FT-NIR fatty acid determination method

Abstract

A method for the rapid analysis of the fatty acid components present in a fat and/or oil-containing material is provided wherein the levels and types of fatty acids present in a sample are determined using Fourier Transform Near Infrared (FT-NIR) spectroscopy. The FT-NIR technique is developed by preparing a calibration matrix based on FT-NIR and Gas Chromatography (GC) analysis of known standards, and subsequently using the calibration matrix to analyze the FT-NIR spectral data obtained from a sample to be tested.

1 . A method for the determination of the fatty acid type and/or content of a fat or oil component of a test sample material, which method comprises preparation of a calibration matrix using a fatty acid reference analytical technique adapted to identify the type and quantity of fatty acids in a baseline reference material, and relating the results obtained to the spectral data obtained from an FT-NIR analysis of said baseline reference material; 
 analysing a test sample material using an FT-NIR technique to obtain FT-NIR spectral data for said test sample material; and    relating said FT-NIR spectra data of said test sample material to said calibration matrix in order to determine a value for the fatty acid content of any or all of the fatty acids present in said test sample material.    
     
     
         2 . A method as claimed in  claim 1  wherein said fatty acid reference analytical technique is any analytical technique which can directly, or indirectly provide specific information on the type and quantity of the fatty acid components of a fat or oil.  
     
     
         3 . A method as claimed in  claim 1  wherein said fatty acid reference analytical technique is based on a GC (gas chromatography) procedure.  
     
     
         4 . A method as claimed in  claim 3  wherein said GC procedure is standard GC, GC Silver Ion, GC-HPLC, GC-TLC, or GC-MS.  
     
     
         5 . A method as claimed in  claim 4  wherein said calibration matrix is prepared using a technique based on data obtained by GC and FT-NIR analysis of selected baseline materials.  
     
     
         6 . A method for the determination of the fatty acid type and/or content of a fat or oil component of a test sample material, which method comprises: 
 identifying a series of baseline materials having a similar composition to that of a test sample material, and containing at least one form of fatty acid having a reflectance or transmission characteristic corresponding to a narrow wave band of light in the near-infrared region of the spectrum;    analysing said baseline materials using a GC technique to determine the fatty acid composition of each of said baseline materials;    analysing said baseline materials using a Fourier Transform-Near Infrared (FT-NIR) technique to produce FT-NIR spectral data for each of said baseline materials;    establishing a calibration matrix to relate the FT-NIR spectral data to the results determined from said GC technique for any or all of said fatty acids identified by said GC technique;    analysing a test sample material using said FT-NIR technique to produce NIR spectral data for said test sample material, and relating the spectral data from said FT-NIR technique to said calibration matrix to determine a value for the fatty acid content of any or all of the fatty acids present in said test sample material.    
     
     
         7 . A method as claimed in  claim 6  wherein said near-infrared region of the spectrum has a frequency range of from between 4000 cm −1  (2.5 microns) and 14000 cm −1  (0.7 microns) wavenumber.  
     
     
         8 . A method as claimed in  claim 7  wherein said frequency range is from between 4300 cm −1  (2.2 microns) to 9000 cm −1  (1.1 microns).  
     
     
         9 . A method as claimed in  claim 8  wherein said frequency range is from between 5400 cm −1  (1.7 microns) to 9000 cm −1  (1.1 microns).  
     
     
         10 . A method as claimed in  claim 6  wherein said FT-NIR technique for testing said test sample material is based on a reflective technique.  
     
     
         11 . A method as claimed in  claim 6  wherein said FT-NIR technique for testing said test sample material is based on a transmission technique.  
     
     
         12 . A method as claimed in  claim 6  wherein said FT-NIR technique for testing said test sample material is based on a transflectance technique.  
     
     
         13 . A method as claimed in  claim 1  wherein said test sample material is a food product.  
     
     
         14 . A method as claimed in  claim 13  wherein said test sample material is vegetable oil, soy oil, flax oil, shortening, lard, mayonnaise, salad dressing, cookies, baked goods, crackers or potato chips.  
     
     
         15 . A method as claimed in  claim 1  wherein said test sample material is living tissue.  
     
     
         16 . A method as claimed in  claim 15  wherein said living tissue is human tissue, fish tissue, or non-human mammal tissue.  
     
     
         17 . A method as claimed in  claim 1  wherein said baseline materials are similar in composition, with respect to the type of fatty acid, to the test sample material but have a range of fatty acid levels.  
     
     
         18 . A method as claimed in  claim 1  wherein said FT-NIR analysis involves use of mathematically modified values to improve the ability to distinguish one material over another.  
     
     
         19 . A method as claimed in  claim 1  wherein the fat or oil content of said test sample material is extracted prior to FT-NIR analysis.  
     
     
         20 . A method as claimed in  claim 1  wherein the test sample material is tested as is.  
     
     
         21 . A method as claimed in  claim 1  wherein the FT-NIR analysis of said test sample material is conducted in a time of less than 2 minutes.  
     
     
         22 . A method as claimed in  claim 1  wherein said calibration matrix is based on a statistical analysis of the spectral data and the GC data from the analysis of said baseline materials.  
     
     
         23 . A method as claimed in  claim 22  wherein said statistical analysis involves multiple linear regression (MLR), principal component regression (PCR), or partial least squares regression (PLSR).