Correlating comprehensive two-dimensional gas chromatography volatile profiles of chocolate with sensory analysis

The identification of key components relevant to sensory perception of quality from commercial chocolate samples was accomplished after chemometric processing of GC×GC-MS (Comprehensive Two-dimensional Gas Chromatography with Mass Spectrometric Detection) profiles corresponding to HS-SPME (Headspace Solid Phase Microextraction) extracts of the samples. Descriptive sensory evaluation of samples was carried out using Optimized Descriptive Profile (ODP) procedures, where sensory attributes of 24 commercial chocolate samples were used to classify them in two classes (low and high chocolate flavor). 2D Fisher Ratio analysis was applied to four-way chromatographic data tensors (1st dimension retention time 1tR × 2nd dimension retention time 2tR × m/z × sample), to identify the crucial areas on the chromatograms that resulted on ODP class separation on Principal Component Analysis (PCA) scores plot. Comparing the relevant sections of the chromatograms to the analysis of the corresponding mass spectra, it was possible to assess that most of the information regarding the sample main sensory attributes can be related to only 14 compounds (2,5-dimethylpyrazine, 2,6-dimethyl-4-heptanol, 1-octen-3-ol, trimethylpyrazine, β-pinene, o-cimene, 2-ethyl-3,5-dimethylpyrazine, tetramethylpyrazine, benzaldehyde, 1,3,5-trimethylbenzene, 6-methyl-5-hepten-2-one, limonene, benzeneethanol and 1,1-dimethylbutylbenzene) among the complex blend of volatiles found on these extremely complex samples

Minimal set of local measurements and classical communication for two-mode Gaussian state entanglement quantification

We develop the minimal requirements for the complete entanglement quantification of an arbitrary two-mode bipartite Gaussian state via local measurements and a classical communication channel. The minimal set of measurements is presented as a reconstruction protocol of local covariance matrices and no previous knowledge of the state is required but its Gaussian character. The protocol becomes very simple mostly when dealing with Gaussian states transformed to its standard form, since photocounting or intensity measurements define the whole set of entangled states. In addition, conditional on some prior information, the protocol is also useful for a complete global state reconstruction.981

Dispelling the myth that habitual caffeine consumption influences the performance response to acute caffeine supplementation

Objective: To investigate the influence of habitual caffeine intake on aerobic exercise performance responses to acute caffeine supplementation. Methods: A double-blind, crossover, counterbalanced study was performed. Forty male endurance-trained cyclists were allocated into tertiles according to their daily caffeine intake: low (58 ± 29 mg.d-1), moderate (143 ± 25 mg.d-1), and high consumers (351 ± 139 mg.d-1). Participants completed three trials in which they performed simulated cycling time-trials in the fastest time possible following ingestion of: caffeine (CAF: 6 mg.kg-1 BM), placebo (PLA), and no supplement (CON). Results: Mixed-model analysis revealed time-trial performance was significantly improved in CAF compared to PLA and CON (29.92±2.18 min vs 30.81±2.67 and 31.14±2.71 min; P = 0.05). Blood lactate and ratings of perceived exertion were not different between trials and tertiles (P>0.05). Conclusion: Performance effects of acute caffeine supplementation during a ~30 min cycling TT performance were not influenced by the level of habitual caffeine consumption

24-Week β-alanine ingestion does not affect muscle taurine or clinical blood parameters in healthy males

Purpose: To investigate the effects of chronic beta-alanine (BA) supplementation on muscle taurine content, blood clinical markers and sensory side-effects. Methods: Twenty-five healthy male participants (age 27±4 years, height 1.75±0.09 m, body mass 78.9±11.7 kg) were supplemented with 6.4 g day−1 of sustained-release BA (N=16; CarnoSyn™, NAI, USA) or placebo (PL; N=9; maltodextrin) for 24 weeks. Resting muscle biopsies of the m. vastus lateralis were taken at 0, 12 and 24 weeks and analysed for taurine content (BA, N=12; PL, N=6) using high-performance liquid chromatography. Resting venous blood samples were taken every 4 weeks and analysed for markers of renal, hepatic and muscle function (BA, N=15; PL, N=8; aspartate transaminase; alanine aminotransferase; alkaline phosphatase; lactate dehydrogenase; albumin; globulin; creatinine; estimated glomerular filtration rate and creatine kinase). Results :There was a significant main effect of group (p=0.04) on muscle taurine, with overall lower values in PL, although there was no main effect of time or interaction effect (both p>0.05) and no differences between specific timepoints (week 0, BA: 33.67±8.18 mmol kg−1 dm, PL: 27.75±4.86 mmol kg−1 dm; week 12, BA: 35.93±8.79 mmol kg−1 dm, PL: 27.67±4.75 mmol kg−1 dm; week 24, BA: 35.42±6.16 mmol kg−1 dm, PL: 31.99±5.60 mmol kg−1 dm). There was no effect of treatment, time or any interaction effects on any blood marker (all p>0.05) and no self-reported side-effects in these participants throughout the study. Conclusions: The current study showed that 24 weeks of BA supplementation at 6.4 g day−1 did not significantly affect muscle taurine content, clinical markers of renal, hepatic and muscle function, nor did it result in chronic sensory side-effects, in healthy individuals. Since athletes are likely to engage in chronic supplementation, these data provide important evidence to suggest that supplementation with BA at these doses for up to 24 weeks is safe for healthy individuals

Twenty-four weeks of β-alanine supplementation on carnosine content, related genes, and exercise

