Influence of foods on the absorption of antimicrobial agents]

Understanding the interaction between foods and antimicrobial agents is an aspect of therapy which may have an important clinical repercussion, which is why it must not be forgotten. This study reviews the interactions of foods with the anti-microbial agents which occur at the level of absorption, considering the mechanisms involved. The food-drug interaction can cause an increase, a decrease, or a delay in the bio-availability of the anti-microbial agents; foods may have no affect on the absorption of the anti-microbial agents, or they may improve the gastrointestinal tolerance. The Food and Drug Administration's bioequivalency criteria for considering whether or not there is an alteration in absorption have an orientative function, as generally all studies are conducted on healthy volunteers, but in clinical practice one must consider the physiological and pathological condition of the patient. The composition of the diet as well as the volume of liquid administered are other aspects which should be considered, as these may exert a different effect depending on the type of drug. After ingesting fatty foods, there is an increased absorption of albendazole, griseofulvin, itraconazole, and mebendazole. All foods but especially carbohydrates reduce the absorption of isoniazide. Among the anti-HIV drugs, the following must be administered on an empty stomach: didanosine, indinavir zalcitabine , and zidovudine ; lamivudine can be administered either on an empty or on a full stomach, because although food delays the absorption, it does not affect the amount absorbed; the absorption of stavudine is not affected by foods; ritonavir should be administered together with tile meals, and saquinavir must be administered after ingestion of food. It is advisable to administer clarithromycin together with foods, and azythromycin on an empty stomach; the same holds true for perfloxacin and rifabutine as for lamivudine.     

Mineralogical Evolution of Kaolin‐Based Drinking Water Treatment Waste for Use as Pozzolanic Material. The Effect of Activation Temperature

This study reports on exhaustive scientific research into the influence of the activation temperature of inert waste from drinking water treatment plants for use as supplementary cementing material in cements. The effect of activation temperature on the mineralogy of the reactive products resulting from pozzolanic activity and on the evolution of the hydrated phases formed during the pozzolanic reaction at 28 d of curing was analyzed with the assistance of different instrumental techniques such as X‐ray fluorescence, X‐ray diffraction, thermogravimetric analysis, infrared spectroscopy, and scanning electron microscopy. The results show that all the activated products (based on metakaolinite) presented high pozzolanic activity at all ages of the reaction (up to 90 d), although 600°C at 2 h are the recommended ideal activation conditions from an energetic and economic viewpoint. The activation temperature (600°C–900°C for 2 h of retention) plays an important role in the reaction kinetics in activated drinking water waste/Ca(OH)₂ systems. The hydrated phases identified under these activation conditions were very similar, but with important differences in the crystalline aluminates phases content. Thus, the formation of stratlingite (C₂ASH₈) is favored at low temperatures (<800°C); whereas at higher temperatures (at 900°C), tetra calcium aluminate hydrate (C₄AH₁₃) appears as the only crystalline phase. Finally, this type of treatment of drinking water waste (based on kaolinite) is ideal to obtain future pozzolans based on recycled metakaoline, a product that is currently listed in international standards for the manufacture of commercial cements.     

Unusual η2‐Allene Osmacycle with Apoptotic Properties

Screening of a library of structurally unusual osmacyclic complexes for their antiproliferate properties in HeLa cells led to the discovery of a highly cytotoxic η²‐allene osmacycle. In this remarkably stable complex, osmium constitutes part of a metallacycle through the formation of a σ‐bond to a carbon in combination with coordination to an allene moiety. The osmacycle strongly induces apoptosis in Burkitt‐like lymphoma cells at submicromolar concentrations. The reduction of the mitochondrial membrane potential, the induction of DNA fragmentation, and the activation of caspases‐9 and ‐3 reveal that programmed cell death occurs through the intrinsic mitochondrial pathway. From the lipophilic and cationic nature of the osmacycle, in addition to a low oxidation potential (E_1/2=+0.27 V vs. Fc/Fc⁺, Fc=ferrocene) it is proposed that mitochondria are the cellular target where oxidative decomposition initiates apoptosis.     

Tiger Nut (Cyperus esculentus) Commercialization: Health Aspects,Composition, Properties,and Food Applications

Abstract: Tiger nut (Cyperus esculentus) is a weed plant (yellow nut sedge) of tropical and Mediterranean regions. Its sweet almond‐like tubers are highly appreciated for their health benefits and nutritive value: high content of fiber, proteins, and sugars. They are rich in oleic acid and glucose, as well as in phosphorus, potassium, and vitamins C and E. In Spain, these tuberous “nuts” are mainly used to manufacture a milky beverage called “horchata de chufa.” Tiger nut has attracted very little scientific and technological interest, except for the production of “horchata de chufa” and some studies on its oil. Development of new products from the tubers could enhance more interest in this crop. In this respect, various opportunities are offered: source of dietary fiber, use of its oil in cooking or salad preparation, production of caramel to be used as a food additive. This review presents an overview of the tiger nut, its products, and the co‐products obtained during commercial processing.     

