Comparative analysis of volatile compounds of an oyster enzymatic hydrolysate adsorbed by V-type starches based on electronic nose, GC-IMS, and GC-MS.

Oyster enzymatic hydrolysates (OEHs) derived from marine sources possess intensely unpleasant flavors, which severely limit their acceptance by consumers. Herein, V-type starches (V6a/h, V7a/h and V8a/h) are utilized for the deodorization of the OEH. Changes of volatile compounds (VOCs) in the OEH between before and after deodorization are determined via the electronic nose (E-nose), gas chromatography-ion mobility spectrometry (GC-IMS), and gas chromatography-mass spectrometry (GC-MS). Results indicate that V-type starches, presenting varying cavity sizes, exhibit selective adsorption capabilities for the OEH VOCs. E-nose results suggest that V6a/h-, V7a/h-, and V8h-type starches selectively adsorb aromatic compounds, such as benzene, ammonia, and short-chain alkanes, whereas V8a-type starch prefers adsorbing organic sulfides, nitrogen oxides, and methyl compounds. GC-IMS and GC-MS results further reveal that V6a/h- and V7a/h-type starches exert selective adsorption effects on aldehydes and alcohols, respectively. Notably, GC-MS results show that V8a/h-type starches selectively adsorb amine compounds, while GC-IMS results show that V8a/h-type starches prefer aldehyde adsorption. This discrepancy is attributed to differences in the sensitivity of the two techniques in detecting VOCs. Moreover, 10 VOCs were identified in the OEH using GC-IMS and GC-MS. The contributions of 12 key off-odors to the OEH flavor decreased after deodorization. Accordingly, the utilization of novel and eco-friendly V-type starches to enhance the OEH flavor provides new perspectives for promoting the application of starch materials in deodorization techniques for aquatic products.