Analysis of total polyphenols, bitterness and haze in pale and dark lager beers produced under different mashing and boiling conditions

Abstract

*Malting and brewing processes should be performed under process conditions in a way that minimizes beer bitterness, maximizes polyphenol content and reduces the amount of raw materials ending up in solution in the form of hazes, particles and precipitates. This work examined the influence of different mashing temperature conditions and boiling procedures on the total polyphenol content, bitterness and haze of pale and dark lager beers produced on an industrial scale. Two hop types (hop pellets and/or hop extract) and different hop varieties (Hallertau Magnum, Styrian Goldings, Saaz, Aurora and Sladek) were utilized with varying times of hop addition into the wort. Measurements of total polyphenols, colour, bitterness, alcohol content, CO 2 and pH were carried out on the beer samples. Results showed that pale lager beers had a lower total polyphenol concentration (110-179 mg/L) than dark beers (230-260 mg/L). Using hop extracts instead of hop pellets led to a lower total polyphenol concentration and to less beer foam creation. The change in the proteolytic temperature during mashing only had an influence on the total polyphenol content in the pale lager beer hopped with the pellets. Conducting proteolysis over a 20 min period led to a haze increase in all of the beers produced. In the dark beer, the haze was substantial after just 10 min at 52°C.

Investigation of Total Polyphenol, Antioxidant Activity and Levels of Metals in Ethiopian Commercial Beers

“…The amount of TPC variation comes from the difference in raw material used mainly from malt and hope and the nature of beer production process [20,21]. The results obtained in this study were in agreement with reported values [1,5,6,20]. So, the difference in amount of total polyphenols can cause difference on their antioxidant activities, avour, color and sensory properties and also may contribute to maintain the endogenous redox balance in humans [9].…”

Sensory Profile, Consumer Preference and Chemical Composition of Craft Beers from Brazil

“…Investigating the Brazilian beers, we found that the contents of phenolic compounds, as well as the antioxidant capacity, were like those of beers produced elsewhere in the world [2]. Polyphenols are already extracted in the initial phase of the fermentation process, i.e., during the wort production [9]. This study showed that polyphenols, especially the bitterness associated with it, have an important relationship with the preference of different beers among Brazilian consumers.…”

Phenols and Melanoidins as Natural Antioxidants in Beer. Structure, Reactivity and Antioxidant Activity

“…In this sense, an extensive study was carried out by Zhao et al in 2010 [47], in which 34 lager beers were analyzed and where TPC ranged between 152 and 339 mg GAE/L. Other later studies on Polish, Belgian, Serbian, Indian or Hungarian beers agree with that study [60,66,72,74,75] In general, ale beers present higher TPC than lagers [76]. In a comparative study between different Brazilian beers, it was observed that brown ale beers presented higher TPC than lager beers and also higher antioxidant properties [69].…”