Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Citation - WoS: 4Citation - Scopus: 4The Volatile Compounds, Free Fatty Acid Composition and Microbiological Properties of Sepet Cheese Packaged With Different Modified Atmosphere Conditions(Kafkas Üniversitesi, 2017) Akpınar, Aslı; Yerlikaya, Oktay; Kınık, Özer; Kahraman, Cihan; Korel, Figen; Uysal, Harun RaşitThe objective of this present study was to investigate traditional sepet cheese samples which were packaged with different modified atmosphere conditions (MAP). The volatile compounds, free fatty acid composition and microbiological properties of Sepet cheeses were analyzed on 1., 45., 90. and 180. day of the storage period at +4°C. In packaking of cheese, three different modified atmosphere packaging conditions were tried. These cheeses were packaged into polystyrene packages that include 100% N2 (N), 80% N2 + 20% CO2 (NC), 100% CO2 (C). In accordance with volatile compounds of sepet cheese samples, it was shown that control cheese sample was different from MAP samples in terms of aroma fractions. MAP samples showed variability in preservation of aroma fractions. When fatty acid composition during the storage period was researched, it was found that there was a significant difference in all samples. When microbiological properties were investigated statistically, it was determined that there was not a significant difference in samples during storage. In general, it could be said that sepet cheeses that were packaged in different modified conditions protected their specialities better.Article Citation - WoS: 1Citation - Scopus: 1Prevalence of Salmonella in Edible Offal in Afyonkarahisar Province, Turkey(Kafkas Üniversitesi, 2012) Akkaya, Levent; Atabay, Halil İbrahim; Gök, Veli; Yaman, HilmiIn this study, the prevalence of Salmonella sp. was examined using a total of 205 edible bovine offal samples collected from different abattoirs (n=105) and butcheries (n=100) by immunomagnetic separation (IMS) method. The isolation rate of Salmonella was found to be 8.57%, 5.71% and 5.71% for the liver, kidney and tripe samples collected from the abattoir, respectively. Of the offal samples obtained from the butcheries, the detection rate of Salmonella sp. was 16% in the liver and 4% in the kidney, tripe and brain samples. Overall, it was found that 8.29% of all the offal samples obtained from the abattoirs and butcheries were determined to be contaminated with Salmonella sp. The results of this study shows that edible offal are cross-contaminated by Salmonella sp. at the abattoirs and retail sale points until they reach to the consumer. It is recommended that adequate hygienic and sanitary measures be taken in these kind of places in order to protect public health.Article Citation - WoS: 8Citation - Scopus: 7Commercially Suitable Pectin Methylesterase From Valencia Orange Peels(Türkiye Klinikleri Journal of Medical Sciences, 2010) Şimşek, Şebnem; Yemenicioğlu, AhmetA simple and effective procedure was developed to extract pectin methylesterase (PME) from Valencia orange peels. Orange peels contain 25-34 μmol of COOH min-1 g-1 of peel PME activity. The enzyme was ionically bound to cell walls and could not be extracted with water. This enables removal of water soluble pectic substances and oils from peels via homogenization and washing with water before enzyme extraction. Enzyme extraction can be conducted simply by addition of suitable amounts of NaCl (optimum: 10 g of NaCl 100 g-1 of extraction mixture) to peel homogenate and stirring (optimum: 30 min at 200 rpm). The PME extracted from orange peels contains almost the same amount of heat-stable and heat-labile fraction, and the enzymes cannot be activated by mild heating. A slight activation of enzyme (almost 20%) was achieved by adding 1 mM CaCl2 to enzyme extracts, but this agent was inhibitory at higher concentrations. The extracts stabilized by Na-benzoate and K-sorbate maintained more than 90% of their PME activity at 4 °C for at least 5 months. The obtained PME was successfully used to prepare low-methoxyl citrus pectin used in edible film formation in the presence of CaCl2. This study shows the potential of using Valencia orange peels as a source of commercial PME. © TÜBİTAK.Article Citation - WoS: 11Citation - Scopus: 16Partial Purification of Hen Egg White Lysozyme by Ethanol Precipitation Method and Determination of the Thermal Stability of Its Lyophilized Form(Türkiye Klinikleri Journal of Medical Sciences, 2007) Gemili, Seyhun; Umdu, Emin Selahattin; Yaprak, Nilgün; Üstok, Fatma Işık; Yener, Fatih Yalçın Güneş; Mecitoğlu Güçbilmez, Çiğdem; Altınkaya, Sacide; Yemenicioğlu, AhmetLysozyme was partially purified from hen egg white by precipitation of non-lysozyme protein impurities during incubation in the prence of ethanol. The thermal stability of the obtained partially purified enzyme was also characterized. The incubation of diluted egg white for 2-8 h in the presence of 20% ethanol was not very effective for the partial purification of lysozyme by precipitation of major egg white proteins; however, 4- to 6-h or 6-h to 8-h incubation of diluted egg white in the presence of 30% and 40% ethanol could be employed more effectively for partial purification of lysozyme. Without applying the incubation period, the highest specific activity was obtained by the treatment of egg white with 40% ethanol. Thus, ethanol at this concentration could be used for a continuous process of partial purification. For batch lysozyme purification, on the other hand, incubation in the presence of 30% ethanol was more appropriate. The activities and protein contents of dialyzed and lyophilized enzymes obtained by 6 h-incubation in the presence of 20%, 30%. and 40% ethanol precipitations were 1878, 6669, and 6115 U/mg powder, and 0.98, 0.90, and 0.93 mg protein per mg powder, respectively. The ranges of thermal inactivation parameters, such as D (D80°C = 29.2-59 min, D90°c = 8.8-21 min) and z (Z80-90°c = 17.4-22.3 °C) values of the enzyme, clearly indicated the moderate and variable heat stability of lyophilized lysozymes obtained from different batches of egg white.