Effects of Rhodobacter sphaeroides Crude Extracts on Volatile Flavor Substances and Flavor Amino Acids of Sausages During Storage

In order to test the effects of the crude extracts from Rhodobacter sphaeroides (CCRS) on the volatile flavor substances and flavor amino acids of sausages during storage, the sausages were respectively processed with addition of CCRS at higher, medium and lower concentrations. Sausage processed without addition of CCRS was used as control. The volatile flavor substances and free amino acids were respectively analyzed using headspace solid-phase micro-extraction gas chromatography mass spectrometry (HS-SPME-GC-MS) and amino acid analyzer. The experimental results showed that a total of 36 volatile flavor substances were detected by GC-MS, including 17 alcohols, 1 ester, 10 aldehydes, 2 acids, 3 alkanes and 3 other components, among which 8 substances were considered the main flavor substances. Multivariate statistical analysis showed that the content and types of alcohols in sausages added CCRS were lower than those in control after 3 months storage. After 6 months storage, the alcohol content in the sausages with CCRS was higher than that of the control. However, the aldehyde content of the sausages with CCRS was lower than that of the control. Moreover, the CCRS promoted the production of ethenyl hexanoate, which was the only one ester in the sausages. On the other hand, the addition of low concentration of CCRS reduced the content of heptaldehyde, octanoic acid and other odor substances. Amino acid analysis suggested that the CCRS increased the proportion of delicate and sweet amino acids. The taste activity value (TAV) analysis indicated that the histidine TAV value was the strongest and had the greatest impact on sausage taste. The present study would provide a theoretical basis and technical support for enhancing the flavor quality of Chinese traditional sausages based on the metabolites of Rhodobacter sphaeroides.