Microbiota of cocoa powder with particular reference to aerobic thermoresistant spore-formers

The microbiological criteria of commercial cocoa powder are defined in guidelines instituted by the cocoa industry. Twenty-five commercial samples were collected with the aim of assessing the compliance with the microbiological quality guidelines and investigating the occurrence and properties of aerobic Thermoresistant Spores (ThrS). Seventeen samples complied with the guidelines, but one was positive for Salmonella, five for Enterobacteriaceae and two had mould levels just exceeding the maximum admissible level. The treatment of the cocoa powder suspensions from 100 °C to 170 °C for 10 min, revealed the presence of ThrS in 36% of the samples. In total 61 ThrS strains were isolated, of which the majority belonged to the Bacillus subtilis complex (65.6%).Strains resporulation and spore crops inactivation at 110 °C for 5 min showed a wide diversity of heat-resistance capacities. Amplified fragment length polymorphism analysis revealed not only a large intraspecies diversity, but also different clusters of heat-resistant spore-forming strains. The heat-resistance of spores of six B. subtilis complex strains was further examined by determination of their D and z-values.We concluded that B. subtilis complex spores, in particular those from strain M112, were the most heat-resistant and these may survive subsequent preservation treatments, being potentially problematic in food products, such as chocolate milk.     

Curcumin induces heme oxygenase-1 in normal human skin fibroblasts through redox signaling: relevance for anti-aging intervention

Scope: Curcumin, a component of the spice turmeric, was tested for its potential hormetic anti‐aging effects as an inducer of mild stress. Methods and results: Early passage young human skin fibroblasts treated with low doses of curcumin (below 20 μM) showed a time‐ and concentration‐dependent induction of heme oxygenase‐1 (HO‐1), followed by compensatory increase in glutathione‐S‐transferase activity, GSH levels and GSH/GSSG ratio. These effects were preceded by induction of oxidative stress (increased levels of reactive oxygen species and DNA damage) and impairment of cells' GSH redox state. Curcumin also induced nuclear factor‐erythroid‐2‐related factor 2 accumulation in the nuclei. The use of the antioxidant N‐acetyl cysteine prevented the induction of HO‐1 by curcumin. Pharmacological inhibition of phosphatidylinositol 3‐kinase, but not other kinases, significantly prevented curcumin‐induced HO‐1 levels, which was corroborated by the induction of phospho‐Akt levels by curcumin. Late passage senescent cells already had higher HO‐1 levels, and further induction of HO‐1 by curcumin was considerably impaired. The induction of stress responses by curcumin in human cells led to protective hormetic effects to further oxidant challenge. Conclusion: Curcumin induces cellular stress responses in normal human skin fibroblasts through phosphatidylinositol 3‐kinase/Akt pathway and redox signaling, supporting the view that curcumin‐induced hormetic stimulation of cellular antioxidant defenses can be a useful approach toward anti‐aging intervention.     

Effects of spontaneous and inoculated fermentation on the volatile profile of lychee (Litchi chinensis Sonn) fermented beverages

The aim of this study was to evaluate the contribution of yeast to the volatile profile of beverages obtained by the fermentation of lychee must through inoculated (Saccharomyces cerevisiae strains UFLA CA116 , UFLA CA1183 and UFLA CA1174 ) and spontaneous fermentation. Higher alcohols and esters were the primary volatiles detected by SPME/GC–MS. A Principal Component Analysis indicated similarities between UFLA CA116 and UFLA CA1183 and between UFLA CA1174 and spontaneous fermentation. Changing the yeast strain used in the fermentation process has the potential to modulate the volatile profile of fermented beverages. The beverage produced by the inoculation of yeast CA1183 showed the most complex aroma profile compared to the other beverages.     

