Drying Oil Research Articles

Fourier Transform Infrared Spectra of Drying Oils Treated by Irradiation

Drying oils, such as linseed oil and tung oil, have the potential as coating materials to improve barrier properties of biobased packaging films. Oil drying is a chemical reaction in which polyunsaturated fatty acids undergo autoxidation. During drying, oils polymerize and form water-resistant films. However, drying rates tend to be too slow for practical applications. Metal driers are used in the paint industry to accelerate drying, but often driers are not safe for food contact. The objective of this work was to investigate the effect of ionizing radiation on the oxidation or drying rate of drying oils. The effect of irradiation dose on the drying rate of linseed and tung oils was monitored by FTIR spectroscopy. The peak at 3010 cm (-1) was found to be a useful index of oxidation rate. The decrease in peak intensity with time was fitted with exponential functions of the form Abs = Abs 0 exp (- t/ k), where Abs 0 is the initial absorbance and 1/ k is the rate constant for the oxidation process. Values for k were 9.91 ( R (2) = 0.98), 6.59 ( R (2) = 0.95)n and 6.44 ( R (2) = 0.97) for radiation levels of 0, 50, and 100 kGy, respectively. The k values suggested that the oxidation rate increased as the radiation dose increased from 0 to 50 kGy. A further increase to 100 kGy had only a limited effect.

Historic Consolidants for Wooden Works of Art in Saxony - An Investigation by GC-MS and FTIR Analysis

This paper deals with the materials used in conservation treatments in the first half of the twentieth century for the preservation and consolidation of wooden art objects from the Saxony region in Germany. The use of such materials must be seen as early attempts to find a conservation treatment for wood. The documentation of conservation treatments provides a reference to the application of oils and oil–resin mixtures. The results from the chemical analysis of samples of historic preservatives from the beginning to the middle of the twentieth century (so-called 'Puckelin') carried out by gas chromatography–mass spectrometry (GC-MS) and Fourier transform infrared (FTIR) analysis confirm the use of tung oil as a drying oil, whereas the use of linseed oil cannot be excluded. Colophony and, probably, amber varnish were used as resinous constituents. There are indications that a conservation material dating from the second half of the twentieth century most likely contained rapeseed oil.

A Comparison of Important Physical and Chemical Characteristics of Six Lallemantia iberica (Bieb.) Fisch. and Mey. Varieties

Lallemantia iberica seed contains up to 30% of a drying oil. Lallemantia iberica seed has traditional uses as reconstitute, stimulant, diuretic and expectorant. The aim of this study is to determine suitable varieties in term of oil content and oil quality. The Lallemantia iberica varieties investigated are Shahindej, Sanandaj, Shazand, Ahar, Dezphul and Myandoab. We were sure about seed`s freshness, because ourselves had been sowing and in researching field of Agricultural and Natural Sources Research Center of west Azerbaijan in Iran. Important characteristic of this varieties including: 1000-seed weight, oil content and fatty acid components were selected and measured. Weight measurements performed by balance with 0.0001 g sensitivity. The overall mean for 1000-seed weight was 4.87 g. Oil content based on dry seed was measured using extraction with Ether method and the grand mean was 28.05%. The mean amount of 1000-seed weight and specific fatty acids are meaningful at 1% level. Analysis of variance revealed the existence of significant variation for oil content at 1% level of significance. The mean amount of the five fatty acids namely Palmitic, stearic, oleic, linoleic and linolenic were 8.07, 2.48, 17.24, 17.33 and 51.22%, respectively, which were detected and measured by gas chromatography. According the results that obtained from our study it is clear that the variety of Shahindej has high (35.04%) oil content, is an appropriate variety for oil extraction, and the variety of Ahar contents high level of Linolenic acid (56.37%).

Hydrophobised sawdust as a carrier for immobilisation of the hydrocarbon-oxidizing bacterium Rhodococcus ruber

Pine sawdust treated by a series of hydrophobising agents (drying oil, organosilicon emulsion, n-hexadecane and paraffin) was examined as carrier for adsorption immobilisation of hydrocarbon-oxidizing bacterial cells Rhodococcus ruber. It was shown that hydrophobising agents based on drying oil turned out to be optimal (among the other modifiers examined) for the preparation of sawdust carriers suitable for the efficient immobilisation. The results obtained demonstrate promising possibilities in developing a wide range of available and cheap, biodegradable cellulose-containing carriers that possess varying surface hydrophobicity.

