Assessment of Metabolome Variation in Field‐Grown Lettuce in Context to Its Different Types and Soil Types as Analyzed via GC‐MS Analysis and Using of Chemometric Tools

ABSTRACT Lettuce (Lactuca sativa L.) is one of the most important ready‐to‐eat vegetables widely consumed worldwide owing to its nutritional and health benefits. A total of 111 peaks were identified via gas chromatography‐mass spectrometry (GC‐MS) with sugars represented the most abundant primary metabolite class detected in lettuce specially in sandy soil grown lettuce compared to that in mud soil. The highest sugar level was detected in iceberg lettuce grown in sand soil at 967.1 mg/g versus lowest in “Baladi” lettuce grown in mud soil at 48.2 mg/g. Glucose represented the major sugar at 733.4 mg in iceberg grown in sand soil (SC) compared to 94.7 mg/g in that grown in muddy soil (MC). Sucrose detected at 212‐434 mg/g compared to traces in samples grown in muddy soil (MB and MC). Higher levels of amino acids were detected in green leaf lettuce in sandy soil (SC) at 130 mg/g, with L‐proline as the major amino form. Iceberg lettuce grown in SC was discriminated from other samples with the aid of chemometric analysis due to its richness in sugars, while green leaf lettuce in SC was discriminated by its richness in amino acids, organic acids, and sugar alcohols.