Assessing the efficacy of novel and conventional disinfectants on Salmonella cross contamination during washing of fresh-cut lettuce and their impact on product shelf life

• Published in: Food science & technology 2022-06, Vol.162, p.113441, Article 113441
• Main Authors: Pablos, Cristina, Romero, Aitor, de Diego, Ana, Corrales, Carla, van Grieken, Rafael, Bascón, Isabel, Pérez-Rodríguez, Fernando, Marugán, Javier
• Format: Article
• Language: English
• Subjects: Antimicrobials; Fresh-cut produce; Salmonella; Sanitation; Sensory quality
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2022.113441

The effect of the application of different disinfectants on the microbial load and sensory quality of fresh-cut lettuce was evaluated during washing, and after subsequent storage at 4 °C under modified atmosphere packaging (MAP). Different families of potential alternative sanitizers were tested: quaternary ammonium compounds (QACs) as benzalkonium chloride (BZK), and didecyldimethylammonium chloride (DDAC); isothiazolinones (mixture of chloromethylisothiazolinone and methylisothiazolinone, CMIT:MIT 3:1); and, essential oils (carvacrol, CAR). All these disinfectants were effective to inactivate Salmonella (103 CFU/mL) present in wash water. In addition, all tested chemicals could reduce Salmonella on produce to levels >95%, with chlorine and BZK-CAR reaching maximum reductions of 99.0%. These disinfectants also enhanced a reduction in natural microbiota present on the produce. The highest reduction corresponded to free chlorine (50 mg/L) (95.1%), CMIT:MIT (50 mg/L) (Kathon®) (94.5%), and BZK (300 mg/L) (91.3%). However, only free chlorine (50 mg/L), CMIT:MIT (50 mg/L) (Kathon®), and DDAC (100 mg/L) resulted in minimal negative impact on end-product quality during 14-day storage. On the contrary, an adequate sensory quality could be only maintained up to 7 days for produce treated with BZK (300 mg/L). •All disinfectants were effective to inactivate Salmonella remaining in wash water.•Quaternary ammonium compounds (QACs) (100–300 mg/L) reduced cross-contamination.•Isothiazolinones (50–300 mg/L) reduced Salmonella and natural microbiota on the produce.•QACs/monoterpenes and free chlorine showed the highest Salmonella reduction on produce.•Chlorine, QACs and isothiazolinones extended the shelf-life of the produce up to 14 days.