Effect of beta-lactoglobulin polymorphism and seasonality on bovine milk composition

The objective was to evaluate the effect of beta-lactoglobulin (beta-lg) polymorphism and seasonality on milk composition (fat, lactose, total solids, milk urea nitrogen, total protein, true protein, casein and somatic cell counts) of Holstein and Girolando cows. Milk and blood samples from 278 Holsteins cows and 156 Girolando cows were taken during two dry seasons and two rainy seasons, for milk composition analysis and to determine beta-lg genotypes, respectively. BB genotype was the most frequent for both breeds, followed by AA genotype for Holstein (BB>AA>AB) and by AB for Girolando cows (BB>AB>AA). No differences were found in milk compositional characteristics among genetic variants of beta-lg (AA, AB and BB) either between Holstein or Girolando cows. No association between milk composition and beta-lg genetic polymorphism was observed. During the dry season, independently of the breed considered, higher contents of lactose, true protein, casein and casein:true protein ratio were found.     

Effect of time of artificial insemination and supplemental estradiol on reproduction of lactating dairy cows

Our objectives were to compare reproductive responses of dairy cows receiving timed artificial insemination (AI) either at 48 or 72 h after induction of luteolysis and supplemented or not with estradiol cypionate (ECP). Holstein cows (971) had their estrous cycles presynchronized with injections of PGF_2α at 37 and 51 d in milk (DIM) and then received an injection of GnRH at 64 DIM and an injection of PGF_2α at 71 DIM. Cows were then assigned to a 2 × 2 factorial randomized block experiment; cows in the CoSynch 48 h (CoS48) received a final injection of GnRH concurrent with timed AI 48 h after PGF_2α, whereas cows in the CoSynch 72 h (CoS72) received GnRH and timed AI 72 h after PGF_2α. Half of the cows in each CoSynch protocol received an injection of 1 mg of ECP 24 h after PGF_2α. Therefore, the 4 treatments were as follows: CoS48-NECP (n = 240), CoS72-NECP (n = 246), CoS48-ECP (n = 245), and CoS72-ECP (n = 240). Blood was sampled at 7 d before and at the first GnRH of the CoSynch from all cows for analysis of progesterone concentration in plasma. Cows were classified as anovular when progesterone was less than 1.0 ng/mL in both samples. Blood was also sampled during proestrus from a subset of 123 cows to measure concentrations of estradiol and at 7 d after timed AI to measure concentrations of progesterone. Ovaries from the same subset of 123 cows were examined by ultrasonography to determine ovulatory follicle diameter and incidence of ovulation. Pregnancy was diagnosed at 40 and 68 d after AI. Prevalence of cyclic cows was 72.4% and was similar among treatments. Concentrations of estradiol increased after ECP treatment and at 72 h of proestrus with CoS72. Pregnancy at 40 and 68 d after AI and pregnancy loss were not affected by timing of AI or supplemental ECP. Delaying timed AI to 72 h and supplementation with ECP increased the proportion of cows displaying estrus at AI, and cows detected in estrus had increased pregnancy per AI associated with improved ovulation and increased postovulatory progesterone concentration. These results indicate that extending the proestrus by delaying timed AI from 48 to 72 h plus supplemental ECP, despite increased expression of estrus at timed AI, did not improve reproductive performance of lactating dairy cows at first AI.     

Phytochemistry Profile,Nutritional Properties and Pharmacological Activities of Mauritia flexuosa

Mauritia flexuosa L. (Arecaceae) is a popular Brazilian fruit known as “buriti” and belonging to the category of functional foods. This work reviewed the phytochemistry profile, nutritional and pharmacological activities of M. flexuosa. The main bioactive compounds reported to buriti were carotenoids, tocopherols, ascorbic acid, phenolic compounds, fiber, phytosterols, and mono‐ and poly‐unsaturated fatty acids. These compounds were mainly related to antioxidant, hypolipemiant, photoprotector, antiaggregant, antithrombotic, anti‐inflammatory, hypoglycemiant, antimicrobial, and antitumor activities. Furthermore, some compounds present in buriti fruit and its properties were tested in vitro and in vivo and showed biotechnology applications, especially for extraction of fiber, polysaccharides, pigments, antioxidants, and oil. Howerer, the buriti fruit shows great relevance to the development of new products in food, pharmaceutical and chemical industry, this fruit is still underexploited and it has need to expand its production chain and processing to encourage their consumption and utilization.     

