Abstract: The feasibility of using Fourier transform infrared (FTIR) spectroscopy and chemometrics as a rapid and non-invasive technique to determine the geographical origin and protein content of Sudanese Acacia gums was investigated. Seventy-two samples of Acacia gums were collected from six different regions (12 samples from each region). Linear discriminant analysis (LDA) was used to discriminate the geographical origin of Acacia gums, and backward interval partial least squares (Bi-PLS) was applied to build a prediction model for the protein content of Acacia gums. The results showed that the recognition rates of LDA for calibration set (48 samples) and prediction set (24 samples) were both 100% when the first 6 principal components were used. In addition, Bi-PLS yielded a good prediction model (RP = 0.937 3 and RMSEP = 0.173%) for protein content by using the optimal combination of 4 out of 20 spectral intervals. Hence, FTIR spectroscopy coupled with chemometrics can be considered as a valid approach for the determination of the geographical origin and protein content of Acacia gums.

Key words: Acacia gums, Fourier transform infrared (FTIR) spectroscopy, geographical origin, protein content, linear discriminant analysis (LDA), backward interval partial least squares (Bi-PLS)