GC–IMS and GC–MS Combined With Multivariate Analysis for Objective Evaluation of Flavor Quality Differences Among Lotus Root Varieties

This study investigated the flavor profiles of 10 lotus root varieties using a combination of headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME–GC–MS), GC–ion mobility spectrometry (GC–IMS), high-performance liquid chromatography (HPLC), electronic tongue (E-tongue), and sensory evaluation techniques. While physicochemical parameters and major volatile organic compounds (VOCs) were similar across the varieties, their concentrations varied significantly. A total of 86 volatiles were detected by GC–MS, whereas GC–IMS identified 38, with orthogonal partial least squares discriminant analysis (OPLS-DA) revealing 29 (GC–MS) and 14 (GC–IMS) significant markers. Key odor-active compounds contributing to aroma differentiation included alcohols, aldehydes, and ketones, such as ( E )-2-nonenal (green, fatty), geraniol (floral), and 1-octen-3-ol (mushroom-like). Notably, Zaohua exhibited a distinctive fresh-green character attributed to elevated ( Z )-2-nonenal content, whereas Yeyong possessed unique floral scent characteristics distinct from other varieties. Sensory and E-tongue analyses confirmed distinctive characteristics in aroma and taste: Hucheng Wild ( HW) showed pronounced sourness and bitterness, whereas Suining White (SW) and E9:11 displayed prominent sweetness and umami attributes. An integrated analysis of VOCs, flavor amino acids, nucleotides, and sensory attributes highlighted the varietal differences in flavor, providing a theoretical foundation for lotus root classification and processing. Practical Applications This study identifies key flavor compounds and taste characteristics across 10 lotus root varieties through integrated sensory analysis and instrumental profiling. The findings provide valuable insights for food producers and breeders, aiding in the selection of lotus root cultivars with desirable taste profiles for both fresh consumption and product development.