Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Citation - WoS: 1Citation - Scopus: 1In Vitro Assessment of Food-Derived Bioaccessibility and Bioavailability in Bicameral Cell Culture System(Türk Biyokimya Derneği, 2020) Özel Taşcı, Cansu; Pilatin, Gözde; Edeer, Özgür; Güleç, ŞükrüBackground: Functional foods can help prevent metabolic diseases, and it is essential to evaluate functional characteristics of foods through in vitro and in vivo experimental approaches. Objective: We aimed to use the bicameral cell culture system combined with the in vitro digestion to evaluate glucose bioavailability. Materials and methods: Cake, almond paste, and pudding were modified by adding fiber and replacing sugar with sweeteners and polyols. Digestion process was modeled in test tubes. Rat enterocyte cells (IEC-6) were grown in a bicameral cell culture system to mimic the physiological characteristics of the human intestine. The glucose bioaccessibility and cellular glucose efflux were measured by glucose oxidase assay. Results and discussion: The glucose bioaccessibilities of modified foods were significantly lower (cake: 2.6 fold, almond paste: 9.2 fold, pudding 2.8 fold) than the controls. Cellular glucose effluxes also decreased in the modified cake, almond paste, and pudding by 2.2, 4, and 2 fold respectively compared to their controls. Conclusion: Our results suggest that combining in vitro enzymatic digestion with cell culture studies can be a practical way to test in vitro glucose bioaccessibility and bioavailability in functional food development.Article Citation - WoS: 12Citation - Scopus: 12Mid-Infrared Spectroscopic Detection of Sunflower Oil Adulteration With Safflower Oil(CSIC Consejo Superior de Investigaciones Cientificas, 2019) Uncu, Oğuz; Özen, Banu; Tokatlı, FigenThe oil industry is in need of rapid analysis techniques to differentiate mixtures of safflower-sunflower oils from pure oils. The current adulteration detection methods are generally cumbersome and detection limits are questionable. The aim of this study was to test the capability of a mid-infrared spectroscopic method to detect the adulteration of sunflower oil with safflower oil compared to fatty acid analysis. Mid-infrared spectra of pure oils and their mixtures at the 10-60% range were obtained at 4000-650 cm(-1) wavenumber and fatty acid profiles were determined. Data were analyzed by multivariate statistical analysis techniques. The lowest level of detection was obtained with mid-infrared spectroscopy at 30% while the fatty acid profile could determine adulteration at around 60%. Adulteration levels were predicted successfully using PLS regression analysis of infrared data with R-2 (calibration) = 0.96 and R-2 (validation) = 0.93. As a rapid and minimum waste generating technique, mid-infrared spectroscopy could be a useful tool for the screening of raw material to detect safflower-sunflower oil mixtures.Article Citation - WoS: 5Citation - Scopus: 5Chemometric Analysis of Chemo-Optical Data for the Assessment of Olive Oil Blended With Hazelnut Oil(Stazione Sperimentale per le Industrie, 2019) Kadiroğlu, Pınar; Korel, Figen; Pardo, MatteoThe main objective of this study was to determine different hazelnut oil concentrations in extra virgin olive oil (EV00) belonging to different geographical regions inside Turkey using the combination of a SAW sensor based electronic nose (e-nose) and a machine vision system (MVS). We leveraged the oil characterisation given by the two easy-to-use and complementary experimental techniques through the adoption of conventional PCA for data exploration and random forests (RF) for supervised learning. The e-nose/MVS combination allows significantly better results both in adulteration detection independently of EVOO's geographical provenance and in EVO0 geographical provenance determination, independently of the adulteration level, with respect to the single characterisation method. RF analysis also produces feature ranking, permitting to shed light on which oils' characteristics influence the learning result. We found that EV00 geographical provenance discrimination is mainly due to yellowness and guaiacol content, while (E)-2-hexenal chiefly determines the prediction of the hazelnut level.Article Citation - WoS: 8Citation - Scopus: 8Usage of Rice Milk in Probiotic Yoghurt Production(North University of Baia Mare, 2016) Uzuner, Aydın Erdem; Kınık, Özer; Korel, Figen; Yıldız, Gamze; Yerlikaya, OktayThere are previous studies focusing on the production of probiotic and fermented dairy products made using vegetable based raw materials like oats and soy, however there is a limited number of studies on the usage of rice milk in fermented dairy products. Four different types of yoghurt samples were produced and stored for 21 days at 4°C. Physical, chemical, microbiological and sensory characteristics of the samples were performed at the 1st, 7th, 14th and 21st days of the storage. It was determined that rice milk increased the viscosity values but decreased the values of the texture, whey separation and the chemical and microbiological properties of yoghurts. Acetaldehyde, acetoin, acetone and diacetyl of carbonyl compounds were detected as main