Prediction of quality properties of the carob fruit with the FTIR spectroscopy

In this study it was aimed to determine the quality properties such as the total phenolic content, antioxidant capacity and antimicrobial activity of the carob fruit and to predict some of these quality parameters using the FTIR spectroscopy. For this purpose, extracts were prepared from carob samples with water, ethanol, methanol and 50-50 v/v mixture of these. The total phenolic content was determined to be the highest in the methanol extract and the second highest in the water extract. The lowest antioxidant capacity was observed in the samples extracted with ethanol and methanol solvents, respectively. The highest antioxidant capacity was observed in the samples extracted with water, followed by 50-50 v/v ethanol and methanol extracts, respectively. In addition, the antimicrobial activity of carob samples extracted with different solvents on Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli microorganisms was also investigated in this study. While the water and ethanol (50%) extract (EW) showed an antimicrobial effect on the Escherichia coli bacteria, no antimicrobial effect was observed on the other bacteria. Similarly, methanol (50%) extract (MW) showed an antimicrobial effect only on the Pseudomonas aeruginosa bacteria. Data obtained from the FTIR spectroscopy was analyzed with the partial least squares (PLS) regression analysis to predict total phenolic content and antioxidant capacity and R2 values were found to be greater than 97%.