Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
Browse
12 results
Search Results
Article Gıda Işınlaması, Uygulamaları ve Tüketicinin Işınlanmış Gıdaya Bakış Açısı(Harran Üniversitesi, 2005) Korel, Figen; Orman, SibelGıda güvenliğinin sağlanması için daha iyi gıda muhafaza yöntemlerine ihtiyaç duyulmaktadır. Gıda ışınlaması, mikoorganizmaların, parazitlerin ve böceklerin gelişimi ile depolama ve dağıtım sırasında oluşabilecek ciddi kayıpları kontrol altında tutabileceği öngörülen yöntemlerden biridir. Işınlama uygulamaları gıda ürünlerinin raf ömrünü artırmaktadır. Bu makalede ışınlamanın gıda ürünlerinin muhafazasında kullanımı ve tüketicilerin ışınlanmış gıdaya bakış açıları incelenmiştir.Conference Object Risk Management of Ready-To Meat Products Contaminated With Listeria Monocytogenes(Technical Research Center of Finland, 2009) Korel, FigenNowadays, the modern life style relies heavily on the availability, quality, and safety of ready-to-eat (RTE) food products. The quality of the raw material, handling, processing, transportation and storage are the important factors influencing the microbial quality of the finished product. The mostly consumed RTE meat products are hamburgers, frankfurters, hot dogs, dry/semi-dry fermented sausages, salami, and deli meats. Several pathogens could be found on RTE meat products, including Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, and Staphylococcus aureus. Vegetative pathogens are destroyed during thorough cooking and processing of these products. Contamination during post-processing in the plant, and further contamination and improper handling during storage, at retail or in home cause microbial growth. Pathogens can multiply under inappropriate conditions causing foodborne diseases and outbreaks.Conference Object Risk Assessment in Miscellaneous Food Processing Industries Including Producers of Vegetables and Spices(Technical Research Center of Finland, 2008) Güldaş, Metin; Ursu, Roxana; Lagouri, Vasiliki; Kısıkkaya, N. Aslı; Uyar, M. Fatih; Mokorel, Primoz; Türe, Hasan; Lee, Solmaz; Korel, Figen; Karpiskova, RenataTesting foods for pathogenic and spoilage bacteria is the cornerstone to ensuring a safe and wholesome food supply. The methods for monitoring of microbial contamination are based on the following principles: → Cultivation of microbes in the presence of different energy sources, → Analysis of their macromolecular composition and their metabolic byproducts, → Use of specific immunological reagents for bacterial classification and identification.Conference Object Antimicrobial Effects in Food and Prevention of Contamination in Food Industry(VTT Technical Research Center of Finland, 2007) Hütt, Pirje; Songisepp, Epp; Güldaş, Metin; Tamme, Terje; Ormancı, Fatma Seda; Ayaz, Naim Deniz; Korel, Figen; Aarnisalo, Kaarina; Hradecka, Helena; Mikelsaar, MarikaThe most commonly recognized food-borne infections are caused by Campylobacter jejuni and Salmonella spp. In the past 25 years, Listeria monocytogenes has become increasingly important as a food-associated pathogen. Though, an annual incidence of human listeriosis is between two and ten reported cases per million in EU countries. Because of its high case fatality rate, listeriosis ranks among the most frequent causes of death due to food-borne illness. L. monocytogenes and C. jejuni has been shown to adapt to different environmental stress factors, including disinfectants. Salmonella enteritidis, C. jejuni and L. monocytogenes may also form a biolfim which helps to survive in the environment. For that reason, the food industrial hygiene has become important to avoid contamination of raw food and food products with these pathogens.Article Citation - WoS: 36Citation - Scopus: 38Antimicrobial Activity of Lactoperoxidase System Incorporated Into Cross-Linked Alginate Films(John Wiley and Sons Inc., 2009) Yener, Fatih Yalçın Güneş; Korel, Figen; Yemenicioğlu, AhmetIn this study, the antimicrobial effect of lactoperoxidase (LPS) incorporated alginate films was investigated on Escherichia coli (NRRL B-3008), Listeria innocua (NRRL B-33314), and Pseudomonas fluorescens (NRRL B-253) in presence of different concentrations of H2O2 (0.2, 0.4, and 0.8 mM) and KSCN (1, 2, and 4 mM). The incorporation of 70 nmol ABTS/min/cm2 LPS into alginate films gave 0.66 to 0.85 nmol ABTS/min/cm2 enzyme activity at 0.2 to 0.8 mM H2O 2 concentration range. The antimicrobial activity of LPS system on target bacteria changed according to the concentrations of KSCN and H 2O2. The growth of all tested bacteria was prevented for a 6-h period by applying LPS system in presence of 0.4 or 0.8 mM H 2O2 and 4 mM KSCN. At 0.8 mM H2O2 and 4 mM KSCN, the LPS system also inhibited growth of L. innocua and P. fluorescens for a 24-h incubation period, whereas E. coli growth could not be inhibited for 24 h under these conditions. At 0.2 mM H2O2 and 1 to 4 mM KSCN, a considerable inhibitory effect was obtained only on P. fluorescens. The decreasing order of the resistance of studied bacteria to LPS system is as follows: E. coli, L. innocua, and P. fluorescens. The developed antimicrobial system has a good potential for use in meat, poultry, and seafood since alginate coatings are already used in these products. Further studies are needed to test the LPS incorporated edible films in real food systems.Article Citation - WoS: 94Citation - Scopus: 106Distribution of Simple Phenols, Phenolic Acids and Flavonoids in