Frequentist and Bayesian approaches for food allergen risk assessment: risk outcome and uncertainty comparisons.

Peer-reviewed probabilistic methods already predict the probability of an allergic reaction resulting from an accidental exposure to food allergens, however, the methods calculate it in different ways. The available methods utilize the same three major input parameters in the risk model: the risk is estimated from the amount of food consumed, the concentration of allergen in the contaminated product and the distribution of thresholds among allergic persons. However, consensus is lacking about the optimal method to estimate the risk of allergic reaction and the associated uncertainty. This study aims to compare estimation of the risk of allergic reaction and associated uncertainty using different methods and suggest improvements. Four cases were developed based on the previous publications and the risk estimations were compared. The risk estimation was found to agree within 0.5% with the different simulation cases. Finally, an uncertainty analysis method is also presented in order to evaluate the uncertainty propagation from the input parameters to the risk.

Food groups for allergen risk assessment: Combining food consumption data from different countries in Europe.

To prevent allergic reactions, food producers have to be able to make a knowledge based decision on whether to label their products with precautionary labelling. As many manufactured food products are sold in different countries across Europe, the allergen risk assessment should be estimated at the European levels. As currently, there are no pan-European food data suitable for food allergy risk assessment. The aim of this paper is to investigate if consumption data, at a meal level, from National Food Consumption Surveys, can be combined to form a common Food Consumption database. In this first attempt we developed a procedure to investigate, if national food consumption data can be combined and grouped using data from Netherlands, France and Denmark. The homogeneity of consumption patterns and the relevance of difference in risk of allergic reaction were compared, using a fixed framework of allergen concentration levels and threshold distribution. Thus, the relevance of using common consumption data across countries was verified. The food groups formed were subsequently evaluated and adjusted based on practical considerations. It resulted in designing 61 food groups that can be used for allergen risk assessment. The summary statistics and descriptive names for each food group are included.

Determinants of meal satisfaction in a workplace environment.

Workplace lunches are recurrent meal occasions that can contribute to the general well-being of employees. The objective of our research was to study which factors influence consumers' satisfaction with these meals by exploring the relative role of food-related, personal, situational factors. Using a longitudinal approach, we monitored a total of 71 participants compiled and experienced 519 meals from their workplace canteen buffet during a three-month period; in addition the composed lunches were photographed. Before and after the lunch choice period respondents filled in a questionnaire on several meal-related variables. A mixed modelling approach was used to analyse the data. Meal satisfaction was directly associated with a positive ambience and a positive evaluation of both the quality of the food eaten and the buffet assortment, whereas the meal's energy content did not contribute to meal satisfaction. Additionally, meal satisfaction was associated with a more positive mood, lower hunger level as well as feeling less busy and stressed after lunch. The buffet assortment, a more positive mood before lunch and mindful eating contributed to the perceived food quality, but not associated with the hunger level before lunch. Time available, mindful eating and eating with close colleagues were positively associated with perceived ambience. The results indicate that consumers' satisfaction with workplace meals can be increased by putting emphasis on the quality of food served, but equally important is the ambience in the lunch situation. Most of the ambience factors were related to available time and mental resources of the participants and the possibility to share the meal with close colleagues. These are factors that can be facilitated by the service provider, but not directly influenced.

The effect of skatole and androstenone on consumer response towards fresh pork from m. longissimus thoracis et lumborum and m. semimembranosus.

Consumer liking was assessed for boneless chops (m. longissimus thoracis et lumborum) and schnitzels (m. semimembranosus) from castrates and entire male pigs with an androstenone content of up to 9.4 ppm and a skatole content of up to 0.92 ppm in the back fat. Skatole affected both odour and flavour as assessed by trained sensory panellists (P<0.05-P<0.001), while androstenone particularly affected flavour (P<0.01-P<0.001). Furthermore, the skatole compound seemed to be more important in explaining the presence of boar taint in the chops, while androstenone seemed to be more important for the schnitzels. For the chops, tenderness was the most important attribute for consumer liking independently of both the androstenone and skatole contents (P<0.001). Furthermore, increasing contents of both androstenone (P=0.05) and skatole (P=0.04) resulted in a decreased liking of the chops. Skatole was the most important factor regarding consumer response towards the schnitzels (P=0.03). The very low liking scores for both chops and schnitzels were mainly attributable to the androstenone content.

The effect of skatole and androstenone on consumer response towards streaky bacon and pork belly roll.

