Comparison of FT-NIR Spectroscopy and ELISA for Detection of Adulteration of Goat Cheeses with Cow's Milk

J AOAC Int. 2016 Jan-Feb;99(1):180-6. doi: 10.5740/jaoacint.15-0190. Epub 2016 Jan 28.

Abstract

This study investigated the ability of two methods to detect adulteration of goat cheeses via the addition of cow's milk, with a negligible effect on the raw materials. Cheeses were produced from a mixture of goat's and cow's milk and were then analyzed by Fourier transform near-IR (FT-NIR) spectroscopy and competitive ELISA. The cheese spectra were scanned in the spectroscope in reflectance mode on an integrating sphere at 80 scans and a resolution of 4 cm(-1). The spectra were evaluated via discriminant analysis, and a calibration was created via a partial least-squares algorithm to quantify the cow's milk admixture. A correlation coefficient of R = 0.999 was reached with a standard error of calibration of 0.0407. The results were statistically processed to a median value via a t-test. Adulteration detection by the ELISA method was performed using a commercial Milk Fraud/Bovine ELISA kit. It was found that the FT-NIR spectroscopy method is capable of detecting an admixture of cow's milk in goat cheese as small as 1%. The ELISA method did not return satisfactory results for the detection of adulteration with cow's milk.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cheese / analysis*
  • Enzyme-Linked Immunosorbent Assay*
  • Goats*
  • Milk / chemistry*
  • Spectroscopy, Near-Infrared