Preparation and antibacterial activity of p-coumaric acid-β-cyclodextrin complex against Alicyclobacillus acidoterrestris in apple juice

To overcome the poor solubility and bioavailability of p-coumaric acid (p-CA), an inclusion complex (p-CA-β-CD) of p-CA and β-cyclodextrin (β-CD) was prepared. FT-IR, XRD, DSC, and SEM were performed to characterize the p-CA-β-CD complex. Additionally, the antibacterial activity of p-CA-β-CD against Alicyclobacillus acidoterrestris and the underlying mechanisms were investigated. The results confirmed the successful fabrication of p-CA-β-CD and demonstrated a significant enhancement in p-CA solubility upon complexation with β-CD. p-CA-β-CD effectively inhibited A. acidoterrestris, with an MIC of 1.4 mg/mL, by damaging cell membrane, reducing intracellular pH and ATP, increasing ROS levels, and altering cell morphology. Moreover, 1MIC of p-CA-β-CD caused 2.89 and 2.18 log reductions of A. acidoterrestris during apple juice storage at 4 °C and 25 °C, respectively, without remarkable effect on physicochemical indexes and sensory quality. These findings suggested that p-CA-β-CD could potentially be an emerging and promising natural agent for controlling A. acidoterrestris in juice.