Identification of cow and buffalo milk based on Beta carotene and vitamin-A concentration using fluorescence spectroscopy

Abstract

The current study presents the application of fluorescence spectroscopy for the identification of cow and buffalo milk based on β-carotene and vitamin-A which is of prime importance from the nutritional point of view. All samples were collected from healthy animals of different breeds at the time of lactation in the vicinity of Islamabad, Pakistan. Cow and buffalo milk shows differences at fluorescence emission appeared at band position 382 nm, 440 nm, 505 nm and 525 nm both in classical geometry (right angle) setup as well as front face fluorescence setup. In front face fluorescence geometry, synchronous fluorescence emission shows clear differences at 410 nm and 440 nm between the milk samples of both these species. These fluorescence emissions correspond to fats, vitamin-A and β-carotene. Principal Component Analysis (PCA) further highlighted these differences by showing clear separation between the two data sets on the basis of features obtained from their fluorescence emission spectra. These results indicate that classical geometry (fixed excitation wavelength) as well as front face (synchronous fluorescence emission) of cow and buffalo milk nutrients could be used as fingerprint from identification point of view. This same approach can effectively be used for the determination of adulterants in the milk and other dairy products.

Characterisation of cow and buffalo ghee using fluorescence spectroscopy

“…The prominent bands appeared at λ em : 380, 440, 480, 552, 635, 660, 670 and 708 nm. The band appearing at 380 nm was assigned to fat‐soluble vitamins and lipids (Ullah et al ), and at 440 nm to vitamin A (Ullah et al ) and oxidised products (Kyriakidis and Skarkalis ; Karoui et al ). Based upon the spectra shown in Figure , the band at 480 nm has been labelled for vitamin A.…”

“…The prominent bands appeared at λ em : 380, 425, 475, 552, 545, 620, 637, 660, 670 and 708 nm. The band at 380 nm was assigned to fat‐soluble vitamins (Ullah et al ) whose intensity increased by increasing exciting wavelengths from 250 to 290 nm. The intensity of this band becomes maximum at excitation wavelength of 290 nm, which might be attributed to the excitation wavelength that effects the natural activation position of fluorophores present in ghee samples.…”

“…However, the intensity of this band in cow ghee spectra is very low which means that cow ghee contains slight quantity of vitamin A. The distinct band at λ em : 525 nm was assigned to beta‐carotene (Ullah et al ), which rises in intensity with the increase in λ ex and becomes maximum at λ ex of 370 nm.…”

“…In literature, the band at 440 nm has been assigned to vitamin A (Ullah et al ) and oxidised products (Kyriakidis and Skarkalis ; Karoui et al ). In this study, vitamin A fluoresces at 490 nm as shown in Figure .…”

“…This study was planned to characterise buffalo and cow ghee and the detection of their adulteration using Fluorescence spectroscopy. It has proved to be a nondestructive and efficient tool for the analysis of beta‐carotene in milk and edible oils (Sikorska et al ; Kongbonga et al ; Ullah et al ), and monitoring the manufacturing processes of dairy products (Andersen and Mortensen ; Karoui and Blecker ; Ahmad et al ; Shaikh and O’Donnell ). Furthermore, the presence of vitamins A, B 12 , D, E, K and CLA was investigated in both ghee types through a comparative analysis of their spectra.…”