Spectrofluorimetric, spectrophotometric and chemometric analysis of wheat seeds infested by Sitophilus granarius

Invisible infestation of wheat seeds by Sitophilus granarius during field ripening or postharvest handling is one of the main problems for grain storage facilities due to the lack of cheap and fast method of infestation detection, especially when small amount of seeds is infected by larvae. In order to determine whether the spectrofluorimetric, spectrophotometric and chemometric analysis of various extracts of wheat seeds infested by Sitophilus granarius larvae could be used for detection of seeds infestation, four different types of extracts: 50 mM Tris-HCl pH 8.9 ; 55% iso-propanol, methanol, and 20% TCA, of non-infested and infested wheat seeds have been examined for fluorescence properties and UV/VIS spectral characteristics, while chemometric analysis included determination of protein, reactive amino group, soluble sugar and polyphenolic content. Analysis of extracts of non-infested and moderately or significantly infested wheat seeds revealed significant differences in UV/VIS spectral characteristics and level of reactive amino groups and polyphenols between infested and non-infested seeds. Obtained results indicate that instrumental analysis of spectral characteristics of seed extracts could be used as a method for determination of seed infestation.