Analysis of selected chemical parameters of twenty-two green leaves used in the Sri Lankan traditional food culture

The research delves into the chemical compositions of traditionally significant twenty-two green leaves, for which chemical analysis is scarce despite their well-documented medicinal value in Ayurvedic medical texts, using standard methods. Moreover, it investigated the impact of the traditional cooking process of “Mallung” on the antioxidant activity of green leaves. The moisture content of twenty-two green leaves varied from 74.49±0.29% to 95.49±0.19%. The ash content of the tested green leaves ranged between 5.95±0.88% and 15.95±0.34%. The results illustrated that the crude fiber content of green leaves was within the range of 9.37±0.58% to 14.25±0.65%. The zinc and iron contents ranged from 13.76 to 68.90 mg/kg and from 39.72 to 335.00 mg/kg, respectively. Senna auriculata (Ranawara) possessed the highest zinc and iron content. The highest manganese content (197.76 mg/kg) was reported for Commelina diffusa (Girapala), and the lowest (13.45 mg/kg) for Senna auriculata (Ranawara). Psychotria sarmentosa (Gonuke) recorded the highest copper content (44.80 mg/kg), while Commelina diffusa (Girapala) recorded the lowest (4.80 mg/kg). The sodium content ranged from 0.36 mg/g to 2.79 mg/g, with Bacopa monnieri (Lunuwila) exhibiting the highest content. Alysicarpus vaginalis (Aswenna) contains the highest potassium content (88.55 mg/g), and Tylophora pauciflora (Kiri anguna) contains the lowest potassium content (9.17 mg/g) among the tested green leaves. The highest calcium content (9.13 mg/g) was reported for Amaranthus viridis (Koora thampala), and the lowest (1.00 mg/g) for Tylophora pauciflora (Kiri anguna). The magnesium content ranged between 0.66-5.96 mg/g, while Senna occidentalis (Peni thora) had the highest amount of magnesium, and Eclipta prostrata (Keekirindiyae) had the lowest amount of magnesium. The highest DPPH radical scavenging antioxidant activity (2062.11 ± 15.35 µmol TE/g DW) was reported for Moringa oleifera (Murunga), while the lowest antioxidant activity (963.38 ± 9.01 µmol TE/g DW) was noted for Eclipta prostrata (Keekirindiyae). The Mallung cooking process did not significantly affect the antioxidant activity.