Introduction: Skeletal muscle carnosine content can be increased through [beta]-alanine supplementation, but the maximum increase achievable with supplementation is unknown. No study has investigated the effects of prolonged supplementation on carnosine-related genes or exercise capacity. Purpose: To investigate the effects of 24-weeks of [beta]-alanine supplementation on muscle carnosine content, gene expression and high-intensity cycling capacity (CCT110%). Methods: Twenty-five active males were supplemented with 6.4 g[middle dot]day-1 of sustained release [beta]-alanine (BA) or placebo (PL) over a 24-week period. Every 4 weeks participants provided a muscle biopsy and performed the CCT110%. Biopsies were analysed for muscle carnosine content and gene expression (CARNS, TauT, ABAT, CNDP2, PHT1, PEPT2 and PAT1). Results: Carnosine content was increased from baseline at every time point in BA (all P<0.0001; Week 4: +11.37+/-7.03 mmol[middle dot]kg-1dm, Week 8: +13.88+/-7.84 mmol[middle dot]kg-1dm, Week 12: +16.95+/-8.54 mmol[middle dot]kg-1dm, Week 16: +17.63+/-8.42 mmol[middle dot]kg-1dm, Week 20: +21.20+/-7.86 mmol[middle dot]kg-1dm, Week 24: +20.15+/-7.63 mmol[middle dot]kg-1dm), but not PL (all P=1.00). Maximal changes were +25.66+/-7.63 mmol[middle dot]kg-1dm (range: +17.13 to +41.32 mmol[middle dot]kg-1dm), and absolute maximal content was 48.03+/-8.97 mmol[middle dot]kg-1dm (range: 31.79 to 63.92 mmol[middle dot]kg-1dm). There was an effect of supplement (P=0.002) on TauT; no further differences in gene expression were shown. Exercise capacity was improved in BA (P=0.05) with possible to almost certain improvements across all weeks. Conclusions: Twenty-four weeks of [beta]-alanine supplementation increased muscle carnosine content and improved high-intensity cycling capacity. Downregulation of TauT suggests it plays an important role in muscle carnosine accumulation with [beta]-alanine supplementation, while the variability in changes in muscle carnosine content between individuals suggests that other determinants other than the availability of [beta]-alanine may also bear a major influence on muscle carnosine content

An evaluation of enteral nutrition practices and nutritional provision in children during the entire length of stay in critical care

&lt;b&gt;Background&lt;/b&gt; Provision of optimal nutrition in children in critical care is often challenging. This study evaluated exclusive enteral nutrition (EN) provision practices and explored predictors of energy intake and delay of EN advancement in critically ill children.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods&lt;/b&gt; Data on intake and EN practices were collected on a daily basis and compared against predefined targets and dietary reference values in a paediatric intensive care unit. Factors associated with intake and advancement of EN were explored.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results&lt;/b&gt; Data were collected from 130 patients and 887 nutritional support days (NSDs). Delay to initiate EN was longer in patients from both the General Surgical and congenital heart defect (CHD) Surgical groups [Median (IQR); CHD Surgical group: 20.3 (16.4) vs General Surgical group: 11.4 (53.5) vs Medical group: 6.5 (10.9) hours; p &lt;= 0.001]. Daily fasting time per patient was significantly longer in patients from the General Surgical and CHD Surgical groups than those from the Medical group [% of 24 h, Median (IQR); CHD Surgical group: 24.0 (29.2) vs General Surgical group: 41.7 (66.7) vs Medical group: 9.4 (21.9); p &lt;= 0.001]. A lower proportion of fluids was delivered as EN per patient (45% vs 73%) or per NSD (56% vs 73%) in those from the CHD Surgical group compared with those with medical conditions. Protein and energy requirements were achieved in 38% and 33% of the NSDs. In a substantial proportion of NSDs, minimum micronutrient recommendations were not met particularly in those patients from the CHD Surgical group. A higher delivery of fluid requirements (p &lt; 0.05) and a greater proportion of these delivered as EN (p &lt; 0.001) were associated with median energy intake during stay and delay of EN advancement. Fasting (31%), fluid restriction (39%) for clinical reasons, procedures requiring feed cessation and establishing EN (22%) were the most common reasons why target energy requirements were not met.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions&lt;/b&gt; Provision of optimal EN support remains challenging and varies during hospitalisation and among patients. Delivery of EN should be prioritized over other "non-nutritional" fluids whenever this is possible.&lt;p&gt;&lt;/p&gt

Produção orgânica de rabanete em plantio direto sobre cobertura morta e viva.

O objetivo deste trabalho foi avaliar o uso de plantas espontâneas e cobertura viva de amendoim forrageiro(Arachis pintoi), associado à aplicação de composto orgânico na produção orgânica do rabanete em plantio direto. O experimento foi instalado na Universidade Federal do Acre, em Rio Branco-AC, de 15/06 a 14/07/2007. O delineamento experimental utilizado foi em blocos casualizados com parcelas subdivididas 4x3, em quatro repetições. As parcelas corresponderam ao sistema de plantio direto com cobertura viva de amendoim forrageiro, cobertura viva de planta espontânea, cobertura morta de planta espontânea e sistema de plantio em canteiro com solo descoberto. As subparcelas foram compostas pelas doses de composto orgânico de 5, 10 e 15 t ha-1 (base seca). O plantio direto na palha de plantas espontâneas teve desempenho semelhante ao preparo convencional do solo, ambos superiores ao plantio sobre as coberturas vivas. A produtividade do rabanete cv. Cometo, não foi afetada pelas doses crescentes de composto orgânico, podendo aplicar-se apenas 5 t ha-1, enquanto em preparo convencional do solo, o aumento da produtividade ultrapassa o plantio direto na palha apenas na dose maior de composto (15 t ha-1)