How gamma-rays and electron-beam irradiation would affect the antimicrobial activity of differently processed wild mushroom extracts?

AIMS: The effects of irradiation (gamma-rays and electron-beams), up to 10 kGy, in the antimicrobial activity of mushroom species (Boletus edulis, Hydnum repandum, Macrolepiota procera and Russula delica) differently processed (fresh, dried, freeze) were evaluated. METHODS AND RESULTS: Clinical isolates with different resistance profiles from hospitalized patients in Local Health Unit of Mirandela, Northeast of Portugal, were used as target micro-organisms. The mushrooms antimicrobial activity did not suffer significant changes that might compromise applying irradiation as a possible mushroom conservation technology. CONCLUSIONS: Two kGy dose (independently of using gamma-rays or electron-beams) seemed to be the most suitable choice to irradiate mushrooms. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides important results in antimicrobial activity of extracts prepared from irradiated mushroom species.

Antioxidant potential of chestnut (Castanea sativa L.) and almond (Prunus dulcis L.) by-products.

The antioxidant properties of almond green husks (Cvs. Duro Italiano, Ferraduel, Ferranhês, Ferrastar and Orelha de Mula), chestnut skins and chestnut leaves (Cvs. Aveleira, Boa Ventura, Judia and Longal) were evaluated through several chemical and biochemical assays in order to provide a novel strategy to stimulate the application of waste products as new suppliers of useful bioactive compounds, namely antioxidants. All the assayed by-products revealed good antioxidant properties, with very low EC(50) values (lower than 380 µg/mL), particularly for lipid peroxidation inhibition (lower than 140 µg/mL). The total phenols and flavonoids contents were also determined. The correlation between these bioactive compounds and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, inhibition of ß-carotene bleaching and inhibition of lipid peroxidation in pig brain tissue through formation of thiobarbituric acid reactive substances, was also obtained. Although, all the assayed by-products proved to have a high potential of application in new antioxidants formulations, chestnut skins and leaves demonstrated better results.

Long-term storage effect on chemical composition, nutritional value and quality of Greek onion landrace "Vatikiotiko".

The effect of storage at two temperatures (5±1 and 25±1 °C and 60-70±5% RH for both temperatures) on marketability and quality features of dry bulbs of local landrace "Vatikiotiko", "Sivan F1", "Red Cross F1" and "Creamgold" was examined. During storage measurements for fresh and dry weight of bulbs, tunic and flesh color, bulb firmness, nutritional value and mineral composition were taken at regular intervals. Storage concluded when either bulbs lost marketable quality or sprouting occurred. "Vatikiotiko" onion can be stored for at least 7months at 25±1 °C, whereas at 5±1 °C storage could be prolonged without significant marketability and quality loss. The fact that "Vatikiotiko" landrace can be considered a "storage" onion has to be capitalized in order to increase total production and yield, since storage could cover the market needs that arise throughout the year.