CHROMATROGRAPHIC PROFILE OF BEER BOTTON RECOVERED BY MICROFILTRATION PROCESS

Microfiltration (MF) is used in the food industry as an alternative to conventional filtration processes. In the brewing industry, after maturation, only the dorn supernatant is sent for filtration, while the beer bottom is discarded as waste and represents a loss of more than 5% of total production. MF becomes a potential alternative for recovering beer from the bottom beer. Thus, this work aimed to characterize the volatile compounds present in the bottom beer recovered by MF. Larger, Weizen, Golden, and IPA-type beers bottom were microfiltrated and the recovered beers were analysed by GC-MS (Agilent Technologies Chromatograph 7890A/ detector 5975C). As these are aqueous samples, they were pre-treated using solid-phase microextraction (SPME). Chromatographic analysis showed a large amount of substances of the class of alcohols, esters and others aromatic compounds. In particular, in all types of beer, ethanol, 3-methyl-1-butanol, octanoic acid, isoamyl acetate and bezenoethanol were identified. The chromatographic profile of microfiltrated beers when compared to commercial samples of the same brand were similar, presenting the same content of each compound, showing no loss after MF. However, in commercial beers a greater number of minority compounds were identified. The absence of minority compounds in microfiltrated samples may be related to the longer contact time of beer with the yeast at the beer bottom, changing its chemical composition. Through this work it was possible to describe the chromatographic profile of the beer bottom submitted to microfiltration and compare to commercial beers. The results are promising and provide the basis for the recovered beer to be incorporated into conventionally filtered beer.