Phenolic compounds and antioxidant activity of red wine made from grapes treated with different fungicides.

The effect of treating grapes with six fungicides, applied under critical agricultural practices (CAP) on levels of phenolic compounds and antioxidant activity of red wines of Monastrell variety was studied. Vinifications were performed through addition of active dry yeast (ADY). Measurement of phenolic compounds was made with HPLC-DAD. Determination of antioxidant activity was through reaction of the wine sample with the DPPH radical. The wine prepared from grapes treated with quinoxyfen shows a greater increase of phenolic compounds than the control wine. In contrast, the wine obtained from grapes treated with trifloxystrobin showed lower total concentration of phenolic compounds, including stilbenes, whilst treatments with kresoxim-methyl, fluquinconazole, and famoxadone slightly reduced their content. Hence, the use of these last four fungicides could cause a decrease in possible health benefits to consumers. Antioxidant activity hardly varied in the assays with quinoxyfen, fluquinconazole and famoxadone, and decreased in the other wines.

Oxidative stress, frailty and cognitive decline.

UNLABELLED: The causes of frailty are complex and must be accepted as multidimensional based on the interplay of genetic, biological, physical, psychological, social and environmental factors, although inflammation and oxidative stress are two factors that play an important role in the development of symptoms with those fragile states. OBJECTIVE: to establish the relationship between oxidative stress, frailty and decline cognitive. METHODS: A review of the literature and data abstraction from papers are showing the relationship between a) oxidative stress and frailty, b) oxidative stress and decline cognitive. RESULTS: The papers reviewed showed that we can establish a relationship between the progress of neurodegenerative disorders and increased oxidative stress. Also found in frailty, that oxidative stress plays an important role as one of the starting points for the appearance of permanent inflammatory states. CONCLUSIONS: Although the literature indicates the relationship between oxidative stress, frailty and decline cognitive, more studies are needed in this regard, especially interventions that asses whether increased intake of antioxidants in older frailty may improve the progress of disease and slow cognitive decline.

Kinetic characterisation and thermal inactivation study of red alga (Mastocarpus stellatus) peroxidase.

Peroxidase (POD) was extracted from red alga (Mastocarpus stellatus) using Triton X-114 and characterised by UV-spectrophotometry. Optimum activity using 2,2´-azinobis(3-ethylbenzothiazolinesulphonic acid) (ABTS) as the H-donor was obtained at pH 5.0. In the presence of the anionic detergent, sodium dodecyl sulphate (SDS), however, POD was inactivated at all the pH values studied and totally inactivated at 1mM SDS. When the enzyme was kinetically characterised, the KM and Vm values for ABTS were found to be 13mM and 40µM/min, respectively. In addition, when the H2O2 concentration was increased, at a fixed concentration of ABTS, the activity was inhibited at the highest H2O2 concentrations. In a study of the effect of several reducing agents, l-cysteine was found to be the most active. A thermal inactivation study showed a first-order inactivation kinetic, and the Arrhenius plot yielded a straight line with a slope equivalent to an activation energy of 121.6kJ/mol. Significant inactivation occurred at temperatures of>35°C, with>90% of the relative activity being lost after only 5min of incubation at 48.4°C.

Influence of fungicides on grape yeast content and its evolution in the fermentation.

The influence of six fungicides (famoxadone, fenhexamid, fluquinconazole, kresoxim-methyl, quinoxyfen, trifloxystrobin) on the yeast content in harvested grapes has been studied along with their effect on it during the wine-making process. Two treatments were carried out with authorized formulates at the manufacturer doses. The first was carried out under good agricultural practices, obeying the security times, and the second one under critical conditions, applied on the day of harvesting. The grapes were harvested two hours after the application. During the wine-making process, samples were taken at 1, 5, 12 and 20 days after the start. The levels observed in the control sample (1.9 log CFU/cm2) were similar to previous studies. The counts in all treated samples were higher than the control sample, without adverse effect of the pesticides on the yeast count even in the grapes treated on the day of harvest. As with the observations on grapes, no effect of the pesticides on the fermentation count was observed. All counts on the treated samples were higher than the control sample. The treatment on the day of harvest did not have any effect on the fermentation count, with superior results being obtained for all the pesticides.