Sailor's Beaufort Recipe!

[ArnaudForestier]

Temp and salt. Beauforts are higher in salt (1.2-1.5 IIRC), which makes the propionic not grow, and low temps (50s) do the same thing. But, the initial inoculation helps to add more flavor to the cheese - usually a note of characteristic sweetness. With the L helveticus in the starter, it makes for a lovely cheese.

Thanks, Pav.  The sweetness is a function, then, of early metabolism, not growth-phase or later breakdown by-products?

[linuxboy]

For propionic, it's proline that causes the sweet flavor. Meaning peptidases, which are not metabolism but proteolysis. 

[ArnaudForestier]

For propionic, it's proline that causes the sweet flavor. Meaning peptidases, which are not metabolism but proteolysis.

Thanks.  Do I have this right, peptidases contained in the P. shermanii are released on lysis, which break the proline peptides into free amino acids? 

[linuxboy]

That's the gist of it, yes. It's actually one peptidase: proline-iminopeptidase. It will cleave away proline even if the proline is bound up in a di or tripeptide.

Proline is not a peptide though, it's an amino acid. How it happens in cheese is that there are complex peptides, and proline-iminopeptidase will cleave out the proline.

[ArnaudForestier]

Gotcha.  I think I was thrown by too quick a read of:

"starter cultures produce proline-specific peptidases that
recognize the pyrolidine ring of proline. These peptidases
also are present in dairy products as a result of starter culture addition. The peptidases break down peptides containing proline into free amino acids that
can be utilized by the cells."

(sorry, will look up where I got this).  I was confusing "peptides containing proline" for "proline peptide," which I understand doesn't make sense.