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.

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.

Investigation on the interaction of heated soy proteins with anthocyanins from cornelian cherry fruits.

The interaction between preheated soy proteins and anthocyanins from cornelian cherries was evaluated using a spectroscopic approach and molecular modeling. Structural changes of glycinin, ß-conglycinin and soy protein isolate were investigated based on spectra of native and heat treated proteins in the presence of anthocyanins rich extracts from fresh cornelian cherry fruits. The fluorescence maximum emission in the presence of anthocyanins showed significant red shifts when compared with individual proteins, indicating the change of polarity in the surroundings of Trp residues from soy proteins toward more hydrophilic, which were attributed to protein-polyphenols interactions. Soy proteins interacted with cornelian cherries anthocyanins mainly through a static quenching mechanism. Glycinin presented a better affinity toward anthocyanins as revealed by the binding constant. The in silico approach was further employed to provide single molecule level details on the interaction between the main soy proteins and anthocyanins prevailing in cornelian cherry extracts. The docking results are consistent with the fluorescence spectroscopy data indicating better affinity of glycinin for cyanidin 3-glucoside and cyanidin 3-rutinoside, compared to the ß-conglycinin. These findings deliver important insights for efficient development of microencapsulated powders based on soy proteins and anthocyanins from cornelian cherries, from the perspectives of obtaining value-added ingredients.

The effect of calcium and magnesium on the interaction between ß-lactoglobulin and carotenoids from sea buckthorn berries.

ß-Lactoglobulin has been shown to interact with carotenoids from sea buckthorn berries. However, previously, no studies have taken into account the effect of calcium and magnesium on the ß-lactoglobulin-carotenoids complex. This study aims to determine the effect of calcium and magnesium on the interaction between ß-lactoglobulin and carotenoids from sea buckthorn berries extract, during heating from the perspective of deepening interaction mechanisms as prerequisites for micro- and nanoencapsulation. Phase diagram, intrinsic fluorescence spectra, quenching experiments and synchronous spectra were employed to acquire information regarding the conformation of protein in the presence of calcium chloride and magnesium chloride. Intrinsic fluorescence data showed that, between 25°C and 60°C, the presence of calcium chloride in the complex favoured the movement of tryptophan residues to domains located at the protein-water interface, while magnesium chloride favoured the burial of tryptophan residues. Higher temperatures generated blue shifts regardless of which salt was present, suggesting exposure of tryptophan residues to the hydrophobic core of the protein. Extrinsic fluorescence intensity of the non-heat-treated complex with magnesium chloride was significantly higher (P < 0.01) than of the complex with calcium chloride, suggesting that 1-anilino-8-naphtalenesulphonic acid was bound to a higher proportion of the ß-lactoglobulin-carotenoids complex. Calcium chloride increased extrinsic fluorescence to a greater extent than magnesium chloride at temperatures above 70°C and was related to small structural changes induced by preheating ß-lactoglobulin.

Transglutaminase mediated microencapsulation of sea buckthorn supercritical CO2 extract in whey protein isolate and valorization in highly value added food products.

Sea buckthorn carotenoids extracted using CO2 supercritical fluids method were encapsulated within whey proteins isolate by transglutaminase (TG) mediated crosslinking reaction, coacervation and freeze drying. The encapsulation efficiency was 36.23 ±â€¯1.58%, with ß-carotene the major carotenoid present in the powder. The confocal analysis revealed that TG-ase mediated cross-linking reaction enhanced the complexes stability to such a manner that a double microencapsulation was performed. The powder showed an antioxidant activity of 2.16 ±â€¯0.14 mMol Trolox/g DW and an antifungal activity against Penicillium expansum MIUG M11. Four variants of domestic ice creams were obtained, with a total carotenoids content variation of 1.63 ±â€¯0.03 mg/g D.W. in sample with 2% powder and 6.38 ±â€¯0.04 mg/g D.W. in samples with 4% extract, having satisfactory antioxidant activity. The storage stability test showed a decrease in both total carotenoids content and antioxidant activity in all samples during 21 days at -18 °C. A protective effect of microencapsulation was evidenced.

pH and heat-dependent behaviour of glucose oxidase down to single molecule level by combined fluorescence spectroscopy and molecular modelling.

BACKGROUND: In the food industry, glucose oxidase (GOX) is used to improve the shelf life of food materials. The pH- and heat-induced conformational changes of glucose oxidase from Aspergillus niger were quantified by means of fluorescence spectroscopy and molecular dynamics simulations. RESULTS: The phase diagram showed an all-or-none transition process, indicating that pH and temperature largely influence the conformational state of GOX. Shifts in maximum wavelength of Trp, Tyr were registered as the protein encounters a lower pH (pH 4.0), suggesting significant changes of the polarity around the chromophore molecule. Quenching experiments using KI showed higher quenching constants of Trp and flavin adenine dinucleotide upon heating or by changing pH value, and were mainly correlated with the conformational changes upon protein matrix. Finally, valuable insights into the thermal behaviour of GOX were obtained from molecular modelling results. CONCLUSIONS: The conformation and structure of GOX protein is dependent upon the pH and heat treatment applied. Molecular dynamics simulation indicated significant changes in the substrate binding region at temperatures over 60 °C that might affect enzyme activity. Moreover, an important alteration of the small pocket hosting the positively charged His(516) residue responsible for oxygen activation appears evident at high temperatures.

Sulfur compounds identification and quantification from Allium spp. fresh leaves.

BACKGROUND: Pyruvic acid concentration is a critical factor in determining Allium spp. pungency. This study was initiated to accurately measure the background pyruvic acid levels in Romanian Allium spp. From the pungency point of view, all analyzed plant varieties in this study are considered low pungent cultivars based on the enzymatically produced pyruvate level (between 42 µmol/g and 222 µmol/g fresh wt). Chromatographic analysis was carried out for the different varieties of the most popular fresh leaves (Allium cepa var. "Diamant", Allium cepa var. "Rubiniu", and Allium ursinum L.) in order to identify the sulfur compounds. The thin layer chromatography analysis led to the identification of allicin, with Rf = 0.377-0.47, as an important sulfur compound. The gas chromatography-mass spectrometry analysis of the leaves' extracts detected disulfides as the major sulfur compounds. Principal component analysis was performed to establish the differences in plant composition. These studies suggest the potential good uses of the fresh leaves of Romanian Allium spp. as condiment, ingredient, or preservative in the food industry.