Phytochemical profiling and heavy metal accumulation in organic and local market food crops: Principal Component Analysis (PCA) - based comparative evaluation

Abstract

This study explores the bioactive compounds in five vegetables, namely Indian mustard ( Brassica juncea ), lettuce ( Lactuca sativa ), spinach ( Spinacia oleracea ), cabbage ( Brassica oleracea L. var. capitata ), curry leaves ( Murraya koenigii ), one underutilized fruit, Indian gooseberry ( Phyllanthus emblica ), and one agricultural waste, rice stubble ( Oryza sativa L. ), obtained from organic sources and a local market in Ghaziabad, India, to evaluate their nutritional significance. These samples were analysed on the basis of their moisture, ash, chlorophyll, carotenoid, flavonoid, and eavy metal contents. It was observed that lettuce had the highest moisture content i.e. > 94%. Rice stubble had the highest ash content (14.26%), whereas Indian gooseberry had the lowest (< 0.9%). Organic mustard had the highest chlorophyll content i.e. 1.89 mg mL⁻¹, whereas organic curry leaves had the highest carotenoid content (0.50 mg mL⁻¹). Indian gooseberry had the highest phenolic compounds as well as flavonoid content. The study is one of the first to use a combined ICP-MS - PCA approach to jointly benchmark heavy metal and bioactive profiles across organic versus market source produce. Heavy metal concentrations in both organic and market vegetable samples were within allowable limits, confirming overall food safety. However, an integrated ICP-MS and PCA framework revealed that organic samples had a slightly lower trace elemental baseline and marginally higher bioactive compound content than market crops, with both categories remaining largely comparable in terms of composition and quality.