Antioxidant properties of polyphenol-rich cocoa products industrially processed

Fermentation and roasting are the main causes of polyphenol degradation during the process for obtaining cocoa products. In the present study, a process for obtaining polyphenol-rich cocoa products on an industrial scale is described. The process avoids the fermentation and roasting steps and includes a step for the inactivation of the enzyme Polyphenol Oxidase (PPO), which helps preserve the polyphenol content present in the raw cocoa bean. In addition, our study evaluates the antioxidant capacity and characterizes the flavonoid profile of the polyphenol-rich cocoa products obtained from the natural polyphenol-rich cocoa cake. Using different protocols, we have obtained three cocoa extracts with high polyphenol content, namely extracts A (167 mg/g), B (374 mg/g) and C (787 mg/g). The scavenging capacity of the extracts was measured as their ability to bleach the stable radicals DPPH and ABTS⁺ while their antioxidant effect was evaluated with the FRAP assay. The results for A, B and C in the DPPH test expressed as Trolox equivalent (μmol)/mg dry weight of extract were 0.2, 1.4 and 3.0, respectively; in the ABTS test the results were 1.0, 4.7 and 9.8. The antioxidant capacity expressed as ascorbic acid equivalent (μmol)/mg dry weight of each product were 17.2, 76.1 and 207.7, respectively. The scavenging properties of cocoa powder against the superoxide anion, H₂O₂, HClO, and peroxynitrite were also determined. The IC₅₀ (μg/mL) values in the hypoxanthine/xanthine oxidase test were 77.5, 12.3 and 10.3, for A, B and C, respectively, while as an HOCl scavenger the IC₅₀ (μg/mL) values were 225.4, 73.2 and 21.5. As a peroxynitrite anion scavenger, only extract C had a relevant effect, with IC₅₀ (μg/mL) values of 76.1 or 110.0 in the absence or presence of bicarbonate. None of the extracts tested showed activity in the hydrogen peroxide test, but B and C significantly increased the deoxyribose degradation in the absence of ascorbate. Likewise, none of the extracts inhibited the ferrous or copper chelating activity at 100 μg/mL, but they inhibited the lipid peroxidation in brain homogenates and human plasma through non-enzymatic generation systems, with extract C giving the best IC₅₀ (μg/mL) values: 17.4 and 8.1 against lipid peroxidation in brain homogenates and human plasma, respectively. In conclusion, if the extractive protocol is well characterized, defined and optimized, cocoa could constitute a source of polyphenols for enriching foods, nutraceuticals and alimentary supplements.     

Robust command governors for constrained linear systems

Robust command governors are designed for discrete-time linear time-variant (LTV) systems with polytopic uncertainty models and subject to unknown bounded disturbances and pointwise-in-time input and state-related constraints.     

Selenoproteome Expression Studied by Non-Radioactive Isotopic Selenium-Labeling in Human Cell Lines

Selenoproteins, in which the selenium atom is present in the rare amino acid selenocysteine, are vital components of cell homeostasis, antioxidant defense, and cell signaling in mammals. The expression of the selenoproteome, composed of 25 selenoprotein genes, is strongly controlled by the selenium status of the body, which is a corollary of selenium availability in the food diet. Here, we present an alternative strategy for the use of the radioactive ⁷⁵Se isotope in order to characterize the selenoproteome regulation based on (i) the selective labeling of the cellular selenocompounds with non-radioactive selenium isotopes (⁷⁶Se, ⁷⁷Se) and (ii) the detection of the isotopic enrichment of the selenoproteins using size-exclusion chromatography followed by inductively coupled plasma mass spectrometry detection. The reliability of our strategy is further confirmed by western blots with distinct selenoprotein-specific antibodies. Using our strategy, we characterized the hierarchy of the selenoproteome regulation in dose–response and kinetic experiments.     

Natural antioxidants and volatile compounds of virgin olive oils obtained by two or three‐phases centrifugal decanters

Research has been carried out to ascertain the influence of different centrifugal decanters employed in olive process on oil yields and qualitative characteristics and composition of volatile compounds of virgin olive oil. Tests were performed in an olive oil mill equipped with centrifugal decanters at two or three‐phases. Results show that oil yields were similar and oils extracted from good‐quality olives do not differ in free fatty acids, peroxide value, UV absorptions and organoleptic assessment. Total phenols and o‐diphenols content as well as induction time values are higher in oils obtained by the centrifugal decanter at two‐phases, because it requires less quantity of water added to olive paste in comparison to the three‐phases centrifugal decanter. The amount of water added determines the dilution of the aqueous phase and lowers the concentration of the phenolic substances more soluble in vegetable waste water. Due to the partition equilibrium law the concentration of the same substances consequently diminishes in the oil. In this research, the coefficient of the partition equilibrium of total phenols between oil and vegetable water has been calculated and discussed. No significant difference occurred, due to the different decanters employed, in the average values of the volatile components of the head‐space of oils.     

