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In this research, the effects of whey protein concentrate based edible coatings containing different concentrations of natamycin and lysozyme–xanthan gum conjugate were investigated. For this purpose, Escherichia coli O157:H7 (as an indicator for gram negative bacteria and also resistant to commercial pasteurization), Staphylococcus aureus (as an indicator of gram-positive bacteria), and Penicillium chrysogenum were inoculated to ultrafiltrated white cheese surface and the microbial properties of cheese samples were evaluated during 28 days storing. The results showed that all coated treatments significantly reduced the growth of Penicillium chrysogenum. Natamycin-containing coatings have been more effective in reducing the mold population than lysozyme-xanthan-containing coatings. Coated samples containing 600 ppm lysozyme-xanthan reduced E. coli O157: H7 growth 2.09 log compared to control samples. Also, the growth rates of Staphylococcus aureus were lower in all samples treated with lysozyme-xanthan than control sample. The lowest growth rate of Staphylococcus aureus was observed in the coated sample containing 600 ppm lysozyme-xanthan on 28^th day, with a microbial population of 2.60 logarithms. Unlike other treatments, the growth rate of Staphylococcus aureus in the sample coated containing 600 ppm lysozyme-xanthan was descending over 28 days. The results of this study showed that whey protein based edible coating can be used as a carrier of natamycin and lysozyme-xanthan in optimal concentration, for increasing the microbial quality of UF cheese.

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One of the methods for solving Navier-Stokes equations in order to analyse aerodynamic flows is using finite volume method. Since aerodynamic flows are mostly in the range of compressible flows, here one of the density based algorithm (CUSP) have been studied to connecting equations. So here by adding LD (Low diffusion) part to the CUSP method a new method LDE (Low diffusion E-CUSP) have been created which containing new improved discretizations and it has been extended for a unstructured two dimensional mesh. Because of using edge-based data structure it gives the ability to solve the unstructured and structured meshes. Also the discretization of time section is done explicitly by Runge-Kutta method. It has acceptable stability range in compare with the amount of calculation utilized. Then, the results of new improved method (LDE) have been studied for a unstructured 2d mesh and compared with old method which it has been improved for unstructured mesh. The results show that the convergence time and the number of iterations to reach desired error are reduced. Also error percentage of numerical results like pressure coefficient is reduced. Moreover, dissipation of this new method does better than first method in terms of capturing shock location in a proper way.