Biopreservative effect of cyclic dipeptides 2,5-diketopiperazines

Cyclic dipeptides, also known as 2,5-diketopiperazines, are compounds well represented in nature as well as in foods and beverages (Gautschi et al., 1997 Hilton, Prasad, Vo, Mouton, 1991). Their active role in foods has been related especially 

Activation of endogenous proteases and peptidases leading to the release of linear dipeptides. 

Dipeptide cyclization toward the protonation of free carboxyl groups followed by the release of water and the formation of new intramolecular peptide bonds. 

Activation of endogenous phytases, leading to the release of metal ions. 

In general, in the presence of substrate, LAB, due to a broad spectrum of peptidases, could greatly contribute to the accumulation of 2,5-diketopiperazine in fermented foods, but at present, experimental evidence is still lacking. 

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