Aplicaçãode SPME e GC-MS para a determinação de off-flavourse ftalatos em cervejas industriais e caseiras

Abstract

Beer quality can be determined by organoleptic attributes, such as aroma, flavor, brightness and transparency, foam formation and stability. Several factors can compromise this quality during the brewing process, whether they are inherent to the process itself or to microbiological aspects. During beer production there is also the formation of compounds such as esters, acids, and higher alcohols, which, in certain concentrations, are harmful to beer quality, and are called off-flavors. Moreover, with the increase in home brewing, which can be produced without the proper equipment for food purposes, there is a concern about human health due to the possible presence of contaminants in beer, such as phthalic acid esters, or phthalates, which are endocrine disruptors with carcinogenic potential, which may come from plastic materials used during production, storage, or even from the raw materials used. In this work, solid-phase microextraction by headspace gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to develop a methodology for the simultaneous determination of off-flavors in industrial and homemade beers. The methodology for off-flavors determination was optimized, validated and applied in the analysis of industrial and homemade beers, being observed the presence of butanoic acid and isovaleric acid in 3 and 4 beers, respectively, isobutanol and isoamyl alcohol in 15 beers, and ethyl acetate and octanoic acid in all analyzed beers. The methodology for the determination of five phthalates in industrial and home brewed beer was optimized, validated and applied to analyze 33 Brazilian beers bottled in different containers (can, plastic and glass). With this, the presence of phthalates was observed in 48% of the samples. Through this study it was not possible to specify the exact origin of the phthalates in the beers, however, 81% of the homemade beers presented phthalates, with concentrations up to 182 μg L-1 and only 31% of the industrial beers presented phthalates. The samples of homemade beers showed a higher amount of phthalates, probably due to the use of material not intended for food purposes throughout the process.