Physico-Chemical Properties, Composition and Oxidative Stability of Camelina sativa Oil

Camelina sativa is a cruciferous oilseed plant. With the aim of describing the general characteristics of the oil obtained from the seeds of plants grown in Slovenia and of comparing it to camelina oil from other countries we determined some physico-chemical properties, fatty acid composition, iodine and saponification value and followed its oxidative stability under different storage conditions. The density at 20 °C was (0.927 0.0001) g/cm3 and the refractive index reached 1.4756 0.0001 at 25 °C. The analysis of fatty acids showed 10.3 % of saturated and 55.8 % of polyunsaturated acids, with 16.9 % of linoleic (C18:2), 35.2 % of -linolenic (C18:33) and 1.6 % of erucic acid (C22:1). Determination of oxidative stability of this highly unsaturated oil revealed that the formation of primary oxidation products was affected by photooxidation. The peroxide value, PV, of fresh oil was (2.38 0.01) meq O2/kg, while after 1 month in daylight at room temperature PV reached (21.0 0.1) meq O2/kg. When stored in darkness PV was (8.12 0.08) meq O2/kg. In the fresh oil, the p-anisidine value, AV, was 6.2 0.1, after 11 months at room temperature 10.4 0.1, and after the same time at 8 °C in darkness 7.1 0.1. Susceptibility to oxidation of camelina oil was measured by the Rancimat test and expressed as the induction period. In fresh camelina oil the induction period was 4.8 h

White Hop Shoot Production in Slovenia: Total Phenolic, Microelement and Pesticide Residue Content in Five Commercial Cultivars

Berba bijelih izdanaka hmelja mogla bi biti opravdana ako bi se dokazalo njihovo pozitivno djelovanje na zdravlje ljudi. Svrha je ovoga rada bila odrediti utjecaj kultivara i godine uzgoja hmelja na ukupni udjel fenola, antioksidacijski potencijal, te udjele mikroelemenata i ostataka pesticida. Biomasa biljaka bitno se razlikovala ovisno o kultivaru (3,1-7,1 g suhe tvari biljke) i godini uzgoja (2009.-2001.). Ukupni maseni udjel fenola, izražen u ekvivalentima klorogene kiseline u suhoj masi, bio je od 0,60 do 1,80 mg/g, ovisno o kultivaru i godini uzgoja. Sposobnost uklanjanja slobodnih radikala uzoraka ubranih u razdoblju od 2010. do 2012. iznosila je od 11 do 19 µg ekvivalenata klorogene kiseline. Reduktivna sposobnost ispitana FRAP metodom bila je <0,01; a bitni utjecaj kultivara (pC≤0,05) i godine uzgoja (py≤0,05) opažen je samo u uzorcima iz 2012. godine. U bijelim izdancima kultivara hmelja Humulus lupulus ‘Dana’ ispitana je prisutnost tragova mikroelemenata i potencijalno aktivnih spojeva zaostalih nakon primjene pesticida. Udjel je cinka u suhoj masi izdanaka hmelja bio vrlo malen (4 mg/kg), a u tlu ga je bilo ispod granice detekcije. Udjel bakra je u izdancima također bio vrlo malen (2,3 mg/kg), dok ga je u tlu bilo 100 mg/kg, što je ispod kritične razine (300 mg/kg). Udjeli svih 182 aktivnih sastojaka iz ostataka pesticida upotrijebljenih u prethodnim sadnjama bili su ispod granica detekcije. Iz rezultata možemo zaključiti da bijeli izdanci hmelja imaju bolja antioksidacijska svojstva od šišarki i lišća hmelja, te da ne sadržavaju ostatke pesticida.Harvesting of white hop shoots might be justified if they can be shown to be beneficial to human health. The aim of the present study is to determine the effects of hop cultivars and year of production on total phenolics, antioxidant potential, microelements and pesticide residues. Biomass per plant was highly variable among the cultivars (3.1-7.1 g dry mass per plant) and depended on hop cultivar and year (2009-2011). Total phenolics as chlorogenic acid equivalents (CAE) on dry mass basis varied from 0.60 to 1.80 mg/g, and showed significant effects across hop cultivar and year. The radical scavenging activities of the samples collected in years 2010-2012 ranged from 11 to 19 μg CAE. Ferric reducing activity was <0.01, with significantly different effects across hop cultivars (pC≤0.05) and year (py≤0.05) observed only in 2012. Traces of microelements and potentially active compounds from the use of pesticides in white hop shoots of Humulus lupulus ‘Dana’ were analysed. The content of zinc in the hop shoots on dry mass basis was very low (4 mg/kg), and it was below the limit of detection in the soil. The content of copper in the hop shoots was also very low (2.3 mg/kg), while in the soil it was below the critical emission (100 vs 300 mg/kg, respectively). All 182 active ingredients from the residues of the previously used pesticides were below the limits of detection. It can be concluded that these white hop shoots are better antioxidants than hop cones and hop leaves, and that they do not contain any pesticide residues

