Biosynthesis of silver nanoparticles from apple pomace and their inhibitory activity on Alicyclobacillus acidoterrestris

In this work, silver nanoparticles using apple pomace extract were synthesized and evaluated for their antimicrobial properties against Alicyclobacillus acidoterrestris , a thermoacidophilic microorganism that is an important contaminant within the juice industry due to its ability to withstand standard pasteurization protocols. The biosynthesized silver nanoparticles exhibited an average size of 100 nm, a spherical shape, a Z potential of −32.8 mV, and moderate short-term stability. Their MIC (Minimal Inhibitory Concentration) and MBC (Minimal Bactericidal Concentration) against A. acidoterrestris ATCC 49025 were 19.53 μg/mL and 78.10 μg/mL, respectively. Furthermore, the tests in homemade and commercial juices showed a reduction of up to 92.6% of the initial population when the nanoparticles were added at a concentration of 2 x MIC, indicating high antimicrobial efficacy.