Consumer liking was assessed for streaky bacon and pork belly roll from entire male pigs with an androstenone (AND) content of up to 9.4 ppm and a skatole (SKA) content of up to 0.92 ppm in the back fat and castrates. No clear effect of either AND or SKA was seen in consumer liking, although an insignificant tendency was seen for SKA. A sensory profile analysis showed that AND increased the boar taint of bacon, while both AND and SKA increased the boar taint of the pork belly roll. Consumer sensitivity towards AND and SKA did not affect liking of the meat products. The lack of effect of AND and SKA on consumer liking could be due to a masking effect of the spices and smoke. Three consecutive weeks' exposure to bacon did not change the liking score, irrespective of the AND and SKA content. This indicates that the consumers did not become more sensitive towards boar taint.

In silico modelling of permeation enhancement potency in Caco-2 monolayers based on molecular descriptors and random forest.

Structural traits of permeation enhancers are important determinants of their capacity to promote enhanced drug absorption. Therefore, in order to obtain a better understanding of structure-activity relationships for permeation enhancers, a Quantitative Structural Activity Relationship (QSAR) model has been developed. The random forest-QSAR model was based upon Caco-2 data for 41 surfactant-like permeation enhancers from Whitehead et al. (2008) and molecular descriptors calculated from their structure. The QSAR model was validated by two test-sets: (i) an eleven compound experimental set with Caco-2 data and (ii) nine compounds with Caco-2 data from literature. Feature contributions, a recent developed diagnostic tool, was applied to elucidate the contribution of individual molecular descriptors to the predicted potency. Feature contributions provided easy interpretable suggestions of important structural properties for potent permeation enhancers such as segregation of hydrophilic and lipophilic domains. Focusing on surfactant-like properties, it is possible to model the potency of the complex pharmaceutical excipients, permeation enhancers. For the first time, a QSAR model has been developed for permeation enhancement. The model is a valuable in silico approach for both screening of new permeation enhancers and physicochemical optimisation of surfactant enhancer systems.

Comparison of estimated energy intake using Web-based Dietary Assessment Software with accelerometer-determined energy expenditure in children.

BACKGROUND: The OPUS (Optimal well-being, development and health for Danish children through a healthy New Nordic Diet) project carried out a school meal study to assess the impact of a New Nordic Diet (NND). The random controlled trial involved 834 children aged 8-11 in nine local authority schools in Denmark. Dietary assessment was carried out using a program known as WebDASC (Web-based Dietary Assessment Software for Children) to collect data from the children. OBJECTIVE: To compare the energy intake (EI) of schoolchildren aged 8-11 estimated using the WebDASC system against the total energy expenditure (TEE) as derived from accelerometers worn by the children during the same period. A second objective was to evaluate the WebDASC's usability. DESIGN: Eighty-one schoolchildren took part in what was the pilot study for the OPUS project, and they recorded their total diet using WebDASC and wore an accelerometer for two periods of seven consecutive days: at baseline, when they ate their usual packed lunches and at intervention when they were served the NND. EI was estimated using WebDASC, and TEE was calculated from accelerometer-derived activity energy expenditure, basal metabolic rate, and diet-induced thermogenesis. WebDASC's usability was assessed using a questionnaire. Parents could help their children record their diet and answer the questionnaire. RESULTS: Evaluated against TEE as derived from the accelerometers worn at the same time, the WebDASC performed just as well as other traditional methods of collecting dietary data and proved both effective and acceptable with children aged 8-11, even with perhaps less familiar foods of the NND. CONCLUSIONS: WebDASC is a useful method that provided a reasonably accurate measure of EI at group level when compared to TEE derived from accelerometer-determined physical activity in children. WebDASC will benefit future research in this area.

Dietary patterns on weekdays and weekend days in 4-14-year-old Danish children.

Little is known about dietary patterns on weekdays and weekend days in children, and the aim of the present study was to investigate 4­14-year-old children's dietary patterns specifically on weekdays (Monday­Thursday) and weekend days (Saturday­Sunday). Dietary data were derived from the Danish National Survey of Dietary Habits and Physical Activity 2003­8, where a total of 784 children aged 4­14 years completed a 7 d pre-coded food record. Principal component analysis was used to identify dietary patterns in the age groups 4­6, 7­10 and 11­14 years. Consistently, two dietary patterns, labelled 'processed' and 'health conscious', emerged on both weekdays and weekend days. Factor scores from corresponding dietary patterns were significantly correlated between weekdays and weekend days with the exception of the 'health conscious' pattern in the 7­10-year-olds. Within each age group, children with high agreement for the 'processed' pattern had a significantly higher dietary energy density, which was reflected in significantly higher intakes of sugar-sweetened beverages and lower intakes of fruit and vegetables, compared with children with high agreement for the 'health conscious' pattern (P< 0·05). Moreover, these variables indicated less healthy dietary intakes on weekend days than on weekdays for both patterns. In conclusion, two distinct dietary patterns, labelled 'processed' and 'health conscious', were identified on both weekdays and weekend days for each age group. While overall major dietary patterns may somewhat track between weekdays and weekends, the specific foods actually eaten became less healthy during weekends.

