Water deprivation and the double- depletion hypothesis: common neural mechanisms underlie thirst and salt appetite

Water deprivation-induced thirst is explained by the double-depletion hypothesis, which predicts that dehydration of the two major body fluid compartments, the extracellular and intracellular compartments, activates signals that combine centrally to induce water intake. However, sodium appetite is also elicited by water deprivation. In this brief review, we stress the importance of the water-depletion and partial extracellular fluid-repletion protocol which permits the distinction between sodium appetite and thirst. Consistent enhancement or a de novo production of sodium intake induced by deactivation of inhibitory nuclei (e.g., lateral parabrachial nucleus) or hormones (oxytocin, atrial natriuretic peptide), in water-deprived, extracellular-dehydrated or, contrary to tradition, intracellular-dehydrated rats, suggests that sodium appetite and thirst share more mechanisms than previously thought. Water deprivation has physiological and health effects in humans that might be related to the salt craving shown by our species.

Effects of cocaine, methamphetamine and modafinil challenge on sleep rebound after paradoxical sleep deprivation in rats

Sleep loss is both common and critically relevant to our society and might lead to the abuse of psychostimulants such as amphetamines, cocaine and modafinil. Since psychoactive substance abuse often occurs within a scenario of sleep deficit, the purpose of this investigation was to compare the sleep patterns of rats challenged with cocaine (7 mg/kg, ip), methamphetamine (7 mg/kg, ip), or modafinil (100 mg/kg, ip) subsequent to paradoxical sleep deprivation (PSD) for 96 h. Our results show that, immediately after 96 h of PSD, rats (10 per group) that were injected with a psychostimulant presented lower percentages of paradoxical sleep compared to those injected with saline (P < 0.01). Regarding slow wave sleep (SWS), rats injected with psychostimulants after PSD presented a late rebound (on the second night subsequent to the injection) in the percentage of this phase of sleep when compared to PSD rats injected with saline (P < 0.05). In addition, the current study has produced evidence of the characteristic effect of each drug on sleep architecture. Home cage control rats injected with modafinil and methamphetamine showed a reduction in SWS compared with the saline group. Methamphetamine affected sleep patterns most, since it significantly reduced paradoxical sleep, SWS and sleep efficiency before and after PSD compared to control (P < 0.05). Cocaine was the psychostimulant causing the least changes in sleep pattern in relation to those observed after saline injection. Therefore, our results suggest that abuse of these psychostimulants in a PSD paradigm aggravates their impact on sleep patterns.

Taurine inhibits serum deprivation-induced osteoblast apoptosis via the taurine transporter/ERK signaling pathway

Taurine has positive effects on bone metabolism. However, the effects of taurine on osteoblast apoptosis in vitro have not been reported. The aim of this study was to investigate the activity of taurine on apoptosis of mouse osteoblastic MC3T3-E1 cells. The data showed that 1, 5, 10, or 20 mM taurine resulted in 16.7, 34.2, 66.9, or 63.75% reduction of MC3T3-E1 cell apoptosis induced by the serum deprivation (serum-free α-MEM), respectively. Taurine (1, 5, or 10 mM) also reduced cytochrome c release and inhibited activation of caspase-3 and -9, which were measured using fluorogenic substrates for caspase-3/caspase-9, in serum-deprived MC3T3-E1 cells. Furthermore, taurine (10 mM) induced extracellular signal-regulated kinase (ERK) phosphorylation in MC3T3-E1 cells. Knockdown of the taurine transporter (TAUT) or treatment with the ERK-specific inhibitor PD98059 (10 μM) blocked the activation of ERK induced by taurine (10 mM) and abolished the anti-apoptotic effect of taurine (10 mM) in MC3T3-E1 cells. The present results demonstrate for the first time that taurine inhibits serum deprivation-induced osteoblast apoptosis via the TAUT/ERK signaling pathway.

