Nutritional quality assessment of tomato fruits after exposure to uncoated and citric acid coated cerium oxide nanoparticles, bulk cerium oxide, cerium acetate and citric acid.

Little is known about the effects of surface modification on the interaction of nanoparticles (NPs) with plants. Tomato (Solanum lycopersicum L.) plants were cultivated in potting soil amended with bare and citric acid coated nanoceria (nCeO nCeO+CA), cerium acetate (CeAc), bulk cerium oxide (bCeO) and citric acid (CA) at 0-500 mg kg. Fruits were collected year-round until the harvesting time (210 days). Results showed that nCeO+CA at 62.5, 250 and 500 mg kg reduced dry weight by 54, 57, and 64% and total sugar by 84, 78, and 81%. At 62.5, 125, and 500 mg kg nCeO+CA decreased reducing sugar by 63, 75, and 52%, respectively and at 125 mg kg reduced starch by 78%, compared to control. The bCeO at 250 and 500 mg kg, increased reducing sugar by 67 and 58%. In addition, when compared to controls, nCeO at 500 mg kg reduced B (28%), Fe (78%), Mn (33%), and Ca (59%). At 125 mg kg decreased Al by 24%; while nCeO+CA at 125 and 500 mg kg increased B by 33%. On the other hand, bCeO at 62.5 mg kg increased Ca (267%), but at 250 mg kg reduced Cu (52%), Mn (33%), and Mg (58%). Fruit macromolecules were mainly affected by nCeO+CA, while nutritional elements by nCeO; however, all Ce treatments altered, in some way, the nutritional quality of tomato fruit. To our knowledge, this is the first study comparing effects of uncoated and coated nanoceria on tomato fruit quality.