Deterministic Approach and Monte Carlo Simulation to Predict Listeria monocytogenes Time to Grow on Refrigerated Ham: A Study Supporting Risk-based Decisions for Consumers' Health.

This study assessed the growth of Listeria monocytogenes in ready-to-eat (RTE) ham during storage under conditions simulating domestic practices with the intention to offer support in the elaboration of food safety policies that should better protect consumers against food poisoning at home. RTE ham, artificially contaminated at either medium (102-103 CFU/g) or high (104-105 CFU/g) concentration, was stored at both isothermal (4℃ in a refrigerator able to maintain a relatively constant temperature and 5℃ and 7℃ in a refrigerator with fluctuating temperature) and dynamic (5℃ and 7℃ with intermittent exposure to ambient temperature, e.g. 25℃) conditions. Under isothermal conditions, the increasing storage temperature determined a significantly increased (p < 0.05) capacity of L. monocytogenes to grow. The kinetic growth parameters were derived by fitting the Baranyi and Roberts model to the experimental data and, based on the maximum specific growth rates, it was estimated the temperature dependence of L. monocytogenes growth in RTE ham. At medium contamination level, sanitary risk time calculation revealed that, unlike storage at 5℃ and 7℃, storage at 4℃ of the RTE ham extends the time period during which the product is safe for consumption by ∼40 and 52%, respectively. However, the real temperature fluctuations included in the Monte Carlo simulations at low L. monocytogenes counts (1, 5 and 10 CFU/g) have shortened the safety margins. Stochastic models also proved to be useful tools for describing the pathogen's behavior when refrigeration of the RTE ham alternates with periods of ham being kept at room temperature, considered dynamic conditions of growth.

Kitchen layouts and consumers' food hygiene practices: Ergonomics versus safety.

Our paper emphasizes the importance of the kitchen layout in facilitating consumers' food hygiene practices. A significant correlation was found between the sink placement (inside or outside the kitchen) and hygienic practices during food handling based on a survey performed on consumers from ten European countries, indicating that those who had the sink in the kitchen were more likely to perform proper hygiene practices than those who have not. The self-reported practices were supported by observed practices in 64 households from five European countries. The observational study combined with the examination of kitchen layouts revealed that the kitchen work triangle with its apexes represented by the kitchen sink, cooking stove and refrigerator, which is recommended for ergonomic reasons by architects and designers, did not necessarily support food hygiene practices in kitchens. Cross-contamination events were associated with the sink - countertop distances longer than 1 m. Based on this, a new kitchen triangle with its apexes represented by the kitchen sink, working place (usually countertop) and cooking stove, with the distance between the sink and the working place less than 1 m is proposed to be used as norm in kitchen designs for combining ergonomics with safety. This triangle is proposedly named the food safety triangle and is aimed to mitigate the risks of foodborne illnesses by creating an arrangement that facilitates hygiene practices. This study is the first to highlight the importance of implementing the concept of food safety in the kitchen design based on significant correlations between kitchen equipment placement and consumers' food safety practices.

Data on European kitchen layouts belonging to vulnerable consumers (elderly people and young families with children or pregnant women) and risk-takers (young single men).

The data presented here capture the structure of kitchen layouts belonging to consumers vulnerable to foodborne diseases and food risk-takers. Data were collected in the frame of the SafeConsume project by multidisciplinary research teams that visited consumers during preparing a meal and had the possibility to examine their cooking routines. Distances between sink and stove, sink and refrigerator, stove and refrigerator, sink and working place (countertop or table), stove and working place were analyzed to correlate food safety practices applied during cooking with kitchen arrangements. The results arising from analyzing the ergonomics of kitchens versus potential cross-contamination events are presented in Mihalache et al., [1]. These data contribute to a better understanding of real kitchen layouts and can be used as a starting point for future research regarding food safety-oriented arrangements instead of ergonomics-focused designs, for food safety risk assessments, as study cases for explaining specific measures that can be established to improve food handling and hygiene practices in homes and for sociological research pointing consumers' behavior during cooking.

Efficacy of Removing Bacteria and Organic Dirt from Hands-A Study Based on Bioluminescence Measurements for Evaluation of Hand Hygiene When Cooking.

