ANALYSIS OF THE EFFECT OF HIGH-PRESSURE HOMOGENIZATION (HPH) ON THE SETTLING VELOCITY OF PARTICLES IN AN ALCOHOLIC RICE BEVERAGE USING VIDEO RECORDING, TURBIDITY AND COMPUTATIONAL FLUID DYNAMIC SIMULATION

초록

High-pressure homogenization (HPH) was applied to an alcoholic rice beverage (ARB). The effects of pressure (48-172MPa) and the number of passes (1-3) on the fluid properties of the ARB, such as particle size, viscosity, turbidity and settling velocity, were investigated. Mean diameters continuously decreased with increasing homogenization pressure (P) and pass number (PN) until it reached a saturated condition (172MPa with PN=2). The viscosity and volume fraction of ARBs proportionally increased with increasing P and PN. The turbidity of HPH-treated samples had stable characteristic until approximately 40min. The settling velocities estimated by three different methods, including video recording, computational fluid dynamics simulation and analytic solutions (free and hindered flow). The free and hindered settling velocity of nonhomogenized and HPH-treated samples were in the range of 1.2x10(-4) to 1.7x10(-4) and 0.3x10(-7) to 4.3x10(-7)m/s, respectively. Practical ApplicationFor alcoholic rice beverages (ARB), the unique translucent milky color differentiates ARB from distilled alcoholic beverage. The translucency is mainly due to the solid particles in the ARB, which could not be completely separated by the coarse filtration. Settling of solid particles caused a phase separation of ARB during storage or even serving in the glass. Our study showed that the high-pressure homogenization (HPH) dramatically reduced the particle size of the ARB. Consequently, the settling velocity of HPH-treated samples were significantly lower than that of nonhomogenized (NH) sample. The phase separation of ARB was delayed significantly after HPH.

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