Differences in Danish children's diet quality on weekdays v. weekend days.

OBJECTIVE: To compare differences in children's diet quality on weekdays (Monday-Thursday), Fridays and weekend days. DESIGN: A representative cross-sectional study in which participants completed a 7 d pre-coded food record. Mean intakes of energy, macronutrients and selected food items (g/10 MJ) as well as energy density were compared between weekdays, Fridays and weekend days for each gender in three age groups (4-6, 7-10 and 11-14 years) using Tobit analysis to account for zero intakes. SETTING: The Danish National Survey of Dietary Habits and Physical Activity 2003-2008. SUBJECTS: Children (n 784; 49·9 % boys) aged 4-14 years. RESULTS: For both genders in all age groups (P < 0·05), energy intake was higher during weekends than on weekdays, and intakes of sugar-sweetened beverages and white bread were higher, whereas intake of rye bread was lower. This contributed to a higher percentage of energy from added sugars, a lower fibre content and a higher energy density on weekend days v. weekdays. In children aged 4-6 and 7-10 years, the diet on weekend days was also characterized by higher intakes of sweets and chocolate and lower intakes of fruit and vegetables. Overall, the diet on Fridays appeared as a mix of the diets on weekdays and weekend days. CONCLUSIONS: Significant differences and distinct characteristic patterns were found in children's diet quality during weekdays, Fridays and weekend days. The present study suggests that in prevention of childhood overweight and obesity, more attention should be paid to the higher energy intake, especially from sugar-rich foods and beverages, on Fridays and weekend days.

Comparison of estimated energy intake from 2×24-hour recalls and a seven-day food record with objective measurements of energy expenditure in children.

OBJECTIVE: The objective of the present study was to evaluate energy intake (EI) estimated from two non-consecutive 24-hour recalls (24-HDRs) and a pre-coded seven-day food record (7-dFR) against objective measurements of energy expenditure (EE) in children. DESIGN: A total of 67 7-8 year-olds and 64 12-13 year-olds completed the 2×24-HDRs, the 7-dFR, and wore ActiReg(®) (PreMed AS, Oslo, Norway), a combined position and motion recording instrument, during the same seven days as the 7-dFR was filled in. RESULTS: In the 7-8 year-olds, EI from the 2×24-HDRs (EI(2×24-HDR)) was overestimated with 3% compared to EE (not significantly different), while EI from the 7-dFR (EI(7-dFR)) was underestimated with 7% compared to EE (P=0.001). In the 12-13 year-olds, the corresponding figures was underestimation by 10% with the 2×24-HDRs (P<0.001) and by 20% with the 7-dFR (P<0.001). For both age groups combined, the 95% limits of agreement were -4·38 and 3.52 MJ/d for the 2×24-HDRs, and -5.90 and 2.94 MJ/d for the 7-dFR. Pearson correlation coefficients between EI and EE were 0.51 for EI(2×24-HDR) and 0.29 for EI(7-dFR), respectively. The proportion classified in the same or adjacent quartiles was 76% for EI(2×24-HDR) and 73% for EI(7-dFR) in the 7-8 year-olds, and 83% for EI(2×24-HDR) and 70% for EI(7-dFR) in the 12-13 year-olds. CONCLUSION: Misreporting of EI seemed modest with both the 2×24-HDRs and the 7-dFR in the 7-8 year-olds when compared to EE measured with ActiReg(®). Under-reporting appeared to be more evident in the 12-13 year-olds, especially with the 7-dFR. Compared to measurements of EE, the 2×24-HDRs seemed to perform slightly better than the 7-dFR in terms of ranking of individuals according to EI.

Flavour development in pork. Influence of flavour precursor concentrations in longissimus dorsi from pigs with different raw meat qualities.

Flavour development and overall eating quality of pan-fried pork chops of longissimus dorsi from eight different raw meat qualities aged for 4 and 15 days were assessed by a trained sensory panel. The raw meat qualities were obtained through combinations of strategic feeding/fasting (control vs. low glycogen concentration), slaughter live-weight (84kg vs. 110kg), and gender (female vs. castrate). The flavour development was investigated for possible correlation with the concentrations of selected individual flavour precursors present in the raw meat: monosaccharides, IMP and degradation products, fatty acids, lactate and thiamine. Differences in precursor concentrations between the raw meat qualities were observed with feeding/fasting and ageing as the main factors with the largest influence of all experimental factors. However, the concentrations of the precursors could not explain the differences in sensory perception of the pan-fried pork chops. Overall, the differences were small.

