الخلاصة:
The young cladodes of Opuntia ficus-indica, consumed as a vegetable, are a valuable source of bioactive
compounds and nutrients, and are the subject of our study on their antioxidant activity and nutritional value by
analyzing primary and secondary metabolites as well as mineral content.
Moisture content, phytochemical composition, mineral analysis, and quantitative determinations: primary
metabolites, total polyphenols, total flavonoids, and antioxidant capacity were carried out following established
experimental protocols on the dry matter and/or the two aqueous extracts prepared by maceration (Ex M) and
decoction (Ex D).
The results revealed the presence of flavonoids, polyphenols, alkaloids, free quinones, tannins, terpenes, and
reducing compounds, while anthraquinones and saponins were absent.
Nutritional analysis showed moisture, fiber, lipid, and ash contents of 92 ± 0,03%, 7,135 ± 0,3%, 1,763 %,
and 26,69 ± 0,37%, respectively. Protein content was higher in the maceration extract (14,46 ± 0,01%) than in the
decoction extract (10,02 ± 0,02%). Carbohydrates were 56.47% in the dry powder, 49.65% in Ex D, and 55.66% in
Ex M. The energy value was low in fresh material (22 kcal/100 g), while the dry matter extracts were much more
energetic (273–281 kcal/100 g DM).
Total polyphenols and flavonoids were also more abundant in the maceration extract (53,53 ± 0,04 μg
GAE/mg and 150,4 ± 0,03 μg RE/mg, respectively) than in the decoction extract. The maceration extract also
contained higher levels of minerals, particularly Zn²⁺, Mg²⁺, P, Ca²⁺, and K⁺.
Antioxidant activity assessed by the DPPH assay showed a strong IC₅₀, comparable to ascorbic acid, with
42,731 ± 0,46 mg/ml for the maceration extract and 49,643 ± 1,9 mg/ml for the decoction extract. Total antioxidant
activity was 35,08 ± 0,06 μg AAE/mg for Ex M and 30,9 ± 0,00 μg AAE/mg for Ex D.
According to our study, higher extraction temperatures have a negative impact on the levels of secondary
metabolites and nutritional compounds in the aqueous extracts of the cladodes, consequently reducing their antioxidant
activity.
