Study of colloidal particles in beer before filtration process

LOZANO, JORGE ENRIQUE; BENÍTEZ, ELISA INÉS; SORRIVAS, VIVIANA

HYDERABAD

Congreso; International Conference and Exhibition on Food Processing and Technology 2012; 2012

OMICS GROUP

The main objective of this work is to study the effect of colioidal partides and yeast on turbidity of Pilsen beer before the filtration process. The colloidal particles are mainly composed of polysaccharides, representing 96.89%, in second place proteins with a concentration dose to 2%; and polyphenols  less than 0.3%. There is also a very Low concentration of yeast «0.25% .The presence of different types of particles in the sample caused multimodal histogram in the partide size distribution and four distinct zones were identified: (i) very small individual particles ( = 0.06 mm (ii) yeast ( = 3 mm); iii) colloidal aggregates ( =17 mm) and (iv) a zone with a high dispersion of size, with two values (101 and 200 mm). Particles size counts well correlate with both the scanning electron microscopy (SEM) digital image analysis, and the turbidity determination. The fractal dimension (Df) of the aggregates was determined by analyzing the SEM images with the Variogram method, obtaining Df> 2.4 values. Those values are typical of aggregates formed by rapid flocculation or diffusion limited aggregation. Results of this study support the formulation of a model valid for the prediction of colloidal particles concentration in beer.