کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4563069 | 1330743 | 2007 | 8 صفحه PDF | دانلود رایگان |
The effect of particles and serum characteristics on turbidity of natural, or “regular”, and modeled cloudy apple juices was studied in this work. Modeled apple juices were made by re-dispersing a determined quantity of apple particles in a simplified serum (mainly glucose, hydrolyzed pectin, and malic acid in water). Only glucose was found to have a significant effect on turbidity. Particle size was affected by soluble solids concentration, which was attributed to conformational changes in juice particles aggregates, simultaneously with a reduction in particle solvatation. Scattering efficiency was determined in natural and modeled cloudy apple juice both experimentally from a nephelometric method, Qav∗, and theoretically with the Mie theory, QMie. Decrease in juice specific turbidity at increasing soluble solids concentrations (X ), was governed by the decrease of Qav∗ at increasing refractive index of the liquid medium nm. As predicted by theory, the scattering efficiency increased at increasing particle size, for a constant nm. Finally, calculated values of Qav∗ and QMie followed a power law relationship when correlated. This non-linear behavior was explained by considering that QMie is the theoretical scattering efficiency of monodisperse-homogeneous spheres, while Qav∗ is the experimental nephelometric scattering efficiency of polydisperse-irregular particles.
Journal: Food Research International - Volume 40, Issue 7, August 2007, Pages 915–922