Analysis of binary taste-taste interactions of MSG,lactic acid,and NaCl by temporal dominance of sensations

Temporal dominance of sensations (TDS) is a relatively novel sensory evaluation technique that measures the temporal evolution of sensory perception. The sensory properties of food or drink products have been described by TDS; however, basic sensory data on TDS are still lacking. We analyzed TDS data for solutions of three basic tastes (umami, salty, and sour) and their binary combinations. The duration of TDS for the main taste of each type of solution (monosodium glutamate [MSG] for umami, sodium chloride [NaCl] for saltiness, and lactic acid for sourness) increased in a concentration-dependent manner. In addition, the duration of the umami taste of MSG was longer than that of MSG/inosine 5′-monophosphate solution with an umami taste of equivalent intensity. The duration of NaCl saltiness was increased by coexistence with MSG and decreased by coexistence with lactic acid. On the other hand, the duration of the umami taste of MSG was suppressed by coexistence with NaCl but not lactic acid, while the duration of the sour taste of lactic acid was suppressed by MSG but not NaCl. These findings provide novel insight into the temporal sequence of basic taste perception during food consumption.     

Sodium Trends in Selected U.S. Total Diet Study Foods, 2003-2011

ObjectiveCharacterize trends in sodium concentrations in the general categories of foods analyzed in the U.S. FDA Total Diet Study (TDS) program from 2003 through 2011. Methods: Trends were assessed for sodium concentrations in a small convenience sample of TDS foods from 2003 to 2011 using simple linear regression with the SAS regression procedure, focusing on sodium concentrations in foods in USDA's sentinel food categories. Results: Levels of sodium in various TDS foods varied over time. Overall, 75 TDS foods did not have statistically significant linear changes in sodium content during that time, and 23 TDS foods did. Certain sentinel foods such as ramen-style noodles showed gradually increasing sodium content from 2003 through 2011. Significance: Over three quarters of foods show no statistically significant linear changes over time. Although a number of selected foods had a statistically significant decline, a limitation to this study is that specific brands of TDS foods were not necessarily the same for each period. The results suggest that some sodium reduction has been occurring in some foods and supports the idea that commercially viable reductions are possible. Such reductions in the sodium content of foods could have large public health implications—rates of hypertension and related health consequences would likely decline—thus saving thousands of lives and billions of dollars each year.     

UK dietary exposure to PCDD/Fs,PCBs, PBDD/Fs,PBBs and PBDEs: comparison of results from 24-h duplicate diets and total diet studies

ABSTRACT

Chemicals in food are monitored to check for compliance with regulatory limits and to evaluate trends in dietary exposures, among other reasons. This study compared two different methods for estimating human dietary exposure to lipophilic persistent organic pollutants (POPs) during 2011/12: (1) the 2012 Total Diet Study (TDS) conducted by the UK Food Standards Agency (FSA) and (2) a 24-h duplicate diet (DD) study of 20 adults from the North East of England. The equivalence of the two approaches was assessed; anything less than an order of magnitude could be considered reasonable and within three-fold (equivalent to 0.5 log) as good. Adult dietary exposure estimates derived from the DD study for both average and high-level (97.5th percentile) consumers compared well with those from the TDS. Estimates from the DD study when compared with those from the TDS were within 10% for P97.5 for total PCDD/F/PCB with divergence increasing to a factor of 3.4 for average BDE-209. Most estimates derived from the TDS were slightly higher than those derived from the DD. Comparison with earlier UK TDS data over the last 30 years or so confirmed a gradual decline in levels of PCDD/F/PCBs in food. Such comparisons also indicated peaks in dietary exposure to ∑PBDE (excluding BDE-209) between 2000 and 2005. Exposure estimates for all measured compounds using both TDS and DD data were found to be within recommended tolerable daily intakes where available or within acceptable margins of exposure.     

