Aroma enhancement in dry cured loins by the addition of nitrogen and sulfur precursors

Impact of paprika and dextrose addition on dry cured loins microbiota and its effect on aroma development

The impact of paprika and dextrose addition on the surface of dry cured loins was analysed attending to differences in microbiota composition and aroma profile. Three different types of loins containing either dextrose (D), paprika (P) or a mixture of dextrose and paprika (DP) were manufactured. The loins were characterized using physic-chemical parameters, free amino acids, volatile compounds and aroma sensorial analysis, as well as applying microbiological counts and metagenomics of the 16S rRNA gene and its rDNA region. The analysis of volatile compounds clearly distinguished all loins, whereas the total content of free amino acids only separated P from D and DP loins. The main sensory differences were linked to paprika addition, which increased the perception of paprika and smoky odors as well as cured, savoury and cheesy notes. Microbial counts analysis could not differentiate between the three loin types; however, metagenomics analysis revealed clear differences in key bacterial and fungal genera among the three loins. Paprika addition favoured dominance of Latilactobacillus in the microbiota of P loins. On the contrary, dextrose addition caused the dominance of Staphylococcus in the microbiota of D loins. In DP loins, both genera were similarly represented in the bacterial community. Regarding fungi, large differences could be observed within the P and D loins, whereas the proportion of Debaryomyces in DP loins increased. The microbiota composition of DP loins controlled the lipid oxidation phenomenon, reducing the generation of derived volatiles producing rancid notes and increase the volatile compounds derived from amino acids such as branched aldehydes, pyrazines and pyrroles, providing particular aroma notes to the loins.

Volatile compounds comparison and mechanism exploration of non-smoked traditional Chinese bacon in Southwestern China and Eastern China

Non-smoked traditional Chinese bacon is popular in China. However, the aromas of the non-smoked bacon from Eastern China (EC bacon) and Southwestern China (SW bacon) differed significantly. This study investigated these differences and the key volatile compound formation mechanisms. A total of 175 volatile compounds were detected in the bacon samples, while 32 key aroma compounds were screened based on odor activity values (OAVs). Multivariate statistical analysis showed that ten odorants could be considered discriminative compounds, including hexanal, octanal, and 1-octen-3-ol, etc. The fatty aroma of EC bacon was mainly attributed to a higher aldehydes content, which is due to more oxidation of fatty acids. Meanwhile, the SW bacon smelled sweeter since there was more ester in the sample. The correlation analysis between the fatty acid profiles and key aroma compounds indicated that the discriminative aldehyde formation in the EC bacon was primarily attributed to oleic and linoleic acid oxidation, which were both potential biomarkers.

Understanding the impact of nitrogen and sulfur precursors on the aroma of dry fermented sausages

The goal of this study was to confirm and acquire more information about the nitrogen and sulfur compounds existing in the volatile profile of dry fermented sausages from the addition of precursors (proline, ornithine and thiamine), and their role in sausage aroma. To this end, the precursors were added to the formulation of sausages, which were submitted to a fermentation and drying process. The sausage aroma was analyzed by olfactometry technique and Free Choice Profile sensory analysis. The results showed that the addition of precursors impacted the aroma, and reduced the level of oxidation in the final sausages while microbial differences were mainly observed in Orn-sausages. Among the aroma compounds detected only 2-methyl-3-(methylthio)furan verified the effect of thiamine supplementation and the impact on the cured and savoury odours detected in Thia-sausages by Free Choice profile sensory analysis, while no clear effect could be attributed to specific volatile compounds in the nitrogen supplemented sausages.