Rheological and sensory performance of a protein-based sweetener (MNEI), sucrose,and aspartame in yogurt

Sweeteners and flavors are generally added to yogurt to make them more palatable. However, the addition of these ingredients may affect the fermentation process of yogurt as well as its physical and sensory characteristics. Consumers prioritize yogurt products that are “natural.” A modified single-chain form of the natural sweet protein monellin extracted from the fruit of Dioscoreophyllum cumminsii, called MNEI, could be a useful alternative to artificial sweeteners. The aim of the present work was to evaluate new rapid sensory methods in combination with rheology to assess the viability of using MNEI to develop sweetened yogurts without the calories of sugar. We studied the gelation and cooling kinetics of 4 yogurt samples (unsweetened or sweetened with MNEI, aspartame, or sucrose) by using a rheometer. Furthermore, the 4 yogurts, with and without addition of a flavoring agent, were characterized from a sensory perspective using a combination of 2 rapid sensory methods, ultra flash profile and flash profile. Rheological results showed that, when added at typical usage levels, aspartame, sucrose, and MNEI did not generally affect the yogurt fermentation process or its rheological properties. Sensory results demonstrated that texture attributes of yogurts with aspartame and sucrose were strongly linked to sweetness and flavor perception, but this was not true for MNEI-sweetened yogurts. In contrast to results obtained from samples sweetened with sucrose and aspartame, MNEI protein did not sweeten the yogurt when added before fermentation. This study highlights the enhancing effect of flavor on sweetness perception, supporting previous reports that noted synergistic effects between sucrose or aspartame and flavors. Hence, future studies should be conducted to determine how sweet proteins behave in yogurt when added after fermentation.     

Effect of cooking on the total antioxidant capacity and phenolic profile of some whole‐meal African cereals

BACKGROUND: At present, sorghum, fonio and millet are not placed as important commodities in the North American and European food basket, but their importance as ingredients in multigrain and gluten‐free cereal products is highlighted. Therefore in this study the phenolic profile (evaluated by liquid chromatography/tandem mass spectrometry), total phenolic content (assessed by Folin–Ciocalteu assay) and total antioxidant capacity were measured in three African whole grains, i.e. sorghum (Sorghum bicolor ssp. bicolor), fonio (Digitaria exilis) and pearl millet (Pennisetum glaucum L.), before and after a cooking procedure. RESULTS: After the cooking process, soluble phenolic acids increased significantly in sorghum, whereas bound ones and anthocyanins decreased significantly. In millet the cooking process significantly enhanced soluble phenolic acids without affecting those bound, whereas in fonio a slight but significant decrease in almost all soluble phenolic acids was observed along with a significant increase in bound ones. Finally, the cooking process negatively affected both total phenolic content and total antioxidant capacity. CONCLUSION: This is one of the few reports dealing with the antioxidant compounds of these three African whole grains in which the effect of cooking was also evaluated. The data suggested that, to improve their antioxidant properties, specific cultivars should be selected and the cooking procedures carefully considered. Copyright © 2012 Society of Chemical Industry     

Molecular Characterization of Plasma HDL,LDL, and VLDL Lipids Cargos from Atherosclerotic Patients with Advanced Carotid Lesions: A Preliminary Report

Carotid atherosclerosis represents a relevant healthcare problem, since unstable plaques are responsible for approximately 15% of neurologic events, namely transient ischemic attack and stroke. Although statins treatment has proven effective in reducing LDL-cholesterol and the onset of acute clinical events, a residual risk may persist suggesting the need for the detection of reliable molecular markers useful for the identification of patients at higher risk regardless of optimal medical therapy. In this regard, several lines of evidence show a relationship among specific biologically active plasma lipids, atherosclerosis, and acute clinical events. We performed a Selected Reaction Monitoring-based High Performance Liquid Chromatography-tandem Mass Spectrometry (SRM-based HPLC-MS/MS) analysis on plasma HDL, LDL, and VLDL fractions purified, by isopycnic salt gradient ultracentrifugation, from twenty-eight patients undergoing carotid endarterectomy, having either a “hard” or a “soft” plaque, with the aim of characterizing the specific lipidomic patterns associated with features of carotid plaque instability. One hundred and thirty lipid species encompassing different lipid (sub)classes were monitored. Supervised multivariate analysis showed that lipids belonging to phosphatidylethanolamine (PE), sphingomyelin (SM), and diacylglycerol (DG) classes mostly contribute to discrimination within each lipoprotein fraction according to the plaque typology. Differential analysis evidenced a significant dysregulation of LDL PE (38:6), SM (32:1), and SM (32:2) between the two groups of patients (adj. p-value threshold = 0.05 and log₂FC ≥ |0.58|). Using this approach, some LDL-associated markers of plaque vulnerability have been identified, in line with the current knowledge of the key roles of these phospholipids in lipoprotein metabolism and cardiovascular disease. This proof-of-concept study reports promising results, showing that lipoprotein lipidomics may present a valuable approach for identifying new biomarkers of potential clinical relevance.     

