Multisite survey of bacterial contamination in ready-to-eat meat products throughout the cooking and selling processes in urban supermarket, Nanjing, China

Characterisation of a colourimetric biosensor SapYZUM13@Mn3O4-NH2 reveals the mechanisms underlying its rapid and sensitive detection of viable Staphylococcus aureus in food

In this study, a colourimetric biosensor based on bacteriophage SapYZUM13 and an aminated Mn3O4 (Mn3O4-NH2) nanozyme was constructed and evaluated for its ability to detect Staphylococcus aureus in food. The biosensor had a detection time of 20 min, with a detection limit of 2 × 101 CFU/mL and recovery rate of 92.42-106.96%, indicating its high reliability and accuracy in detecting the food pathogen. Mechanistically, SapYZUM13@Mn3O4-NH2 exhibited oxidase-mimicking capability, producing O2•- free radicals which oxidise 3,3',5,5'-tetramethylbenzidine (TMB) to yield blue-coloured oxTMB. In the presence of S. aureus, the oxidase activity decreased remarkably owing to shielding of the nanozyme active sites. Moreover, SapYZUM13@Mn3O4-NH2 could detect viable S. aureus from various sources, likely because of the special receptor-binding proteins of SapYZUM13 adsorbing to the wall teichoic acids on the S. aureus cell surface. Thus, SapYZUM13@Mn3O4-NH2 has broad application prospects for the detection of viable S. aureus in various foods.

Pre-Harvest Food Safety Challenges in Food-Animal Production in Low- and Middle-Income Countries

Food safety remains a significant global public health concern, with the risk of unsafe food varying worldwide. The economies of several low- and middle-income countries (LMICs) heavily rely on livestock, posing a challenge to ensuring the production of safe food. This review discusses our understanding of pre-harvest critical issues related to food safety in LMICs, specifically focusing on animal-derived food. In LMICs, food safety regulations are weak and inadequately enforced, primarily concentrating on the formal market despite a substantial portion of the food sector being dominated by informal markets. Key critical issues at the farm level include animal health, a low level of good agriculture practices, and the misuse of antimicrobials. Effectively addressing foodborne diseases requires a comprehensive One Health framework. Unfortunately, the application of the One Health approach to tackle food safety issues is notably limited in LMICs. In conclusion, considering that most animal-source foods from LMICs are marketed through informal channels, food safety legislation and policies need to account for this context. Interventions aimed at reducing foodborne bacterial pathogens at the farm level should be scalable, and there should be strong advocacy for the proper implementation of pre-harvest interventions through a One Health approach.

Effect of cold atmospheric plasma torch distance on the microbial inactivation and sensorial properties of ready-to-eat olivier salad

This study aimed to investigate the effect of the cold atmospheric plasma torch (CAPT) nozzle distance from the surface of Olivier salad and the treatment time in the reduction of microbial load and sensory properties of the product simultaneously. In this study, the CAPT nozzle was placed at 3, 5, and 7 cm distances from the surface of the Olivier salad, and its efficiency in inactivating the microbial population, decimal reduction time (D-value), and sensory evaluation of the product were evaluated. The results showed that reducing the distance and increasing the plasma treatment time (30, 60, 90, and 120 s) both reduced the microbial load of the product. The maximum inactivation and the minimum D-value are related to the 3 cm distance for 120 s, which has been 3.77, 2.91, and 1.52 log CFU/g for Coliform, Total viable count (TVC), mold and yeast, respectively. The lowest D-value was related to Coliform (4.41 s). CAPT treatment had no significant sensible effect on the product's sensory characteristics compared to the control sample. The treated sample at a 3 cm distance for 90 s and the microbial reduction to an acceptable amount and high acceptancy from sensory evaluators were selected as the superior treatment in this study. Also, the results showed that CAPT could be used successfully in ready-to-eat (RTE) products.

Impact of a Carboxymethyl Cellulose Coating Incorporated with an Ethanolic Propolis Extract on the Quality Criteria of Chicken Breast Meat

Recently, the demand for composite edible coatings has increased significantly as a new trend to confront the serious processing and storage problems that always arise regarding chicken meat. We aim to develop a carboxymethyl cellulose (CMC) coating containing various concentrations (0, 1, 2, 3, and 4%) of an ethanolic propolis extract (EPE) to maintain the quality and extend the shelf life of chicken breast meat stored at 2 °C for 16 days. The influence of the CMC and EPE coating on the physicochemical and microbiological quality parameters of chicken breast meat, e.g., pH, color, metmyoglobin (MetMb), lipid oxidation (thiobarbituric acid reactive substance, TBARS), and microbiological and sensory analyses, was studied. Significantly lower weight loss and pH (p ≤ 0.05) were noted in the coated samples compared with the uncoated samples (control) over the storage period. MetMb content was significantly reduced (p ≤ 0.05) in the coated samples compared to the control. Additionally, the addition of EPE to CMC was more effective in inhibiting microbial growth, preventing lipid oxidation, and keeping the overall acceptability of coated chicken breast meat compared to the control. This work presents CMC and EPE as alternative preservatives to produce active packaging coatings.