Facial affective reactions to bitter-tasting foods and body mass index in adults.

Differences in food consumption among body-weight statuses (e.g., higher fruit intake linked with lower body mass index (BMI) and energy-dense products with higher BMI) has raised the question of why people who are overweight or are at risk of becoming overweight eat differently from thinner people. One explanation, in terms of sensitivity to affective properties of food, suggests that palatability-driven consumption is likely to be an important contributor to food intake, and therefore body weight. Extending this approach to unpalatable tastes, we examined the relationship between aversive reactions to foods and BMI. We hypothesized that people who have a high BMI will show more negative affective reactions to bitter-tasting stimuli, even after controlling for sensory perception differences. Given that hedonic reactions may influence consumption even without conscious feelings of pleasure/displeasure, the facial expressions were included in order to provide more direct access to affective systems than subjective reports. Forty adults (28 females, 12 males) participated voluntarily. Their ages ranged from 18 to 46 years (M=24.2, SD=5.8). On the basis of BMI, participants were classified as low BMI (BMI<20; n=20) and high BMI (BMI>23; n=20). The mean BMI was 19.1 for low BMI (SD=0.7) and 25.2 for high BMI participants (SD=1.8). Each subject tasted 5 mL of a grapefruit juice drink and a bitter chocolate drink. Subjects rated the drinks' hedonic and incentive value, familiarity and bitter intensity immediately after each stimulus presentation. The results indicated that high BMI participants reacted to bitter stimuli showing more profound changes from baseline in neutral and disgust facial expressions compared with low BMI. No differences between groups were detected for the subjective pleasantness and familiarity. The research here is the first to examine how affective facial reactions to bitter food, apart from taste responsiveness, can predict differences in BMI.

Understanding apple consumers' expectations in terms of likes and dislikes. Use of comment analysis in a cross-cultural study.

Apple consumers' expectations in Argentina and France were studied by comment analysis of open-ended questions. In an on-line survey consumers stated: attributes which defined quality in an apple; visual, flavor and texture characteristics they liked/did not like to find in an apple. Influence of country, consumption frequency and cultivar knowledge were analyzed by contingency tables, Chi-square per cell tests and Multiple Factor Analysis. Consumers' quality expectations were not the same in both countries. Argentineans and French consumers agreed that quality apples should be juicy (most used term in both countries), tasty, firm and fresh. However, for Argentineans quality was more related to visual characteristics, whereas for French it was driven by flavor. Argentineans used more words but French were more specific, particularly for flavour description. Moreover, frequency of consumption, varieties knowledge and the number of terms given were highly related. Frequent consumers knew more varieties and were more prolific in relation to flavour. Less frequent consumers knew fewer apple varieties and gave more words in the visual category. The use of comment analysis allowed identifying the terms that consumers used in their day to day life to describe apples, finding separately likes and dislikes, in spite of the different languages.

Impact of music on the dynamic perception of coffee and evoked emotions evaluated by temporal dominance of sensations (TDS) and emotions (TDE).

The aim of the present work was to study the temporal effect of music on sensory perception and on the emotional changes while drinking coffee. Two different commercial filter coffees were evaluated by a group of 48 consumers using the Temporal Dominance of Sensations (TDS) method. The description was performed in silence and also while listening to two different musical fragments: one with a "sweet" connotation and the other with a "bitter" one. Under the same conditions (drinking coffee with and without musical stimuli), a different group of 72 consumers evaluated their perceived emotions (joy, fear, neutral, rejection, disgust, surprise, sadness and anger) by Temporal Dominance of Emotions (TDE). Data was analyzed by dominance curves and by ANOVA and MANOVA of the durations of dominance (for emotions and sensations). Coffee perception, in both cases, was modified by the musical stimuli. The duration of dominance of bitter was increased in the presence of "bitter" music, while it decreased with the "sweet" music. Moreover, the sweet attribute was practically not chosen for describing the coffee on its own, but its choice and duration as dominant increased while listening to the "sweet" musical fragment. Music had a larger impact on the perceived emotions. The "sweet" music was related to the emotion of joy, which was accompanied by surprise and also some sadness when drinking coffee (regardless of the type of coffee being drunk). The "bitter" music was linked to the emotions anger and fear. The effect of "sonic seasoning" and translation of emotions with a familiar product was observed.

