a transesterification in which lipophilic groups from the coffee oil is added carbohydrate components after the first but before the second extraction the spent coffee grounds may be pre treated prior to the enzymatic hydrolysis the pre treatment may be performed to make it easier for the enzymes to access their substrate the pre treatment may involve exposure of the interior of the plant cells and or loosening of the lignin from the cellulose in a preferred embodiment the pre treatment involves addition of water to the spent coffee grounds steam exploding the spent coffee grounds and separating in an intermediate extract and pretreated spent coffee grounds the intermediate extract from the steam explosion procedure may be used in the final product purified or may be discarded or used for another application if it contains too many off flavours generally however the steam explosion procedure is controlled so that the intermediate extract either as is concentrated and or dried is added to the combined extract if only a u201c mild u201d temperature steam explosion is performed the amount of off flavours are generally low and acceptable therefore the intermediate extract can be added to the combined extract preferred conditions for the steam explosion involves that the steam explosion is performed in the temperature range of 50 170 u00b0 c at a pressure of 0 1 to 10 barg for 0 1 to 5 hours to loosen up the structure of the lignocellulose and to partially break down the structure of the hemicellulose it may be advantageously to use a certain temperature regimen for the pre treatment the temperature regimen may comprise in any order a low temperature.