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In 1998-2000 studies on length and abundance of flowering and on nectar productivity of zucchini and marrow (Cucurbita pepo L.) were carried out in Lublin area. Flowers visitors were also monitored. Flowering of plants lasted from the end of June till the end of September. The mean number of flowers per plant of zucchini reached: 31 (male flowers) and 26 (female flowers), and for marrow 226 and 22, respectively. Flowers lived, on average, for 5 hours. Female flowers of marrow secreted the highest amount of nectar - 1.354 g per 10 flowers, on average. Sugar content in nectar was 21.84%-27.31%. The mean total amount of sugars secreted by 10 flowers of Cucurbita pepo L. was 21.5-304.3 mg. Pollinators were mainly bumblebees and honey bees.
The study was conducted on experimental plots in the conditions of Lublin. In the years 1998–2000 flowering, nectar secretion and insect visitation of male and female flowers of two winter squash (Cucurbita maxima Duch.) cultivars: ‘Ambar’ and ‘Amazonka’, were studied. The plants flowered from July to October. The flower life span was within the range of 7–10 hours. Female flowers of cv. Ambar were marked by the most abundant nectar secretion (129 mg). The nectar sugar content can be estimated as average (25%–35%). Winter squash nectar contained 84% of sucrose as well as 8–9% of fructose and 7%–8% of glucose. Flowers of the studied taxa were frequently foraged by the honey bee (66%–98% of total insects) and bumblebees (1%–30%).
The present study investigated the size and structure of the nectaries in flowers of marrow – Cucurbita pepo convar. giromontiina cv. ‘Weiser Busch’. The diameter and thickness of nectariferous layer were compared in female and male flowers of this taxon. The micromorphology as well as the anatomical and ultrastructural characters of the nectary from the female flower were observed using light, scanning and transmission electron microscopy. The density and size of stomata of the nectary epidermis from both types of flowers were examined using light microscopy. The nectaries in female flowers were found to have a larger size than in male flowers. The stomata occurring in the nectary epidermis of both types of flowers have a similar size and density. We observed that nectar was released onto the surface of the nectary not only via the stomata, but also through the walls of the epidermal cells. In TEM examination, large nuclei, different-shaped plastids, ER tubules, dictyosomes, and ribosomes were observed in the nectariferous tissue cells. A large number of mitochondria accompanying the plastids were found in the parenchyma cells of the nectary. The degradation of the nectary parenchyma cells in the flowers living for about 6 hours was asynchronous.
The structure, micromorphology and distribution of trichomes on Dracocephalum moldavicum L. shots were investigated using light and scanning electron microscopy (SEM). There were distinguished 3 types of non-glandular trichomes, 3 types of glandular trichomes and papillae of the osmophore in the epidermis of the corolla. The highest density of non-glandular and glandular trichomes was found on the abaxial surface of the calyx, on bracts and in the upper part of the stem. Structural variations in the head and stalk of long glandular trichomes were demonstrated. The dimensions of particular types of trichomes are given in the present paper. Differences in the structure of the trichomes of this species are presented, compared to literature data. The micromorphology of particular trichome types is documented in numerous photographs showing the rich ornamentation of the cuticle of non-glandular trichomes.
In the years 2007-2008, the flowering biology of Malus sargentii, an ornamental apple tree native to Japan, was studied in the conditions of Lublin (Poland). The daily rate of flower opening, flowering duration and flower visitation by insects were determined. The amount of nectar produced per flower and sugar content in the nectar were investigated. The size of nectaries and the micromorphology of their surface were examined using light and scanning electron microscopy. It was found that the greatest amount of flowers opened between 11.00 and 13.00. During this time, the largest number of insects was observed in the flowers. Bees (90%) were predominant among the insects, with a much smaller number of bumblebees (6%) and butterflies (4%). The flower life span was 5 days. Over this period, the flower produced, on the average, 0.71 mg of nectar with an average sugar content of 32%. The nectaries of Malus sargentii are orange-yellow coloured and they represent the hypanthial type. Due to the protrusion of the nectariferous tissue, they are classified as automorphic nectaries. The surface of the epidermal cells of the nectary was distinguished by distinct cuticle folds. A small number of stomata were located only in the basal part of the nectary. At the beginning of flowering, all stomata were closed, but secretion traces were observed near well-developed outer cuticular ledges.
W artykule przedstawiono definicję dodatków do żywności oraz uwarunkowania prawne ich stosowania. Przedstawiono również charakterystykę koncentratów spożywczych. Następnie podano rodzaje dodatków do żywności, które stosowane są w produkcji koncentratów obiadowych, koncentratów deserowych, koncentratów napojowych i sosów majonezowych. Opisano dodawane do tych produktów substancje wzmacniające smak, ekstrakty drożdżowe, aromaty, barwniki i skrobie modyfikowane. Przedstawiono ich właściwości funkcjonalne oraz kwestię ich bezpieczeństwa dla zdrowia konsumentów.
