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Öğe Cold press in oil extraction. A review(Natl Univ Food Technologies, 2018) Cakaloglu, Busra; Ozyurt, Vasfiye Hazal; Otles, SemihIntroduction. The aim of this review is to explain the working principle of the cold press machine and discuss the effect of the extraction efficiency. The advantages and disadvantages of the extraction by means of cold press were explained by referring to other extraction methods. Material and method. The oil extraction from oilseeds by cold press method investigated for this study. The studies related with cold press were examined and the comparison of cold press with other methods used in oil production from oily seeds was compiled. Results and discussion. Cold press extraction is one of the methods of mechanical extraction as well as required less energy than other oil extraction techniques and also environmental friendly. It is used to extract oil from a range of matrices and is produced especially in the oil production from oilseeds. High-quality oils can be obtained by performing production at low temperatures using cold press method. It has an environmentally friendly use with no solvents. In other words, the cold-press extraction does not involve either heat or chemical extraction. The soybean, sunflower, rapeseed, corn, grapeseed, hemp, flaxseed, rice bran, olive and pumpkin oils were obtained by cold press extraction method. Moreover, these oils are interesting for consumers due to their natural and safe as well as prevent certain diseases and improve human health due to including a higher level of lipophilic phytochemicals such as antioxidants. These oils have better nutritive properties than refined oils. However, they have a lot of advantages, one of the disadvantages of this technique is low productivity. Another disadvantage of this technique is hard to extract same quality product. The cold pressed oils can add to food as natural antioxidative additives due to phytochemicals and as fatty acid supplements due due to invaluabile double bond fatty acid. There are several studies to investigate the other chemical compounds in the oils and try to use in food products. Conclusion. While observing the studies, it was generally focused on cold press extraction.Öğe Determination of 3-nitrotyrosine in food protein suspensions(Elsevier Science Bv, 2017) Ozyurt, Vasfiye Hazal; Otles, SemihTo explain the formation of protein nitration marker, 3 nitrotyrosine (3NT), in food products was the basis for the present study. For the accurate detection as protein nitration marker of 3NT in food products, i) a new method was improved, which is optimized parameters affected the formation of 3NT, ii) HPLC-DAD was applied as a straightforward and rapid methodology and iii) finally the suspensions representing meat and dairy products were prepared and this method was used to these suspensions to evaluate the convenience of it. For comparative purposes, the spectrophotometric method of the determination of 3NT level was also employed to assess the 3NT level. The results showed that optimized method enabled detection of 3NT level in food systems and 3NT could act as a protein nitration biomarker in food. This study will shed light on the understanding of precise mechanisms about protein nitration and contribute to the change of amino acids during processing and storage.Öğe EFFECT OF FOOD PROCESSING ON THE PHYSICOCHEMICAL PROPERTIES OF DIETARY FIBRE(Poznan Univ Life Sciences, 2016) Ozyurt, Vasfiye Hazal; Otles, SemihProducts derived from the manufacturing or processing of plant based foods: cereals, fruits, vegetables, as well as algae, are sources of abundant dietary fibre. Diets high in dietary fibre have been associated with the reduced risk of cardiovascular disease, diabetes, hypertension, obesity, and gastrointestinal disorders. These fibre-rich products and byproducts can also fortify foods, increase their dietary fibre content and result in healthy products, low in calories, cholesterol and fat. Traditionally, consumers have chosen foods such as whole grains, fruits and vegetables as sources of dietary fibre. Recently, food manufacturers have responded to consumer demand for foods with a higher fibre content by developing products in which high-fibre ingredients are used. Different food processing methods also increase the dietary fiber content of food. Moreover, its chemical and physical properties may be affected by food processing. Some of them might even improve the functionality of fibre. Therefore, they may also be applied as functional ingredients to improve physical properties like the physical and structural properties of hydration, oil-holding capacity, viscosity. This study was conducted to examine the effect of different food processing methods on the physicochemical properties of dietary fibre.