Lentiviral-mediated RNAi targeting caspase-3 inhibits apoptosis induced by serum deprivation in rat endplate chondrocytes in vitro

Current studies find that degenerated cartilage endplates (CEP) of vertebrae, with fewer diffusion areas, decrease nutrient supply and accelerate intervertebral disc degeneration. Many more apoptotic cells have been identified in degenerated than in normal endplates, and may be responsible for the degenerated grade. Previous findings suggest that inhibition of apoptosis is one possible approach to improve disc regeneration. It is postulated that inhibition of CEP cell apoptosis may be responsible for the regeneration of endplates. Caspase-3, involved in the execution phase of apoptosis, is a candidate for regulating the apoptotic process. In the present study, CEP cells were incubated in 1% fetal bovine serum. Activated caspases were detected to identify the apoptotic pathway, and apoptosis was quantified by flow cytometry. Lentiviral caspase-3 short hairpin RNA (shRNA) was employed to study its protective effects against serum deprivation. Silencing of caspase-3 expression was quantified by reverse transcription-polymerase chain reaction and Western blots, and inhibition of apoptosis was quantified by flow cytometry. Serum deprivation increased apoptosis of rat CEP cells through activation of a caspase cascade. Lentiviral caspase-3 shRNA was successfully transduced into CEP cells, and specifically silenced endogenous caspase-3 expression. Surviving cells were protected by the downregulation of caspase-3 expression and activation. Thus, lentiviral caspase-3 shRNA-mediated RNAi successfully silenced endogenous caspase-3 expression, preventing inappropriate or premature apoptosis.

SENSORY ANALYSIS OF A MODEL SYSTEM USING 5'-IMP AND CYSTEINE AT DIFFERENT pH

Sensory analysis was used to get an overall flavour description of a reaction mixtures containing 5'-IMP and Cysteine. Ribose/cysteine systems were used as reference systems. Results from triangle and aroma profiling show a clear correlation between the terms used and the volatile analysis described in literature for these model systems. For instance reactions at pH 3.0 and 4.5 for 5'-IMP/cysteine systems, which were described as "meaty" and "boiled meat" by panellists, presented, in the literature, the higher number of "meaty" compounds in volatile analysis (1, 7, 8, 20) .

Sensory evaluation of black instant coffee beverage with some volatile compounds present in aromatic oil from roasted coffee

The oil obtained from Brazilian roasted coffee by supercritical CO2 extraction shows considerable aromatic properties, mainly composed by five aromatic compounds, 2-methylpyrazine; 2-furfurylalcohol, 2,5-dimethylpyrazine; γ-butyrolactone and 2-furfurylacetate. Sensory analyses were used to verify the influence of a mixture of these important classes of aromatic coffee compounds (pyrazines, furans and lactones) and of the roasted coffee aromatic oil on the coffee aroma and flavour of black instant freeze and spray-dried coffee beverages. In the acceptance evaluation of the aroma, the samples prepared with freeze-dried instant coffee without the mixture of volatile compounds (sample 4) were not significantly different from the freeze-dried instant coffee in which the aromatic coffee oil was added (sample 5) and from the sample prepared with freeze-dried coffee in which the mixture of the five volatile was added (sample 3), coincidentally from the same drying process. Therefore, sample (3) did not differ from samples prepared with spray dried instant coffee without (sample 1) and to which (sample 2) the mixture of volatile was added. Therefore, with respect to this attribute, the addition of this mixture did not interfere in this drink acceptance. Taking into consideration the flavor, samples prepared with freeze-dried instant coffee in which the aromatic coffee oil was added (5) and the samples with (3) and without (4) the mixture of the five volatile was added did not differ significantly, however sample (4) did not differ from samples (1) and (2). Regarding this attribute, the addition of the aromatic oil of roasted coffee or a mixture of volatile in samples of freeze-dried instant coffee had a better acceptance than those dried by spray dryer (1) and (2). Thus, the enrichment of drinks with the aromatic oil of roasted coffee, or even with the mixture of the five components did not influence the consumer acceptance with respect to the aroma, but exerts influence with respect to flavour.

Soy and Brazil nut beverage: processing, composition, sensory, and color evaluation

Despite its high nutritional value, soymilk consumption in Western countries is limited mainly due to undesirable flavors developed during the traditional elaboration process. Brazil nut (Bertholletia excelsa) has pleasant flavor and recognized nutritional value. Thus, the aim of this work was to elaborate a soy and Brazil nut beverage exploring the use of two national products of high nutritional quality. The process for manufacturing a soy and Brazil nut beverage consisted of elaboration, formulation, and homogenization of soymilk and Brazil nut milk. The addition of five levels (10, 20, 30, 40, and 50%) of Brazil nut milk to soy beverages was investigated. Although no significant differences in consumer average preference (p > 0.05) were observed among the beverages, analyzing both the consumer preference frequency distribution of the products and the Internal Preference Mapping (IPM), it was possible to conclude that the beverage with 30% of Brazil nut milk reached the most adequate performance demonstrating the sensory benefits Brazil nuts brought to the product. Regarding proximate composition, it did not present a better performance in terms of nutritional value, except for the oil content. The soy and Brazil nut beverage presented visual stability and no phase separation despite the non-stability shown by Brazil nut beverage itself. When Brazil nut milk was added to soy beverage, the final product became whiter than soy beverage, which is appealing to consumers who normally search for a clearer soymilk. The soy and Brazil nut beverage processing can be considered an alternative to increase the use of Brazil nuts in the Brazilian diet.