中国总膳食研究三十年之演变

总膳食研究是世界卫生组织极力推荐成员国评估某个国家和地区在不同人群组对于膳食中化学危害物暴露量和营养素摄入量的最经济、有效、可靠的方法。中共中央和国务院于2019年5月9日发布《关于深化改革加强食品安全工作的意见》将开展总膳食研究作为实施风险评估和标准制定专项行动的基础性工作,来完善风险评估基础数据库。本文从中国总膳食研究的意义、启动、发展与定型的历史演变过程解读这30年的发展历程,并对其在食品安全暴露科学中的作用进行述评。     

Occurrence of toluene in Canadian total diet foods and its significance to overall human exposure

Levels of most VOCs in foods are usually low because of their volatility, and human exposure to VOCs is expected to be mainly via inhalation of ambient and indoor air. However, dietary exposures to VOCs can be significant to overall exposures if elevated concentrations of VOCs are present in foods consumed in high amounts and/or on a regular basis, and this was demonstrated in this study with the occurrence data of toluene from the recent 2014 Canadian Total Diet Study (TDS). Concentrations of toluene in the composite samples of most food types from the 2014 TDS are low and similar to the results from the previous 2007 TDS with some exceptions, such as beef steak (670 ng/g (2014 TDS) vs. 14 ng/g (2007 TDS)), poultry, chicken and turkey (307 ng/g (2014 TDS) vs. 8.8 ng/g (2007 TDS)). Toluene concentrations in most of the grain-based and fast food composite samples from the 2014 TDS are considerably higher than those from the 2007 TDS, with the highest level of 4655 ng/g found in the composite sample of crackers from the 2014 TDS (compared to 18 ng/g from 2007 TDS). Dietary exposure estimates for toluene based on the occurrence results from the 2014 TDS show that for most of the age groups, grain-based foods are the primary source, accounting for an average of 77.5% of the overall toluene intake from the diet. The highest dietary exposures to toluene were observed for the adult age groups, with estimated average exposures ranging from 177.4 to 184.5 µg/d. Dietary exposure estimates to toluene are well below oral doses associated with toxicological effects and also below the maximum estimated intake (819 µg/d) from air inhalation for adult group (20 – 70 years) based on the results from CEPA (Canadian Environmental Protection Act) assessment in 1992.     

US Food and Drug Administration's Total Diet Study: intake of nutritional and toxic elements, 1991-96

The Food and Drug Administration (FDA) has conducted the Total Diet Study (TDS) annually since 1961. The TDS is designed to monitor the US food supply for levels of toxic chemical contaminants (pesticide residues, industrial chemicals and toxic elements) and nutritional elements. Foods are generally collected four times a year, once from each of four regions of the country. The foods are prepared table-ready before being analysed. From the results of the TDS, dietary intakes of these analytes are estimated for selected age- sex groups in the US population. This paper reports on the dietary intake of 10 nutritional and four toxic elements based on measurements made in foods collected in the TDS between 1991 and late 1996. Average daily intakes were estimated for 14 age-sex groups in the US population, as well as the contribution of specific food groups to total intakes. For most nutritional elements, teenage boys and adult males had the highest daily intakes. Intakes by infants were below the intake references for seven of 10 nutritional elements, and young girls and women had inadequate intakes of at least half the nutritional elements. Intakes by children between 2 and 10 years of age, teenage boys, and adult males met or exceeded the reference intakes for the majority of nutritional elements. Intakes by all population groups were well below the reference intakes for all toxic elements.     

Evaluation of U.S. Total Diet Study Data on Selenium

The potential usefulness of FDA's U.S. Total Diet Study (TDS) selenium (Se) data to the nutrition community was evaluatedas part of the TDS modernization program. TDS Se data collected from 2003 – 2010 was evaluated by comparing these data to Se concentration data in USDA's Standard Reference 26 (SR26) Database. We also evaluated trends in Se concentrations over time and differences in Se concentrations by Market Basket (MB). Comparable SR26 foods were identified for most TDS foods; however, for many TDS foods, there was more than one match in SR26. TDS was found to be a unique source of analytical Se concentration data for four food mixtures and for several SR26 foods with imputed Se concentrations. Se concentrations in TDS foods were similar to analyzed Se concentrations in most corresponding SR26 foods. Se concentrations in whole wheat bread were significantly higher in MB 2 (U.S. West Region, collected in the winter) than in MB 1 (U.S. North Central Region, collected in the fall), 3 (U.S. South Region, collected in the spring), and 4 (U.S. North East Region, collected in the summer). Se concentrations in whole wheat bread were also significantly higher in MB 4 than in MB 3. Se concentrations in boiled eggs were significantly higher in MB 2 than in other market baskets. The U.S. Total Diet Study suspended analysis of Se in 2010, but FDA is evaluating the potential benefits of adding Se analysis back to the TDS program. Results of this study demonstrate the potential value of TDS concentration data for Se and other nutrients to the U.S. nutrition community. However, it is clear that TDS data on generic foods (e.g. tuna, canned in water) are less useful than TDS data on more specifically defined foods (e.g. tuna, white, canned in water). Potential geographical and/or seasonal differences in Se contents of some foods may warrant additional investigation.     

