22:31 Jan 17 

Hello,
There's another table above with the following title:
MONITORAGGIO IDROLISI 20/10/97 MEN C PS HMCCM005 (71.7 GR) a 78 ˚C PROVA 93/A
It has the following headings (separated by double slashes):
time (min) // DP // 1/DP // 1-1/DP // In (1-1/DP)˚1000 // In (1-1/DP)˚1000

Before that there are two graphs regarding "cinetica idrolisi"

That's the whole document...

21:30 Jan 17 

Without more context it's just a guess, but in my opinion here min. refers to minima velocità di idrolisi, which also depends on the DP (degree of polymerization), the viscosity /density of the fluid. Hence, the sentence should be read as: la minima velocità è retta (mantenuta) da 30 a 120 minuti.
Can't you give more context?

19:48 Jan 16 

Does anyone know if it is "minute line"?

19:18 Jan 16 

These are the other column headings (separated by double slashes):
DP // 1/DP // 1-1/DP // In(1-1/DP)1000 // min. retta da 30 a 120 min.

19:13 Jan 16 

Hi, it comes after a couple of graphs, yes. The graph has five columns.

18:18 Jan 16 

need more context - is it talking about a graph?