22 research outputs found

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

    Get PDF
    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

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

    Get PDF
    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

    Interlaboratory study on lipid oxidation during accelerated storage trials with rapeseed and sunflower oil analyzed by conjugated dienes as primary oxidation products

    Get PDF
    11 Páginas.-- 5 Figuras.-- 2 Tablas.-- Material suplementarioAccelerated storage tests are frequently used to assess the oxidative stability of foods and related systems due to its reproducibility. Various methods and experimental conditions are used to measure lipid oxidation. Differences between laboratories make it necessary to determine the repeatability and reproducibility of oxidation tests performed under the same conditions. The objective of the present interlaboratory study was to evaluate the outcome of a storage test for two different bulk oils, sunflower oil (SFO) and rapeseed oil (RSO), during a period of 9 weeks at 20°C, 30°C, 40°C, and 60°C. Sixteen laboratories were provided with bottled oils and conducted the storage tests according to a detailed protocol. Lipid oxidation was monitored by the formation of conjugated dienes (CD) and the activation energy (Ea) was determined for comparative purposes and statistically evaluated. An increase in CD formation was observed for both oils when the storage temperature was increased in all laboratories. The Ea,1 ranged from 47.9 to 73.3 kJ mol−1 in RSO and from 27.8 to 62.6 kJ mol−1 in SFO, with average values of 58.2 and 46.8 kJ mol−1, respectively. The reproducibility coefficients were 10.9% and 18.2% for RSO and SFO, respectively. Practical applications: In order to compare results on oxidative stability of foods derived from different studies, the reproducibility of storage tests and methods employed to evaluate the oxidation level should be considered. This study provides fundamental data on the reproducibility of lipid oxidation under accelerated storage conditions and defines important parameters to be considered for the conduction of experiments.Open access funding enabled and organized by Projekt DEAL. We thank Brökelmann + Co – Oelmühle GmbH + Co for the donation of the vegetable oils. The authors gratefully acknowledge Lina Stuthmann from the Food Technology Division, Kiel University and Inge Holmberg from the National Food Institute, Technical University of Denmark for their skillful help.Peer reviewe

    Voda v živilih

    Full text link

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

    Get PDF
    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

    Adsorpcijske izoterme vode na nekaterih vzorcih malodekstrina

    Full text link

    The temperature dependence of dynamic viscosity for some vegetable oils

    Full text link

    Eyringsche Aktivierungsfunktionen der Viskosität einiger höherer Alkohole in Cyclohexan

    No full text

    Camelina (Camelina sativa (L.) Crantz) oilcake – untapped resource of phenolic compounds

    No full text
    The work includes a comprehensive study of phenolic compounds, their occurrence and identification in the residues after pressing of the oil from camelina seeds of Slovenian origin, i.e. oilcake. In addition, the efficiencies of antioxidant determinations using different methods according to different mechanisms are presented. These data demonstrate that almost all of the phenolic compounds in these seeds remain in the seed oilcake. The following antioxidants were confirmed: sinapine, 4-vinylphenol, 4-vinylguaiacol, 4-vinylsyringol, 4-vinylcatechol, ellagic acid, protocatechuic acid, <em>p</em>-hydroxybenzoic acid, sinapic acid, salicylic acid, catechin, quercetin and quercetin glucoside. The oilcake has high reducing power and radical scavenging activity. Heat treatment of seeds affects the amount of free, soluble and insoluble bound phenolic compounds as well as antioxidant capacity of individual fractions. Potential applications of camelina oilcake in the food industry are further justified by comparisons with other oilcakes and synthetic antioxidant

    Relevance and Standardization of In Vitro Antioxidant Assays: ABTS, DPPH, and Folin–Ciocalteu

    No full text
    Trolox, gallic acid, chlorogenic acid, caffeic acid, catechin, epigallocatechin gallate, and ascorbic acid are antioxidants used as standards for reaction with chromogenic radicals, 2,2-diphenyl-1-picrylhydrazyl (DPPH⋅) and 2,2′-azino-bis-3-ethylbenzotiazolin-6-sulfonic acid (ABTS⋅+), and Folin–Ciocalteu (FC) reagent. The number of exchanged electrons has been analyzed as function of method and solvent. A majority of compounds exchange more electrons in FC assay than in ABTS and DPPH assays. In reaction with chromogenic radicals, the largest number of electrons was exchanged in buffer (pH 7.4) and the lowest reactivity was in methanol (DPPH) and water (ABTS). At physiological pH, the number of exchanged electrons of polyphenols exceeded the number of OH groups, pointing to the important contribution of partially oxidized antioxidants, formed in the course of reaction, to the antioxidant potential. For Trolox, small impact on the number of exchanged electrons was observed, confirming that it is more suitable as a standard compound than the other antioxidants
    corecore