Quality Improvement of Zao Pepper by Inoculation with Lactobacillus plantarum 5-1: Probiotic Ability and Fermentation Characteristics of Lactic Acid Bacteria

Zao pepper is a fermented type with a distinct flavor, and Zao pepper-based dishes are popular. However, in spontaneous fermentation (SF), the adverse microorganisms of Zao pepper are uncontrollable and alter the product quality. Lactic acid bacteria (LAB) inhibit the growth of harmful bacteria and endow a sour taste in SF. Therefore, the purpose of this study was to isolate autochthonic LAB from SF and through inoculated fermentation (IF) to improve Zao pepper quality. Four LAB strains were selected for probiotic experiments by sensory evaluation based on the flavor of Zao pepper in vitro. Intriguingly, Lactobacillus plantarum 5-1 showed superior safety and probiotics, with the fastest growth and acid-production rate. Moreover, the nitrite reductase viability of L. plantarum 5-1 reached 4.73 μmol/mL·h. The use of IF via L. plantarum 5-1 increased the total acid content 2-fold and reduced the nitrite content by 0.36-fold compared to SF in Zao pepper. In addition, IF improved the color and texture of Zao pepper. These results indicate that the autochthonic L. plantarum 5-1 improved the quality of Zao pepper, providing a new strategy for enhancing the stability of fermented pepper.