Öğe EFFECTS OF THE THERMOSONICATION CLARIFICATION ON THE RHEOLOGICAL PROPERTIES OF APPLE JUICE(Galati Univ Press, 2019) Ozyurt, Vasfiye Hazal; Icier, Filiz; Otles, SemihIn this study, the clarification of apple juice (AJ) was performed by using a bath type sonicator at different temperatures. The effects of thermosonication applied on the rheological properties, and some physico-chemical characteristics (total soluble solids: Brix, pH, titratable acidity, color, cloud value and total phenolics content) of these apple juices were studied. Using four different rheological models, namely Herschel Bulkley, Power-law, Bingham, and Newtonian, the flow behaviors of apple juices were assessed. The results showed higher lightness values for thermosonicated apple juices. The amounts of total soluble sugar and titratable acidity of control and thermosonicated apple juices weren't affected. The total phenolic contents of thermosonicated apple juices were significantly higher than control. The apple juices were found to be pseudoplastic fluids with a shear thinning nature. The thermosonication treatment was statistically significant in the change of rheological properties. The Herschel Bulkley model was found to be the best fit to the experimental data of all samples. Results revealed that the sonication technique could successfully be implemented on an industrial scale for the processing of apple juices. The obtained data could be taken into account in the industrial production of AJ with ultrasound treatment, particularly in the estimation of pumping requirement and the change of velocity profiles.Öğe Influence of process conditions on ultrasound-assisted protein extraction from cold pressed tomato seed waste(Wiley, 2021) Ozyurt, Vasfiye Hazal; Tetik, Irmak; otles, SemihTomato seed waste is obtained in large amounts in tomato paste processing. In this study, ultrasound-assisted protein extraction of tomato seed waste was used and extraction parameters were optimized using response surface methodology. Effects of independent variables (liquid:solid ratio, ultrasound duration, and extraction duration) were evaluated on the extraction yield, and optimal extraction conditions were determined as 52 ml/g, 2 min 18 s and 60 min, respectively. The optimum protein yield was found as 35.75%. Structural and physicochemical properties of tomato seed waste protein were also determined. These obtained results present important information for the determination quality characteristics of tomato seed oil in optimum extraction conditions. It can be concluded that ultrasound-assisted extraction is an efficient technique for the extraction of protein from tomato seed waste, and the obtained protein has the potential applications in the food industry. Novelty impact statement Defatted tomato seed cake obtained from tomato seed oil processing was used to obtain tomato seedprotein isolate. Ultrasound-assisted extraction methods were optimized by response surface methodology to maximize protein yield. The physicochemical properties of tomato seed protein isolate were searched, whether it may be a new protein source.Öğe Investigation of the effect of sodium nitrite on protein oxidation markers in food protein suspensions(Wiley, 2020) Ozyurt, Vasfiye Hazal; Otles, SemihThe aim of this study is to investigate the effect of sodium nitrite (NaNO2) on protein oxidation and the use of 3-nitrotyrosine (3NT) as a protein oxidation marker in suspensions of the food protein. Food proteins, namely bovine serum albumin, casein, and myofibrillar protein, were suspended in 100 mM sodium phosphate buffer and nitrated with 25 mu M iron (III) chloride, 2.5 mM hydrogen peroxide, and 150 mg/kg NaNO2 at 37 degrees C for a period of 24 hr. the food protein suspensions were analyzed at different sampling periods for the loss of tryptophan (TRY) residues as well as the formation of Schiff bases (SBs), protein carbonyls, 3NT, and dityrosine (DT). It was found that NaNO2 has pro-oxidant activity in NaNO2-added food protein suspensions due to the increased amounts of SBs, protein carbonyls, 3NT, and DT as well as decreased TRY fluorescence. Positive correlations between the 3NT and other protein oxidation markers except for TRY fluorescence were found in NaNO2-added food protein suspensions. in conclusion, these findings on the detection of 3NT indicate that it might be a useful tool as a new protein oxidation biomarker in food samples. Practical applications Sodium nitrite (NaNO2) supports protein oxidation in different food protein suspension. 3-nitrotyrosine (3NT) was found in food protein suspensions and can be a potential biomarker for protein nitration in food sample due to potential relationship between 3NT and other oxidation markers. the results showed that this study has formed novel insight into interaction between NaNO2 and food proteins and indicate that it might affect the food quality and its nutritional value. Moreover, the relationship between protein oxidation/nitration and food quality as well as the comprehension of the scientific and technological meaning of these phenomena has been hindered because of the lack of knowledge about the basic chemistry behind the protein oxidation and nitration pathways. For the clarification of these phenomena, further studies are still needed.Öğe Lipid-Protein Oxidation and In Vitro Digestibility of Fermented Turkey Sausages as Affected by Lipid Formulation(Wiley, 2022) Serdaroglu, Meltem; Ozturk-Kerimoglu, Burcu; Zungur-Bastioglu, Asli; Kavusan, Hulya Serpil; Otles, Semih; Ozyurt, Vasfiye HazalThis research investigates the effects of using different lipid formulations (100% beef fat, 85% beef fat+15% olive oil, or 70% beef fat+30% olive oil) in fermented turkey sausages on protein-lipid oxidation, in vitro digestibility, and related quality parameters. The use of olive oil results in decreased fat content, modified fatty acid profile, and increased pH value, acidity, and water activity, besides changes are recorded in instrumental quality and sensory features. Lipid oxidation is higher in samples with 30% olive oil than in the others. Carbonyl content increases depending on oil level and storage time. alpha-aminoadipic semialdehyde