Daniel Perrone

Fast simultaneous analysis of caffeine, trigonelline, nicotinic acid and sucrose in coffee by liquid chromatography–mass spectrometry

A rapid liquid chromatography-mass spectrometry method for the simultaneous quantification of caffeine, trigonelline, nicotinic acid and sucrose in coffee was developed and validated. The method involved extraction with hot water, clarification with basic lead acetate and membrane filtration, followed by chromatographic separation using a Spherisorb(®) S5 ODS2, 5μm chromatographic column and gradient elution with 0.3% aqueous formic acid/methanol at a flow rate of 0.2mL/min. The electrospray ionization source was operated in the negative mode to generate sucrose ions and in the positive mode to generate caffeine, trigonelline and nicotinic acid ions. Ionization suppression of all analytes was found due to matrix effect. Calibrations curves prepared in green and roasted coffee extracts were linear with r(2)>0.999. Roasted coffee was spiked and recoveries ranged from 93.0% to 105.1% for caffeine, from 85.2% to 116.2% for trigonelline, from 89.6% to 113.5% for nicotinic acid and from 94.1% to 109.7% for sucrose. Good repeatibilities (RSD<5%) were found for all analytes in the matrix. The limit of detection (LOD), calculated on the basis of signal-to-noise ratios of 3:1, was 11.9, 36.4, 18.5 and 5.0ng/mL for caffeine, trigonelline, nicotinic acid and sucrose, respectively. Analysis of 11 coffee samples (regular or decaffeinated green, ground roasted and instant) gave results in agreement with the literature. The method showed to be suitable for different types of coffee available in the market thus appearing as a fast and reliable alternative method to be used for routine coffee analysis.

Modeling Weight Loss and Chlorogenic Acids Content in Coffee during Roasting

Roasting is a key step in the production of a high-quality coffee. Roasting degree is directly related to coffee chemical composition and may be determined objectively by weight loss after roasting. Chlorogenic acids (CGA) are thermally labile phenolic compounds that play an important role in the final cup quality and health benefits of coffee. Considering the interest in finding a reliable method to predict weight loss and CGA content in coffee, models have been developed to estimate these parameters during roasting. Weight loss was successfully modeled (r = 0.99) independent of the instant temperature. CGA degradation followed first-order Arrhenius-compliant kinetic models with good predictability (r = 0.98), especially for light to moderately dark samples. In both cases distinct models for Coffea arabica and Coffea canephora were calculated, because of differences in chemical composition and cell wall structure between these species. The proposed models may become important predictive tools in the coffee industry.

Effect of drying method on volatile compounds, phenolic profile and antioxidant capacity of guava powders.

We studied the chemical composition of oven and freeze dried guava powders for future use as antioxidant-rich flavour enhancers. Among thirty-one volatiles in guava powders, terpenes were predominant, even after both drying processes. In contrast, esters and aldehydes, volatiles characteristic of fresh guava fruit, appeared to have been decreased by drying. Insoluble phenolics were predominant and among the sixteen compounds identified, quercetin-3-O-rutinoside and naringenin corresponded to 56% of total phenolics. Drying processes decreased total phenolics contents by up to 44%. Oven drying promoted the release of insoluble flavonoids, generating mainly quercetin. Antioxidant capacity also decreased due to both drying processes, but guava powders still presented similar antioxidant capacity in comparison to other tropical fruit powders. Our results suggest that oven drying is a viable option for the production of a functional ingredient that would improve the phenolic content of cereal foods while adding desirable guava flavour.

The increase in human plasma antioxidant capacity after acute coffee intake is not associated with endogenous non-enzymatic antioxidant components

This study evaluated the association between the main plasma endogenous non-enzymatic antioxidant components and the increase in human antioxidant capacity (AC) after acute coffee intake. Ten adults were tested before and 90 min after consumption of coffee or water, in a crossover design, with a 7-day interval between tests. AC (FRAP and TRAP), ascorbic acid, α-tocopherol and γ-tocopherol, albumin, bilirubin and uric acid were analyzed in plasma/serum. After coffee consumption FRAP and TRAP increased 2.6% and 7.6% (P<0.05), whereas after water consumption FRAP and TRAP decreased 2.5% and 1.0% (P <0.05), respectively. In general, AC assays correlated with uric acid and α-tocopherol (r >0.75; P <0.04), independently of treatment and time point. Changes in AC assays after coffee intake did not correlate with endogenous components, which remained unchanged. These results suggest that coffee components spare endogenous antioxidants or are themselves the main contributors to plasma AC increase after coffee intake.

Starch, inulin and maltodextrin as encapsulating agents affect the quality and stability of jussara pulp microparticles.

The influence of encapsulating carbohydrates (EC) with varying properties on the technological and functional properties of jussara pulp microparticles produced by spray drying were evaluated using experimental design. Microparticles produced with sodium octenyl succinate (OSA) starch at 0.5 core to EC ratio and with mixtures of inulin and maltodextrin at 1.0 and 2.0 core to EC ratio showed darker color, and higher anthocyanins contents and antioxidant activity. Seven microparticles showing high water solubility and desirable surface morphology. Hygroscopicity (10.7% and 11.5%) and wettability (41s and 43s) were improved when OSA starch and mixtures of inulin and maltodextrin were used. The anthocyanins contents and color of the microparticles did not change when exposed to light at 50°C for 38days. Finally, microparticles produced at 1.0 core to EC ratio with 2/3 OSA starch, 1/6 inulin and 1/6 maltodextrin were selected. These microparticles may be applied as colorant in numerous foods, whilst adding prebiotic fiber and anthocyanins.

