Purpose The nutritional and bioactive value of plants remains key for sustainable agriculture. However, whether pesticides affect the nutritional and bioactive compounds of leafy vegetables, spinach and lettuce, has not been thoroughly investigated. Methods This research involved three experiments: spinach and lettuce grown in pesticide-untreated soil (SFP/LFP), pesticide-treated soil (SCP/LCP), and pesticide-untreated soil but sprayed with pesticide preharvest (SSP/LSP). Finally, various metabolites—protein, sugar, proline, chlorophylls, carotenoids, vitamins, polyphenols, and oxidative indicators—were assayed via spectrophotometry. Results Pesticide-treated vegetables presented altered levels of their metabolites. Chlorophyll a (mg/g D.W.) decreased in lettuce from 16.80 ± 0.29 (LFP) to 10.25 ± 0.04 (LSP) and 7.29 ± 0.12 (LCP). In spinach, a similar statistically significant difference (P ≤ 0.05) was observed: 7.94 ± 0.47 (SFP), 7.09 ± 0.38 (SSP), and 6.97 ± 0.29 (SCP). The statistically significant decrease in the carotenoid and chlorophyll b contents followed the same pattern as that reported for chlorophyll a. Pesticide treatment also led to a decrease in the total phenolic content: 16.23% (LSP), 18.92% (LCP), 1.00% (SSP), and 64.00% (SCP). However, the total soluble protein content increased by 28.79% (LSP), 32.86% (LCP), 19.09% (SSP), and 11.34% (SCP). The increase in vitamins A and C was significant across all the experimental groups; the vitamin A content (mg/100 g) increased in the LSP at10.92 ± 0.64, the LCP content was 16.61 ± 0.08, the SSP content was 8.08 ± 0.11 and the SCP content at 8.45 ± 1.15 compared with 3.96 ± 0.19 (LFP) and 2.50 ± 0.05 (SFP) of the normal controls. The vitamin C content (mg/100 g) in the LSP content was 14.31 ± 0.25, the LCP content increased to 12.15 ± 0.32, the SSP content was 13.51 ± 0.25 and the SCP content gave 18.35 ± 0.39 in comparison with 8.87 ± 0.40 (LFP) and 6.38 ± 0.08 (SFP) of the normal controls. Additionally, significant differences (P ≤ 0.05) in malondialdehyde levels (nmol/g FW) were detected between non-pesticide-treated vegetables, LFP (0.21 ± 0.00) and SFP (0.26 ± 0.00), and pesticide-treated vegetables, LSP (0.30 ± 0.01), LCP (0.40 ± 0.01), SSP (0.54 ± 0.03), and SCP (0.30 ± 0.01).The activities of antioxidant enzymes, such as superoxide dismutase (U/mg protein), significantly increased (P ≤ 0.05) in the pesticide-treated vegetables, including LSP (189.68 ± 2.42), LCP (190.79 ± 2.21), SSP (242.96 ± 1.28) and SCP (185.22 ± 1.28), compared with the nonpesticide-treated vegetables, LFP (171.83 ± 2.56) and SFP (179.92 ± 3.02). A similar significant difference in activities was also recorded for catalase and peroxidase antioxidant enzymes. Conclusions Pesticide treatment significantly impacts spinach and lettuce vegetables, leading to alterations in their nutritional and bioactive compounds, hence distorting their nutritional quality and health benefits.

Pesticides’ Impact on the Nutritious and Bioactive Molecules of Green Leafy Vegetables: Spinach and Lettuce

期刊论文
发表日期：

2025年2月24日

查看全文

Daniel Hassan Mhya,
Abdulrashid Mohammed

摘要

Purpose

The nutritional and bioactive value of plants remains key for sustainable agriculture. However, whether pesticides affect the nutritional and bioactive compounds of leafy vegetables, spinach and lettuce, has not been thoroughly investigated.

Methods

This research involved three experiments: spinach and lettuce grown in pesticide-untreated soil (SFP/LFP), pesticide-treated soil (SCP/LCP), and pesticide-untreated soil but sprayed with pesticide preharvest (SSP/LSP). Finally, various metabolites—protein, sugar, proline, chlorophylls, carotenoids, vitamins, polyphenols, and oxidative indicators—were assayed via spectrophotometry.

Results

Pesticide-treated vegetables presented altered levels of their metabolites. Chlorophyll a (mg/g D.W.) decreased in lettuce from 16.80 ± 0.29 (LFP) to 10.25 ± 0.04 (LSP) and 7.29 ± 0.12 (LCP). In spinach, a similar statistically significant difference (P ≤ 0.05) was observed: 7.94 ± 0.47 (SFP), 7.09 ± 0.38 (SSP), and 6.97 ± 0.29 (SCP). The statistically significant decrease in the carotenoid and chlorophyll b contents followed the same pattern as that reported for chlorophyll a. Pesticide treatment also led to a decrease in the total phenolic content: 16.23% (LSP), 18.92% (LCP), 1.00% (SSP), and 64.00% (SCP). However, the total soluble protein content increased by 28.79% (LSP), 32.86% (LCP), 19.09% (SSP), and 11.34% (SCP). The increase in vitamins A and C was significant across all the experimental groups; the vitamin A content (mg/100 g) increased in the LSP at10.92 ± 0.64, the LCP content was 16.61 ± 0.08, the SSP content was 8.08 ± 0.11 and the SCP content at 8.45 ± 1.15 compared with 3.96 ± 0.19 (LFP) and 2.50 ± 0.05 (SFP) of the normal controls. The vitamin C content (mg/100 g) in the LSP content was 14.31 ± 0.25, the LCP content increased to 12.15 ± 0.32, the SSP content was 13.51 ± 0.25 and the SCP content gave 18.35 ± 0.39 in comparison with 8.87 ± 0.40 (LFP) and 6.38 ± 0.08 (SFP) of the normal controls. Additionally, significant differences (P ≤ 0.05) in malondialdehyde levels (nmol/g FW) were detected between non-pesticide-treated vegetables, LFP (0.21 ± 0.00) and SFP (0.26 ± 0.00), and pesticide-treated vegetables, LSP (0.30 ± 0.01), LCP (0.40 ± 0.01), SSP (0.54 ± 0.03), and SCP (0.30 ± 0.01).The activities of antioxidant enzymes, such as superoxide dismutase (U/mg protein), significantly increased (P ≤ 0.05) in the pesticide-treated vegetables, including LSP (189.68 ± 2.42), LCP (190.79 ± 2.21), SSP (242.96 ± 1.28) and SCP (185.22 ± 1.28), compared with the nonpesticide-treated vegetables, LFP (171.83 ± 2.56) and SFP (179.92 ± 3.02). A similar significant difference in activities was also recorded for catalase and peroxidase antioxidant enzymes.

Conclusions

Pesticide treatment significantly impacts spinach and lettuce vegetables, leading to alterations in their nutritional and bioactive compounds, hence distorting their nutritional quality and health benefits.