Sensory analysis of hydrolysed meat preparations

The use of hydrolysed meat in diets contributes to the improvement of protein, vitamin and mineral supply. This work aims at checking the acceptance pattern in meat hydrolysates. Four preparations have been developed with three types of hydrolysates in domestic-like conditions. Acceptance was verified by means of sensory analysis using the nine-point hedonic scale. Sensory tests have been carried out in three sessions (according to the kind of hydrolysates). In the evaluation file, information on age groups has been included. The statistical analysis has been made by ANOVA and Tukey test. The best accepted preparation have been the turkey and chicken hydrolysed balls. Hydrolysates can be used in many different kinds of preparations, but it is necessary to know both the age group it will be used to and its sensory and chemical-physical features to ensure the taste and the original appearance of the final product.

Sensory evaluation of rice fortified with iron

The objective of this study was to examine sensory differences between conventional rice and iron-fortified Ultra Rice rice (UR) and determine consumer acceptance. Differences between both types of rice were analyzed using the Duo-Trio Test on 37 non-trained judges. The Acceptance Test evaluated general rice appearance, color, aroma and taste by 43 non-trained judges, using a 7-point hedonic scale with extremes ranging from "really disliked" and "really liked." There were no significant differences between the analyzed samples of conventional rice and UR rice using Duo-Trio Test. Mean values from the Acceptance Test for the evaluated attributes (general appearance, color, aroma e taste) were 5.6 and 5.9, corresponding to "liked" and "really liked" according to the hedonic scale, respectively. The iron did not alter the sensory characteristics of the final product, and the iron-fortified rice was well accepted.

Effect of wheat flour protein variations on sensory attributes, texture and staling of Taftoon bread

The quality of flat breads depends in part on the textural properties of breads during storage. These properties are largely affected by flour protein quality and quantity. The present study aimed to examine differences between sensory properties, textural and staling of Tandoori breads made from flours of different quality and different quantities of protein. This was implemented by using three flours with 9.4, 11.5 and 13.5% protein contents and different protein qualities shown by Zeleney sedimentation volume 16.25, 22.75 and 23.25 mL respectively. Bread strips were submitted to uniaxial compression between two parallel plates on an Instron Universal Testing machine, and firmness of the breads was determined. Results indicated the differences in the sensory attributes of breads produced by flours of different protein content and quality, demonstrating that high protein high quality flours are not able to sheet and expand under the high temperature - short time conditions employed in Taftoon bread production and are therefore not suitable for this kind of bread. Results showed that flour with 11.5% protein content, produced bread with better sensory characteristics and acceptable storage time.

Sensory evaluation and nutritional value of cakes prepared with whole flaxseed flour

The objective of this study was to evaluate the nutritional value, the oxidative stabilitiy, and consumer acceptance of cakes containing four different concentrations of flaxseed flour (5, 15, 30 and 45%) as partial replacement for wheat flour. The oxidative stability of polyunsaturated fatty acids was evaluated through the lipid peroxidation test (TBARS) in the flour and cakes. Linolenic acid was determined by gas chromatography as well as contents of protein, lipid, ash, and dietary fiber. Consumer acceptance was assessed using a structured hedonic scale of nine points. The oxidative stability of lipid flaxseeds was not affected by the heat treatment during flour processing and cake baking. Cakes made with 5, 15, and 30% of flaxseed flour, the most accepted by consumers, had dietary fiber levels ranging from 3.5 to 6.2 g and linolenic acid ranging from 445 to 2,500 mg.100 g-1 of the product. The cakes received claims of good and excellent source of dietary fiber and linolenic acid, respectively, both are bioactive compounds. The use of up to 30% of flaxseed flour in the preparation of cakes is a useful strategy to optimize the consumption of food rich in functional ingredients.

