Dynamics of volatile compounds in TSH 565 cocoa clone fermentation and their role on chocolate flavor in Southeast Brazil.

The effects of indigenous fermentation on volatile compound profiles in a Theobroma cacao L, TSH565 clone, resistant to Moniliophtora perniciosa and Phytophthora spp. were evaluated in Southern Brazil. Sixty-three volatile flavor compounds in pulp and 36 in grains were identified by SPME-HS/GC-MS and classified as terpenes, alcohols, esters, ketones and aldehydes, among others. The relative amount of these compounds and their evolution until the end of the fermentation process were assessed in both fresh and fermented grains/pulp masses. ß-myrcene and ß-cis-ocimene, among terpenes, were detected in high amounts and are associated to a fine chocolate aroma. The sensory evaluation of chocolates manufactured from the fermented cocoa was performed by trained panelists, which defined 15 sensory descriptors. Chocolates from the TSH565 cultivar were characterized by a rich, fruity, intense cocoa flavor and bitterness, which are valuable sensorial and commercial attributes.

Analysis of the cocobiota and metabolites of Moniliophthora perniciosa-resistant Theobroma cacao beans during spontaneous fermentation in southern Brazil.

BACKGROUND: Cocoa bean fermentation is a spontaneous process involving a succession of microbial activities, yeasts, lactic acid, and acetic acid bacteria. The spontaneous fermentation of cocoa beans by Theobroma cacao TSH565 clonal variety, a highly productive hybrid resistant to Moniliophthora perniciosa and Phytophthora spp., was investigated. The natural cocobiota involved in the spontaneous fermentation of this hybrid in southern Brazil, was investigated by using both a culture-dependent microbiological analysis and a molecular analysis. The changes in the physicochemical characteristics and the kinetics of substrate utilization and metabolite production during fermentation were also evaluated. RESULTS: Yeasts (178) and bacteria (244) isolated during fermentation were identified by partial sequencing of the ITS and 16S rDNAs, respectively. After 144 h of fermentation, the indigenous yeast community was composed of Hanseniaspora spp., Saccharomyces spp., and Pichia spp. The bacterial population comprised Lactococcus spp., Staphylococcus spp., Acetobacter spp. and Lactobacilli strains. The kinetics of substrate transformation reflected the dynamic composition of the cocobiota. Substrates such as glucose, fructose, sucrose, and citric acid, present at the beginning of fermentation, were metabolized to produce ethanol, acetic acid, and lactic acid. CONCLUSION: The results described here provide new insights into microbial diversity in cocoa bean-pulp mass fermentation and the kinetics of metabolites synthesis, and pave the way for the selection of starter cultures to increase efficiency and consistency to obtain homogeneous and best quality cocoa products. © 2018 Society of Chemical Industry.

In vitro physiological and antibacterial characterization of ZnO nanoparticle composites in simulated porcine gastric and enteric fluids.

BACKGROUND: Diarrhea in piglets is one of the main causes of animal death after weaning; zinc oxide (ZnO) has been used in high doses for the control of this sickness. The aim of this study was to determine the physicochemical properties of ZnO nanoparticles synthesized and immobilized on a chitosan/alginate (CH/SA) complex and investigate the antimicrobial activity and in vitro release profile of zinc (Zn2+) from these new compounds. The ZnO nanoparticles composites were prepared and combined with CH/SA or CH/SA and sodium tripolyphosphate (TPP). The structure and morphology of the composites were analyzed by characterization methods such as X-ray diffraction, FTIR spectroscopy, thermogravimetric analysis, atomic absorption spectrophotometry and scanning electron microscopy. RESULTS: The crystallite size of ZnO nano was 17 nm and the novel ZnO composites were effective in protecting ZnO in simulated gastric fluid, where Zn2+ reached a concentration six-fold higher than the levels obtained with the unprotected commercial-zinc oxide. In addition, the novel composites suggest effective antimicrobial activity against Escherichia coli and Staphylococcus aureus. CONCLUSIONS: The results described herein suggest that the novel nano composites may work as an alternative product for pig feeding as verified by the in vitro assays, and may also contribute to lower the zinc released in the environment by fecal excretion in animals waste.