Administration of low-dose LH induces ovulation and prevents vascular hyperpermeability and vascular endothelial growth factor expression in superovulated rats

The administration, to rats, of a combination of pregnant mares serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) in high doses induces the ovarian hyperstimulation syndrome (OHSS) which is characterized by increased vascular permeability (VP) and simultaneous overexpression of vascular endothelial growth factor (VEGF) in ovarian cells. hCG has a longer half-life than LH and a greater biological activity, expressed in a higher incidence of complications such as OHSS. Similarly, FSH may also be related to the ovulatory changes within the follicle as there is a simultaneous surge in spontaneous cycles. The aim of this study was to compare the capacity of hCG, FSH and LH to induce ovulation and simultaneously prevent OHSS in the animal model. Immature female rats were treated with 10 IU PMSG for 4 days, and ovulation was triggered with saline, 10 IU hCG, 10 IU FSH, 10 IU LH or 60 IU LH. The number of oocytes ovulated into the tubes, VP and mRNA VEGF expression were evaluated and compared. All the hormones employed were as effective at triggering ovulation, with similar significant P values when compared with the control for which saline was used. The use of 10 IU LH resulted in significantly lower VP and VEGF expression than that seen in the groups treated with 10 IU hCG, 10 IU FSH or 60 IU LH. In conclusion, FSH and hCG, as well as a sixfold increase in LH, displayed similar biological activities, including increased VP due to excessive VEGF expression. The use of lower doses of LH produced similar rates of ovulation, while preventing the undesired changes in permeability. These experiments should therefore encourage clinicians to determine the optimal dose of LH to be employed in women in order to trigger ovulation and, at the same time, avoid the risk of OHSS.     

Methylmercury Causes Neurodegeneration and Downregulation of Myelin Basic Protein in the Spinal Cord of Offspring Rats after Maternal Exposure

Methylmercury (MeHg) is one of the most dangerous toxic pollutants spread throughout the earth. Chronic MeHg intoxication by contaminated food ingestion is the most common threat to human health, including impairment to the developing fetus. The present study aims at investigating the effects of maternal exposure to MeHg during gestation and lactation on the spinal cord of offspring. Pregnant rats received oral doses of MeHg (40 μg/kg/day) over a period of 42 days (21 gestation and 21 lactation). Control animals received the vehicle only. Total mercury concentration was measured in blood samples from offspring collected at the 41st postnatal day. Counting of motor neurons and immunoreactivity for myelin basic protein (MBP) were assessed in the spinal cords in both control and MeHg-intoxicated animals. Our results showed that MeHg promoted an increase in blood Hg levels. In addition, it caused a reduction in the number of spinal cord motor neurons as well as decreased MBP immunoreactivity in the cervical, thoracic and lumbar segments. Our present findings suggest that MeHg intoxication during rat pregnancy and lactation is associated with a pattern of motor neuron degeneration and downregulation of myelin basic protein in different segments of a developing spinal cord. Further studies are needed to establish the effect of MeHg intoxication in both young and adult rats.     

The Role of Cytoskeleton Revealed by Quartz Crystal Microbalance and Digital Holographic Microscopy

The connection between cytoskeleton alterations and diseases is well known and has stimulated research on cell mechanics, aiming to develop reliable biomarkers. In this study, we present results on rheological, adhesion, and morphological properties of primary rat cardiac fibroblasts, the cytoskeleton of which was altered by treatment with cytochalasin D (Cyt-D) and nocodazole (Noc), respectively. We used two complementary techniques: quartz crystal microbalance (QCM) and digital holographic microscopy (DHM). Qualitative data on cell viscoelasticity and adhesion changes at the cell–substrate near-interface layer were obtained with QCM, while DHM allowed the measurement of morphological changes due to the cytoskeletal alterations. A rapid effect of Cyt-D was observed, leading to a reduction in cell viscosity, loss of adhesion, and cell rounding, often followed by detachment from the surface. Noc treatment, instead, induced slower but continuous variations in the rheological behavior for four hours of treatment. The higher vibrational energy dissipation reflected the cell’s ability to maintain a stable attachment to the substrate, while a cytoskeletal rearrangement occurs. In fact, along with the complete disaggregation of microtubules at prolonged drug exposure, a compensatory effect of actin polymerization emerged, with increased stress fiber formation.