Quality of <i>Kapi</i>, Salted Shrimp Paste of Thailand, Inoculated with <i>Bacillus</i> spp. K-C3

<p>The use of <i>Bacillus</i> spp. K-C3, isolated from commercial <i>Kapi</i>, salted shrimp paste of Thailand, as the starter culture for <i>Kapi</i> production, at different levels including 10², 10⁴, and 10⁶ CFU/g dry weight sample named <i>Kapi</i>-B2, <i>Kapi</i>-B4, and <i>Kapi</i>-B6, respectively, in comparison with naturally fermented <i>Kapi</i> (<i>Kapi</i>-C) was studied. All inoculated samples exhibited higher extent of proteolysis and lipolysis as indicated by higher trichloroacetic acid (TCA)-soluble peptide, degree of hydrolysis, and free fatty acid content in the final products. The greater rate of fermentation in the inoculated samples directly affected characteristics of <i>Kapi</i> and yielded <i>Kapi</i> with browner color and enhanced lipid oxidation as indicated by peroxide value (PV) and thiobarbituric acid reactive substance (TBARS) values. Increased antioxidative properties, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activities, and ferric reducing antioxidant power (FRAP), were obtained in <i>Kapi</i> with added inoculum. Moreover, those inoculated samples also contained higher intensity of volatile compounds, in which <i>N</i>-containing compounds, mainly pyrazine derivatives, were dominant. <i>Kapi</i>-B4 and <i>Kapi</i>-B6 showed the highest extent of these aforementioned values compared with <i>Kapi</i>-C and <i>Kapi</i>-B2. Therefore, inoculation with <i>Bacillus</i> spp. K-C3 at the level higher than 10⁴ CFU/g dry weight sample is a potential means to accelerate the fermentation rate and yielded <i>Kapi</i> with preferable characteristics.</p