Evaluación de la calidad de cervezas tipos lager mediante espectroscopia de impedancia electroquímica

Abstract

In the present research work, the effect of alcoholic strength, residual sugars, hydroxymethylfurfural and hop concentration of five brands of lager-type beer was evaluated by means of the frequency response determined by electrochemical impedance spectroscopy, the measurement of sugars was also carried out. reducers by using the UV visible spectrophotometer. The beers analyzed were the following: “A” (American), “B” (Ecuadorian 1), “C” (Ecuadorian 2), “D” (Mexican) and “E” (Amsterdam). The target impedance analysis was performed on the SQUIDSTAT TM PLUS Potentiostat which is equipped with the Squidstat User Interface v2.09.28.2018 Beta software. To carry out the analyses, a working electrode (gold wire), a counter electrode (platinum wire) and a reference electrode (Ag/AgCl electrode) were used. According to the results obtained from the impedance of beers A and E, they showed a certain similarity between their characteristics due to the fact that they have certain similarities between their composition and alcoholic strength, and they also present a higher impedance value compared to the other beers (B, C and D). In the degrees of alcohol, an analysis was carried out on the equipment to be able to observe the curves in the beers (A, B, C, D and E) and a calibration curve was established using a 5mL solution of absolute alcohol, then it was calibrated. up to 100 mL with distilled water, ethanol was measured to make the relationship with the beers and it was observed that in the curves of beers A and E the points join the ethanol curve, beers B, C and D have less of 5 % of the ethanol curve. Through impedance, the presence of residual sugars was observed in beer B (Ecuadorian 1), no presence of HMF was observed by the impedance method and by this method it was also observed that beer B (Ecuadorian), approached the three are hops (0.5, 1 and 1.5).