Biochemical profile and biofunctional effects of Crithmum maritimum L. from three harvests under different N:P:K...

In the present study, we investigated the effects of different fertilization regimes on the biochemical profile and bioactive properties of Crithmum maritimum over three consecutive growing periods.

The applied fertilization regimes included six treatments that differed in the amounts of N:P:K (mg/L), namely, 100:100:100 (CM₁₁₁), 200:100:100 (CM₂₁₁), 200:200:200 (CM₂₂₂), 300:100:100 (CM₃₁₁), 300:200:200 (CM₃₂₂), and 300:300:300 (CM₃₃₃) mg/L of N:P:K, and the control treatment (CM₀; no fertilizers added). The fresh biomass yield of the aboveground part was evaluated for three consecutive growing periods (2021-2023), while biochemical and functional properties assessment included the evaluation of proximate composition, lipophilic (free sugars and organic acids) and hydrophilic compounds (tocopherols and fatty acids) content, phenolic compounds profile, antioxidant activity (thiobarbituric acid reactive substances (TBARS) and oxidative hemolysis inhibition assay (OxHLIA)), and antimicrobial and anti-inflammatory properties.

High nutrient inputs (CM₃₃₃) significantly increased the fresh biomass yield in the 1st harvest, whereas a lower amount of nutrients led to higher productivity in the successive harvests (CM₃₂₂ and CM₂₂₂ for the 2nd and 3rd harvest, respectively). This study demonstrated that high nutrient inputs in C. maritimum significantly enhanced the levels of fat, protein, fiber, and energy in the 2nd and 3rd harvest, while the control treatment (CM₀) recorded the highest fat and energy content in the 1st harvest. Moreover, low to moderate inputs favored higher ash and carbohydrate content. Glucose remained the dominant sugar, with total sugar levels peaking under high fertilization in later harvests, whereas in the 1st harvest the CM₀ recorded the highest content of fructose, trehalose and total sugars content. Fertilization impacted organic acids in a varied manner: low inputs favored quinic and succinic acids, whereas higher nutrient levels increased oxalic and malic acid content. α-Τocopherol was the sole tocopherol detected, peaking under the CM322 treatment. Regarding fatty acids, high nutrient inputs promoted unsaturated fats and reduced palmitic acid, with the second harvest providing the most nutritious profile and optimal PUFA (polyunsaturated fatty acids)/SFA (saturated fatty acids) and omega-6/omega-3 ratios, while the control treatment had the highest SFA content in the 2nd and 3rd harvest. The second harvest also yielded the highest total phenol content under high-input regimes, whereas lower inputs peaked in the first and third harvests. Antioxidant performance fluctuated by fertilization regime and harvesting, with the second harvest generally showing the highest overall capacity. Crithmum maritimum extracts exhibited limited antimicrobial efficacy compared to standard controls and no activity against fungi, and they showed moderate inhibition against specific pathogens, such as Staphylococcus aureus, Escherichia coli, and methicillin-resistant S. aureus (MRSA), depending on the treatment. Finally, the extracts demonstrated no significant anti-inflammatory effects across any tested fertilization regimes.

In conclusion, moderate to high nutrient inputs seem to beneficially affect fresh yield in C. maritimum, whereas targeted nutrient inputs may regulate the chemical profile and improve the quality of the edible leaves.