Optimization of the Production Process of Liquid-Smoked Bacon Using Liquid Smoke-Assisted Curing and Its Impact on Product Quality

In order to improve the flavor quality and production efficiency of liquid-smoked bacon, the traditional use of liquid smoke was improved and the production process with liquid smoke-assisted curing was optimized by response surface methodology. The independent variables were volume fraction and addition level of liquid smoke, curing time and roasting time. The response was sensory scores. The quality of liquid-smoked bacon was compared with that of traditional bacon from west Hunan Province. Partial least squares-discriminant analysis (PLS-DA) was used to evaluate the changes of flavor substances during the roasting of liquid-smoked bacon. The results showed that the optimal process conditions were as follows: adding 2% of liquid smoke at a volume fraction of 70%, curing for 4 days and roasting for 8 days. Compared with commercially available west Hunan-style bacon, liquid-smoked bacon had higher moisture content and brightness value, and lower salt and nitrite contents (3.8% and 1.20 mg/kg respectively), and its sensory score was 84.56 ± 1.10 out of 100 points. The taste activity value (TAV) analysis showed that inosine monophosphate (IMP), guanosine monophosphate (GMP), alanine, glutamic acid, lysine, arginine, valine, histidine, and adenosine monophosphate (AMP) were mainly responsible for the taste of liquid-smoked bacon. PLS-DA showed that the content of taste substances varied depending on the roasting time, and citrulline, tryptophan, cysteine, hypoxanthine (Hx), GMP, glutamine, glycine, isoleucine, and leucine were the key indexes influencing the differences in the flavor of liquid-smoked bacon with different roasting times.