Turkish Monovarietal Extra Virgin Olive Oils for Two Harvest Years(Elsevier Ltd., 2009) Ocakoğlu, Derya; Tokatlı, Figen; Özen, Fatma Banu; Korel, FigenMonovarietal extra virgin olive oils extracted from six dominant and economically important Turkish olive cultivars (memecik, erkence, domat, nizip-yaglik, gemlik, ayvalik) were examined for their simple phenolics, phenolic acids and flavonoid compounds over 2005 and 2006 harvest years. Total phenol contents, oxidative stabilities and chromatic ordinates as colour parameters were also measured. The most typical phenolic compounds that were identified in both years are hydroxytyrosol, tyrosol, vanillic acid, p-coumaric acid, cinnamic acid, luteolin, and apigenin. Multivariate data were analysed by principal component and partial least square-discriminant analyses. It was observed that phenolic profiles of olive oils depended highly on harvest season. In addition, oils of different olive cultivars have different distribution of phenols. No significant correlation was observed between oxidative stability and phenolic compounds. Increase in peroxide value over an accelerated oxidation period of 11 days showed weak correlations with total phenol content, vanillin, syringic acid and colour parameter a*, as 0.56, 0.55, -0.42, and 0.51, respectively, in terms of correlation coefficient r.Conference Object Evaluation and Production of Ready-To Meals(Technical Research Center of Finland, 2009) Baysal, Taner; Tamme, Terje; Ehavald, Helen; Korel, Figen; Overes, Maarten; Hödrejärv, Ülle; Kala, Aet; Roasto, MatiReady-to-eat (RTE) is defined as the status of the food being ready for immediate consumption at the point of sale or serve. It could be served as raw or cooked, hot or chilled, and can be consumed without further heat-treatment including reheating (Anon., 2001). RTE vegetables and salads, also called minimally-processed products, are raw products that must preserve as much as possible the nutritional, sensorial and microbial qualities of fresh products. A very wide range of vegetables are used, both cut and whole. Even during refrigerated storage, the fresh fruits and vegetables are characterized by active metabolism.Conference Object Microbial Risks Associated With Traditional Cheeses(VTT Technical Research Center of Finland, 2009) Korel, FigenNowadays, there is a growing interest towards traditional cheeses. These cheeses are especially popular in Mediterranean countries due to their unique flavor and texture. Traditionally they are produced from raw milk of cow, sheep or goat and fermented by naturally occurring indigenous lactic acid bacteria. The quality of these cheeses is based on the microbial associations within the respective region and production recipes change from one town to another and even from one manufacturer to another within the same town. Hygiene practices in the dairy and in the cheese rooms are the most important criterion in traditional cheese manufacturing.Article Citation - WoS: 125Citation - Scopus: 147Incorporation of Partially Purified Hen Egg White Lysozyme Into Zein Films for Antimicrobial Food Packaging(Elsevier Ltd., 2006) Mecitoğlu, Çiğdem; Yemenicioğlu, Ahmet; Arslanoğlu, Alper; Elmacı, Zehra Seda; Korel, Figen; Çetin, Ali EmrahLysozyme, partially purified from hen egg white by precipitation of non-enzyme protein with ethanol and lyophilized after dialysis, was incorporated into zein films. The recovery and specific activity of the enzyme after partial purification varied between 45% and 72% and 2173 and 3448 U/mg, whereas the activity of the lyophilized enzyme varied between 2900 and 3351 U/mg. The partially purified enzyme was very stable and lost almost no activity in lyophilized form or in zein films stored at -18 and 4°C for up to 8 and 4 months, respectively. During partial purification and in zein film preparation, ethanol treatment caused 123-137% and 132-315% activation of the enzyme, respectively. In zein films incorporated with 187-1318 U/cm2 (63-455 μg/cm2) lysozyme, the release rates at 4°C, changed between 7 and 29 U/cm2/min, increased at high lysozyme concentrations. Zein films incorporated with partially purified lysozyme showed antimicrobial effect on Bacillus subtilis and Lactobacillus plantarum. By the addition of disodium EDTA, the films also became effective on Escherichia coli. The results of this study showed that the partially purified lysozyme may be used in antimicrobial packaging to increase food safety.Article Citation - WoS: 17Citation - Scopus: 20Composition, Color and Mechanical Characteristics of Pretreated Candied Chestnuts(Taylor and Francis Ltd., 2006) Korel, Figen; Balaban, Murat ÖmerRaw-peeled chestnuts were treated with citric acid or sodium metabisulphite, steamed, and dipped into sugar solutions containing dextrose and sucrose, or dextrose and fructose. Composition, mineral content, weight change, rheological properties, and color were measured at each step. Carbohydrate content increased during processing. Candied chestnuts were low in protein (1.31-1.35%) and lipids (0.29-0.78%) but high in carbohydrates (73.48-76.13%). Their mineral concentrations were: Ca 19.08-46.70, Cu 0.19-0.52, Fe 0.88-1.98, K 180.5-659.1, Mg 26.83-69.57, Mn 0.70-2.42, Zn 1.51-6.95 mg/100 g sample. Rheological properties were affected by processing steps. Dipping into sugar solutions did not affect rheological properties. Color changes were quantified, and average L*, a*, and b*values measured.