Effects of sous-vide cooking combined with ultrasound pretreatment on physicochemical properties and microbial communities of Russian sturgeon meat (Acipenser gueldenstaedti).

BACKGROUND
The production of Russian sturgeon expands rapidly in China. It is necessary to adopt some restrictive measures which can extend the shelf life of sturgeon meat. Previous studies found that sous-vide cooking (SVC) at 60°C increased the protein and lipid oxidation. The addition of antioxidant substances reduced the acceptance of the product. Therefore, the effect of combination of sous-vide cooking (SVC) and ultrasound pretreatment was investigated.


RESULTS
Results showed that SVC 50°C combined with ultrasound effectively restrained the growth of total viable counts (TVC) in samples. Meanwhile, the main dominant genera transformed from Pseudomonas to Carnobacterium and the number of microbial species decreased. The odor profile of Russian sturgeon meat was more stable and the Lipoxygenase (LOX) activity decreased more rapidly after treating with SVC and ultrasound. Importantly, more stable protein aggregates were formed in samples treated by SVC 50°C with ultrasound pretreatment, so the protein and lipid oxidation were slowed down during storage. Additionally, higher springiness values were obtained and the color of sturgeon meat was lighter under these conditions.


CONCLUSION
The combination of SVC 50°C and ultrasound pretreatment effectively inhibited the microbial growth of Russian sturgeon meat at lower oxidation levels. These findings can theoretically support the preservation and development of sturgeon meat, as well as the application of SVC technology. This article is protected by copyright. All rights reserved.