Self-expanding stents for the palliation of esophageal and gastric cardia cancer

Twenty-one endoscopic tube implantations were carried out in 24 patients with malignant stenosis of esophagus and gastric cardia using self-expanding metallic stents. The indications to endoscopic intubation were advanced stage of the tumor in 17 cases and risk factors which made resection inadvisable in 7 cases. In 3 patients it proved impossible to implant a stent endoscopically because the Authors were not able to pass the guide wire through the stenosis, while correct stent placement was achieved in 21 patients. Functional results were good in 18 patients, while 3 patients did not have any improvement of symptoms. Complications occurred in 9 patients (42.85%): 2 bleedings, 3 neoplastic obstructions, 1 food obstruction and 3 distal dislodgements of the prostheses were observed, but could readily be corrected. No death occurred. The median survival time was 151 days (range 25-545). This study suggests that endoscopic placement of metallic self-expanding stents is safe and has to be preferred to plastic stents for easier implantation and lower morbidity.     

Development of a clinical chart to compute different disease activity indices for systemic lupus erythematosus

Between 1990 and 1995 a European Consensus Group carried out a multicenter study to reach agreement of the definition of disease activity in systemic lupus erythematosus (SLE). A new index, the European Consensus Lupus Activity Measurement (ECLAM) index, was developed. In a second phase of the study, a prospective survey aimed at validating ECLAM and 4 other scales as steady-state and transition indices for disease activity in SLE was completed. We present the results of this survey. A standardized clinical chart was developed, together with a computer program that could automatically calculate the ECLAM score, as well as the scores for some of the disease activity scales most widely used at present, i.e., the British Isles Lupus Assessment Group, Systemic Lupus Activity Measure, SLE Disease Activity Index, and the SLE Index Score (SIS). With the participation of 28 centers in 15 different European countries, data from 121 prospectively selected new lupus patients were collected. The validity of the 5 activity scales was assessed by comparing the computed scores for each patient to a gold standard, i.e., the physician's subjective judgment on disease activity measured using a semiquantitative scale. All the indices were found to be valid instruments for measuring disease activity in SLE in both the steady-state and transition phases. The results for the various indices closely correlated with one another. Thus, the computerized chart developed by the European Consensus Group offers a simple and reliable instrument to assess disease activity and could be used to monitor lupus patients both in clinical practice and in clinical trials.     

Effect of calcaneal lengthening on relationships among the hindfoot, midfoot, and forefoot

To better understand the bony component of pes planus and the means by which the Evans calcaneal lengthening corrects them, we studied the standing radiographs of seven adult patients who had undergone calcaneal lengthening to treat symptomatic pes planus. Weightbearing AP and lateral views done preoperatively and postoperatively were used for the study. For each set of films, the following parameters were measured: on the lateral view; overall length of the calcaneus, lateral talometatarsal angle, lateral talocalcaneal angle, and the calcaneal pitch angle; and on the dorsoplantar view, the talometatarsal and talocalcaneal angle. In addition, the relative coverage of the talus by the navicular was described by an angular measurement based on the relationship of the center of the talus to the center of the navicular. The average improvements in lateral talocalcaneal angle (a reflection of hindfoot valgus) was 6.4 degrees when the long axis of the calcaneus was used and 6.8 degrees when the inferior surface of the calcaneous was used for the measurement. The lateral talometatarsal angle improved an average 11.3 degrees (from an average of 19.7 degrees to 8.4 degrees). The dorsoplantar talometatarsal angle (a measure of forefoot adduction/abduction) improved 15.8 degrees (preoperative average 26.8 degrees, postoperative average 11 degrees). The calcaneal pitch angle improved an average 10.8 degrees (preoperative average 3.2 degrees, postoperative average 14 degrees). The relationship between the talus and navicular was defined by an angular measurement based on the center of each articular surface before and after correction using this measurement. An average improvement of 26 degrees occurred in the alignment of these two articular surfaces.(ABSTRACT TRUNCATED AT 250 WORDS)     

Large-area self-catalysed and selective growth of ZnO nanowires

A simple procedure to selectively grow zinc oxide nanowires (ZnO NWs) on a large scale without any catalyst is reported. The process is based on the use of a zinc metal layer deposited onto substrates before the NW growth. The zinc layer, which becomes liquid at the synthesis temperature, favours the correct local conditions for a selective growth of pure ZnO NWs in an effective area of several square centimetres (up to 20?cm(2) in our laboratory-scale reactor). The?proposed method is suitable for patterned ZnO NW synthesis.     

A robust fault detection and isolation filter design under sensitivity constraint: An LMI approach

This paper deals with the design of a residual generator (RG) for linear time‐invariant systems subject to simultaneous different faults, disturbances and measurement noises. The objective is to design an RG filter that maximizes the transmission from a potential fault to a related residual, while minimizing the ones from nuisances (disturbances, measurement noises and other faults). The isolation of each fault is carried out by designing a bank of RG filters, each one insensitive, as much as possible, to nuisances and capable of detecting the occurrence of its related fault. The design is carried out through ℋ︁_∞ filtering techniques under an eigenstructure assignment constraint. Under mild assumptions, the RG filter can be obtained by solving a λ‐parameterized linear matrix inequality optimization problem. A comparison with existing fault detection and isolation (FDI) methods is considered in order to exhibit the relative merits of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd.