Selenium uptake and fruit quality of pear (Pyrus communis L.) treated with foliar Se application

Abstract

Consuming selenium (Se)‐rich fruit may play an important role in human health by supplementing Se. The aims of this study were to (1) determine the Se tolerance of pear trees and (2) explore the effects of different Se sources and spraying dates on Se concentrations and transformation of inorganic Se into organic Se compounds in various parts of the pear tree and on fruit quality. Spraying Se(IV) or Se(VI) at a concentration of > 40 mg L−1 resulted in leaf yellowing, marginal withering, and finally leaf abscission. Furthermore, fruit growth and appearance were adversely affected at high Se doses. At the same application stage, Se concentrations in different parts of the fruit were 1.1–4.7 times higher under Se(VI) compared to Se(IV) treatment. For the same Se source, Se concentrations under treatment at the fruit expanding stage were 1.9–2.5 times higher than under treatment at the fruit‐setting stage. Of the total Se in the fruit, 40% accumulated in the juice under Se(IV) treatment and > 70% under Se(VI) treatment. However, regardless of the Se source, the Se in the juice was almost all inorganic, while the transformation of inorganic Se into organic Se compounds was > 80% and 70% in the peel and pomace, respectively. Foliar Se application somewhat improved fruit quality by increasing the concentration of soluble solids. Compared to other species, Se tolerance in pear trees was relatively low. Given the high accumulation of Se and efficient transformation of inorganic Se into organic Se compounds in the peel, consumption of unpeeled Se‐rich pears is recommended.

Selenium biofortification in the 21st century: status and challenges for healthy human nutrition

“…like chickpea ( Cicer arietinum L.), soybean ( Glicine max L.), and alfalfa ( Medicago sativa L.) accumulate SeMet and SeCys, but not methylated Se amino acids (Chan et al 2010 ; Hajiboland and Amjad 2008 ; Poblaciones et al 2014 ). Organic Se has been found in olive trees ( Olea europaea L.), and pear trees ( Pyrus communis L.), but the Se species have not been determined (D’Amato et al 2018a ; Deng et al 2019 ). Leafy vegetables like lettuce ( Lactuca sativa L.), basil ( Ocimum basilicum L.) and Cichorium spp ., instead, contain only inorganic Se (Hawrylak-Nowak 2008 ; Stibilj et al 2011 ).…”

“…In the few studies accomplished in this area of research, spraying leaves or fruits with Se was the only approach used to enrich fruits (e.g. pears, peach, apples, olives) with Se (D’Amato et al 2017 2018a b ; Deng et al 2019 ; Pezzarossa et al 2012 ). Se foliar fertilization of olive trees increased the accumulation of several nutritional components of olives and EVOO, such as mineral elements, pigments (carotenoids and chlorophylls) and phenolic compounds (e.g.…”

Current Knowledge on Selenium Biofortification to Improve the Nutraceutical Profile of Food: A Comprehensive Review

“…The daily consumption of pears and peach treated with 1 mg of Se L –1 does not induce toxicity but can even provide a rational Se supplementation for human nutrition. Se accumulated in the pear juice was almost all inorganic, so the application of selenite is considered more suitable than selenate from the viewpoint of food safety . In apples and pomegranates, Se supplementation via foliar spray enhanced fruit quality. , In particular, in apples, in addition to the increase of Se content, an increase in the flesh firmness, titrable acidity, soluble solid content, and activities of antioxidant enzymes were observed, while in pomegranates, Se fertilization led to an important increase of the content of phenolic compounds, antioxidants, and anthocyanins …”

Selenium Increases Fruit Quality By Reducing Ethylene Production And The Stone Cell Content In Pear (Pyrus Ussuriensis)

“…Therefore, bioforti cation of Se-enriched food is very important for increasing the Se concentration in food and will be helpful for human health [8]. Foliar spraying and soil application are both effective means to increase the Se content in food, and the latter is much more effective [9].…”