High pressure processing pretreatment of dried shrimps (Litopenaeus vannamei) for volatile and taste attributes assessment

Pretreatment methods and drying process play vital role in the quality and flavor changes of shrimp. The volatile and taste profiles in high pressure processing (HHP at 300MPa-5min, 300MPa-10min, 500MPa-5min, and 500MPa-10min) pretreatment shrimps after hot-air drying process were investigated by using the electronic tongue, electronic nose, high performance liquid chromatography, and gas chromatography/mass spectrometry. The results showed that HHP pretreatment endowed shrimps with better volatile and taste attributes to varying degrees, which significantly ( P < 0.05 ) increased total umami free amino acids (1.18−2.16 times), total sweet free amino acid (1.09−1.27 times) contents ( P < 0.05), promoted the production of pleasant taste nucleotides (1.52−1.83 times) and organic acids (1.19−1.78 times), and produced more volatile components (1.10−1.46 times) when compared to untreated group. Glycine, alanine, valine, lysine, histidine, arginine, guanosine monophosphate, inosine monophosphate, and succinic acid were main non-volatile active components. The equivalent umami values is: 500MPa-5min > 500MPa-10min > 300MPa-10min > 300MPa-5min > control group. Compared with control group, HHP pretreatment endowed shrimps with richer aldehydes, ketones, alcohols and pyrazine compounds, while control endowed shrimps with richer hydrocarbons. Based on these flavor profiles, the principal component analysis of E-tongue and E-nose data showed a distinct difference among the different pretreatment group. Generally, HHP at 500 MPa-5min was beneficial for improving EUC and volatile compounds of dried shrimps. The findings may provide theoretical reference for the development of high-quality drying technology for shrimps.