Isolation and Characterization of Lactic Acid Bacteria from Guizhou-Style Meat Products and Its Effect on Flavor and Quality of Fermented Loin Ham

The objective of the current study was to isolate and identify lactic acid bacteria from a series of Guizhou-style fermented cured meat products, such as Jinping sour pork, Rongjiang sour pork, Kaili sausage, Zunyi sausage, Weining dry-cured ham, Panxian dry-cured ham, Kaili air-dried meat, Zunyi air-dried meat, and Bijie air-dried meat, as well as to illustrate their protein degradation capacity, physiological and biochemical characteristics, practical applicability, and safety. A strain named SJ-4, with strong protein degradation capacity and the potential to be used as a meat starter culture, was selected from the isolated strains, and was used as an inoculum to produce fermented loin ham. Effects of the starter culture on the color, texture, electronic tongue response value and flavor of fermented lion ham were examined using naturally fermented lion ham as a control. The results showed that the strain was tolerant to 6 g/100 mL NaCl and 150 mg/kg NaNO₂, did not produce NH₃, H₂S or H₂O₂, had no amino acid decarboxylase activity, and had the ability to decompose protein butnot fat. Under the optimum growth conditions of 37 ℃ and pH 6.0, the strain entered the logarithmic growth phase after 4 h cultivation, and the pH dropped to 3.80 after 18 h, proving that it can be used as a meat starter culture. Strain SJ-4 was identified as Lactobacillus plantarum according to its morphological, physiological and biochemical characteristics and 16S rDNA sequence alignment. Inoculation with SJ-4 significantly affected the color, hardness and cohesiveness of fermented loin ham (P < 0.05), and was beneficial for the formation of flavor compounds, increasing the contents of key flavor components such as nonanal and 3-hydroxy-2-butanone. Therefore, Lactobacillus plantarum SJ-4 can be developed as a high-activity meat starter culture.