Effect of the pre-treatment of the whey prior to the application of ultrafiltration so gencial for agroindustrial purposes

Abstract

 The whey to be used as an ingredient requires somepretreatment in order to improve its microbial quality, eliminate the fat and avoid the clogging of the membrane when applying tangential ultrafiltration. 
The purpose of this investigation was to evaluate the effectiveness of the centrifugation sequence, calcium 
precipitation and microfiltration as pretreatment. A sample of whey from the processing of pasteurized white cheese was used in a dairy industry in the state of Yaracuy. This was filtered with linen cloth to retain suspended particles and then a pretreatment was applied, using the following procedure: centrifugation at 15,000 rpm; calcium precipitation (addition of 1.2 g / L CaCl2); pH adjustment to 7.3; heating at 55 ° C for 8 min; cooling at 4 ° C and centrifugation at 4,500 rpm for 15 min and, finally, microfiltration with membrane of 0.1 m2, porosity 0.22 pm at 1.0 at 1.5 bar and 25 ° C. For comparative purposes, the microbiological quality of the crude and pretreated whey was evaluated through the presence of aerobic bacteria, total and fecal coliforms, molds and yeasts, E. coli, S. aureus and Salmonella; in addition to pH, fat content, protein and turbidity. The pretreatment allowed obtaining a clarified, microbiologically innocuous whey, without particles 
in apparent suspension, with reduction of fat content, protein and turbidity in 72.8%; 29.7% and 97.8%, 
respectively; which can be used as raw material for obtaining protein concentrates as an ingredient for the 
food industry.