Abstract: A method of hydrolyzing a coffee extraction residue material to produce a mannan oligomer solution having oligomers from DP 1 to DP 10 is disclosed. The coffee material, preferably spent grounds from a commercial percolation system, is hydrolyzed in a reactor in the presence of an acid catalyst. A tubular plug flow reactor is convenient, although any reactor providing for the relatively high temperature, short time reaction will suffice. Particular acid catalysts include sulphuric acid, phosphoric acid, acetic acid and carbon dioxide gas. Depending on the specific time, temperature and catalyst concentration selected, a mannan oligomer solution having any desired distribution of oligomers between DP 1 and DP 10 is produced.

Abstract: A method for hydrolyzing coffee extraction residue materials to produce manno-saccharides having a degree of polymerization from 1 to 10 and subsequently neutralizing and reducing said mixture of manno-saccharides to their corresponding alcohols. The coffee material, preferably spent coffee grounds from a commercial percolation system, is hydrolyzed in a Plug Flow tubular reactor in the presence of an acid catalyst, such as sulfuric acid. Depending on the time, temperature, pressure and catalyst concentration selected, manno-saccharides or mannose is produced. The manno-saccharides or mannose produced are separated from coffee residue material in the form of a syrup and neutralized with calcium hydroxide. The neutralized mixture of manno-saccharides or mannose is reduced to their corresponding alcohols or mannitol.