Increased chemical acetylation of peptides and proteins in rats after daily ingestion of diacetyl analyzed by Nano-LC-MS/MS.

Background: Acetylation alters several protein properties including molecular weight, stability, enzymatic activity, protein-protein interactions, and other biological functions. Our previous findings demonstrating that diacetyl/peroxynitrite can acetylate L-lysine, L-histidine, and albumin led us to investigate whether diacetyl-treated rats suffer protein acetylation as well.

Methods: Wistar rats were administered diacetyl daily for four weeks, after which they were sacrificed, and their lung proteins were extracted to be analysed by Nano-LC-MS/MS (Q-TOF).

Inactivation of Alicyclobacillus acidoterrestris in orange juice by saponin extracts combined with heat-treatment.

Alicyclobacillus acidoterrestris is a spoilage-causing bacterium in fruit juices. The inactivation of this bacterium by commercial saponin and saponin purified extract from Sapindus saponaria fruits combined with heat-treatment is described. We investigated heat treatment (87, 90, 95, and 99°C) with incubation time ranging from 0 to 50min, in both concentrated and reconstituted juice.