Nondestructive assessment of freshness in packaged sliced chicken breasts using SW-NIR spectroscopy

A technique was developed to predict the freshness of packaged sliced chicken breast employing a nondestructive visible and short-wavelength near-infrared (SW-NIR) spectroscopy method. Spectra were recorded at 0, 7 and 14days using a camera, spectral filter (400-1000nm) and a halogen flood lighting system which were developed and calibrated for the purpose. Physicochemical, biochemical and microbiological properties such as moisture (x w), water activity (a w), pH, total volatile basic nitrogen (TVB-N), ATP breakdown compounds (K 1 values) and mesophilic bacteria (cfu g -1) were determined to predict freshness degradation. The spectra obtained were related to the storage time of the samples. The best wavelengths for modeling freshness were 413, 426, 449, 460, 473, 480, 499, 638, 942, 946, 967, 970 and 982nm. A linear correlation was found between the visible and SW-NIR spectroscopy and parameters such as microbiological counts, K 1 and T-VBN indexes. © 2010 Elsevier Ltd.We wish to thank the Polytechnic University of Valencia and Generalitat Valenciana for the financial support they provided through the PAID-06-08-3251 and GVPRE/2008/170 Projects, respectively.Grau Meló, R.; Sánchez Salmerón, AJ.; Girón Hernández, LJ.; Ivorra Martínez, E.; Fuentes López, A.; Barat Baviera, JM. (2011). Nondestructive assessment of freshness in packaged sliced chicken breasts using SW-NIR spectroscopy. Food Research International. 44:331-337. doi:10.1016/j.foodres.2010.10.011S3313374

Large deflection of clamped circular plate and accuracy of its approximate analytical solutions

A different set of governing equations on the large deflection of plates are derived by the principle of virtual work (PVW), which also leads to a different set of boundary conditions. Boundary conditions play an important role in determining the computation accuracy of the large deflection of plates. Our boundary conditions are shown to be more appropriate by analyzing their difference with the previous ones. The accuracy of approximate analytical solutions is important to the bulge/blister tests and the application of various sensors with the plate structure. Different approximate analytical solutions are presented and their accuracies are evaluated by comparing them with the numerical results. The error sources are also analyzed. A new approximate analytical solution is proposed and shown to have a better approximation. The approximate analytical solution offers a much simpler and more direct framework to study the plate-membrane transition behavior of deflection as compared with the previous approaches of complex numerical integration