High Hydrostatic Pressure Treatments for Beer Stabilization

Abstract

Crude cloudy beers from a small-scale brewery were treated with high hydrostatic pressure (HHP-600 MPa, 5 min) or heat pasteurized (60 °C, 10 min). The treatments did not affect pH, ethanol, extract, bitterness, or phenolics in comparison with untreated beers; HHP beers retained permanent haze, similar to untreated samples. Heat pasteurized beer resulted in a more rapid increase of the a* (red) and a slower decrease of the b* (yellow) color parameters than in HHP samples. The microbiological stability of HHP beers was comparable with heat-treated beers, and the development of yeast and lactic acid bacteria was inhibited for 49 d of storage.

Effects of High Pressure Homogenization on Beer Quality Attributes

“…Previous results obtained using high hydrostatic pressure (HHP) at 600 MPa/5 min indicated a higher level of haze than that obtained in pasteurized beer (60°C/10 min) 5 , which was attributed to the stronger protein-tannin complexes generated after protein denaturation by pressure, with consequent exposure of hydrophobic sites. This result suggests that, even though HHP and HPH have different mechanisms of action 6 , the effect of both processes on beer protein and protein-tannin complex formation can be similar and results in analogous larger amounts of haze formation.…”

“…However, the heat can cause protein denaturation, promoting the formation of new tannin-protein complexes, with consequent turbidity enhancement 17 . In addition, heat processing promotes the Maillard reaction, resulting in an alteration of beer colour to reddish 5 and the formation of undesirable flavours 17 . These are related to oxidation and staling 8 , with the development of paper and cardboard flavours (longchain aldehydes) 22 .…”

Alternative Methods for Shelf Life Extension of Unfiltered Beers from Microbreweries

“…Při aplikaci vysokého hydrostatického tlaku je tedy důležité zajistit takové parametry, při kterých dochází k omezení metabolické aktivity a reprodukčních schopností buněk, avšak nedojde k jejich usmrcení celé buňky a tím i k uvolnění intracelulárního obsahu do piva a tudíž k jeho senzorickému znehodnocení. Bylo prokázáno, že v pivu ošet-řeném tlakem 400 MPa, nebo vyšším (při teplotě 20 až 25 °C), dochází k úspěšné inaktivaci buněk, prokázané pomocí kontrolních kultivací, při nichž nebyl zjištěn žádný nárůst buněčné populace (Castellari et al, 2000).…”

“…Therefore, it is important to set up such parameters that reduce metabolic activity and reproduction of cells, but do not cause total cell destruction, that would change the sensorial properties of the beer. It was demonstrated in control cultures that a pressure of 400 MPa or higher at temperature of 20 °C to 25 °C successfully inactivated cells and prevented any increase in the cell population (Castellari et al, 2000).…”

Inactivation of Lactobacillus brevis in Beer Utilizing a Combination of High-Pressure Homogenization and Lysozyme Treatment

“…However, the heat can cause protein denaturation, promoting the formation of new tannin-protein complexes, with consequent turbidity enhancement 23 . In addition, heat processing promotes the Maillard reaction, resulting in an alteration of beer colour to a reddish hue 4 and the formation of undesirable flavours 23 . These are related to oxidation and staling 9 , with the development of paper and cardboard flavours (long chain aldehydes) 31 .…”