Impact of Different Wort Boiling Temperatures on the Beer Foam Stabilizing Properties of Lipid Transfer Protein 1
Date
2004
Authors
Van Nierop S.N.E.
Evans D.E.
Axcell B.C.
Cantrell I.C.
Rautenbach, Marina
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Beer consumers demand satisfactory and consistent foam stability; thus, it is a high priority for brewers. Beer foam is stabilized by the interaction between certain beer proteins, including lipid transfer protein 1 (LTP1), and isomerized hop α-acids, but destabilized by lipids. In this study it was shown that the wort boiling temperature during the brewing process was critical in determining the final beer LTP1 content and conformation. LTP1 levels during brewing were measured by an LTP1 ELISA, using antinative barley LTP1 polyclonal antibodies. It was observed that the higher wort boiling temperatures (∼102 °C), resulting from low altitude at sea level, reduced the final beer LTP1 level to 2-3 μg/mL, whereas the lower wort boiling temperatures (∼96 °C), resulting from higher altitudes (1800 m), produced LTP1 levels between 17 and 35 μg/mL. Low levels of LTP1 in combination with elevated levels of free fatty acids (FFA) resulted in poor foam stability, whereas beer produced with low levels of LTP1 and FFA had satisfactory foam stability. Previous studies indicated the need for LTP1 denaturing to improve its foam stabilizing properties. However, the results presented here show that LTP1 denaturation reduces its ability to act as a binding protein for foam-damaging FFA. These investigations suggest that wort boiling temperature is an important factor in determining the level and conformation of LTP1, thereby favoring satisfactory beer foam stability.
Description
Keywords
fatty acid, lipid transfer protein, polyclonal antibody, altitude, article, beer, brewing, conformation, foam, heat treatment, isomerization, temperature, Altitude, Beer, Carrier Proteins, Chemistry, Physical, Fatty Acids, Nonesterified, Food Handling, Heat, Protein Conformation, Hordeum vulgare subsp. vulgare, Humulus
Citation
Journal of Agricultural and Food Chemistry
52
10
52
10