Evaluation of Nano Zinc (ZnO) for Surface Enhancement of ATR-FTIR Spectra of Butter and Spread

The effect of nano zinc (ZnO) particles in surface enhancement of attenuated total reflection-Fourier transform mid-infrared spectroscopy (ATR-FTIR) has been studied in butter and spread. Due to the health implications associated with consumption of trans fats, the studies also included the determination of band corresponding to trans fats of butter/spread in the nano-zinc-treated samples. The FTIR spectra of nano-zinc-treated butter showed enhancement of bands related to (aEuro center dot CaEuro center dot O, aEuro center dot CH(2)aEuro center dot) at wave number 1,238 cm(-1) and (OaEuro center dot CaEuro center dot C) band of esters at wave number 1,100 cm(-1). Shifting in wave number to 1,150 cm(-1) and reduction in its peak intensity was observed with the band corresponding to 1,162 cm(-1) (aEuro center dot CaEuro center dot O stretch). Reduction in peak intensity of the bands at about 2,915 and 2,850 cm(-1) (CaEuro center dot H groups) was also observed. In the case of spread, nano zinc reduced the peak intensities of FTIR bands at 2,915 cm(-1), 2,850 cm(-1) (aEuro center dot CaEuro center dot HaEuro center dot (CH(2)) stretches), 1,746 cm(-1) (aEuro center dot Ca center dot O ester), 1,465 cm(-1) (aEuro center dot CaEuro center dot H (CH(2), CH(3))), 1,375 cm(-1) (aEuro center dot CaEuro center dot H (CH(3))) and 1,156 cm(-1) (CaEuro center dot O, aEuro center dot CH(2)). Trans fats band corresponding to a center dot CaEuro center dot H stretch (trans bonds, 966 cm(-1)), was observed in pure butter and spread. Trans fatty acids in butter and spread were quantified with the aid of calibration/validation standards using trielaidin and triolein and by using partial least squares regression analysis. However, the band at 966 cm(-1) was hindered in Zn-treated butter and reduced in Zn-treated spread.