Enhancing raw trout fillet quality with Lactiplantibacillus plantarum postbiotics and potassium sorbate.

Abstract

This study investigates the impact of Lactiplantibacillus plantarum postbiotics (LPP) on microbiological and chemical alterations in raw rainbow trout fillets stored at 4°C. LPP, containing chemicals such as methyl ester, oleic acid, and eucalyptol, demonstrated considerable radical scavenging action and improved cellular safety, enhancing cell survival by 118.70% to 170.60% and elevating SOD (20.10-33.14 mU mg-1) and GSH-Px (99.80-120.30 mU mg-1) activity. The use of LPP (1.5%, 0.8%, 0.5%) and potassium sorbate (PS) in raw fish fillets resulted in a significant decrease in microbial proliferation, with the 1.5% LPP treatment achieving a reduction in Listeria monocytogenes count by 5.6 ± 0.07 log CFU g-1 by day 2. Additionally, chemical parameters showed marked stability; the pH value increased from 6.22 ± 0.08 to 6.4 ± 0.03 in the 1.5% LPP-treated fillets by day 12. Total volatile basic nitrogen levels for the same treatment remained below the acceptable threshold of 25 mg 100 g-1 until day 8 (21.23 ± 0.19 mg 100 g-1), while TBA levels peaked at 1.1 ± 0.02 mg kg-1 on day 12. This approach prolonged shelf life by up to 12 days, maintaining fillet quality with no adverse sensory consequences.