Oxidative degradation of lipids during mashing.
Although hardly any polyunsaturated fatty acids (PUFAs) are present in the endproduct, the ingredients used for the production of beer contain a high concentration of PUFAs, such as linolic and linolenic acid. These compounds are readily oxidized, resulting in the formation of lipid-derived products that reduce the taste and quality of beer enormously. During mashing relatively high amounts of PUFAs are exposed to atmospheric oxygen at a relatively high temperature. This makes mashing a critical step in the brewing process with regard to the formation of lipid-derived off-taste products. F1 phytoprostane (PPF1) changes in antioxidant capacity and monohydroxy fatty acids (OH-FAs) were used as markers for the detection of oxidative damage to fatty acids during mashing. The pattern of OH-FA formation indicates that enzymatic oxidation of PUFAs is more important than nonenzymatic oxidation during the mashing process. Nevertheless, substantial nonenzymatic radical formation is evident from the increase of specific OH-FAs and PPF1s. It was found that a low oxygen tension reduces oxidative damage and gives a high antioxidant capacity of the mashing mixture. This indicates that mashing should be done under low oxygen pressure.
Arts
Mariken J T J
MJ
Department of Pharmacology and Toxicology, Maastricht University, Maastricht, The Netherlands. mariken.arts@gmail.com
Grun
Christoph
C
de Jong
Ruud L
RL
Voss
Hans-Peter
HP
Bast
Aalt
A
Mueller
Martin J
MJ
Haenen
Guido R M M
GR
D001515:Beer / Q000032:analysis*; D003517:Cyclopentanes / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis / Q000737:chemistry; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D005511:Food Handling / Q000379:methods*; D006900:Hydroxylation; D008055:Lipids / Q000737:chemistry*; D010084:Oxidation-Reduction
D003517:Cyclopentanes; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008055:Lipids; C486066:phytoprostane F1