Isoflavones and soyasaponins in soy infant formulas in Brazil: Profile and estimated consumption

In the present study we determine the contents of isoflavones and soyasaponins in seven soy-based infant formulas available in the Brazilian market to estimate the intake of these bioactive compounds by infants. The mean contents of isoflavones and soyasaponins were 65.9mg/kg and 55.0mg/100g, respectively. β-Glycosylated isoflavones and soyasaponin B-I were the most abundant components in the analysed samples. The mean estimated intake of isoflavones by infants fed soy-based formulas was 0.8mg/day/kg of body weight, which is twice that of Japanese adults. For soyasaponins, the mean estimated intake was 9.2mg/day/kg of body weight, which is up to 6 times higher than the daily intake of saponins from beans by vegetarians. Considering the estimated intake of these bioactive compounds from soy-based formulas and the paucity of data regarding their bioavailability, the potential biological effects of isoflavones and soyasaponins in infants should not be overlooked and merits further investigation.

Phenolic compounds of Brazilian beers from different types and styles and application of chemometrics for modeling antioxidant capacity.

In the present study we aimed at investigating, for the first time, phenolic compounds in Brazilian beers of different types and styles. We also aimed at applying chemometrics for modeling beers antioxidant capacity as a function of their physicochemical attributes (density, refractive index, bitterness and ethanol content). Samples (n=29) were analyzed by PCA originating five groups, especially according to ethanol contents and bitterness. In general, Group V (alcoholic beers with very high bitterness) presented higher refractive index, bitterness, ethanol and phenolics contents than Groups I (non-alcoholic beers) and II (alcoholic beers with low bitterness). Brazilian beers phenolics profile was distinct from that of European beers, with high contents of gallic acid (0.5-14.7 mg/L) and low contents of ferulic acid (0.2-1.8 mg/L). Using PLS, beers antioxidant capacity measured by FRAP assay could be predicted with acceptable precision by data of ethanol content and density, bitterness and refractive index values.

Breads enriched with guava flour as a tool for studying the incorporation of phenolic compounds in bread melanoidins.

In the present study we aimed at studying, for the first time, the incorporation of phenolic compounds into bread melanoidins. Fermentation significantly affected the phenolics profile of bread doughs. Melanoidins contents continuously increased from 24.1 mg/g to 71.9 mg/g during baking, but their molecular weight decreased at the beginning of the process and increased thereafter. Enrichment of white wheat bread with guava flour increased the incorporation of phenolic compounds up to 2.4-fold. Most phenolic compounds showed higher incorporation than release rates during baking, leading to increases from 3.3- to 13.3-fold in total melanoidin-bound phenolics. Incorporation patterns suggested that phenolic hydroxyls, but not glycosidic bonds of melanoidin-bound phenolics are cleaved during thermal processing. Antioxidant capacity of bread melanoidins increased due to enrichment with guava flour and increasing baking periods and was partially attributed to bound phenolics. Moreover, FRAP assay was more sensitive to measure this parameter than TEAC assay.

Zinc supplementation, production and quality of coffee beans

Apesar da importância do zinco na nutricao do cafeeiro, quase nao ha informacoes que relacionem o suprimento de zinco e a qualidade dos graos. Este trabalho avaliou o efeito de zinco sobre a producao e a qualidade dos graos de cafe. O experimento foi conduzido com Coffea arabica L. na Zona da Mata de Minas Gerais, Brasil. O delineamento utilizado foi inteiramente ao acaso, com dois tratamentos: suplementacao com zinco (oito parcelas) e controle, sem zinco (quatro parcelas). Cada parcela util constou de quatro plantas competitivas. Foram avaliados a produtividade, numero de graos defeituosos, graos atacados por brocas, tamanho de graos, qualidade da bebida, teor de zinco nos graos, potassio lixiviado, condutividade eletrica, indice de coloracao, acidez total titulavel, pH, teores de acidos clorogenicos e atividade antioxidante dos graos de cafe. O zinco afetou positivamente a qualidade dos graos de cafe, que apresentou menor percentagem de graos de tamanhos medio e pequeno, menor incidencia de broca, menor lixiviacao de potassio e condutividade eletrica, maiores teores de zinco e acidos clorogenicos e maior atividade antioxidante, em comparacao com os graos do controle.

Physicochemical, nutritional, and sensory analyses of a nitrate-enriched beetroot gel and its effects on plasmatic nitric oxide and blood pressure

Background Beetroot (Beta vulgaris L.) is a dietary source of natural antioxidants and inorganic nitrate (NO3-). It is well known that the content of antioxidant compounds and inorganic nitrate in beetroot can reduce blood pressure (BP) and the risk of adverse cardiovascular effects. Objective The aim of the present study was to formulate a beetroot gel to supplement dietary nitrate and antioxidant compounds able to cause beneficial health effects following acute administration. Design and subjects A beetroot juice produced from Beta vulgaris L., without any chemical additives, was used. The juice was evaluated by physicochemical and microbiological parameters. The sample was tested in five healthy subjects (four males and one female), ingesting 100 g of beetroot gel. Results The formulated gel was nitrate enriched and contained carbohydrates, fibers, saponins, and phenolic compounds. The formulated gels possess high total antioxidant activity and showed adequate rheological properties, such as high viscosity and pleasant texture. The consumer acceptance test for flavor, texture, and overall acceptability of beetroot gel flavorized with synthetic orange flavor had a sensory quality score >6.6. The effects of acute inorganic nitrate supplementation on nitric oxide production and BP of five healthy subjects were evaluated. The consumption of beetroot gel increased plasma nitrite threefold after 60 min of ingestion and decreased systolic BP (−6.2 mm Hg), diastolic BP (−5.2 mm Hg), and heart rate (−7 bpm).