Attenuated total reflectance - fourier transform infrared (ATRFTIR) spectroscopy: A tool to determine groundnut seed quality

ATR-FTIR spectroscopy is proved to be a simple, reliable, rapid and easy-to-use technique to assess the groundnut seed quality. Groundnut seeds are highly sensitive to deterioration mainly due to their chemical composition and moisture content. The high oil content and fatty acids of groundnut seeds reduces the seed viability well in advance due to lipid peroxidation process, which is the most frequent cause of seed ageing. As a result, not only lipid peroxidation, but also a series of reactions that produce toxic products occur.

Eleven groundnut seed lots were tested for their seed germination potential as well as the oil quality parameters, ATRFTIR analysis, antioxidant enzyme activities and physiological seed quality parameters.

The results indicated that the FTIR spectra of the seed lots having higher germination (>70%) exhibited deviations at different wave numbers within the range of 4000-400 cm^-1 when compared with seed lots having lower germination (<70%). The peak intensity was found to follow an increasing trend to a decrease in germination percentage of the seed lots. The seeds lose its viability, the activity of antioxidant enzyme decreases leading to an alteration in free fatty acid, acid value, saponification value, iodine value and peroxide value. Finally, the study concluded that the changes in seed germination from 92 to 12 per cent and their corresponding enzyme activity are closely correlated with FTIR spectral data. Hence, ATR FTIR may be used as a tool to predict the quality of the groundnut seeds during storage.