Analysis of potential lard adulteration in chocolate and chocolate products using Fourier transform infrared spectroscopy

Fourier transform infrared (FTIR) spectroscopy, in combination with attenuated total reflectance (ATR) and partial least square (PLS) regression, was used to detect the presence of lard in chocolate formulation. The spectral bands associated with lard, cocoa butter and their blends (ranging from 0% to 15% of lard in cocoa butter) were recorded, interpreted and identified. A semi-quantitative approach is proposed to measure the percent of lard in blends on the basis of spectral data at the frequency region 4000–650 cm−1, using the equation y = 0.9225x + 0.5539. The coefficient of determination (R2) was 0.9872 with a standard error (SE) of 1.305. In this paper, the potential of FTIR spectroscopy as a rapid analytical tool for the quantitative determination of adulterants especially lard, in chocolate, is demonstrated.

[1]  D. Bertrand,et al.  Characterization of edible oils, butters and margarines by Fourier transform infrared spectroscopy with attenuated total reflectance , 1994 .

[2]  Nerea Cabo,et al.  Infrared spectroscopy in the study of edible oils and fats , 1997 .

[3]  Eric R. Ziegel,et al.  Statistics and Chemometrics for Analytical Chemistry , 2004, Technometrics.

[4]  P. Lambelet,et al.  Detection of pig and buffalo body fat in cow and buffalo ghees by differential scanning calorimetry , 1983 .

[5]  R. Goodacre,et al.  Fourier transform infrared spectroscopy and chemometrics as a tool for the rapid detection of other vegetable fats mixed in cocoa butter , 2001 .

[6]  Yusuf Al-Qaradawi,et al.  The Lawful and the Prohibited in Islam: Al-Halal Wal-haram Fil Islam , 1980 .

[7]  M. Mirghani,et al.  Detection of lard mixed with body fats of chicken, lamb, and cow by fourier transform infrared spectroscopy , 2001 .

[8]  J. Miller,et al.  Statistics and chemometrics for analytical chemistry , 2005 .

[9]  Y. Man,et al.  Compositional and thermal analysis of RBD palm oil adulterated with lipase-catalyzed interesterified lard , 2002 .

[10]  E. Anklam,et al.  Detection and quantification of cocoa butter equivalents in chocolate model systems: analysis of triglyceride profiles by high resolution GC , 1999 .

[11]  A. Rauf,et al.  Triacylglycerols-Profiling by High Performance Liquid Chromatography: A Tool for Detection of Pork Fat (Lard) in Processed Foods , 1995 .

[12]  E. K. Kemsley,et al.  Mid-infrared spectroscopy and authenticity problems in selected meats: a feasibility study , 1997 .

[13]  E. K. Kemsley,et al.  Quantitative analysis of potential adulterants of extra virgin olive oil using infrared spectroscopy , 1995 .

[14]  M. Guillén,et al.  Characterization of edible oils and lard by fourier transform infrared spectroscopy. Relationships between composition and frequency of concrete bands in the fingerprint region , 1997 .