Electrochemical Determination of Ascorbigen in Sauerkrauts

Ascorbigen (ABG), 2-C-(indol-3-yl)methyl-α-l-xylo-hex-3-ulofuranosono-1,4-lactone, was synthesised and its structure and purity was confirmed by means of ¹H NMR and ¹³ C NMR spectra and HPLC-PDA, respectively. The electrochemical behaviour of ABG was studied by cyclic voltammetry (CV) method for pH within the range of 3.0–7.0 and further characterisation was performed by differential pulse voltammetry (DPV) at pH 5.0. Voltammetric studies of ABG at glassy carbon electrode showed one irreversible oxidation peak (centred at E _p = 0.950 V for pH 5.0). The anodic peak current potential related to the irreversible oxidation of ABG was shifted towards more positive potentials with decreasing pH values. The linear response between concentration of ABG within the range of 0.08–0.75 mM and recorded current was observed. The DPV method was shown to be more sensitive when compared to the CV method. ABG showed a significant reducing activity provided by CV, whilst the antioxidant activity of ABG against O₂^−• was negligible. Electrochemical behaviour of ABG standard was applied successfully for the quantification of natural ABG in sauerkrauts by DPV and HPLC-CoulArray methods. Based on the developed analytical methods, ABG content increased during natural fermentation of cabbage at 0.5% and 1.5% NaCl levels, and results were comparable with those found in the literature.     

Kinetic study of the antioxidant compounds and antioxidant capacity during germination of Vigna radiata cv. emmerald, Glycinemax cv. jutro and Glycine max cv. merit

The purpose of this study was to determine the antioxidant capacity and the content of antioxidant compounds in raw mung bean seeds and sprouts (Vigna radiata cv. emmerald) germinated for 2, 3, 4, 5 and 7 days and of soybean seeds of Glycine max cv. jutro germinated for 2, 3 and 4 days and of Glycine max cv. merit germinated for 2, 3, 4, 5 and 6 days. Antioxidant compounds, such as vitamin C and E, total phenolic compounds and reduced glutathione (GSH) were studied. Antioxidant capacity was measured by superoxide dismutase-like activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), trolox equivalent antioxidant capacity (TEAC) and inhibition of lipid peroxidation in unilamellar liposomes of egg yolk phosphatidylcholine (PC). The results indicated that changes in the contents of vitamin C, vitamin E and GSH depended on the type of legume and germination conditions. Sprouts of mung bean and soybeans provided more total phenolic compounds than did raw seeds. The SOD-like activity increased after germination of mung bean seeds for 7 days, by 308%, while no change was observed in sprouts of Glycine max cv. jutro and an increase was observed after 5 and 6 days of germination (∼20%) in Glycine max cv. merit. PRTC and TEAC increased during the germination process and retentions of 28–70% and 11–14%, respectively, for soybean, and 248% and 61%, respectively, for mung bean were observed at the end of germination. The inhibition of lipid peroxidation increased by 389% in 5–7 days’ germination of Vigna radiata cv. emmerald sprouts, and 66% in Glycine max cv. merit sprouts whilst, in Glycine max cv. jutro, germination did not cause changes in lipid peroxidation inhibition. According to the results obtained in this study, germination of mung bean and soybean seeds is a good process for obtaining functional flours with greater antioxidant capacity and more antioxidant compounds than the raw legumes.     

Assessment of protein fractions of three cultivars of <Emphasis Type="Italic">Pisum sativum</Emphasis> L.: effect of germination

Protein composition, nitrogen and amino acid content of Osborne fractions in different cultivars of Pisum sativum L. (cv. ucero, cv. ramrod and cv. agra) seeds were investigated and the effect of germination on these parameters was also analysed. Albumins comprised the main protein fraction in raw seeds, globulins were constituted mainly by vicilin, with a smaller proportion of the glutelin and prolamine fractions. Regarding the amino acid profile of pea protein fractions, although differences among pea cultivars were found, in general albumin, glutelin and prolamine fractions presented Asp, Glu and Gly as the major non-essential amino acids (NEAA) and Lys as the main essential amino acid (EAA). The globulin fraction, however, presented Asp, Glu, Gly and Arg as the major NEAA and Leu, Phe, Lys, and Thr as the main EAA. In general, the albumin fraction accounted for more sulphur amino acids and Lys, followed by the glutelin + prolamine fraction. Germination caused an increase in the total protein content of P. sativum cv. ucero and P. sativum cv. ramrod. In the albumin fraction a wide number of proteins underwent degradation and convicilin disappeared from the globulin fraction of pea sprouts whilst vicilin and legumin decreased slightly. In general, all the Osborne fractions of pea sprouts presented higher EAA contents than raw seeds. The estimated essential amino acid indexes of protein fractions for P. sativum cv. ucero (EAAI_adult and EAAI_egg) improved with the germination process whilst for P. sativum cv. ramrod and P. sativum cv. agra depended on the Osborne fraction.     

Quality characteristics of a non‐fermented dry‐cured sausage formulated with lemon albedo

Dry‐cured sausages were treated with two types of dehydrated lemon albedo (raw and cooked) at five concentrations (0–100 g kg^?1 in 25 g kg^?1 increments). Several physical and chemical analyses were made during the drying stage, and compositional, textural and sensory analyses were conducted on the finished products. The addition of albedo improved the nutritional properties as a result of fibre addition and may have beneficial effects due to the presence of active biocompounds as evidenced by a decrease in residual nitrite levels and delayed oxidation (based on TBARS values). The sensory properties of samples that resembled the control sausages were those that contained up to 50 g kg^?1 dehydrated raw albedo and 75 g kg^?1 dehydrated cooked albedo. Copyright © 2004 Society of Chemical Industry