Determination of astaxanthins contribution to the aroma characteristics and aroma‐active compounds of hot‐air‐dried shrimp products using sensory evaluation, E‐nose and GC–MS

Summary The study investigated the contribution of astaxanthin to the aroma characteristics and aroma‐active compounds (AACs) of dried shrimp ( Litopenaeus vannamei ) products. Three forms of astaxanthin (diester, monoester and free forms) were isolated from fresh shrimp. The astaxanthins were added to fresh shrimp and dried. The aroma characteristics and AACs of the dried shrimp samples were analysed using electronic nose (E‐nose), and sensory evaluation as well as gas chromatography–mass spectrometry (GC–MS). The potential correlation between sensory attributes and AACs was determined via partial‐least‐squares regression (PLSR) analysis. E‐nose and sensory evaluation of dried shrimp samples revealed a significant effect of astaxanthin on the aroma characteristics of dried shrimp, resulting in increased sensory scores of smoky, toasted, meaty and caramel aroma, while reducing fishy aroma. GC–MS analysis showed that astaxanthin had a significant effect on the concentration of AACs in shrimp products. The levels of 2,5‐dimethylpyrazine, 2‐ethyl‐3,6‐dimethylpyrazine and 2,3,5‐trimethylpyrazine, benzaldehyde, 3‐methylbutyraldehyde and 2‐nonanone were increased, while the concentration of trimethylamine was reduced. However, the effects of astaxanthin on the concentration of AACs depended on its form: the diester astaxanthin had the greatest effect, followed by monoester astaxanthin and free form. The PLSR results indicated a good correlation between most variables of sensory attributes and AACs.