CeO₂ and ZnO Nanoparticles Change the Nutritional Qualities of Cucumber (Cucumis sativus)

Abstract

There is lack of information about the effects of nanoparticles (NPs) on cucumber fruit quality. This study aimed to determine possible impacts on carbohydrates, proteins, mineral nutrients, and antioxidants in the fruit of cucumber plants grown in soil treated with CeO2 and ZnO NPs at 400 and 800 mg/kg. Fourier transform infrared spectroscopy (FTIR) was used to detect changes in functional groups, while ICP-OES and μ-XRF were used to quantify and map the distribution of nutrient elements, respectively. Results showed that none of the ZnO NP concentrations affected sugars; however at 400 mg/kg, CeO2 and ZnO NPs increased starch content. Conversely, CeO2 NPs did not affect starch content but impacted nonreducing sugar content (sucrose). FTIR data showed changes in the fingerprint regions of 1106, 1083, 1153, and 1181, indicating that both NPs altered the carbohydrate pattern. ZnO NPs did not impact protein fractionation; however, CeO2 NPs at 400 mg/kg increased globulin and decreased glutelin. Both CeO2 and ZnO NPs had no impact on flavonoid content, although CeO2 NPs at 800 mg/kg significantly reduced phenolic content. ICP-OES results showed that none of the treatments reduced macronutrients in fruit. In case of micronutrients, all treatments reduced Mo concentration, and at 400 mg/kg, ZnO NPs reduced Cu accumulation. μ-XRF revealed that Cu, Mn, and Zn were mainly accumulated in cucumber seeds. To the best of the authors' knowledge this is the first report on the nutritional quality of cucumber fruit attributed to the impact of CeO2 and ZnO NPs.

Preservation of bioactive compounds of a green vegetable smoothie using short time–high temperature mild thermal treatment

“…Similar to mesophiles, dynamic heating system during a milder heat treatment (70 C for 15 s) induced greater yeasts and moulds reductions (3.7 log units) in a fruit smoothie (Walkling-Ribero et al, 2010). Furthermore, data from Zhao et al (2014) showed better heat transmission in cucumber juice compared to our smoothie since initial yeasts and moulds (4 log CFU g À1 ) were greatly reduced below the detection limit (1 log CFU g À1 ).…”

1H NMR and GC–MS based metabolomics reveal nano-Cu altered cucumber (Cucumis sativus) fruit nutritional supply

“…Moreover, nCeO 2 decreased the antioxidant properties of the rice grains (Rico et al, 2013). Our previous study (Zhao et al, 2014) also showed that ZnO NPs and CeO 2 NPs at certain doses induced sugar, starch, and protein content alterations in cucumber fruits. Majumdar et al (2015) reported that phaseolin and lectins in bean (Phaseolus vulgaris) seed, which are associated with nutrient storage and carbohydrate metabolism, were down-regulated in a dose dependent way due to exposure of the plants to nCeO 2 .…”

Uptake, translocation and physiological effects of magnetic iron oxide (γ-Fe2O3) nanoparticles in corn (Zea mays L.)

“…There are several papers that have already reported the effects of NPs on crops over full growth cycle. For example, CeO 2 NPs could affect the yield and quality of cucumber (Zhao et al, , 2014b and corn (Zhao et al, 2015), but had no impact on the final biomass and yield, Ce concentration in shoots, as well as sugar and starch contents in wheat grains (Du et al, 2015). The investigation of uptake, translocation and physiological effects of g-Fe 2 O 3 NPs in corn seedlings could lay a foundation for NPs potential impact in the whole life circle of corn.…”