Spectral, Thermal, Mineral and Phenolic Characteristics of Plant Seeds from Ten Families

Seeds are a main dietary component for humans and animals. In this work, the physical, spectral,
thermal, mineral and phenolic characteristics of seeds from 47 species belonging to 10 families
(Arecaceae, Amaranthaceae, Anacardiaceae, Asteraceae, Fabaceae, Lamiaceae, Malvaceae,
Rutaceae, Sapindaceae and Sapotaceae) are described. The seeds had moisture and ash contents in
the 1.6–12.9% and 1.0–5.5% range, respectively, and the seed coat represented from 12 to 85% of
the seed weight, depending on the species. The protein, starch and oil-associated vibrations in the
seeds were characterized by infrared spectroscopy. The thermal behavior of the seeds, which
involved an initial dehydration step, followed by free/bound moisture and volatile extractives release,
and by protein, starch and oil decomposition, was studied by thermogravimetric (TG) and differential
scanning calorimetry (DSC) techniques, evidencing noticeable differences between families. The total
polyphenol and mineral contents widely varied from 185 to 3441 mg/100 g and from 831 to 7904
mg/100 g, respectively. Cluster analysis was used to categorize seed potentiality in terms of mineral
contents. Variations in seed proximate parameters, spectral, thermal, phenolic and mineral
characteristics as a function of the family to which the seeds belong to are also discussed.