The presence of ruderal and mid-field vegetation promotes conservation of biodiversity and provides an additional source of food for insect pollinators. The white deadnettle is a common synanthropic plant visited frequently by various groups of insects, as it is a source of pollen and nectar. In 2012–2013, in the city of Lublin (Poland), signalling and food attractants in L. album flowers were analysed using light and scanning electron microscopy. The pipetting method was used for determination of nectar abundance in the flowers, and the content of sugars in the nectar was assessed with the use of an Abbe refractometer. It was found that the white dead-nettle flowers emitted a fragrance and were equipped with nectar guides, and the corolla and stamens had glandular trichomes and papillae secreting essential oils. On the stamens, there are also non-glandular trichomes, which play a role of pollen presenters. The nectary in the L. album flower has a shape of an irregular disc partly surrounding the base of the ovary. The content of sugars in the nectar was 43%. Sugar and honey yields per ha were calculated, and the values obtained were 153 kg and 191 kg, respectively.
Dodatki stosowane w produkcji żywności muszą być bezpieczne dla konsumenta. Obecnie w Unii Europejskiej trwa ponowna ocena ich bezpieczeństwa przez EFSA. Oceną są objęte dodatki dopuszczone do żywności przed 20.01.2009 r. Wyniki oceny poszczególnych substancji dodatkowych mogą być przyczyną zmian w ustawodawstwie UE. Program ponownej oceny powinien być zakończony do końca 2020 r., ale prawdopodobnie będzie trwał dłużej.
Jednym z warunków stosowania aromatów w żywności jest ich bezpieczeństwo dla konsumenta. W załącznikach do rozporządzenia nr 1334/2008 określono szczegółowe warunki, jakie muszą spełniać aromaty, aby mogły być stosowane w żywności. W załączniku I do rozporządzenia ustanowiono unijny wykaz substancji aromatycznych oraz materiałów źródłowych dopuszczonych do żywności. Obecnie w Unii Europejskiej trwa proces oceny przez EFSA bezpieczeństwa substancji aromatycznych. Z tego względu unijna lista substancji aromatycznych ulega ciągłym zmianom. W przypadku niektórych rodzajów aromatów ich ocena przez EFSA jest niezbędna tylko wówczas, gdy aromaty te są uzyskiwane z surowców innych niż żywność.
Similarly to fungal spores and pollen grains, pteridophytic spores can cause allergies in humans. Pteridophyta spore concentrations in the air of Lublin, under the conditions of central-eastern Poland, were first studied over the period 2013–2014. The volumetric method was used in this study. The research showed that that spores of ferns belonging to the following genera: Asplenium, Athyrium, Blechnum, Botrychium, Cystopteris, Dryopteris, Matteuccia, Osmunda, Polypodium and Pteridium, occur in aeroplankton. Spores were recorded in low concentrations and they occurred in a dispersed pattern during the season. They were found to be absent on some days. Among the above-mentioned genera, Dryopteris and Athyrium showed the highest content of spores in aerosol. In both years of the study (2013 and 2014), similar annual spore counts were recorded, respectively 69 and 63. The most spores were identified in August.
Blooming biology and pollen production of the following species: Pulsatilla zimmermannii Soó, P. halleri (All.) Willd., and P. vulgaris Mill. grown in UMCS Botanical Garden in Lublin, Poland (51°16'N, 22°30'E) was studied. The species attract insect visitors with large (size 6–8 cm in diameter), colourful, campanulate, actinomorphic flowers. The androecium is multistaminate (min–max: 142–282 anthers per flower), spirally arranged. Minute droplets of nectar were noted at the base of androecium and on staminodes. The anthers dehisced subsequently and pollen of a single flower was available to insects for 5–11 (7) days. On average, P. zimmermannii was found to produce the highest amount of pollen (9.16 g per 1 m2 ), which was 2 times more pollen than P. vulgaris (4.22 g per 1 m2 ), while P. halleri produced 7.63 g per 1 m2 . Pollen grains of the Pulsatilla species are medium in size (P axis ranged 29.8–38.4 μm, and E axis ranged 32.3–39.6 μm) and are oblate-spheroid in shape (P/E index ranged between 0.90 and 0.95). If planted together, the species will provide pollen from first days of April until end of the month, i.e. during the period when seasonal activity of Apoidea insects begins. Pulsatilla species might contribute to lists of garden plants that attract insect visitors with abundant pollen reward and minute nectar.
Trwająca obecnie w Unii Europejskiej ponowna ocena bezpieczeństwa substancji dodatkowych w wielu przypadkach skutkuje zmianami w unijnych przepisach o dodatkach do żywności. W artykule omówiono zmiany ustawodawstwa dotyczące dwóch barwników - annato E160 b oraz dwutlenku tytanu E171. Ponadto przedstawiono zagadnienia związane z interpretacją zapisów rozporządzenia w sprawie dodatków do żywności w odniesieniu do suplementów diety. Poruszono również kwestię zastosowania ekstraktów roślinnych zawierających substancje (np. azotyny), które mogą pełnić funkcje technologiczne w końcowym produkcie spożywczym
System wczesnego ostrzegania RASFF został ustanowiony w Unii Europejskiej w celu powiadamiania o bezpośrednim lub pośrednim niebezpieczeństwie dla zdrowia konsumenta. Dzięki niemu kraje członkowskie Unii Europejskiej mają możliwość szybkiej wymiany informacji o zagrożeniach pojawiających się w żywności, a także o działaniach podejmowanych w celu zwalczania takich zagrożeń. Do systemu RASFF zgłaszane są m. in. środki spożywcze niespełniające wymagań przepisów w zakresie substancji dodatkowych do żywności. W niniejszym artykule przedstawiono analizę powiadomień w systemie RASFF z tego obszaru, odnotowanych w latach 2012-2018
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