flavor components of yoghurt samples. In the sensory analysis, scores decreased as the rice milk proportions in yoghurt was increased and the panelists reported that P1 sample (25% rice milk + 75% cow's milk) was the closest sample to the control sample (100% cow's milk). Generally speaking, samples containing rice milk did not give good results. However, P1 samples were the most favored products among the samples containing rice milk as they were the closest product to the control group. The consumption of such products is continuously increasing as the customers' tendency to consider them as functional products rather than traditional food products increase.Article Kinetic and Structural Characterization of Interaction Between Trypsin and Equisetum Arvense Extract(Türk Biyokimya Derneği, 2014) Uslu, Mehmet Emin; Bayraktar, Oğuz; Ceylan, ÇağatayObjective: In this study the inhibitory effect of E. arvense extract on trypsin activity and the effect of trypsin on E. arvense extract were studied. In addition the nature of the interaction between the extract and trypsin was investigated. Methods: The inhibitory effect ethanol extract of E. arvense on trypsin activity was determined using trypsin enzyme assay. The structural effects of the extract-trypsin interaction for the extract were analyzed by FTIR. Finally, the HPLC analyses were carried out to analyze the individual components of the extract and the supernatant and soluble precipitate phases. Results: E. arvense extract was found to decrease total percent activity of trypsin to 5% in 24 hour at 24 °C. FTIR analyses indicated that the interaction between trypsin and E. arvense extract caused changes in the structure and hydrogen bonding behavior and composition of the extract proteins. These interactions also caused the extract lipids to accumulate in the insoluble precipitate phase. Most of the phenolics remained in the supernatant phase enhancing the inactivation of trypsin. However, the precipitated compounds were shown to be of apolar in nature as shown in the HPLC chromatograms. Conclusion: The methods that were used showed that the high phenolic content of E. arvense was the main reason for the inhibition of trypsin enzyme activity by denaturing the enzyme.Article Citation - WoS: 1Citation - Scopus: 2Structural and Functional Characterization of Solution, Gel, and Aggregated Forms of Trypsin in Organic Solvent-Assisted and Ph-Induced Phase Changes(Türk Biyokimya Derneği, 2015) Ceylan, Çağatay; Karaçiçek, BilgeIn this study the effect of three different physicochemical parameters on pHtriggered gelation and aggregation of bovine pancreatic trypsin changes and structural and functional changes in these changes in alcohol-water mixtures were studied. Methods: Trypsin gelation times were studied using inverted tube method. Trypsin stability was studied using trypsin enzyme assay. Protein secondary structural changes were monitored using FTIR spectroscopy. Gel and aggregate macrostructures and morphologies were viewed using Scanning Electron Microscopy. Results: The solution phase was observed in the absence of both NaOH and CaCl2. The gel phase was observed in the absence of the either. The aggregate phase was observed in the presence of the both agents all depending on trypsin concentrations used. Trypsin stability studies showed that there were a nearly 53 and 32% specific activity losses after the gelation and aggregation processes. According to FTIR studies β–sheet structure in 1637 cm-1 band disappeared in trypsin gel and trypsin aggregates. Increases in α–helix structure in 1651 cm-1 in trypsin gel and aggregates were observed. Iodoacetamide delayed the gelation and prevented the aggregation indicating the importance of intermolecular disulfides in the both processes. Conclusion: Trypsin gelation was caused by the denaturation of the protein three dimensional structures. The gel and aggregate formation indicates a secondary structural change towards α–helix structure formation at the expense of β–sheet structure and formation of intermolecular disulfide bonds.Article Citation - WoS: 20Citation - Scopus: 23Antimicrobial Potential of Polylysine in Edible Films(Japanese Society for Food Science and Technology, 2011) Uysal Ünalan, İlke; Arserim Uçar, Dılhun Keriman; Arcan, İskender; Korel, Figen; Yemenicioğlu, AhmetThe antimicrobial activity of edible films from whey proteins, alginate, zein and chitosan incorporated with polylysine (PL) and PL- ethylenediaminetetraacetic acid (Na 2EDTA) combination have been tested on different bacteria including Escherichia coli, Listeria innocua, Salmonella Typhimurium and Stapylococcus aureus. The PL-containing films of whey proteins, alginate and chitosan were effective on L. innocua, but had limited effect on E. coli. On the other hand, the PL-containing zein films showed good antimicrobial activity on both E. coli and L. innocua as well as on S. aureus. PL-Na 2EDTA combination also gave zein films effective on S. Typhimurium. The incorporation of PL alone or PL-Na 2EDTA combination did not cause any significant change in mechanical properties of zein films. Zein has a good potential to develop novel antimicrobial packaging materials incorporated with PL.