Food Control

Improved control measures starting in the 1990s have greatly reduced the prevalence of L. monocytogenes in many food categories, particularly in meats and meat products. However, the rate of listeriosis has remained constant during the last decade and the more severe, systemic (invasive) form of listeriosis is now recognized as occurring more frequently in small outbreaks than previously recognized. This review addresses the recent advances in epidemiology and virulence, in growth and modelling, and insights from the risk assessments. Recognition of recent outbreaks from food vehicles not traditionally associated with L. monocytogenes (celery, cantaloupe, mung bean sprouts, stone fruits, caramel apples and ice cream) was facilitated by PFGE and, increasingly, whole genome sequencing. The Key Events framework, an understanding of the key individual biochemical steps from ingestion to infection, provides a structure for relating new knowledge on strain variability, mutations, and host susceptibility to the probability of illness. Guidance for determination of the growth/no growth potential of a food has been issued by several regulatory authorities and the risk assessments indicate that prevention of growth remains a principle control element. The recognition of biofilm formation and the possible existence of dormant, non-dividing persister cells will require additional attention. The recent outbreaks underscored the individual characteristics of specific foods (melons vs all fruit; microenvironments in the caramel apples) and raised questions about the current understanding of infectivity of lower doses and the susceptibility of specific individuals. Advances have been made in these areas, but further research is clearly necessary to control this pathogen.

Implementing science-based interventions is vital for ensuring a risk-based official food safety control. The aim of this study was to investigate the prevalence of Listeria monocytogenes ( L. monocytogenes ) on surfaces in food establishments, identify risk factors for this hazard, and analyse the influence of these factors on the detection of the hazard in food establishments producing ready-to-eat (RTE) food in Spain between July 2024 and March 2025. A total of 184 inspection reports from various food sectors were studied, and 731 samples from food contact surfaces (FCS) and non-food contact surfaces (NFCS) were analysed. Prevalence, prevalence ratio and population attributable fraction were calculated. The results revealed a higher prevalence of L. monocytogenes on NFCS (22.5%) than on FCS (15.2%). The study identified critical risk factors associated with contamination. In particular, the ineffective separation between unprocessed and RTE areas was a significant factor for both surfaces. The highest risk factor influencing the presence of the hazard was unidentified stages of risk of cross-contamination with L . monocytogenes . This case study demonstrates how food control authorities can use science-based evidence to identify risk factors of L. monocytogenes and prioritise tailored interventions to effectively reduce this pathogen from food production environments.

The increasing use of agro-industrial by-products as sources of functional food ingredients raises important questions regarding the presence and fate of pesticide residues throughout processing. This study investigated pesticide residues during the valorization of the orange juice industry by-products (OJB) into phenolic-rich extracts and functional jelly candies. Pesticide residues were determined in OJB, freeze-dried extract (FOE), spray-dried extract (SOE), and jelly candies formulated with each extract, using QuEChERS extraction, LC–MS/MS, and GC–MS/MS. Processing factors were calculated to evaluate residue carryover throughout the production chain, and dietary risk assessments were performed considering consumption by both adults and children. Twenty pesticide residues were detected in OJB, with two exceeding the maximum limit permitted for citrus crops. Of these, 16 compounds persisted in FOE, 11 in SOE, 6 in jelly candies containing FOE, and 4 in those containing SOE. Selected compounds, including azoxystrobin, imazalil, tebuconazole, and bifenthrin, remained detectable throughout the entire processing chain. Residue persistence appeared to be influenced by physicochemical properties such as hydrophobicity, vapor pressure, and solubility, although no single parameter fully explained the observed behavior. Despite the presence of pesticide residues, dietary exposure estimates yielded very low hazard index values for both adults and children. These findings demonstrate the importance of this toxicological approach to the upcycling trend. Tracking pesticide residues during the processing transformation of agro-industrial by-products into functional ingredients and food products may be a good criterion for selecting the best processing choices, guided by the safety of the resulting product and its beneficial and functional aspects.