Dialysis outcome quality initiative (DOQI) guideline for hemodialysis adequacy

Photosensitivity is defined by a pattern of occipital or more diffuse spikes and waves. Several techniques are needed for exploration: intermittent light stimulation (ILS), patterns, TV-screen, video games. Photosensitivity is a genetic characteristic. Only diffuse spikes and waves induced by ILS are correlated with epilepsy. Pure photogenic epilepsy is characterized by seizures induced by visual stimuli alone, usually by TV-screen. Video games may also have a triggering effect due to the slow-moving patterns or intense brightness. Several epileptic syndromes are associated with photosensitivity with or without visually-induced seizures. These syndromes are most often generalized and idiopathic.     

Chitosan–Quercetin Bioconjugate as Multi‐Functional Component of Antioxidants and Dual‐Responsive Hydrogel Networks

Multifunctional hydrogels based on chitosan–quercetin (CHITQ) conjugate are prepared by a thermo‐induced radical procedure in the presence of N‐isopropylacrylamide (NIPAAm), acrylamide (AAm), and N,N′‐methylenebis(acrylamide) (MEBA). At first, quercetin (Q) is grafted onto chitosan backbone with a functionalization degree of 275 mg of Q per gram of conjugate, as calculated by ¹H‐NMR analyses to impart antioxidant properties to the polysaccharide. Then, a pH and temperature sensitive hydrogel was obtained by involving CHITQ and NIPAAm in the polymerization reaction. The accessibility of phenolic moieties is modified in response to the hydrogel swelling/deswelling, as confirmed by antioxidant tests performed at different temperatures. Dual stimuli‐responsive hydrogels are proposed for the delivery of caffeine as model drug. The release profiles of caffeine depict a system particularly performing as on/off device at acidic pH with excellent applicability prospects.     

Modulation of the biological activity of microRNA-210 with peptide nucleic acids (PNAs)

Herein we describe the activity of a peptide nucleic acid (PNA) that targets microRNA‐210 (miR‐210), which is associated with hypoxia and is modulated during erythroid differentiation. PNAs directed against miR‐210 were designed to bind with high affinity to the target RNA strand and to undergo efficient uptake in target cells. A polyarginine–PNA conjugate directed against miR‐210 (Rpep‐PNA‐a210) showed both very high affinity for RNA and efficient uptake into target cells without the need for transfection reagents. An unmodified PNA of the same sequence displayed the ability to bind RNA, but cellular uptake was very poor. Consistent with this, only Rpep‐PNA‐a210 strongly inhibited miR‐210 activity, as evaluated by assays on undifferentiated K562 cells and on cells treated with mithramycin, which was found to induce erythroid differentiation and miR‐210 overexpression. Targeting miR‐210 by Rpep‐PNA‐a210 resulted in: 1) a decrease in miR‐210 levels as measured by RT‐PCR, 2) up‐regulation of raptor mRNA, 3) a decrease in γ‐globin mRNA, and 4) decreased expression of differentiated functions (i.e., proportion of benzidine‐positive cells, content of embryo‐fetal hemoglobins). The efficient delivery of anti‐miR PNAs through a suitable peptide carrier (Rpep‐PNA‐a210) leads to the inhibition of miR‐210 activity, altering the expression of miR‐210‐regulated erythroid functions.     

Aminolysis of Styrene Oxide Over Heterogeneous Acidic Catalysts

Silica alumina and silica zirconia mixed oxides are shown to be effective and regioselective catalysts for the aminolysis of styrene oxide under very mild experimental conditions, giving the corresponding primary ??-amino-alcohol in good to excellent yield.     

Cellular uptakes, biostabilities and anti-miR-210 activities of chiral arginine-PNAs in leukaemic K562 cells

A series of 18‐mer peptide nucleic acids (PNAs) targeted against micro‐RNA miR‐210 was synthesised and tested in a cellular system. Unmodified PNAs, R₈‐conjugated PNAs and modified PNAs containing eight arginine residues on the backbone, either as C2‐modified (R) or C5‐modified (S) monomers, all with the same sequence, were compared. Two different models were used for the modified PNAs: one with alternated chiral and achiral monomers and one with a stretch of chiral monomers at the N terminus. The melting temperatures of these derivatives were found to be extremely high and 5 M urea was used to assess differences between the different structures. FACS analysis and qRT‐PCR on K562 chronic myelogenous leukaemic cells indicated that arginine‐conjugated and backbone‐modified PNAs display good cellular uptake, with best performances for the C2‐modified series. Resistance to enzymatic degradation was found to be higher for the backbone‐modified PNAs, thus enhancing the advantage of using these derivatives rather than conjugated PNAs in the cells in serum, and this effect is magnified in the presence of peptidases such as trypsin. Inhibition of miR‐210 activity led to changes in the erythroid differentiation pathway, which were more evident in mithramycin‐treated cells. Interestingly, the anti‐miR activities differed with use of different PNAs, thus suggesting a role of the substituents not only in the cellular uptake, but also in the mechanism of miR recognition and inactivation. This is the first report relating to the use of backbone‐modified PNAs as anti‐miR agents. The results clearly indicate that backbone‐modified PNAs are good candidates for the development of very efficient drugs based on anti‐miR activity, due to their enhanced bioavailabilities, and that overall anti‐miR performance is a combination of cellular uptake and RNA binding.