The influence of ripening stage and cultivation system on the total antioxidant activity and total phenolic compounds of yellow passion fruit pulp

BACKGROUND: This work aimed to investigate the influence of both ripening stage and cultivation system on the total phenolic compounds (TPC) and total antioxidant activity (TAA) of passion fruit pulp. TPC extraction was optimized using a 2³ central composed design. The variables were fruit pulp volume, methanol volume and extraction solution volume. TPC was determined using the Folin–Ciocalteu reaction, and TAA using the ABTS radical reaction. RESULTS: The conditions to extract TPC were 2 mL passion fruit pulp and 9 mL extraction solution containing 40% methanol:water (v/v). TPC values increased in the passion fruit pulp during ripening for both cultivation systems, ranging from 281.8 to 361.9 mg gallic acid L^?1 (P?0.05) for the organic pulp and from 291.0 to 338.6 mg gallic acid L^?1 (P?0.05) for the conventional pulp. CONCLUSION: TPC values increased during ripening for both organic and conventional passion fruit. The same was true for TAA values for conventional passion fruit. For organic passion fruit, however, TAA values were highest at the initial ripening stages. These results suggest that antioxidant compounds exert strong influence on the initial ripening stages for organic passion fruit, when TPC still did not reach its maximum level. Copyright © 2012 Society of Chemical Industry     

Assessment of chemical mixtures and groundwater effects on Daphnia magna transcriptomics

Small organisms can be used as biomonitoring tools to assess chemicals in the environment. Chemical stressors are especially hard to assess and monitor when present as complex mixtures. Here, fifteen polymerase chain reaction assays targeting Daphnia magna genes were calibrated to responses elicited in D. magna exposed for 24 h to five different doses each of the munitions constituents 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, 2,6-dinitrotoluene, trinitrobenzene, dinitrobenzene, or 1,3,5-trinitro-1,3,5-triazacyclohexane. A piecewise-linear model for log-fold expression changes in gene assays was used to predict response to munitions mixtures and contaminated groundwater under the assumption that chemical effects were additive. The correlations of model predictions with actual expression changes ranged from 0.12 to 0.78 with an average of 0.5. To better understand possible mixture effects, gene expression changes from all treatments were compared using high-density microarrays. Whereas mixtures and groundwater exposures had genes and gene functions in common with single chemical exposures, unique functions were also affected, which was consistent with the nonadditivity of chemical effects in these mixtures. These results suggest that, while gene behavior in response to chemical exposure can be partially predicted based on chemical exposure, estimation of the composition of mixtures from chemical responses is difficult without further understanding of gene behavior in mixtures. Future work will need to examine additive and nonadditive mixture effects using a much greater range of different chemical classes in order to clarify the behavior and predictability of complex mixtures.     

Poly(lactic acid) biocomposites with mango waste and organo-montmorillonite for packaging

Poly(lactic acid) (PLA) is a biodegradable polymer used in packaging, but its properties can be improved by manufacturing composite matrixes. The combination of PLA, starch, and nano-montmorillonite leads to materials with superior mechanical properties. Mango lump is rich in cellulose and starch. The goal of this study is to develop and characterize biocomposites based on PLA, mango waste, and nano-organo-montmorillonite for packaging. The samples were microstructurally, morphologically, and mechanically characterized. Physical interaction between the phases was observed. The mango components displaced the PLA X-ray diffraction peaks and the clays altered their intensity, by interfering with chain packing. The addition of single components to PLA increased the samples’ transition temperatures, but the addition of multiple components diminished them. PLA showed adhesiveness to cellulose fibers and nonadhesiveness to starch granules. Thicker samples presented better mechanical properties. PLA–mango–“chocolate clay” samples are relatively stable materials, while PLA–mango–“bofe clay” samples could represent promising highly biodegradable materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47512.     

Effect of vitamin A supplementation on iron status in humans: A systematic review and meta-analysis

Anemia is a worldwide public health problem that can be related to many causes, including vitamin A deficiency. The aim of this study was to assess and estimate the effect of vitamin A supplementation (VAS) on iron status biomarkers and anemia in humans. Six databases, including Cochrane, EMBASE, LILACS, Pubmed, Scopus and Web of Science, were searched for clinical trials and cohort studies that investigated the effect of vitamin A supplementation alone on iron status and anemia, without time-restriction. The search yielded 23 eligible studies, 21 clinical trials and 2 cohort studies, with children, teenagers, pregnant or lactating women. The meta-analysis of the clinical trials showed that VAS reduces the risk of anemia by 26% and raises hemoglobin levels, compared to non-treated group, independent of the life stage. VAS did not alter the prevalence of iron deficiency among the clinical trials conducted with children and teenagers (RR 0.82, 95% CI 0.60 to 1.12, p = 0.204), whereas a significant increase in serum ferritin levels was observed in trials conducted with pregnant and lactating women (WMD 6.61 μg/L; 95% CI 6.00 to 7.21 μg/L; p < 0.001). Therefore, vitamin A supplementation alone may reduce the risk of anemia, by improving hemoglobin and ferritin levels in individuals with low serum retinol levels.     

The role of salt abuse on risk for hypercalciuria

Background  

Elevated sodium excretion in urine resulting from excessive sodium intake can lead to hypercalciuria and contribute to the formation of urinary stones. The aim of this study was to evaluate salt intake in patients with urinary lithiasis and idiopathic hypercalciuria (IH).     

Calcium/chitosan spheres as catalyst for biodiesel production

Chitosan, an abundant biopolymer extracted from crustacean shells, can be used as a structuring agent by the insertion of calcium oxide and used as a catalyst in transesterification reactions. These calcium‐incorporated chitosan spheres were calcined in order to obtain a porous calcium catalyst without organic material. The materials were characterized using X‐ray diffraction, thermogravimetric analysis, Fourier transform infrared and X‐ray photoelectron spectroscopies, temperature‐programmed desorption of CO₂, scanning electron microscopy and specific surface area analysis. Afterwards the calcined calcium/chitosan spheres were used in the transesterification reaction of sunflower oil with methanol. The conversion of sunflower oil to methyl esters (Y_FAME), under optimized reaction conditions, which were determined by factorial experimental design (X_MR, 1:9; X_CAT, 3 wt%; time, 4 h; temperature, 60 °C; magnetic stirring, 1000 rpm), was 56.12 ± 0.32 wt%. These results show that chitosan can be used as a precursor for the formation of calcium/chitosan spheres, yielding a porous calcium oxide (with higher surface area) that can be used as an alkaline catalyst for biodiesel production. © 2014 Society of Chemical Industry     

Aging-induced structural relaxation in cornstarch plasticized with urea and glycerol

In present work structural properties and aging of thermoplastic starches prepared by plasticization of cornstarch with urea, glycerol and their mixtures are studied using solid-state ¹H NMR and ¹³C NMR spectroscopy and WAXS measurements. Broad line ¹H NMR spectra reveal phase separation of plasticizers during aging of the samples with the same or higher relative amount of glycerol than the amount of urea. Glycerol in the TPS samples induces motion of starch chain segments, the mobility of which depends on the relative amount of glycerol. At the scale of nm, formation of B-type crystallites in the samples containing glycerol and also of single-helical crystallinity in all samples is observed during one-year aging through cross-polarization magic angle spinning ¹³C NMR spectra. Urea, when used as the sole plasticizer, prevents the ordering of starch chains in B-type crystallites. WAXS diffractograms show that regular crystals do not form in any of the samples.