Salinity influenced proximate, minerals, anti-nutrients and phytochemical composition of trachyandra ciliata kunth (wild cabbage): a promising edible halophyte

Abstract

Climate change, drought, and soil salinization present huge limitations to global agricultural output, which threatens food security. This necessitates the cultivation and domestication of wild edible halophytes as alternatives to mainstream food crops, especially in arid and semi-arid regions. Trachyandra ciliata is one of the under-researched and underutilized edible halophytes native to South Africa. The plant was used as a food source by Khoisan people in the past although its edibility and nutritional capacity are undocumented. Thus, the current study explored the effect of varying salinity concentrations on minerals, proximate, phytochemical, and anti-nutrient composition of T. ciliata to evaluate its edibility and promote its cultivation among South African households. Plants were subjected to varying salinity treatments from 0, 50, 100,150, and 200 mM prepared by adding sodium chloride (NaCl) to the nutrient solution. Salinity significantly influenced the mineral, proximate, antinutrient, and phytochemical composition of T. ciliata. Control and 50 mM treatments recorded significantly higher macro and micronutrient content in the flower buds and leaves, except for heavy metals such as Zn and Cu, which increased with increasing salinity and significantly higher in the roots. Leaves under low salinity treatments recorded higher moisture and protein content, while leaves also recorded higher ash content under high salinity. On the other hand, flower buds under low salinity recorded significantly high fat and NDF composition. Phytochemicals and antinutrients increased with increasing salinity concentrations. The low antinutrient content and high nutritional, mineral and phenolic contents validate the edibility and suitability of T. ciliata for human consumption.