From salt marshes to the plate: Could Salicornia ramosissima by-products be a promising functional ingredient for foods and nutraceuticals?

Salicornia ramosissima is an edible halophyte that has been commercialized in the European market as a promising crop rich in polyphenols, minerals, and vitamins [1, 2]. Despite the culinary uses of S. ramosissima, the leaves and shoots that it produces throughout the rest of the year are considered as biowaste. Nevertheless, this by-product is rich in pro-healthy compounds with interesting bioactivity. Hence, the repurposing of S. ramosissima by-product as a functional ingredient may be a valuable opportunity for agri-food industries [2].

The present study evaluates the influence of in vitro gastrointestinal digestion on the bioaccessibility, antioxidant/antiradical properties, antioxidant enzyme activities, and neuroprotective effects of S. ramosissima by-products (SPs) and its aqueous extract (SE), when prepared using an eco-friendly conventional technique. The cell viability was assessed on the same intestinal cells.

The phenolic and flavonoid concentrations of SEs and SPs increased during in vitro digestion, achieving 208% and 120% bioaccessibility, respectively. Likewise, the antioxidant/antiradical properties improved upon digestion, while the phenolic profiling unveiled that the polyphenols underwent metabolic biotransformation via the action of digestive enzymes and pH. Both SPs and SEs revealed radical scavenging potential, especially for O₂^•− (53% and 91% inhibition, respectively, for SP and SE), along with neuroprotective properties (31% and 22%, respectively) upon digestion. Additionally, SPs and SEs upmodulated the activities of superoxide dismutase (57% and 26%, respectively), catalase (53 and 43 nmol/min/g dry weight (DW)), and glutathione peroxidase (53 and 125 U/g DW), as well as protected against lipid peroxidation (1638 and 2164 nmol malondialdehyde/g DW). The extract safety was attested on the intestinal cells up to 250 µg/mL.

This study provides new insights into the influence of gastrointestinal digestion on the phytonutrients of S. ramosissima biowaste, sustaining its repurposing as a functional ingredient for foods and nutraceuticals endowed with promising health benefits.