Identifying core foods for total diet studies: a comparison of four different approaches

Total diet studies (TDS) are recognised as a cost-effective approach in estimating dietary exposure to chemicals in food. It has been advised that candidate foods for inclusion in TDS analysis should represent a large part of the typical diet to estimate accurately the exposure of a population group. To date a variety of approaches have been used to determine which foods should be included in a core TDS food list, with no agreed method. Therefore, the aim of this study was to compare four of these approaches by creating TDS food lists for adult populations in Europe using summary statistics data from the EFSA Comprehensive Food Consumption Database. Both a food group approach and a total diet approach were employed, and foods were selected for inclusion in the TDS food lists if they met the criteria as defined by consumption weight and/or a 5% consumer rate. Using all four approaches the representation of the diet across the TDS food lists was > 85%. The food group approach showed a slight advantage in diet representation, but produced considerably longer TDS food lists in comparison with the total diet approach. The addition of a 5% consumer rate to both approaches had little impact on results. In conclusion, the total diet approach may act as a more cost-effective approach in comparison with the food group approach while still achieving comprehensive results in the creation of core TDS food lists.     

Preference mapping of salmon–sauce combinations: The influence of temporal properties

Food–food combinations are complex stimuli where the dynamic nature of sensory interactions plays an important role for perception and acceptance. The aim of this study was to investigate if TDS provides additional insight about drivers of liking compared to DA in a preference mapping context. A trained sensory panel performed DA and TDS on six different samples (combinations of salmon and culinary sauces), and sixty-one consumers rated acceptance for the same samples. In addition to TDS SCORES, this study introduces the use of extracted parameters based on dominance information from TDS; the area of dominance based on the integrated area under the dominance curves and the number of dominant sensations and blends within a specified time period. Results from preference mappings showed that the TDS approaches generally provided similar but less detailed information regarding drivers of liking and disliking compared to DA. Moreover, with the use of the extracted TDS parameters, it was possible to identify the time of dominance of certain attributes and the number of perceived sensations and blends in specific time periods as potential drivers of liking and disliking. The results also showed that TDS has a potential to provide complementary information about the dynamic nature of sensory interactions in food–food combinations compared to DA.     

Exploring the common and unique variability in TDS and TCATA data – A comparison using canonical correlation and orthogonalization

Temporal Dominance of Sensations (TDS) and Temporal Check-all-that-Apply (TCATA) from three different case studies are compared by means of canonical correlation analysis, orthogonalization and principal component analysis of the vertically unfolded data (which means that the matrices compared have samples*timepoints in the rows and attributes in the columns). The multivariate analyses decompose the datasets into common and distinct components. The results showed that the major part of the variation is common between the two methods for the cases investigated, but that there were subtle differences showing better discrimination for TCATA than TDS. TDS showed a more complex data structure and more unique variation. The unique variation in TDS is, however, difficult to interpret. The methods are more different towards the end of the mastication, this can be explained both by the difficulty of assessors to agree on the dominant attributes at the bolus stage for TDS, and that assessors may forget to unclick attributes in TCATA. This work builds on recent methodological studies on temporal methods that aim to better understand differences among methodologies and ultimately to identify what methods could be better for answering different objectives.     

A harmonised approach for identifying core foods for total diet studies

Total diet studies (TDS) are used to gather information on chemical substances in food, thereby facilitating risk assessments and health monitoring. Candidate foods for inclusion in a TDS should represent a large part of a typical diet to estimate accurately the exposure of a population and/or specific population groups. There are currently no harmonised guidelines for the selection of foods in a TDS, and so the aim of this study was to explore the possibility of generating a harmonised approach to be used across Europe. Summary statistics data from the European Food Safety Authority’s (EFSA) Comprehensive Food Consumption Database were used in this research, which provided data from national food consumption surveys in Europe. The chosen methodology for the selection of foods was based on the weight of food consumed and consumer rate. Using the available data, 59 TDS food lists were created, representing over 51 000 people across 17 countries and seven population groups. All TDS food lists represented > 85% of the populations’ diets (85.9–96.3%), while the number of foods in the TDS food lists ranged from 15 to 102. Comparison of the TDS food lists indicated that the most commonly consumed foods included wheat bread and rolls, pastries and cakes, tomatoes, apples, bananas, and chicken, while cow’s milk, tap water and orange juice were the most commonly consumed beverages across Europe. This work was complete to support EFSA and other institutions in the development of harmonised TDS into the future.     

