Effect of the extract from custard apple (Annona squamosa) leaves prepared with pulsed electric field‐assisted process on the diversity of microorganisms and shelf‐life of refrigerated squid rings

Abstract

AbstractAntibacterial and antibiofilm properties of ethanolic custard apple leaf extract (CALE) prepared without and with pulsed electric field (PEF) assisted process (6 kV cm−1, 300 pulses, 142 kJ kg−1 for 5 min) (PEF‐CALE) were comparatively investigated. PEF‐CALE showed higher bacterial inhibition against Bacillus subtilis, Listeria monocytogenes, Escherichia coli, and Pseudomonas aeruginosa, compared to CALE. Antibiofilm properties of both extracts towards the aforementioned bacteria were augmented with increasing concentrations (P < 0.05). The impact of PEF‐CALE in extending the shelf‐life of squid rings (SQR) was also investigated. Based on the microbiological limit, the shelf‐life of refrigerated squid rings pretreated with 400 mg kg−1 PEF‐CALE was extended by more than 6 days when compared to the control. Pseudomonas lundensis, Pseudomonas fragi, and Shewanella baltica were the most abundant spoilage bacteria found in SQR. Overall, PEF‐CALE exhibited promising antimicrobial activities, which could serve as biopreservative agent for inhibiting bacterial growth in SQR during refrigerated storage.