Comparing Heavy Metals, Nutritional Value, and Toxicity in Organic <i>vs</i> Conventional <i>Moringa oleifera</i> Leaves from Chennai District

Background: The analysis of organic versus conventional Moringa powder reveals significant differences in heavy metal content and underscores their implications for safety and nutritional value. Aim: To compare the concentrations of heavy metals, proximate composition, and brine shrimp lethality between organic and conventional Moringa oleifera leaves sourced from Chennai District. Methods: Organic and conventional M. oleifera leaves were collected from Chennai District. The samples were dried at 40°C and ground into powder. The concentrations of heavy metals—lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg)—were determined using Atomic Absorption Spectrophotometry. Proximate analysis was conducted to measure moisture content, crude fat, crude protein, and ash value. Additionally, a brine shrimp lethality assay was performed to evaluate the toxicity of the samples, with IC50 values calculated for each. Results: Heavy Metal Concentrations: Organic M. oleifera (Sample “I”) contained significantly lower levels of heavy metals compared to conventional M. oleifera (Sample “II”). Chromium: 1.76 mg/kg (organic) vs. 12.10 mg/kg (conventional); Cadmium: 0.02 mg/kg (organic) vs. 0.20 mg/kg (conventional); Lead: 0.48 mg/kg (organic) vs. 2.05 mg/kg (conventional); Arsenic: 0.06 mg/kg (organic) vs. 0.21 mg/kg (conventional). These findings underscore the greater safety of organic M. oleifera, as excessive heavy metal exposure is linked to respiratory issues, kidney damage, developmental problems, and increased cancer risk. Proximate Composition: The nutritional profiles of the samples were similar: Crude Protein: 23.88 g/100g (organic) vs. 23.81 g/100g (conventional) and Crude Fat: 6.36 g/100g (organic) vs. 6.28 g/100g (conventional). This suggests that both samples offer comparable nutritional benefits, although the organic variant is safer due to reduced heavy metal content. The organic sample exhibited a higher IC50 value, indicating lower toxicity compared to the conventional sample in brine shrimp lethality assay. Conclusion: The study highlights significant differences in heavy metal content, toxicity, and safety between organic and conventional M. oleifera leaves collected from Chennai District. While both samples displayed similar nutritional profiles, the organic sample proved to be the safer choice due to substantially lower heavy metal contamination, likely attributable to organic farming practices that avoid synthetic chemicals. Major Findings: The study found that organic Moringa oleifera leaves have significantly lower heavy metal content (Cr, Cd, Pb, As) than conventional ones, making them safer. Both types had similar nutritional values, but organic samples showed lower toxicity in the brine shrimp lethality test, likely due to the absence of synthetic chemicals. Organic Moringa is the safer and preferable option.