Pitfalls in drying oils identification in art objects by gas chromatography

Drying oils identification in art objects is an important step in the scientific investigation of the artifact which provides conservators and art historians with valuable information concerning materials used and painting techniques applied. The present communication is devoted to pitfalls and troubleshooting in drying oils identification by means of GC-MS analysis of fatty acids composition in a microsample of an art object. We demonstrate that in the case of nonlinear instrument response the ratios of palmitic to stearic (P/S), distinctive for each oil type and used for drying oil identification, depend on sample dilution so that different dilutions of the same sample can give different P/S ratios. This phenomenon can hinder drying oil identification and lead to erroneous interpretations. This is an important observation as nowadays very often the P/S ratio is calculated from the corresponding peak area ratios or by the use of one-point calibration method. In these approaches, the linearity of the instrument response is not controlled and ensured. In the case analyzed, the nonlinear instrument response was attributed to incomplete sample evaporation in the injector. Packing of the glass liner with deactivated glass wool improved the sample evaporation and ensured the linearity of the instrument response and independence of the P/S ratio from sample dilution.

Proximate Composition and Selected Physicochemical Properties of the Seeds of African Oil Bean (Pentaclethra marcrophylla)

Flour produced from the seeds of African oil bean (Pentaclethra marcrophylla) was evaluated for proximate chemical composition, some mineral constituents and physicochemical properties of the ether extract. The results showed that the seed contained 5.3% moisture, 47.4% fat/oil, 36.2% protein, 1.5% ash and 9.6% carbohydrate. The mineral content of the defatted seed flour was found to be Na (236.2), K (181.3), Ca (104.5), P (101.6) and Fe (34.8) ppm. The proximate and mineral compositions suggest that the seed, as a che ap source of protein, oil and macro minerals, may find a good use as human food or b e incorporated into animal feed. The oil was found to have a saponification value of 189.85, iodine value 161.95, acid value 7.01, unsaponifiable matter 36, specific gravity 0.890 and a refractive index of 1.465. The high degree of unsaturation makes it suitable for cooking purposes and for use as a drying oil for cosmetics, paints and varnishes.

Identification of drying oils in mixtures of natural binding media used for artistic and historic works by capillary electrophoresis

AbstractTo characterise the technologies and to find the appropriate treatments, the identification of the binding media of artistic and historic objects is of high importance for the restorer and conservator. Often applied together with other binders, in the present paper, the applicability of a CZE method was ascertained for the identification of the constituents of drying oils in mixtures with animal glues and/or plant gums. The drying oils are identified after alkaline hydrolysis due to their content of long‐chain saturated and unsaturated fatty acids (palmitic, stearic, oleic, linoleic, linolenic) and shorter‐chain dicarboxylic acids (pimelic, suberic, azelaic, sebacic). The dicarboxylic acids occur as products of the unsaturated acids by oxidative degradation during the drying process. The possible interferences in CE caused by the other binders are amino acids and/or monosaccharides. Such interferences could be expected as indirect UV detection has to be used, which is highly unspecific. It was found that none of the constituents of the animal glues or plant gums migrate in the time window of the analytes, thus not obstructing the identification of the analytes in any of the oil mixtures with one binder, or with a combination of both. No interference is observed even in excess of the glues. The method was applied for the identification of a drying oil in a paint layer from a ceremonial mask originating from Papua New Guinea. There is evidence that the oil is most probably from candlenut tree (Aleurites moluccana).

Characterisation of natural polysaccharides (plant gums) used as binding media for artistic and historic works by capillary zone electrophoresis

The monosaccharide constituents of plant gums were separated by capillary electrophoresis at pH 12.1 and detected with indirect UV absorbance. The plant gums investigated were gum arabic, gum acacia, gum tragacanth, cherry gum and locust bean gum (carob gum). The monosaccharides obtained after hydrolysis with 2 M trifluoroacetic acid and lyophilisation of the hydrolysate were arabinose, galactose, mannose, rhamnose, xylose, fucose, and glucose, and the two sugar acids galacturonic and glucuronic acid, in accordance with the literature. They were separated in a background electrolyte consisting of NaOH to adjust the pH, 20 mM 2,6-pyridinedicarboxylic acid as chromophore for detection and 0.5 mM cetyltrimethylammonium bromide as additive to reverse the electroosmotic flow. Based on their electropherograms, the plant gums could be identified by their typical composition (depicted in a decision scheme) as follows: a peak of glucuronic acid, together with that of rhamnose, is indicative for gum arabic. Peaks of galacturonic acid and fucose point to gum tragacanth. Locust bean gum shows a major peak for mannose (with the concomitant galactose peak in ratio 4–1), whereas a glucuronic acid and a mannose peak together with a prominent arabinose peak indicates cherry gum. The method was applied to identify the plant gums in samples like watercolours and in several paint layers like gum tempera or those with egg white or drying oils as additives. Artificial aging experiments of thin layers of gum arabic on paper or glass carried out with UV-A radiation (366 nm) did not result in changes of the saccharide patterns, in contrast to the simultaneously conducted aging of a drying oil layer.