The objective of this study was to evaluate the efficacy of dirt removal (bacteria and organic matter) of several hand-cleaning procedures. The results from the hand hygiene experiment indicated that washing hands with warm water and soap for 20 s is the most effective method investigated when hands are either dirty or greasy. Even if not proper washing, rinsing under running water for 5 s is a cleaning procedure that may significantly reduce the probability of cross-contamination, as it removes 90% of the hands' dirt. Although less effective than water and soap, the usage of antibacterial wipes was significantly more effective than wet wipes, indicating that they are a better choice when water and soap are not available. The results of this study enable us to inform consumers about the effectiveness of hand-cleaning procedures applied in their homes when cooking. Moreover, it can make consumers understand why, during the COVID-19 pandemic, authorities recommended washing hands as a preventive measure of infection and using an anti-bacterial hand gel or wiping hands with an antimicrobial wipe if water and soap are not available.

Consumer practices and prevalence of Campylobacter, Salmonella and norovirus in kitchens from six European countries.

About 40% of foodborne infections are acquired in the home. The aim of the present study was to track contamination of pathogens during domestic food preparation and link the contamination to preparation practices. Research participants from 87 households in six European countries were observed and interviewed during shopping and preparation of a chicken and vegetable meal. The presence of Salmonella spp., Campylobacter spp. and norovirus on raw chicken, kitchen surfaces, cloths and sponges was determined. The prevalence of Campylobacter on raw chicken varied from 8.3% in Norway (NO) to 80% in France (FR) and Portugal (PT), with a mean prevalence of 57%. Campylobacter was found on half of the products that had been frozen and appeared to be less prevalent on chicken from supermarkets than other sources. Salmonella was found in 8.6% of raw chicken samples, exclusively from Hungary (HU). A relationship between observed practices and spread of pathogens to kitchen surfaces was found only for the use of cutting boards for chicken and/or vegetables. After food preparation, Campylobacter and Salmonella were isolated from 23% (samples derived from HU, RO, UK) and 8.7% (HU), respectively of cutting boards. Research participants in France and Portugal were more likely to buy products that fitted their recipe, with less need for using cutting boards. Using the same board and knife for vegetables after using it for chicken and without washing with detergent was common in Portugal and Romania, but not in the other countries. Contamination with Campylobacter to other kitchen surfaces or washing utensils were found in five households (UK, RO, PT). Rinsing chicken in sinks was common in three countries (PT, HU, RO), and washing vegetables in the same sink was also usual. Prevalence of Norovirus was low, with detection in one out of 451 samples. The participants' awareness of the risk posed by pathogens from raw chicken differed among the six countries, with higher awareness in Norway and the UK than the other countries studied. In conclusion, practices intended to avoid cross-contamination from chicken to kitchen surfaces and washing utensils are not established among consumers in all European countries. Nevertheless, cross-contamination events that disseminate infectious doses of pathogens seems to be rare, probably due to the relatively low levels of pathogens in food combined with food preferences. Food safety interventions must consider the national food culture, preferences, practices and the prevalence and levels of pathogens in food. Emphasis should be on providing and promoting chicken products with lower risk (prevalence of pathogens, ready-to-cook) and safe use of cutting boards.

Cross-Linked Microencapsulation of CO2 Supercritical Extracted Oleoresins from Sea Buckthorn: Evidence of Targeted Functionality and Stability.

Oleoresin supercritical extracts from sea buckthorn were microencapsulated in whey proteins isolate and casein, in two states: native (N) and cross-linked mediated by transglutaminase (TG). The encapsulation efficiency showed values higher than 92% for total carotenoids and lycopene. Phytochemicals content was 352.90 ± 1.02 mg/g dry weight (DW) for total carotenoids in TG and 302.98 ± 2.30 mg/g DW in N, with antioxidant activity of 703.13 ± 23.60 mMol Trolox/g DW and 608.74 ± 7.12 mMol Trolox/g DW, respectively. Both powders had an inhibitory effect on α-glucosidase, of about 40% for N and 35% for TG. The presence of spherosomes was highlighted, with sizes ranging between 15.23-73.41 µm and an agglutination tendency in N, and lower sizes, up to 35 µm in TG. The in vitro digestibility revealed a prolonged release in an intestinal environment, up to 65% for TG. Moisture sorption isotherms were studied at 20 °C and the shape of curves corresponds to sigmoidal type II model. The presence of cross-linked mediated aggregates in TG powders improved stability and flowability. Our results can be used as evidence that cross-linked aggregates mediated by transglutaminase applied for microencapsulation of oleoresins have the potential to become new delivery systems, for carotenoids and lycopene, being valuable in terms of their attractive color and biological and bioaccessibility properties.