MODELADO MATEMATICO DEL PROCESO DE PASTEURIZACION DE CERVEZA ARTESANAL UTILIZANDO FLUIDODINAMICA COMPUTACIONAL (CFD)

ZARITZKY, NOEMÍ; DUCOS, MARTIN; SANTOS, M.V.; LESPINARD, ALEJANDRO R.; LIBKIND, D.

SAN CARLOS DE BARILOCHE

Workshop; IWOBY 2nd Intenational Workshop on Brewing Yeasts; 2021

UNCO, Fundación CRELTEC, CONICET

Pasteurization is the process of heating packaged and non-packaged food to eliminate live microorganisms that can deteriorate the finished product or be dangerous for the consumers, extending their shelf-life. After the pandemic (2020) the craft brewing sector has shifted mainly towards can packaging due to lockdown measures and shutdown of pubs, bars and restaurants which force brewers to find new commercial opportunities. In order to eliminate the cold transportation and minimize distribution costs a correct pasteurization process is an attractive alternative, since the product achieves a better shelf life with a clean-label formulation without the use of food preservatives. Since pasteurization is a thermal process it may affect flavor and quality of the beverage, therefore it must be carefully performed and monitored. The numerical simulations of the energy and momentum equations that describe the entire thermal process has proven to bring an advantage in terms of costs and development time, and helps to optimize food safety and quality of the process. The determination of the surface heat transfer coefficients (h) is an important parameter for numerical purposes since it is applied at the boundary condition in the mathematical formulation. In this contest, the aims of this study were: a) to perform transient heat transfer experiments measuring time-temperature histories in a metallic solid object with the exact same shape of a 473 cc can and to apply the finite element method to calculate the h values for i) pasteurizing by immersion in a hot water bath and ii) using a pilot scale spray pasteurizer; b) to numerically insert these h values in a CFD model in order to numerically simulate the pasteurization of craft beer packed in cans; c) to experimentally measure the time-temperature curve in a pilot scale spray pasteurizer and compare the measurements with numerical results. The h values and root mean square error (rmse) of cans submitted to pasteurization by immersion in a hot water bath and a batch spray unit were 700 W/m2 K (rmse= 1.33 K) and 950 W/m2 K (rmse=0.996 K), respectively. An excellentfit was obtained using the CFD model achieving a rmse of 2.02 K between experimental and numerical predictions.