Time-intensity and reaction-time methodology applied to the dynamic perception and liking of bitterness in relation to body mass index.

There are very few studies which have considered perception temporality when relating perceived intensity and hedonic responses in relation to body mass index (BMI; kg/cm2). The aim of the present study was to determine the relationship between BMI with the dynamic perception and liking of bitter tasting solutions. For this purpose, two different categories of bitter products were applied: 6-n-propilthiouracil (PROP) solutions (0.010, 0.032 and 0.060 mmol/L) and commercial beverages (coffee, yerba mate infusion and grapefruit juice). The proposed methodology to evaluate perception and hedonic response was based on the measurement of reaction-time (R-T) and multiple-sip time-intensity (T-I) registers in people with a high BMI (25 < BMI < 30; overweight group) and a normal BMI (<25; normal-weight control group). The multiple-sip evaluation to describe perception of PROP solutions and liking of beverages was used as a more ecologically valid laboratory methodology to simulate a situation of usual consumption. In this sense, working with a multiple-sip design helped confirm that bitter taste has a cumulative effect since in every case the sip effect was significant when evaluating the maximum intensity; this effect was more important as the bitterness increased. Regarding the body weight group comparisons, the normal BMI group perceived bitter taste more intensely and the time to react to it was shorter (faster reaction) for both PROP solutions and the three beverages. Interestingly, even though the high BMI group rated the bitter taste as less intense, they had a lower level of acceptance than normal BMI. This result suggests that the hedonic rather than the sensory component might be playing a crucial role in the perception of bitter taste in individuals with high BMI.

Simplified prediction of Staphylococcus aureus growth in a cooked meat product exposed to changing environmental temperatures in warm climates.

In this work, a simplified method is used to estimate the growth of Staphylococcus aureus in a pasteurized meat product left for several hours at environmental temperatures (diurnal time) in warm climates of different cities in Argentina. Hourly temperature data for a warm January (the hottest month of the year) day, and literature data on the kinetics of S. aureus growth inoculated in a pasteurized meat product were used for calculations. As shown by results, if a cooked meat product is left exposed to environmental temperature at diurnal time, predictions made when using a constant temperature value (i.e. average daily) may not be accurate. Growth estimations in contaminated food left under ambient conditions during diurnal time, should consider the changing environmental temperature for correct results.

Group and individual gustatory reaction times and Piéron's law.

Simple reaction times (SRT) to eight substances belonging to the four classical taste families were evaluated. The same eight subjects participated in all experiments. The functional relationship between SRT and concentration for group and for individual data were examined. Equations presented by different authors to describe RT data are discussed. The Piéron function [(SRT - t0) = betaI-alpha] best fits the gustatory data collected in the present experiments. These results, together with others taken from previous studies, show that the exponent of salt and acid taste functions is lower than 1.0 with a relatively short t0. Sweet and bitter exponents were equal t0 or higher than 1, with a larger t0. Individual performances correlated with taste families for salt and acid. However, the limited samples of some solutions sets some limits to the interpretation of RT to taste substances.

[Intrafamilial contagion with the hepatitis B virus]. / Contagio intrafamiliar del virus de la hepatitis B.

BACKGROUND: A study of the intrafamilial transmission of the hepatitis B virus (HBV) and its relationship with the viral replication and epidemiological factors. METHODS: The intrafamilial transmission of 106 chronic carriers of HBV was evaluated: 79 were asymptomatic carriers (AC) and 27 had chronic liver disease (CLD). Overall 347 relatives of the first group individuals and 112 of the second group were investigated. In the index cases, all HBV markers were investigated, and also DNA-HBV in those with CLD. In the relatives, HBsAg, HBsAc and HBcAc were investigated. Also, a survey to evaluate the influence of socioeconomic and cultural factors was also carried out. RESULTS: The prevalence of markers was significantly higher in the relatives of patients with CLD (HBcAg, HBcAc and evidence of contact) followed by AC and controls. The most infective relation in AC was that of other contacts with significant differences from the mother-child relationship (HBsAc p less than 0.003, HBcAc p less than 0.01, and evidence of contact p less than 0.001). By contrast, in CLD the most infective relation was mother-child. The mother-child relation was more infective than the father-child one (HBsAg p less than 0.05, HBcAc p less than 0.03, and evidence of contact p less than 0.02). Regarding viral replication, it was found that the HBeAg and DNA positive patients were more infective. The prevalence of HBcAc and the evidence of contact increased with the time of living together of spouses. Finally, it can be stated in a general sense that, according to the results of the survey, the socioeconomic factors have a small influence on the familial transmission. CONCLUSIONS: The relatives of HBV carriers, particularly in the case of HC with high replication, have a high risk of transmission. Thus, their investigation and subsequent vaccination is mandatory.

