Microbial inactivations with hydrolysed lactoferrin and other natural antimicrobials in fresh-cut fennel

- Different natural antimicrobials were studied on fresh-cut fennel.
- Enterobacteriaceae was the most sensitive microbial group to studied sanitizers.
- Psychrophiles was the most resistant microbial group to studied sanitizers.
- Hydrolysed lactoferrin showed the highest psychrophilic reduction (2.5 log units).

Natural antimicrobials (nisin, lactoferrin, thymol and citrus extract) were studied as sustainable alternatives to conventionally used NaOCl in fresh-cut (FC) fennel. Enterobacteriaceae was the most sensitive microbial group to studied sanitizers according to δ values, while psychrophiles were the most resistant. Based on inactivation modelling and sensory scores, nisin (N-250; 0.250 g L−1), lactoferrin (L-50; 50 g L−1), together with hydrolysed L-50 (LFH), were selected and studied comparing to water-washed (CTRL) and NaOCl (150 mg NaOCl L−1) on FC fennel. LFH achieved the highest psychrophilic reduction of 2.5 log units. Although NaOCl achieved the highest mesophilic, Enterobacteriaceae, lactobacilli and yeasts and moulds reductions of 1.7, 1.0, <1.7 and 1.6, respectively, N-250 still achieved 0.50-1.0 log unit reductions compared to CTRL. Conclusively, LFH and N-250 are natural antimicrobial treatments with good microbial inactivation rates which may be a good alternative to conventional NaOCl used by the FC industry.