Effects of Different Smoking Materials and Methods on the Quality of Chinese Traditional Bacon (Larou)

Investigating flavor and quality characteristics in Chinese bacon from different regions using integrated GC-IMS, electronic sensory assessment, and sensory analysis

To investigate the variance in the quality and flavor profiles of bacon from different regions, gas chromatography-ion mobility spectrometry and electronic sensory techniques (including electronic nose and tongue [e-nose and e-tongue, respectively]) were employed for the flavor analysis of the sourced bacon samples. Both the e-nose and e-tongue successfully distinguished the aromas and flavors of different bacon varieties. Additionally, organic sulfides, aromatic benzenes, and short-chain alkanes, were more abundant in different bacon types. Employing GC-IMS technology, identified 52 volatile flavor compounds within diverse bacon samples, culminating in the establishment of a distinct fingerprint for each individual sample. The relative odor activity value identified 1-propene-3-methylthio, 2-heptanone, phenylacetaldehyde, furfuryl methyl sulfide, and 1-octene as the primary contributors to bacon flavor. These flavor substances were the main cause of the differences in bacon flavor in different regions. The interaction of volatile flavor compounds resulted in notable disparities between the odor profiles detected using the e-nose and e-tongue, even among bacon with similar volatile flavor constituents. In addition, the color and texture of the bacon varied significantly. Bacon from HB (Hubei), YN (Yunnan), and CQ (Chongqing) showed darkness in color. Meanwhile, the hardness of bacon from HN (Hunan), HB (Hubei), and SC (Sichuan) was relatively low. These results not only provide theoretical and technical insights for bacon flavor identification and control but also offer a foundation for consumers to make informed choices when purchasing bacon.

Decoding of the enhancement of saltiness perception by aroma-active compounds during Hunan Larou (smoke-cured bacon) oral processing

The enhancement of saltiness induced by odrants perceived from the retronasal cavity during Larou oral processing was analyzed. During the oral processing of Xiangtan Larou, the smoky attribute was the dominant when chewing 0-15 times, followed by the savory (15-24 times) and meaty (24-42 times). Partial least squares analysis predicted 33 aroma compounds from the retronasal cavity significantly (p < 0.05) contributing to the aroma perception. A total of 12 aroma compounds with saltiness-enhancement ability were confirmed by odorant-NaCl mixture model experiments. Results revealed that 2-methoxy-4-vinylphenol (1.00-1000.00 μg/L) had the strongest enhancing effect on saltiness at NaCl (2969.85 mg/L), followed by diallyl sulfide (0.156-2.50 μg/L), 2,5-dimethylthiophene (0.156-50.00 μg/L), 2,6-dimethylphenol (1.00-100.00 μg/L), 2,5-dimethylpyrazine (0.391-50.00 μg/L), and 2,3-butanedione (0.50-100.0 μg/L). The sulfur-containing, nitrogen-containing, and phenolic odorants with savory, roasty, sulfide, meaty or smoky, attributes showed the better ability in saltiness enhancement.

Quantitative Proteomics Reveals the Relationship between Protein Changes and Volatile Flavor Formation in Hunan Bacon during Low-Temperature Smoking

This study aimed to investigate the changes in proteins and volatile flavor compounds that occur in bacon during low-temperature smoking (LTS) and identify potential correlations between these changes. To achieve this, a combination of gas chromatography-mass spectrometry and proteomics was employed. A total of 42 volatile flavor compounds were identified in the bacon samples, and, during LTS, 11 key volatile flavor compounds with variable importance were found at a projection value of >1, including 2',4'-dihydroxyacetophenone, 4-methyl-2H-furan-5-one, Nonanal, etc. In total, 2017 proteins were quantified at different stages of LTS; correlation coefficients and KEGG analyses identified 27 down-regulated flavor-related proteins. Of these, seven were involved in the tricarboxylic acid (TCA) cycle, metabolic pathways, or amino acid metabolism, and they may be associated with the process of flavor formation. Furthermore, correlation coefficient analysis indicated that certain chemical parameters, such as the contents of free amino acids, carbonyl compounds, and TCA cycle components, were closely and positively correlated with the formation of key volatile flavor compounds. Combined with bioinformatic analysis, the results of this study provide insights into the proteins present in bacon at various stages of LTS. This study demonstrates the changes in proteins and the formation of volatile flavor compounds in bacon during LTS, along with their potential correlations, providing a theoretical basis for the development of green processing methods for Hunan bacon.