Instrumental color and sensory acceptance of soy-based emulsions: a response surface approach

Response Surface Methodology (RSM) was applied to evaluate the chromatic features and sensory acceptance of emulsions that combine Soy Protein (SP) and red Guava Juice (GJ). The parameters analyzed were: instrumental color based on the coordinates a* (redness), b* (yellowness), L* (lightness), C* (chromaticity), h* (hue angle), visual color, acceptance, and appearance. The analyses of the results showed that GJ was responsible for the high measured values of red color, hue angle, chromaticity, acceptance, and visual color, whereas SP was the variable that increased the yellowness intensity of the assays. The redness (R²adj = 74.86%, p < 0.01) and hue angle (R²adj = 80.96%, p < 0.01) were related to the independent variables by linear models, while the sensory data (color and acceptance) could not be modeled due to a high variability. The models of yellowness, lightness, and chromaticity did not present lack of fit but presented adjusted determination coefficients bellow 70%. Notwithstanding, the linear correlations between sensory and instrumental data were not significant (p > 0.05) and low Pearson coefficients were obtained. The results showed that RSM is a useful tool to develop soy-based emulsions and model some chromatic features of guava-based emulsions through RSM.

Sensory profile of Italian salami with coriander (Coriandrum sativum L.) essential oil

The descriptive terminology and sensory prolife of four samples of Italian salami were determined using a methodology based on the Quantitative Descriptive Analysis (QDA). A sensory panel consensually defined sensory descriptors, their respective reference materials, and the descriptive evaluation ballot. Twelve individuals were selected as judges and properly trained. They used the following criteria: discriminating power, reproducibility, and individual consensus. Twelve descriptors were determined showing similarities and differences among the Italian salami samples. Each descriptor was evaluated using a 10 cm non-structured scale. The data were analyzed by ANOVA, Tukey test, and the Principal Component Analysis (PCA). The salami with coriander essential oil (T3) had lower rancid taste and rancid odor, whereas the control (T1) showed high values of these sensory attributes. Regarding brightness, T4 showed the best result. For the other attributes, T1, T2, T3, and T4 were similar.

Sensory profile of 'Douradão' peaches cold stored under controlled atmosphere

The sensory quality of 'Douradão' peaches cold stored in three different conditions of controlled atmosphere (CA1, CA2, CA3 and Control) was studied. After 14, 21 and 28 days of cold storage, samples were withdrawn from CA and kept for 4 days in ambient air for ripening. The sensory profile of the peaches and the descriptive terminology were developed by methodology based on the Quantitative Descriptive Analysis (QDA). The panelists consensually defined the sensory descriptors, their respective reference materials and the descriptive evaluation ballot. Fourteen panelists were selected based on their discrimination capacity and reproducibility. Seven descriptors were generated showing similarities and differences between samples. The data were analyzed by ANOVA, Tukey test and Principal Component Analysis (PCA). Results showed significant differences in the sensory profiles of the peaches. The PCA showed that CA2 and CA3 treatments were more characterized by the fresh peach flavor, fresh peach appearance, juiciness and flesh firmness, and were effective in keeping the good quality of the 'Douradão' peaches during the 28 days of cold storage. The Control and CA1 treatments were characterized by the mealiness and were ineffective for quality maintenance of the fruits during cold storage.

Stability of volatile profile and sensory properties of passion fruit juice during storage in glass bottles

This study aimed at assessing the stability of passion fruit juice in glass bottles during a 120-day storage period, regarding its volatile compounds profile and sensory properties (aroma and flavor). Samples were obtained from a Brazilian tropical juice industry (Fortaleza, Brazil) and submitted to sensory and chromatographic analyses. The characteristic aroma and flavor of passion fruit were evaluated by a trained panel with a non-structured scale of 9 cm. The headspace volatile compounds were isolated from the product by suction and trapped in Porapak Q, analyzed through high-resolution gas chromatography and identified through gas chromatography-mass spectrometry (GC-MS). Twelve odoriferous compounds were monitored: ethyl butanoate, ethyl propanoate, 3-methyl-1-butanol, 3-methyl-2-butenol, (E)-3-hexenol, (Z)-3-hexenol, 3-methylbutyl acetate, benzaldehyde, ethyl hexanoate, hexyl acetate, limonene and furfural. The slight variations observed in the volatile profile were not enough to provoke significant changes in the characteristic aroma and flavor of the passion fruit juice.