Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2019
Authors
Mekjell MelandAbstract
No abstract has been registered
Abstract
Large amounts of fruit seeds are discarded yearly in different producing industries, which is a waste of a potentially valuable resource as well as a serious disposal problem. Plum is the most important type of commercial fruit in Serbia and seeds could be obtained as a byproduct of alcoholic beverage processing. Their exploitation should be greater and more information about cultivars’ kernels and their composition is required. Also, consumers’ tendency for “natural foods” arises a need for characterization of genotypes with high phenolic contents which could be used in processed food products. Discarding large amounts of plum seeds is a waste of potentially precious sources of phytochemicals. In order to characterize the phenolic profile of approximately 30 plum cultivars, phenolic acids and flavonoids, as potential antioxidants, were determined by ultra-high-performance liquid chromatography (UHPLC) coupled with hybrid mass spectrometry, which combines the Linear Trap Quadrupole (LTQ) and OrbiTrap MS/MS mass analyzer together with chemometric analysis. The UHPLC–LTQ OrbiTrap MS technique was proven to be reliable for the unambiguous detection of phenolic acids, their derivatives, and flavonoid aglycones based on their molecular masses and fragmentation pattern. The phenolic acids prevail over the flavonoids, with protocatechuic acid, p-hydroxybenzoic acid, ferulic acid, and chlorogenic acid as the most abundant ones. In addition, catechin was the most abundant flavonoid.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
The presence of pollinators in orchards is crucial to obtain high fruit set and yields of fruits. Despite the fact that sour cherry cultivars are mainly autogamous, insect visits are still of great importance for their propagation. In order to attract and reward pollinators, flowers have to provide adequate nourishment to them. Besides nectar, bees gather pollen, which are a prerequisite for normal colony growth and development of their broods. ‘Oblačinska’ sour cherry (Prunus cerasus L.), an autochthonous cultivar, is the most highly planted cultivar in Serbian commercial orchards. Since the cultivar is actually a mixture of different clones, variability in numerous traits and, particularly, its yields has been reported. Since phenolic compounds are considered to be fundamental pollen chemicals, the aim of this study was to determine the phenolic compounds profile in pollen collected from 15 ‘Oblačinska’ sour cherry clones with varying productivity levels. Solid phase extraction (SPE), combined with ultra-high-performance liquid chromatography coupled with a diode array detector and a triple quadruple mass spectrometer (UHPLC DAD-MS/MS), was used to analyse the polyphenolic profile of pollen. Among 23 components quantified, rutin was the most abundant phenolic compound. It ranged from 98.49 (clone V/P) to 358.83 mg kg-1 (clone III/9) and was observed to contribute, on average, 56% of the total phenolic compounds in pollen as quantified in different ‘Oblačinska’ sour cherry clones. In addition to this compound, clones contained significant amounts of chlorogenic acid (12.92%), astragalin (8.19%), and hyperoside (5.59%) as well. Cluster analysis grouped pollen clones in four different clusters, which showed that clones III/9, IV/8, and V/P had unique phenolic profiles. Despite the significant differences among the studied clones, the contents of chlorogenic acid, rutin, naringin, hyperoside, astralgin, and phlorizin were distinguishable between the clusters.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Mekjell MelandAbstract
No abstract has been registered
Authors
Mekjell MelandAbstract
Sweet cherry production worldwide is grown in the open land. Production technique is more or less similar with scions grafted on dwarfing and semi-dwarfing rootstock and trees arranged in single rows. Sweet cherries can be grown in Norway in areas with suitable local climatic conditions up to 60°N. All orchards have high density planting systems and are rain covered. Rain-induced fruit cracking in cherries remains a problem at an international level. The most common systems in Norway are multibay high tunnel systems and retractable rain covers. Covered orchard tunnel systems offer not only the advantage of rain exclusion but also allow additional manipulation of the environment, tree growth and fruiting. In general, sweet cherry high tunnel production gives increased yields of larger fruit than in the open land, but investment costs are higher. This overview article describes results from different experiments about high tunnels sweet cherry production mainly conducted at Nibio Ullensvang, Norway during the last ten years.
Abstract
Cherries (Prunus avium L. and Prunus cerasus L.) are economically important fruit species in the temperate region. Both are entomophilous fruit species, thus need pollinators to give high yields. Since cherry’s flower is easy-to-reach, bees and other pollinators can smoothly collect nectar as a reward for doing transfer of pollen to receptive stigma. Nectar in cherry is usually attractive for insects, especially to honey bee (Apis melifera) who is the most common pollinator. Nectar is predominantly an aqueous solution of sugars, proteins, and free amino acids among which sugars are the most dominant. Trace amounts of lipids, organic acids, iridoid glycosides, minerals, vitamins, alkaloids, plant hormones, non-protein amino, terpenoids, glucosinolates, and cardenolides can be found in nectar too. Cherry flower may secrete nectar for 2–4 days and, depending on the cultivar, produces up to 10 mg nectar with sugar concentration from 28% to 55%. Detailed chemical analysis of cherry nectar described in this chapter is focused on sugar and phenolic profile in sour cherry. The most abounded sugars in cherry nectar was fructose, glucose, and sucrose, while arabinose, rhamnose, maltose, isomaltose, trehalose, gentiobiose, turanose, panose, melezitose, maltotriose, isomaltotriose, as well as the sugar alcohols glycerol, erythritol, arabitol, galactitol, and mannitol are present as minor constituents. Regarding polyphenolics, rutin was the most abundant phenolic compound followed by naringenin and chrysin. Cherry cultivars showed different chemical composition of nectar which implies that its content is cultivar dependent.