Physico-Chemical Properties, Composition and Oxidative Stability of Camelina sativa Oil

Camelina sativa is a cruciferous oilseed plant. With the aim of describing the general characteristics of the oil obtained from the seeds of plants grown in Slovenia and of comparing it to camelina oil from other countries we determined some physico-chemical properties, fatty acid composition, iodine and saponification value and followed its oxidative stability under different storage conditions. The density at 20 °C was (0.927 0.0001) g/cm3 and the refractive index reached 1.4756 0.0001 at 25 °C. The analysis of fatty acids showed 10.3 % of saturated and 55.8 % of polyunsaturated acids, with 16.9 % of linoleic (C18:2), 35.2 % of -linolenic (C18:33) and 1.6 % of erucic acid (C22:1). Determination of oxidative stability of this highly unsaturated oil revealed that the formation of primary oxidation products was affected by photooxidation. The peroxide value, PV, of fresh oil was (2.38 0.01) meq O2/kg, while after 1 month in daylight at room temperature PV reached (21.0 0.1) meq O2/kg. When stored in darkness PV was (8.12 0.08) meq O2/kg. In the fresh oil, the p-anisidine value, AV, was 6.2 0.1, after 11 months at room temperature 10.4 0.1, and after the same time at 8 °C in darkness 7.1 0.1. Susceptibility to oxidation of camelina oil was measured by the Rancimat test and expressed as the induction period. In fresh camelina oil the induction period was 4.8 h

Impact of selected polyphenolics on the structural properties of model lipid membranes – a review

This review is a presentation of data gathered on the interactions of several polyphenolics (i.e., phenolic acids, stilbenes, flavonoids) with lipid bilayers of different lipid compositions. These polyphenolics have been investigated through a combination of fluorescence spectroscopy, electron paramagnetic resonance spectroscopy, and differential scanning calorimetry, to detect changes in membrane fluidity. Among the investigated phenolic acids, the least polar phenolic acid, p-coumaric acid, has the greatest effect on lipid membrane structure. It appears to have a greater ability to cross membranes by passive transport than more polar phenolic acids. On the other hand, among the flavonoids that have been studied, the anthocyanins cyanidin 3-glucoside and its aglycone are inactive. All of the flavonols tested, except for epigallocatechin-3-gallate, promote small decreases in membrane fluidity. Computer simulation of electron paramagnetic resonance spectra for flavonoids indicated two or three regions in the phosphatidylcholine/ phosphatidylserine (2.4:1) membrane with different fluidity characteristics. The effects of the different flavonoids are correlated to their structural characteristics, whereby even the difference in one -OH group can be important, as can the number of H-bonds they form. The role of membrane composition and flavonoid structure in these interactions with lipid membranes are of great importance for bioavailability of these compounds and for their biological effects in an organism</p

Relationships between Xanthohumol and Polyphenol Content in Hop Leaves and Hop Cones with Regard to Water Supply and

Abstract: The effect of water supply – especially of drought stress – on the content of some secondary metabolites in hops (Humulus lupulus L.) was studied. The experiment took place in 2006. Some relevant data from 2005 were included for comparison. Leaves and cones of nine hop cultivars grown under field conditions as well as in a pot experiment under three water regimes were analyzed. The cultivars ranged from those most grown in Slovenia to promising crossbreed being tested. Leaves were sampled from July 18, 2006 to August 18, 2006, while cones were picked in the time of technological maturity. Standard analytical methods were applied to determine the contents of xanthohumol, polyphenols and α-acids in hop leaves and hop cones. The contents of the secondary metabolites in question depended more on the cultivar under investigation than on the water supply, at least as far the growing conditions for a relatively normal development of the plant were met