Investigating temporal sensory data via a graph theoretic approach

A graph theoretic approach is applied to investigate perception dynamics in the Sensometrics 2018 Data Analysis Workshop data sets. First, temporal check-all-that-apply (TCATA) data are investigated: ten sensory attributes are modelled as vertices and concurrent perception as edges, the size and width of each corresponding to the momentary elicitations and the concurrent elicitations, respectively. A temporal dominance of sensations (TDS) data set does not lend itself as readily to this type of analysis because the task for each assessor involves selection of only one dominant attributes at a time. For this reason, TDS data sets considered in this workshop are (re-)analyzed within localized temporal ranges, considering dominance elicitations within localized temporal ranges to be adjacent-dominant. In TDS by Modality (M-TDS), assessors taste the sample to evaluate the five taste and flavour attributes via TDS, then retaste the sample to evaluate the five texture attributes via TDS. M-TDS results from these two separate tasting timelines are adjoined as if they arose from a single evaluation timeline, which ignores systematic biases that may be introduced by the evaluation protocol (e.g. texture attributes are always evaluated with carryover effects from the first tasting). Data from each of these temporal sensory method are then analyzed using a graph theoretic approach. Cliques and attribute structures are identified. TCATA and TDS results are more similar to one another than either is to M-TDS results. Implications of method choice and various data pre-processing decisions are discussed.     

Dietary exposure estimates of isoflavones from the 1998 UK Total Diet Study.

The phyto-oestrogen contents of the 1998 UK Total Diet Study (TDS) food group composites were determined. Each TDS set consisted of composite samples, one for each of the 20 designated food groups. These composites then represented the average consumption of all the individual food elements in each group, processed into the form in which they were consumed. In the TDS, individual composites of the bread, processed meat and fish food groups contained >5 mg kg(-1) of the individual isoflavones (daidzein, genistein and glycitein). Individual composites from the groups, miscellaneous cereals, other vegetables, fruit products and nuts contained >1 mg kg(-1). After weighting for average consumption of food from each TDS food group, an estimated daily intake of 3 mg day(-1) of combined isoflavone aglycones was obtained from the TDS sample collection model for the average (adult) consumer. The UK dietary intake of phyto-oestrogens is higher than previously estimated due in part to the use of soya in processed foods.     

Li, Cr, Mn, Co, Ni, Cu, Zn, Se and Mo levels in foodstuffs from the Second French TDS

In 2006, the French Food Safety Agency (AFSSA) conducted the Second French Total Diet Study (TDS) to estimate dietary exposures to the main minerals and trace elements from 1319 samples of foods typically consumed by the French population. The foodstuffs were analysed by inductively coupled plasma-mass spectrometry (ICP-MS) after microwave-assisted digestion. Occurrence data for lithium, chromium, manganese, cobalt, nickel, copper, zinc, selenium and molybdenum were reported and compared with results from the previous French TDS. The results indicate that the food groups presenting the highest levels of these essential trace elements were “tofu” (for Li, Mn, Ni, Cu, Zn and Mo),“fish and fish products” particularly “shellfish” (for Li, Co, Cu, Zn, Se and Mo), “sweeteners, honey and confectionery” particularly dark chocolate (for Cr, Mn, Co, Ni and Cu), “cereals and cereal products” (for Mn, Ni and Mo) and “ice cream” (for Cr, Co and Ni).     

