology in this study and compared to conventional solvent extraction (CSE). The optimal extraction conditions for tomato were determined using the multi-level factorial design. For this purpose, different powers (360, 600 and 900 W) and times (30, 60 and 90 s) were used for MAE and also different temperatures (40, 50 and 60 degrees C) and times (10, 20 and 30 min) were used for CSE. Total phenolic content (TPC), antioxidant activity (AA), and morphological changes were measured by the Folin-Ciocalteu assay, DPPH-scavenging activity, scanning electron microscopy (SEM) respectively. Phenolic compounds of tomato extracts were determined by using Fourier transform infrared (FTIR) spectroscopy and high performance liquid chromatography (HPLC). According to the results, MAE increased TPC and AA compared to CSE. The highest TPC (436.20 +/- 4.34 mg GAE/kg FW) and antioxidant activity (39.15 +/- 0.91 % of DPPH inhibition) was observed for MAE at 900 W, 90 s which was related with morphological changes, determined by SEM. Multivariate analysis (PCA and PLS) were used to discriminate and construct chemometric models in order to predict AA or TPC of the extracts using IR spectra. The bands found in the FTIR spectrum were found to be associated with chlomgenic acid and ferulic acid. Furthermore, chlorogenic acid, caffeic acid, p-coumaric acid, and ferulic acid were quantified with HPLC. Chlorogenic acid was detected as the main phenolic compound in tomato extracts. The highest amount of chlorogenic acid, caffeic acid, p-coumaric acid, and ferulic acid was found as 52.33 +/- 0.80, 5.03 +/- 0.37, 0.803 +/- 0.017 and 0.506 +/- 0.013 mg/kg FW, respectively with MAE at 900 w 90 s.Öğe Recent advances in gelatinisation and retrogradation of starch by high hydrostatic pressure(Wiley, 2021) Okur, Ilhami; Sezer, Purlen; Oztop, Mecit Halil; Alpas, HamiStarch is the major polysaccharide following cellulose, but native starch has limited application due to physicochemical and functional properties. To handle such problems, starch is usually modified with either thermal or more recently by non-thermal technologies such as high hydrostatic pressure (HHP). HHP is a non-thermal technique that can be applied to a variety of food materials with minimum effect on nutritional quality. High-pressure levels can cause physicochemical changes in starch such as partial/completely gelatinisation, reduction in solubility and swelling power, increasing pasting temperature and content of slowly digestible starch (SDS) and retention of retrogradation. These physicochemical changes depend on the starch type, pressurisation level, treatment time and temperature. This review has evaluated and synthesised the current research about the effect of HHP on starch gelatinisation, retrogradation and physicochemical properties of starch.Öğe Recovery of phenolic compounds from peach pomace using conventional solvent extraction and different emerging techniques(Wiley, 2024) Baltacioglu, Cem; Baltacioglu, Hande; Okur, Ilhami; Yetisen, Mehmet; Alpas, HamiThe study compared high-pressure, microwave, ultrasonic, and traditional extraction techniques. The following extraction conditions were implemented: microwave-assisted extraction (MAE) at 900 W power for durations of 30, 60, and 90 s; ultrasonic-assisted extraction (UAE) at 100% amplitude for periods of 5, 10, and 15 min; and high-pressure processing (HPP) at pressures of 400 and 500 MPa for durations of 1, 5, and 10 min. The highest yield in terms of total phenolic content (PC) was obtained in UAE with a value of 45.13 +/- 1.09 mg gallic acid equivalent (GAE)/100 g fresh weight (FW). The highest PC content was determined using HPP-500 MPa for 10 min, resulting in 40 mg GAE/100 g, and MAE for 90 s, yielding 34.40 mg GAE/100 g FW. The highest value of antioxidant activity (AA) was obtained by UAE in 51.9% +/- 0.71%. The PCs were identified through the utilization of Fourier transform infrared (FTIR) spectroscopy and high-performance liquid chromatography (HPLC). Utilizing multivariate analysis, the construction of chemometric models were executed to predict AA or total PC of the extracts, leveraging the information from IR spectra. The FTIR spectrum revealed bands associated with apigenin, and the application of HPP resulted in concentrations of 5.41 +/- 0.25 mg/100 g FW for apigenin and 1.30 +/- 0.15 mg/100 g FW for protocatechuic acid. Furthermore, HPLC analysis detected the presence of protocatechuic acid, caffeic acid, p-coumaric acid, and apigenin in both green extraction methods and the classical method. Apigenin emerged as the predominant phenolic compound in peach extracts. The highest concentrations of apigenin, p-coumaric acid, and protocatechuic acid were observed under HPP treatment, measuring 5.41 +/- 0.25, 0.21 +/- 0.04, and 1.30 +/- 0.15 mg/kg FW, respectively.
