Drying methods differentially affect the lipidome of the edible halophytes sea asparagus Salicornia ramosissima and sea purslane Atriplex portulacoides

Halophytes have gained recognition as a nutritional and functional food, but detailed evidence regarding how post-harvest drying affects their lipidomic integrity remains limited. This study compared the effect of freeze-drying(-55 °C), oven-drying(60 °C) and sun-drying(17-27 °C) on the lipid profile of two halophytes (Salicornia ramosissima and Atriplex portulacoides), using GC-MS and LC-MS/MS. Total lipid content was not significantly affected by the drying method. However, oven- and sun-drying significantly reduced base-labile esterified fatty acids (FA), particularly FA18:3n-3 and FA16:0, compared with freeze-drying. This reduction was more noticed in sun-drying, suggesting the release of free FA by lipases. Overall, 270 and 275 lipid species were identified in S. ramosissima and A. portulacoides, respectively. Drying induced a decrease in relative abundance of membrane phospholipids (phosphatidylcholine and phosphatidylethanolamine) with an increase in relative abundance of their lyso-forms, ceramides, triacylglycerols and diacylglycerols. These results suggest that post-harvest drying induces lipidomic shifts which may influence the nutritional qualities of these halophytes, depending on the drying method applied.