The green bean ( Phaseolus vulgaris L.) is a very widely grown food crop that contributes significantly to human dietary needs in many countries due to its high content of protein. This study evaluates foliar applications of ZnSO ₄ versus that of zinc oxide nanoparticles (ZnO NPs) to leaves of the green bean cv. ‘Strike’ and records the plant responses in terms of Zn uptake and concentrations of photosynthetic pigments and bioactive compounds. The experiment was conducted under greenhouse conditions in Chihuahua, Mexico, with a completely randomised experimental design with 10 replicates. The two treatments were foliar applications of either an aqueous solution of ZnSO ₄ or an aqueous suspension of ZnO NPs (both 150 mg · L ⁻¹ ). The application of ZnO NPs significantly increased concentrations of Zn ²⁺ in the leaflets, roots, stems and pods of chlorophylls a and b (values 15.40 μg · g ⁻¹ and 11.64 μg · g ⁻¹ , respectively). Sucrose concentration was also increased by Zn ²⁺ applications, but no differences were found in total phenols (TP), total flavonoids (TFl) or antioxidant capacity (AC). In the pods and seeds, Zn ²⁺ application left sucrose and TFl concentrations unchanged, but the TP increase was significant. The AC was affected by both zinc sources and only in the pods. The applications of ZnSO ₄ or ZnO NPs significantly increased the biomass accumulation (79.10 g · p ⁻¹ and 84.70 g · p ⁻¹ DW) and yield (55.64 g · p ⁻¹ and 53.80 g · p ⁻¹ FW). These results suggest that the application of ZnO NPs could represent a worthwhile biofortification strategy in the commercial production of green bean cv. ‘Strike’.

Fruits is a scientific journal for original articles and reviews on fruit crops in temperate, Mediterranean, subtropical and tropical regions

Biofortification of food crops is implemented through the application of mineral fertilizers, to improve the levels of essential mineral elements for human nutrition. Magnesium is a key macronutrient in crop production and quality; however, worldwide, it is the most limiting macronutrient in agriculture. Magnesium plays an important role in manipulating physiological and biochemical processes in plants. Therefore, the objective of this study was to evaluate the efficacy of biofortification with magnesium chloride and sulfate on the accumulation of bioactive compounds and antioxidant capacity in snap bean cv. Strike. Two sources of Magnesium were applied via edaphic route: Magnesium chloride and magnesium sulfate at doses of 0, 50, 100 and 200 ppm during 2018 in Mexico. Accumulation of bioactive compounds (total phenols, total flavonoids and total anthocyanins) and antioxidant capacity in snap bean fruits were evaluated. Results obtained indicate that the concentration of total flavonoids, total anthocyanins and antioxidant capacity in the edible parts of snap beans were higher in the MgSO4 treatment than in the MgCl2 treatments, exceeding 30, 59 and 6% respectively. This is one of the first studies on the edaphic agronomic biofortification of Mg+ and its effect on nutraceutical quality in snap bean. An interesting result is that MgSO4 produced high concentrations of anthocyanins in edible snap beans. These results can be applied as a new strategy to reduce malnutrition and improve the health of the population in poor urban and rural communities in developing countries.

Biosynthesis of volatile compounds (VC), as well as activity of related enzymes (lipoxygenase LOX, alcohol acyltransferase AAT, and alcohol dehydrogenase ADH), and fatty acids (palmitic, stearic, oleic, linoleic and linolenic acids) were assessed in Golden Delicious fruit apples (Malus domestica Borkh.) during 1 ºC storage at different atmosphere conditions. Three atmosphere conditions were used: 21 % O2 and > 1 % CO2 (Regular Atmosphere, RA), 3 % CO2 and 2 % O2 (Controlled Atmosphere, CA), and CA, with 7 d under RA conditions (CA + RA), to evaluate the effect of shorts periods under air storage. CA conditions inhibited the production of butyl acetate and hexyl acetate esters, and increased hexanol concentration. Production of the branched ester 2-methyl butyl acetate did not decrease under CA conditions. As a result of 7 d under RA, butyl acetate and hexyl acetate in CA + RA increased, mainly after one month of storage. Storage under CA conditions inhibited LOX and AAT activity at some stages whereas ADH activity increased during CA storage. LOX activity showed high correlation with production of aldehydes (r2 = 0.85) and cis-2-hexenal (r2 = 0.94), during storage of apples under CA conditions. Good correlation was found between AAT activity and total esters and butyl acetate content under CA storage of apples (r2 = 0.92 and r2 = 0.93, respectively). While most fatty acids increased in concentration during RA and CA storage, linolenic acid content decreased. No correlation between volatile compounds content and fatty acid production was found.