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Ticari Salmonella Faj Preparatının Beyaz Peynirde Salmonella spp. Üzerine Etkisinin Araştırılması
2018
Esra Uğur | Zübeyde Öner
Bu çalışmada, ticari faj preparatının çiğ sütten yapılmış beyaz peynirde Salmonella kontrolü üzerine etkisi araştırılmıştır. Bu amaçla Salmonella faj preparatı kullanılmıştır. Beyaz peynir üretimi 4 grupta yapılmıştır. Bunlar; 1-kontrol grubu (çiğ süt), 2-çiğ süt+patojen (Salmonella Typhi, %0,05), 3- çiğ süt+faj ilave edilen (%0,1), 4-patojen (%0,05) + faj (%0,1) grubu olarak belirlenmiştir. Beyaz peynir örneklerinde olgunlaşmanın 0., 30., 60. ve 90. günlerinde fizikokimyasal ve mikrobiyolojik analizleri yapılmıştır. Yapılan fiziko-kimyasal analizler; pH, titrasyon asitliği (ºSH), kuru madde, kuru maddede yağ, tuz ve kuru maddede tuz tayinidir. Mikrobiyolojik analizler; toplam aerobik mezofil bakteri, laktik asit bakterileri, Stafilokok spp., koliform grubu bakteri, Salmonella spp. ile faj ilave edilen peynir örneklerinde faj titresi analizidir. Ayrıca faj ilave edilen örneklerin sütlerinde ve peynir altı sularında faj titresi durumu incelenmiştir. Peynir örneklerinde, faj uygulamasının veya söz konusu bir patojen bulaşısının örnekler arasında fiziko-kimyasal ile genel mikrobiyolojik özellikleri bakımından farklılık gösterici etkisinin olmadığı elde edilen veriler sonucunda belirlenmiştir. Bu değerler tüm peynir gruplarında sadece süreye göre değişkenlik göstermiştir. Salmonella spp. sayısında ise 90. günde 2 ve 4 numaralı grup arasındaki fark kontrol grubuna göre kıyaslandığında istatistiksel olarak önemli bulunmuştur. Bunun haricinde Salmonella spp. sayıları gruplar arasında farklı bulunmamış, sadece olgunlaşmanın doğal süreci olarak günlere göre azalış göstermiştir. Bu çalışma sonucunda, çiğ sütten yapılan beyaz peynirlerde bakteriyofaj ilavesinin peynirin fiziko-kimyasal ve mikrobiyolojik özelliklerine etki etmediği ve faj etkisi ile patojen bakteri sayısında önemli bir fark olmadığı tespit edilmiştir.
Afficher plus [+] Moins [-]Modelling Chemical Preservation of Plantain Hybrid Fruits
2017
Ogueri Nwaiwu | Martin Itumoh
New plantain hybrids plants have been developed but not much has been done on the post-harvest keeping quality of the fruits and how they are affected by microbial colonization. Hence fruits from a tetraploid hybrid PITA 2 (TMPx 548-9) obtained by crossing plantain varieties Obino l’Ewai and Calcutta 4 (AA) and two local triploid (AAB) plantain landraces Agbagba and Obino l’Ewai were subjected to various concentrations of acetic, sorbic and propionic acid to determine the impact of chemical concentration, chemical type and plantain variety on ripening and weight loss of plantain fruits. Analysis of titratable acidity, moisture content and total soluble solids showed that there were no significant differences between fruits of hybrid and local varieties. The longest time to ripening from harvest (24 days) was achieved with fruits of Agbagba treated with 3% propionic acid. However, fruits of PITA 2 hybrid treated with propionic and sorbic acid at 3% showed the longest green life which indicated that the chemicals may work better at higher concentrations. The Obino l’Ewai cultivar had the highest weight loss for all chemical types used. Modelling data obtained showed that plantain variety had the most significant effect on ripening and indicates that ripening of the fruits may depend on the plantain variety. It appears that weight loss of fruits from the plantain hybrid and local cultivars was not affected by the plantain variety, chemical type. The chemicals at higher concentrations may have an effect on ripening of the fruits and will need further investigation.
Afficher plus [+] Moins [-]The Influence of Different Ripening Stages, Harvest and Drying Methods on Quality of Unsulfured Sun-Dried Apricots
2020
Emrah Çoban | Hüseyin Karlıdağ | İbrahim Kutalmış Kutsal
This study was carried out between 2017 and 2018 to determine physical and chemical influences of two drying methods (drying on wooden fruit drying trays and drying cloths), two harvesting periods (commercial / physiological maturity and late harvest), and two harvesting methods (harvesting by hand and shaking) on dried fruit samples of Hacıhaliloğlu and Kabaaşı cultivars. Titrable acidity, browning level, total phenolic content, antioxidant activity (ABTS), color (L*, a*, b*), pH, humidity and water activity (aw) parameters of dried fruit samples were examined. Results indicated that different harvesting periods, methods and drying methods significantly affected almost all fruit quality parameters. L value was higher in apricots dried on trays than dried on the cloths. L* values of dried apricots ranged from 27,13 to 54,74. Similarly, moisture content and water activity values were also found to be lower in apricots dried on wooden fruit drying trays than dried on clothes. When chemical parameters were examined, it was observed that phenolic compounds and total antioxidant contents decreased with fruit ripening. The effect of the applications on drying efficiency was not determined as significant, on the contrary, the individual weights of the dried apricots harvested at the late period were found significantly higher and the number of dried apricots per kilogram was lower. As a result of the study, it was concluded that in sun-dried apricot production, harvesting at late period and the drying on trays positively affected various quality parameters.
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