is only detected in products containing 30% olive oil and their concentrations increased with storage. gamma-glutamic semialdehyde also increases by olive oil inclusion, but decrements are recorded during storage. Increasing olive oil results in increased pepsin digestibility but losses are recorded in both pepsin and trypsin plus (alpha-chymotrypsin digestion rates during storage. Practical applications: Inclusion of vegetable oils into meat product formulations has been preferred recently to supply healthier products, but in this situation, oxidative deterioration again becomes a considerable problem affecting overall quality. The data obtained from the present work wil contribute to understand the impacts of formulation and processing operations on the formation of oxidation products and change in digestibility, thereby to pioneer further research on this topic.Öğe Nitration of tyrosine and its effect on DNA hybridization(Elsevier Advanced Technology, 2018) Topkaya, Seda Nur; Ozyurt, Vasfiye Hazal; Cetin, Arif E.; Otles, SemihOne major marker of nitrosative stress is the formation of 3-Nitrotyrosine (3-NT) from Tyrosine (Tyr) by adding a nitro group (-NO2) with nitrating agents. Nitration of Tyr often causes loss of protein activity and is linked with many diseases. In this article, we detect 3-NT and discriminate it from Tyr with Differential Pulse Voltammetry (DPV) as it is a very important biomarker. We first examined redox (oxidation/reduction) properties and stability of 3-NT in detail. Second, we provided the Tyr and 3-NT discrimination with DPV and compared with the chromatography. We then explored the interaction of 3-NT and DNA oligonucleotides. Our findings demonstrate that 3-NT can be used as a new electrochemical indicator, which is able to detect hybridization of probe (single stranded DNA-ssDNA) and hybrid (double stranded DNA-dsDNA) both via 3-NT reduction and guanine oxidation signal changes at the same time. The signal differences enabled us to distinguish ssDNA and dsDNA without using a label or a tag. Moreover, we achieved to detect hybridization of DNA by using the reduction signal of 3-NT obtained at -0.4 V vs. Ag/AgCl. More importantly, we observed the changes of the reduction signals of 3-NT after the interaction of probe and hybrid sequences. We showed that 3-NT signal decreases more with hybrid than the probe. Our platform, for the first time, demonstrates the detection of hybridization both guanine oxidation and indicator reduction signal changes at the same time. Moreover, we, for the first time, demonstrated the interaction between 3-NT and DNA.Öğe Optimization of cold press and enzymatic-assisted aqueous oil extraction from tomato seed by response surface methodology: Effect on quality characteristics(Wiley, 2021) Ozyurt, Vasfiye Hazal; Cakaloglu, Busra; Otles, SemihTomato seeds, which are the byproducts of tomato paste processing, were used to obtain tomato seed oil using two different extraction methods: cold press extraction (CPE) and enzyme-assisted aqueous extraction (EAAE). To maximize oil amount, the experimental parameters of those two methods were optimized separately by response surface methodology. The optimized methods were used to evaluate their quality characteristics. The maximum oil amounts for tomato seed oil using CPE and EAAE were found as 12.80% and 9.66%, respectively. These obtained results present important information for the determination quality characteristics including the physical, chemical, microbiological, and bioactivity properties of tomato seed oil in both extraction methods used. The comparison of two methods shows that they are both ecology friendly extraction methods. It also helps to a great extend to evaluate quality characteristics and bioactivity properties of tomato seed oil. Therefore, tomato seed oils extracted by two methods are promising for future usage as functional food. This manuscript will comprise the basis of our future studies analyzing the new compounds obtained from agro-food waste. Practical applications Recently, world agricultural and food sector has faced an important problem, which is food waste. Food wastes have the high-value compounds such as carbohydrates, protein, lipids, nutraceuticals, etc. The wastage of these high-value compounds causes both an environmental and economical problems. To come up with this problem, there is a need for green and sustainable approaches leading to extract of these compounds with low environmental impact. We extracted tomato seed oil using two different green technologies and also evaluated their quality and functional properties, whether they use as food additives, preservatives, texturizing agent, coloring agents, etc. Two different extraction methods were optimized separately by response surface methodology to maximize oil amounts. Both tomato seed oils might be used as a good alternative in future in the preventing and therapeutic strategies.