Sankuan Xie,Jia Song,Bingqian Fan,Xuan Li,Yingqi Li,Fangming Mou,Yu Zheng,Min Wang
Polyphenols (PPs) are the main contributors to the health functions of Shanxi aged vinegar (SAV) and are mainly produced during the smoking process. This study aimed to explore the feasibility of regulating the accumulation of total water-soluble PPs (TWSP) by changing environmental factors based on the distribution of PPs. A total of eleven PPs, such as vanillin, vanillic acid, and (e)-ferulic acid, were detected during the smoking process. During the smoking process, the content of TWSP gradually increased and was accompanied by changes in environmental factors. Spearman correlation analysis and verification experiments showed that temperature, amino acids, and reducing sugars, as the main influencing factors, promoted the accumulation of TWSP. The in situ regulation strategy of changing environmental factors significantly increased the accumulation of TWSP by 12.24%.Keywords:Shanxi aged vinegar;polyphenols;smoking;influencing factors;in situ regulation
ABSTRACT Larou is a traditional smoked meat product in China. In this experiment, larou was processed with different smoking materials and methods to determine whether differences in processing methods would affect the quality of the larou and the concentrations of carcinogens. Pork bellies were marinated, dried, and divided into four groups and then directly smoked with four different smoking materials for 40 min. The smoking material for larou that was most effective was then used with an indirect smoking device with an nano-activated carbon fiber filter and evaluated as a single-factor variable. The surface area of the nano-activated carbon filter was 978.00 m 2 /g, and this filter effectively adsorbed the ash particles from the smoke. For the group smoked with pomelo skins (PS), the highest concentrations and number of phenols were 4.48% and 11, respectively, which increased the smoke flavor significantly. The moisture was 32.64%, and the Staphylococcus, lactic acid bacteria, and yeast and mold levels were 0.98, 1.10, and 0.59 log CFU/g, indicating inhibition of harmful bacteria and a beneficial microbial environment for larou fermentation. The benzo[ a ]pyrene (B[ a ]P) concentration in PS smoke determined with the indirect smoking device was 1.82 μg/kg, whereas that determined with the direct smoking device was 36.1 μg/kg, a significant difference ( P < 0.01). These findings suggested that indirect smoking with PS could effectively maintain microbial quality and reduce the B[ a ]P[mc] concentrations in larou. This processing method can be used for the production of this meat product.
Lapsang Souchong black tea enjoys a good reputation in China for its unique smoky flavor. A total of 61 odorants in smoked Lapsang Souchong (SLS) and 49 odorants in the reference sample (non-smoked Lapsang Souchong, NSLS) were identified, respectively. The odorants of tea origin decreased significantly after the smoking process, while the pyrolysis products of pine wood increased markedly. Phenols (66.6%) were the most abundant odorants in SLS, among them, 18 phenols were newly found compared to NSLS. Aroma recombinates of SLS and NSLS proved the successful identification and quantitation of their respective key aroma compounds. The omission and addition tests clearly corroborated 3-ethylphenol, p -cresol, m -cresol, and 2-methoxy-4-methylphenol were the crucial factor for the strong smoky pine aroma characteristics of SLS tea. The findings offer a new insight into the flavor role of phenols to SLS tea, which will help to deeply explore the effect of smoking process on aroma changes during tea production.