Quality characteristics and bacterial community of a Chinese salt-fermented shrimp paste

Abstract

Huanghua shrimp paste is well-known as a traditional salt-fermented food in China. So far, however, little is known about its quality characteristics and bacterial community. The quality of Huanghua salt-fermented shrimp paste was evaluated in this work by determining the pH values, amino acid nitrogen (AAN), malondialdehyde (MDA), nitrite and biogenic amines (BAs). Moreover, the bacterial community of shrimp paste was analyzed by using the high-throughput sequencing technology. The results showed that the pH, AAN, MDA, nitrite and total BA content in shrimp paste were in ranges of 6.77–8.25, 0.16–0.35 g/100 g, 0.25–1.10 mg/kg, 0.18–0.49 mg/kg and 18.20–469.02 mg/kg, respectively. The main BAs were tryptamine, histamine and tyramine. Bacterial community analysis indicated that Firmicutes and Proteobacteria were the most dominant phylum in all shrimp paste samples. Enterococcaceae, Pseudomonadaceae and Staphylococcaceae were the most predominant family. The major bacteria genera in shrimp paste were Tetragenococcus, Lactobacillus and Halanaerobium. The correlation between AAN, histamine and tyramine contents and Tetragenococcus were 0.71, 0.62 and 0.67 (R2 values), respectively. These findings expand the understanding for Huanghua salt-fermented shrimp paste and provide a theoretical basis for improving the fermentation process of shrimp paste.