Flavour formation in pork semimembranosus: Combination of pan-temperature and raw meat quality.

Flavour development and overall eating quality of pork semimembranosus were investigated with regard to different raw meat qualities (feeding/fasting strategy; control/low glycogen level, gender; castrate/female, slaughter live-weight; 84kg/110kg) combined with frying temperature (150°C/240°C). It was further investigated whether the precursor levels of glycogen, IMP, inosine, and hypoxanthine in the raw meat were correlated to the raw meat quality and fried/grilled attributes. Pork schnitzels were fried on a pan (155°C) or grill-pan (240-250°C) to a core temperature of 70°C. Frying temperature was the one factor with greatest influence on the sensory attributes, and pan-grilled schnitzels had significantly higher scores in fried/grilled attributes regardless of meat quality compared to pan-fried schnitzels. Texture was not appreciably influenced by any treatment. There was no correlation between precursor levels and raw meat qualities or fried sensory attributes. Gender and slaughter live-weight had no pronounced influence on flavour and overall eating quality.

In silico prediction of cytochrome P450 2D6 and 3A4 inhibition using Gaussian kernel weighted k-nearest neighbor and extended connectivity fingerprints, including structural fragment analysis of inhibitors versus noninhibitors.

Inhibition of cytochrome P450 (CYP) enzymes is unwanted because of the risk of severe side effects due to drug-drug interactions. We present two in silico Gaussian kernel weighted k-nearest neighbor models based on extended connectivity fingerprints that classify CYP2D6 and CYP3A4 inhibition. Data used for modeling consisted of diverse sets of 1153 and 1382 drug candidates tested for CYP2D6 and CYP3A4 inhibition in human liver microsomes. For CYP2D6, 82% of the classified test set compounds were predicted to the correct class. For CYP3A4, 88% of the classified compounds were correctly classified. CYP2D6 and CYP3A4 inhibition were additionally classified for an external test set on 14 drugs, and multidimensional scaling plots showed that the drugs in the external test set were in the periphery of the training sets. Furthermore, fragment analyses were performed and structural fragments frequent in CYP2D6 and CYP3A4 inhibitors and noninhibitors are presented.

Two subpopulations of Listeria monocytogenes occur at subinhibitory concentrations of leucocin 4010 and nisin.

In situ analyses of single Listeria monocytogenes cells at subinhibitory concentrations of leucocin 4010 and nisin revealed two subpopulations when measured by fluorescence ratio imaging microscopy (FRIM) after staining with 5(6)-carboxyfluorescein diacetate succinimidyl ester. One subpopulation consisted of cells with a dissipated pH gradient (DeltapH), and the other consisted of cells that maintained DeltapH. The proportion of cells belonging to each subpopulation was estimated, and the concentrations of bacteriocins required to dissipate DeltapH for 90% of the cell population (ED90) was predicted. ED90 increased after the addition of sodium chloride (1 to 3% [wt/vol]) to the bacteriocin solutions, while ED90 decreased by the addition of sodium nitrite (60 and 100 ppm). Other meat additives, including sodium phosphate, sodium lactate, sodium citrate, and sodium acetate slightly increased ED90. The inhibitory effect of sodium chloride on the antilisterial activity of leucocin 4010 and nisin was confirmed on the surfaces of meat sausages. This study highlights the important practical implications of applying subinhibitory concentrations of bacteriocins, which results in unaffected target cells. In situ analyses by FRIM in combination with modeling of single-cell data can be applied to ensure that sufficient concentrations of bacteriocins are used in food preservation.

In silico prediction of membrane permeability from calculated molecular parameters.

A data set consisting of 712 compounds was used for classification into two classes with respect to membrane permeation in a cell-based assay: (0) apparent permeability (P(app)) below 4 x 10(-6) cm/s and (1) P(app) on 4 x 10(-6) cm/s or higher. Nine molecular descriptors were calculated for each compound and Nearest-Neighbor classification was applied using five neighbors as optimized by full cross-validation. A model based on five descriptors, number of flex bonds, number of hydrogen bond acceptors and donors, and molecular and polar surface area, was selected by variable selection. In an external test set of 112 compounds, 104 compounds were classified and 8 compounds were judged as "unknown". Among the 104 compounds, 16 were misclassified corresponding to a misclassification rate of 15% and no compounds were falsely predicted in the nonpermeable class.