A Comprehensive Characterization of Heat Treatment-Induced Changes in Volatile Compounds and Flavor Attributes Among Lotus Root Varieties.

This study investigated the effects of three thermal processing methods (microwave, MW; sous-vide, SV; and air frying, AF) on the texture, color, volatile, and nonvolatile components of three lotus root varieties (Zaohua, SW, and E9:11). The results indicated that SV effectively preserved texture, color, and umami compounds, particularly in the SW variety. Both MW and SV treatments showed similarities in the composition and content of volatile compounds. AF, by increasing hardness, chewiness, and the composition and content of flavor compounds, significantly improved the edible quality, making it the most effective method for enhancing flavor compounds. The high stability of pyrazines in the E9:11 variety and the stable high content of ketones in the Zaohua variety highlight their aromatic potential. The SW variety demonstrated strong resistance to MW treatment, which helped preserve alcohol-based flavor compounds, while also exhibiting distinctive taste characteristics under SV treatment. Based on the analysis of 134 identified volatile compounds, 10 key differential aroma compounds, including 2,4-nonadienal, (E, E)-2,4-nonadienal, and nonanal, were identified using odor activity value (OAV) and variable importance in projection (VIP) analyses. The results guide the development of quality lotus root products and the selection of apt processing methods.