Role of ns-LTP1 in the Development of Primary Gushing

Abstract

Our investigations were focussed on ns-LTP1 (non specific lipid transfer protein 1) as the main inductor of the primary gushing phenomenon. We asserted that gushing beer contains more ns-LTP1 than non-gushing beer and these overbalance is responsible for over foaming. Surprisingly, less to non ns-LTP1 was detectable in a set of gushing beers.

We showed that loss of ns-LTP1 depends on fungal infestation and heating procedure. ns-LTP1 degrading activity of heated culture filtrates of Fusarium culmorum and Fusarium graminearum support the assumption that heat stable extracellular proteinases secreted by the two Fusaria strains are responsible for protein degradation. Heating procedure also results in a destruction of naturally occurring proteinase inhibitors in wheat kernels. This is the condition precedent to an effective operation of the fungal proteases.

Furthermore our results support the conception that not ns-LTP1 itself, but rather glycated peptides generated during proteolytic fragmentation of modified ns-LTP1 species initiate gushing activity.