La suplementación de la L-arginina no afecta la producción de óxido nítrico ni la recuperación muscular / No effect of L-arginine supplementation on nitric oxide production and muscle recovery

Introducción: La L-arginina (L-Arg) es un aminoácido semiesencial y precursor de la síntesis de óxido nítrico (NO). Recientemente, los suplementos nutricionales que contiene L-Arg son comercializados con la pretensión de promover vasodilatación, debido al aumento de la producción de NO en músculo. El resultado de la vasodilatación elevaría la perfusión sanguínea, promoviendo un mayor aporte de nutrientes y oxigeno, los cuales pueden mejorar el rendimiento y la recuperación muscular. Propósito: Identificar el efecto agudo de la suplementación con L-Arg sobre la ratio de recuperación del trabajo (WRR), potencia media, trabajo total (TW3S) y los indicadores de producción de NO, nitrito y nitrato plasmático (NOx), durante el ejercicio de contra-resistencia. Métodos: Diecisiete hombres sanos y entrenados, participaron en un estudio, doble ciego, controlado con placebo. Se tomaron muestras de sangre antes y 90 min después de la ingesta de 6 g de LArg o placebo. El protocolo de ejercicio (3 series de 10 repeticiones máximas de extensión de codo isocinético concéntrico en 60º.s-1 con 2 min de descanso entre las series) se inició 80 minutos después de la suplementación. Mediciones de NOx se realizaron por el método de Griess usando un espectrofotómetro de absorción a 540 nm. Resultados: No se encontraron diferencias significativas entre el grupo suplementado con L-Arg vs placebo en lo referente parámetros de WRR, potencia media y TW3S (2630,4 ± 758,0vs 2573,1 ± 669,9 Joules). Además, no se observó diferenciasignificativa en el NOx plasmático, en ningún momento, entre el grupo suplementado con L-Arg vs placebo, antes de la suplementación (9,8 ± 2,3vs 9,5 ± 1,4 micro mol/L) o inmediatamente después del ejercicio (11,9 ± 5,5 vs 10,2 ±2,3 micro mol/L). Conclusión: Nuestros resultados indican que la ingesta aguda de L-Arg no aumenta la producción de NO, ni mejora el rendimiento recuperación muscular. En base a estos resultados, es precipitado recomendar suplementos nutricionales que contienen L-Arg como ayuda ergogénica para optimizar la recuperación muscular después del ejercicio de contra-resistencia en individuos sanos y entrenados (AU)

Introduction: L-arginine (L-Arg) is a semi-essential aminoacid precursor to nitric oxide (NO) synthesis. Recently, nutritional supplements containing L-Arg have been marketed with the purpose of promote vasodilation, due to an increased production of NO in the exercising muscle. The resulting vasodilation would elevate blood perfusion, leading to a higher nutrient and oxygen delivery, which may enhance exercise performance and muscular recovery. Purpose: Identify the acute effect of L-Arg supplementation on work recovery ratio (WRR), average power, total work (TW3S) and indicators of NO production, plasma nitrite and nitrate(NOx), during a resistance exercise protocol. Methods: Seventeen healthy and resistance-trained males participated in a randomized, double-blind, placebo-controlled study. Blood samples were collected before and 90 min (immediately post-exercise) after ingestion of oral 16g of L-Arg or placebo. The exercise protocol (3 sets of 10 maximal voluntary contractions of isokinetic concentric elbow extension at 60 o.s-1with 2-min of rest between sets) was initiated 80 min after supplementation. NOx measurements were made by a traditional Griess reaction colorimetric method using a spectrophotometer monitoring absorbance at 540 nm. Results: No significant difference between L-Arg versus placebo supplemented groups was observed on WRR, average power and TW3S (2630.4 ± 758.0 versus 2573.1 ± 669.9 Joules). Furthermore, no significant difference was observed in plasma NOx at any time point between L-Arg versus placebo supplemented groups at baseline (9.8 ± 2.3 vs. 9.5 ± 1.4 micre mol/L) and immediately post-exercise (11.9 ± 5.5 vs. 10.2 ±2.3 micremol/L). Conclusion: Our data indicates that acute ingestion of L-Arg does not increase NO production nor enhances muscle performance and recovery. Based on this fact, it is still premature to recommend nutritional supplements containing L-Arg as an ergogenic aid to optimize muscle recovery after resistance exercise bouts in healthy and resistance-trained subjects (AU)