[Immunological profile against the hepatitis B virus in different population groups (author's transl)]. / Determinación del perfil immunológico frente al virus HVB en grupos de población.

To study the immunological profile against the hepatitis B virus 742 sera (107 from the Renal Unit and 635 from other hospital services) were assayed for HBsAg, HBsAc, and HBcAc. The results obtained appear to indicate that the simultaneous determination of the three tests is unnecessary for diagnosis, although it is important for follow-up and prognosis. The isolated measurement of HBsAg is a good diagnostic test, but although it appears early it lasts little, a reason why it should perhaps be complemented with the other tests when considering the time factor. If only one technique is to be made available HBcAc determination seems necessary because it appears simultaneously with the HBsAg and it persists for a long time thereafter. A high degree of positivity of HBsAc and HBcAc was found in dialysis patients, a fact apparent also in the other population groups.

Detection of specific IgG and IgM antibodies in the haemagglutination inhibition test and the enzyme-linked immunoassay for the diagnosis of rubella infection.

A study has been carried out on the sera of 710 women who wished to know their state of rubella immunity using haemagglutination inhibition (HAI) and enzyme-linked immunoassay (ELISA) techniques. The majority of the women presented no symptoms. The ability of HAI to detect low antibody levels (1:8, 1:16) appears to be greater than that of Rubazyme ELISA IgG, employing the recommendations of the manufacturers. The correlation between HAI and IgG values above HAI titres of 1:16 is nearly 100%. In an additional study of 17 primary infections in pregnant women with definite rubella symptoms, the total titre of antibodies was determined by HAI and IgG and specific IgM with ELISA Rubazyme in successive samples. In four cases, IgM was clearly positive and no increase in either HAI or IgG antibodies could be demonstrated over three successive samples taken at an interval of 15 to 20 days. Therefore, we consider it necessary to determine IgM antibodies (evaluating these in the absence of the rheumatoid factor) in every doubtful case occurring in pregnant women, irrespective of whether clinical signs are present or not.

Simplified prediction of Staphylococcus aureus growth in a cooked meat product exposed to changing environmental temperatures in warm climates / Predición simplificada del crecimiento de Staphylococcus aureus en productos cárnicos cocidos expuestos a temperaturas ambientes cambiantes en climas cálidos

In this work, a simplified method is used to estimate the growth of Staphylococcus aureus in a pasteurized meat product left for several hours at environmental temperatures (diurnal time) in warm climates of different cities in Argentina. Hourly temperature data for a warm January (the hottest month of the year) day, and literature data on the kinetics of S. aureus growth inoculated in a pasteurized meat product were used for calculations. As shown by results, if a cooked meat product is left exposed to environmental temperature at diurnal time, predictions made when using a constant temperature value (i.e. average daily) may not be accurate. Growth estimations in contaminated food left under ambient conditions during diurnal time, should consider the changing environmental temperature for correct results.

En este trabajo se utiliza un método simplificado para predecir el crecimiento de Staphylococcus aureus en un producto cárnico pasteurizado dejado por varias horas a temperatura ambiente diurna en zonas de clima cálido. En la predicción, se utilizaron datos de la temperatura horaria para un día caluroso típico de enero (mes más caliente del año) en varias ciudades de la Argentina y datos de la literatura sobre tiempos de generación y tiempo lag de la bacteria inoculada en un producto cárnico pasteurizado. Los resultados indicaron que cuando el producto se deja a temperatura ambiente diurna durante varias horas, no se debe utilizar para la predicción un valor de temperatura promedio (ej.: temperatura media diaria), sino que hay que tener en cuenta la evolución de este parámetro a lo largo del período considerado.