Öğe OPTIMIZATION OF EXTRACTION PARAMETERS FOR FUCOXANTHIN, GALLIC ACID AND RUTIN FROM NITZSCHIA THERMALIS(Odessa Natl Acad Food Technologies, 2019) Ozyurt, Vasfiye Hazal; Erdogan, Aysegul; Demirel, Zeliha; Dalay, Meltem Conk; Otles, SemihRecently, microalgae have become important in their health, and cosmetic applications since they are viewed as new sources of carotenoids. Fucoxanthin is also a type of carotenoid. The anti-diabetic, anti-obesity, anti-cancer, and antioxidant properties of fucoxanthin have been widely reported. Since these valuable properties, they also represent a valuable resource of nutraceuticals for functional food applications. This study aims to determine the amount of fucoxanthin, gallic acid, and rutin in Nitzschia thermalis obtained from the Ege University Microalgae Culture Collection. The extraction parameters have been optimized using response surface methodology. The extraction temperature (25, 35, and 45 degrees C), the extraction time (10, 20, and 30 min) and the biomass/solvent ratio (0.005, 0.001, and 0.015 g ml(-1)) have been assessed as response variables in the Box - Behnken design. The amount of fucoxanthin was determined by the C-30 column at 450 nm, while both the amount of gallic acid and rutin were separated in the C-18 column at 275 nm by HPLC-DAD. In the present study, the optimum extraction conditions providing the maximum amount of fucoxantin, gallic acid, and rutin were selected by applying the "desirability" function approach in response surface methodology. Finally, the temperature has been determined to be 27.30 degrees C, the extraction time 10 minutes, and the biomass ratio 0.05 g ml(-1). Under these conditions, the optimum fucoxanthin level has been determined as 5.8702 mg g(-1), the gallic acid level as 0.0140 mg g(-1), and the rutin level as 0.0496 mg g(-1). The findings are in good agreement with international published values for fucoxanthin content. In addition, response surface methodology was shown to be an effective technique for optimising extraction conditions for maximum fucoxanthin yield. In conclusion, these findings may be applied in the development of extraction methodologies for value added microalgea products as well as can serve as a reference for the extraction of fucoxanthin having high gallic acid and rutin from other brown microalgae, and therefore it could potentially be applied in both pharmaceutical and food industries.Öğe PROBIOTIC AND PREBIOTIC BEVERAGES(Woodhead Publ Ltd, 2019) Otles, Semih; Ozyurt, Vasfiye Hazal[No abstract available]Öğe Protein oxidation and in vitro digestibility of heat-treated fermented sausages: How do they change with the effect of lipid formulation during processing?(Wiley, 2019) Ozturk-Kerimoglu, Burcu; Nacak, Berker; Ozyurt, Vasfiye Hazal; Serdaroglu, MeltemIn the present work, it was aimed to evaluate the oxidative stress indicators and in vitro digestibility during the processing of heat-treated Turkish sausages (sucuk) manufactured using different lipid formulations. The utilization of olive oil in sausage formulations had considerable impacts on proximate composition, pH, and water activity. The increased olive oil content increased primary lipid oxidation products, whereas it decreased the secondary ones. The use of olive oil increased the total carbonyl content, while it decreased the alpha-aminoadipic semialdehyde concentration. In general, pepsin, trypsin, and alpha-chymotrypsin activities of the treatments were similar to each other. The heat treatment during the processing significantly increased most of the oxidation markers. Though strong correlations were recorded between specific oxidation markers, no relationship was detected between oxidation parameters and in vitro digestibility. The results indicated that the lipid formulation and processing operations had significant impact on chemical and functional properties of heat-treated fermented sausages, within the complex interrelationships between oxidation mechanisms. Practical applications The present work pointed out the changes and correlations between specific oxidation markers and in vitro digestibility of heat-treated fermented sausages during the production procedure. Oxidation reactions that occur in both proteins and lipids could have drastic impact on overall quality; for this reason, it is of great importance to provide the data for lightening these impacts regarding the product types and production applications. Since heat-treated muscle foods are widely manufactured to meet industrial needs, the data obtained from this research would contribute to understand the effects of formulation and processing operations in the formation of oxidation products and change in digestibility, thereby to pioneer further research on this topic.Öğe Structured lipids intended for infant nutrition(Academic Press Ltd-Elsevier Science Ltd, 2020) Otles, Semih; Ozyurt, Vasfiye Hazal[No abstract available]Öğe Usage of betalain extracts in food(Pamukkale Univ, 2019) Ozyurt, Vasfiye Hazal; Sarali, Hazal; Otles, SemihWith the development of the food industry, changes in environmental factors create an effect of color loss in the stages such as, processing, storing and selling the food. Colour los is one of the most important factor for consumers purchasing the product. That's why for preventing the color loss natural and synthetical colorants are used. Consumers directed to use of natural products with the increasing health issues as a result of industrialization. With increasing attention of usage of natural products, producers are directed to use of natural colorants. Betalain is a natural colorant that was used in flowers and fruits also, it belongs to Caryophyllales family. At the same time, through its antioxidant, anticancer and antilipidemic effects, it creates a positive effect on health. Thus, nowadays using betalain as a natural colorant became an interesting subject. in this article, it was purposed giving information in the areas of the molecular and chemical structure of betalain, their stability, extraction, and usage in foods of betalain and its effects on the health.
