Effects of Deficit Irrigation, Rootstock, and Roasting on the Contents of Fatty Acids, Phytoprostanes, and Phytofurans in Pistachio Kernels

Abstract

Pistachio (Pistacia vera L.) is a drought-tolerant species grown under the semiarid conditions of the Mediterranean basin. For this reason, it is essential to make an exhaustive quantification of yield and quality benefits of the kernels because the regulated deficit irrigation will allow significant water savings with a minimum impact on yield while improving kernel quality. The goal of this scientific work was to study the influence of the rootstock, water deficit during pit hardening, and kernel roasting on pistachio (P. vera, cv. Kerman) fruit yield, fruit size, and kernel content of fatty acids phytoprostanes (PhytoPs) and phytofurans (PhytoFs) for the first time. Water stress during pit hardening did not affect the pistachio yield. The kernel cultivar showed a lower oleic acid and a higher linoleic acid contents than other cultivars. Kernels from plants grafted on the studied rootstocks showed very interesting characteristics. P. integerrima led to the highest percentage of monounsaturated fatty acids. Regarding the plant oxylipins, P. terebinthus led to the highest contents of PhytoPs and PhytoFs (1260 ng/100 g and 16.2 ng/100 g, respectively). In addition, nuts from trees cultivated under intermediate water deficit during pit hardening showed increased contents of the 9-series F1-phytoprostanes and ent-16­(RS)-9-epi-ST-Δ14-10-phytofuran. However, roasting of pistachios led to PhytoP degradation. Therefore, plant cultivar, deficit irrigation, rootstock, and roasting must be considered to enhance biosynthesis of these secondary metabolites. New tools using agricultural strategies to produce hydroSOS pistachios have been opened thanks to the biological properties of these prostaglandin-like compounds linking agriculture, nutrition, and food science technology for further research initiatives.

Isoprostanoids, Isofuranoids and Isoketals – From Synthesis to Lipidomics

“…Numerous studies have shown a link between oxidative stress in plants and phytoprostane or phytofuran levels. These metabolites are excellent biomarkers capable of reporting particular environmental conditions (Figure 6): lack of water, [128] high temperatures, [120] the environment pollution [129,130] . In the case of monitoring plants in cultivation, the quantification of oxylipins would be relevant to identify changes in crops and managed cultivation efficiency [120] .…”

Metabolomics-Based Evaluation of Crop Quality Changes as a Consequence of Climate Change

“…Phytoprostanes and phytofuranes, products of heat-treated polyunsaturated fatty acid oxidation, are bioactive compounds related to beneficial effects in both humans and plants [ 61 ]. In pistachios ( Pistacia vera L.), phytoprostanes increased under moderate stress but decreased under severe stress, showing similar contents as fruits under control conditions [ 61 ]. This decrease under severe conditions could be explained by a decrease in these compounds when their concentration reaches a threshold as stress increases.…”

“…This decrease under severe conditions could be explained by a decrease in these compounds when their concentration reaches a threshold as stress increases. The phytofurane total content was similar in plants under moderate stress compared with controls but decreased with severe stress [ 61 ].…”

“…In this sense, phytoprostanes and phytofuranes can be considered as potential osmotic stress biomarkers. While their increase under drought stress can be a consequence of enhanced ROS production resulting in the formation of lipid peroxidation products, their decrease under severe conditions can be caused by the oxidation of linolenic acid to jasmonic acid [ 61 ].…”

“…Moreover, when individual analyses of individual compounds are performed, the obtained profiles depend on the severity of the stress; therefore, they can be used as markers to determine which kind of stress the plant has suffered [ 62 ]. For example, the most abundant phytoprostanes in pistachios increased, as did their total content, under moderate stress, while less abundant phytoprostanes were highest in plants under full irrigation regimes [ 61 ].…”