Impact of texture TDS and flavour TDS tasks and of chocolate-chip biscuit characteristics on oral processing features

The objective of the present study was to investigate differences in oral activity when biscuits of the same type but with subtle composition differences are consumed and how performing a Temporal Dominance of Sensations (TDS) task modifies the way one eats. In addition, comparisons were made between performing a texture TDS (T-TDS) and a flavour TDS (F-TDS). Oral activity while eating biscuits with and without conducting a TDS task was recorded using a 3.dimensional motion capture system to monitor the evolution of jaw movements.The results showed that oral activity evolved over the consumption time, differed depending on the texture of the sample and was affected to a small but significant extent when a TDS task was performed simultaneously (the differences averaged <4 cycles, 1 s in duration, 0.1 cycles/s in frequency, and 1 mm in lateral displacement). The biscuit samples were affected equally. Almost no differences were found on comparing oral activity during the execution of the T-TDS and the F-TDS tasks.Overall, the present results show differences in oral activity even for food products of the same category with subtle differences in composition. Performing TDS tasks (regardless of their modality) during sample consumption affected the total number, frequency and lateral amplitude of the chewing movements which should be taken into account for future research. However, these differences were small and affected both samples equally.     

COMPARISON OF CHLORINE WITH AN IODINE-BASED COMPOUND ON EGGSHELL SURFACE MICROBIAL POPULATIONS IN A COMMERCIAL EGG WASHER

Microbial contamination of egg shells is of great importance in the commercial production of table eggs. The objective of this project was to determine the effectiveness of an iodine-based disinfectant (IBD) on the microbial population of eggshell surfaces under simulated industry egg processing conditions with a commercial egg washer used as the delivery system for sanitizers. Recirculated egg washer water containing 3.69–5.81 log colony-forming units (CFU)/mL aerobic organisms and 2.02–2.47 g/L total dissolved solids (TDS) was obtained from a commercial egg processing facility and used to simulate conditions found in the commercial egg industry. Sanitizing treatments consisted of distilled deionized water (DDW), IBD, and chlorine (CL; 200 ppm). Enumeration of aerobic plate populations indicated that IBD and CL treatment significantly (p < 0.05) decreased microbial populations on the shell compared to DDW treatment when egg wash water TDS were lower (2.02 – 2.03 g/L) and wash water aerobic plate counts (APC) were higher (5.05 – 5.85 log CFU/mL). When egg wash water TDS was higher (2.47 g/L) and wash water APC were lower (3.69 log CFU/mL) sanitizers were not effective in reducing egg shell microbial populations. No difference in egg shell APC counts was detected between the IBD and CL. In a second trial, cycloheximide or tetracycline amendments were added to media to test the effectiveness of the treatments on either mold and fungi or bacteria alone. When wash water TDS were higher (2.44–2.46 g/L) the sanitizers were again less effective against bacteria compared to samples from lower TDS while fungal populations did not show any significant differences among the treatments. It was concluded from this study that the IBD is an effective sanitizer when used in conjunction with a commercial egg washer but potential efficacy is dependent on the level of TDS in the egg wash water.     

Establishing a food list for a Total Diet Study: how does food consumption of specific subpopulations need to be considered?

A Total Diet Study (TDS) consists of selecting, collecting and analysing commonly consumed foods to obtain concentration data of different chemical compounds in foods as eaten. A TDS food list summarises the most consumed foods and represents the dietary habits of the general population of the country under study. The work reported here investigated whether TDS food lists that were initially designed for the whole population of the country under study also sufficiently cover the dietary pattern of specific subpopulations that are extra vulnerable for certain contaminants. The work was performed using data of three European countries: the Czech Republic, France and the UK. Each national food consumption database was combined with the corresponding national TDS food list (containing 336, 212 and 119 food items for the Czech Republic, France and the UK, respectively). The data were aggregated on the highest level of hierarchy of FoodEx-1, a pan-European food classification system, including 20 main FoodEx-1 groups. For the group ‘milk and dairy products’, the coverage of the consumption by the food list was investigated for more refined subgroups. For each food group or subgroup and country, the average percentage of coverage of the diet by the national TDS food list was calculated for different subpopulations, including children versus adults, women versus men, vegetarians versus non-vegetarians, and women of child-bearing age versus older women. The average diet of the different subpopulations was sufficiently covered by the food list of the Czech Republic and France. For the UK the average coverage was low due to a different food-coding approach and because food lists were not derived directly from national food consumption data. At the level of the 20 main food groups, differences between the subpopulations with respect to the average coverage of consumption by the TDS food list were minimal. The differences were more pronounced when looking in detail at the coverage of the dairy consumption. TDS food lists based on the mean consumption of the general population are also applicable to study the chemical exposure of different subpopulations, e.g. children, women of child-bearing age and vegetarians. This lowers the effort when performing a TDS.