Method for Online Monitoring of Mashing Processes Using Infrared Spectroscopy

Abstract

The invention relates to a system and method for controlling an enzymatic pre-treatment process, e.g. a mashing process. The system and method provide for accurate determination of specific sugar molecules as well as the average length of the sugar chains in real-time during e.g. a mashing process. Further information on, e.g., the concentration of dissolved protein and free amino acids can also be obtained simultaneously.

We claim: 
     
         1 . A system for controlling an enzymatic pre-treatment process, the system comprising:
 an analyzing unit configured to be connected in fluid communication, on-line and/or in-line with a container, and connected to an IR spectrometer, the analyzing unit configured for bringing a sample mixture into direct contact with the IR spectrometer for measuring attenuated total reflectance (ATR) IR spectra of a liquid part (solutes and solvents) of the sample mixture during an enzymatic pre-treatment process, and   a calculation unit connected with the IR spectrometer, the calculation unit being adapted for calculating:
 a ratio between specific species in the sample mixture based on the IR spectra of the sample mixture, and/or 
 a concentration of one or more specific species based on the IR spectra of the sample mixture, and/or 
 a degree of polymerization of one or more of specific species based on the IR spectra of the sample mixture. 
   
     
     
         2 . A system according to  claim 1  wherein the analyzing unit is an ATR-IR cell adapted for containing a small part of the sample mixture during measurements of ATR-IR spectra of the liquid part of the sample mixture during the enzymatic pre-treatment process, wherein the ATR-IR cell is mounted sealed to an ATR-IR plate comprising a crystal, the ATR-IR plate being part of an ATR-IR spectrometer. 
     
     
         3 . A system according to  claim 2  further comprises a connection unit connecting the analyzing unit with a container configured for holding an enzymatic pre-treatment process, the connection unit being adapted for guiding the small part of the sample mixture from the container and to the analyzing unit whereby ATR-IR spectra of the liquid part of the sample mixture is measured by the ATR-IR spectrometer. 
     
     
         4 . A system according to  claim 2 , further comprising
 a container configured for holding an enzymatic pre-treatment process; and   an extraction probe that protrudes inside the container, the probe configured for extracting the small part of the sample mixture for the ATR-IR spectra measurement at a user-determined position inside the container.   
     
     
         5 . A system according to  claim 1  wherein the analyzing unit is a spectroscopic unit comprising an ART-IR unit, a spectrophotometer for measuring IR spectra, and a computer, wherein the ART-IR unit comprises an ATR-IR plate with a crystal. 
     
     
         6 . A system according to  claim 5  wherein the spectroscopic unit is attached directly to a wall of a container or is attached to a wall of a container by connecting means. 
     
     
         7 . A system according to  claim 6 , wherein the ATR plate can be turned up to 90 degrees around its own axis. 
     
     
         8 . A system according to  claim 1 , further comprising the analyzing unit being connected in fluid communication, on-line and/or in-line with a container configured for holding an enzymatic pre-treatment process, where the container comprises a tank, a pipe, and/or a vessel. 
     
     
         9 . A system according to  claim 1 , further comprising the analyzing unit being connected in fluid communication, on-line and/or in-line with a container configured for holding an enzymatic pre-treatment process, wherein the container contains material to be enzymatically pre-treated. 
     
     
         10 . A system according to  claim 9 , wherein the material to be enzymatically pre-treated further comprises one or more enzymes added to the sample. 
     
     
         11 . A system according to  claim 9 , where the container comprises a tank, a pipe, and/or a vessel. 
     
     
         12 . A method of using the system of  claim 1 , said method being adapted for controlling an enzymatic pre-treatment process, wherein the method comprises steps of:
 a) providing a sample into a container configured for holding an enzymatic pre-treatment process and disposed in fluid communication with the analyzing unit, where the sample includes one or more enzymes or does not include one or more enzymes;   b) obtaining a sample mixture and performing the enzymatic pre-treatment process by:
 adding one or more enzymes to the sample if the sample does not contain one or more enzymes already, or 
 adding one or more enzymes to the sample already containing one or more enzymes; 
   c) continuously exposing a portion of the sample mixture to the infrared (IR) spectrometer;   d) continuously measuring attenuated total reflectance (ATR) IR spectra of the sample mixture with the IR spectrometer in real time at wavenumbers between 400-3500 cm −1  during the enzymatic pre-treatment process, and   e) feeding the measured IR spectra to a calculating unit which unit:
 calculates information relating to specific species present in the sample mixture during the enzymatic pre-treatment process based on the IR spectra, wherein the information relating to the specific species present in the sample mixture includes:
 a ratio between the different specific species, and/or 
 a concentration of one or more of the specific species, and/or 
 a degree of polymerization of one or more of the specific species; and 
 
 feeds the information relating to the specific species in the sample mixture back to a user and/or to a control system connected to the container. 
   
     
     
         13 . A method according to  claim 12 , further comprising a step of:
 f) stopping the enzymatic pre-treatment process when:
 a predetermined ratio between the specific species in the sample mixture is obtained, and/or 
 a concentration of one or more of the specific species reached a predetermined level, and/or 
 a degree of polymerization of one or more of the specific species reached a predetermined level. 
   
     
     
         14 . A method according to  claim 12  further comprising a step of stirring the sample mixture during at least part of the enzymatic pre-treatment process, a step wherein water is added to the sample mixture during the enzymatic pre-treatment process, or both. 
     
     
         15 . A method according to  claim 12  further comprising an action of increasing or decreasing the temperature in the sample and/or the sample mixture:
 prior to starting the enzymatic pre-treatment process, and/or 
 during the enzymatic pre-treatment process, and/or 
 in an amount sufficient to stop the enzymatic pre-treatment process. 
 
     
     
         16 . A method according to  claim 12 , wherein the container includes a tank, and the enzymatic pre-treatment process is stopped by one or more of:
 the system opening the tank automatically;   removing the sample mixture from the tank, or   increasing or decreasing a temperature in the tank.   
     
     
         17 . A method according to  claim 12  wherein the sample is selected from naturally occurring carbohydrates or from crops containing disaccharide and polysaccharide. 
     
     
         18 . A method according to  claim 12  wherein the enzymatic pre-treatment process is a mashing process conducted prior to a fermentation process. 
     
     
         19 . A method according to  claim 12  wherein multiple enzymes are added to the sample mixture either at the same time or at different times and wherein a temperature of the sample mixture is adjusted during the pre-treatment process to account for differences in temperature at which each of the enzymes is most active. 
     
     
         20 . A method according to  claim 12  wherein the IR spectra are measured at wavenumbers between 400-3000 cm −1 , between 400-2000 cm −1 , between 500-1500 cm −1 , between 700-1400 cm −1 , or between 800-1300 cm −1 .