Properties of Zein Films Coated with Drying Oils

Zein films prepared by resin were coated with either flax oil or tung oil and cured by UV- or gamma-radiation. Coated zein films were then evaluated for tensile and water barrier properties. Film microstructure was examined by transmitted light microscope. Tensile strength, elongation, and toughness of oil-coated samples increased substantially with respect to uncoated films. Flax oil coated samples showed an increase in elongation of 300%. It was suggested that oil coatings fill in pinholes and cracks existing in zein films, affecting their mechanical properties. Water vapor permeability also decreased statistically for coated film (except for tung oil coated-UV treated films), suggesting water vapor transfer was controlled by film hydrophobicity and microstructure. Moreover, the liquid water transmission rate of coated films was at least 10 times slower than for control films. Examination of film microstructure revealed that flax oil coatings had uniform coverage and smooth finish, which explained their high elongation, low water vapor permeability. Tung oil coatings cured under UV light showed patterns of intertwined dark and light regions, which may be caused by cross-linking and drying at different times. The oriented structures were found when tung oil coatings were cured by gamma-radiation.

A DSC study of the effect of lead pigments on the drying of cold pressed linseed oil

Cold pressed linseed oil and paints prepared using the inorganic pigments; lead white and red lead, were characterised using non-isothermal differential scanning calorimetry (DSC) in an air atmosphere to determine the effect of the pigment on the oxidative polymerisation of the drying oil medium. For each paint sample, the onset temperature for oxidation was reduced from 166°C to the range 50 to 60°C when a heating rate of 5 K min –1 was used. In order to determine the rate of drying, the non-isothermal experiments were carried out using a range of heating rates. A change in the mechanism oxidative polymerisation was observed as the heating rate was increased.

Modifying The Drying Property Of Rubber-Seed Oil

Rubber-seed oil, a semi drying oil, was modified by boiling and blowing process in the presence of a drier to enhance its drying property. The oil boiling and blowing process was carried out with variation in temperature, time and type of drier used. The levels of unsaturation of the oil in the natural and modified states were determined by the iodine value using Wij's method. The effects of temperature, time and type of drier used on iodine value and viscosity of the modified oil were examined. It was found that low iodine value and high viscosity of the boiled and blown oil enhanced the drying property of the oil and these two parameters were used to select oil samples for putty making. Putty was prepared using the selected oil samples and whiting. The best operating conditions (local optimum) for the oil modification process, which gave the best putty, were determined by testing the quality of the putty in terms of adhesion, cohesion, drying time and colour. The local optimum conditions for the oil modification process were found to be boiling and blowing with lead grains either at 150oC for 3 hours or at 200oC for 2 hours. KEY WORDS: Rubber-seed oil, boiling, blowing, drying property, putty. Global Journal of Engineering Research Vol.3(1&2) 2004: 17-20

Production of linolenic acid in yeast cells expressing an omega‐3 desaturase from tung (Aleurites fordii)

AbstractTung oil is an industrial drying oil containing ca. 90% PUFA. We previously reported on enzymes required for the synthesis of linoleic (6% of FA) and eleostearic (80%) acids and here describe the cloning and functional analysis of an omega‐3 FA desaturase (FAD3) required for the synthesis of linolenic acid (1%). The tung FAD3 cDNA was identified by screening a tung seed cDNA library using the polymerase chain reaction and degenerate primers encoding conserved regions of the FAD3 enzyme family. Expression of this cDNA in yeast cells, cultured in the presence of linoleic acid, resulted in the synthesis and accumulation of linolenic acid, which accounted for up to 18% w/w of total cellular FA. Tung FAD3 activity was significantly affected by cultivation temperature, with the greatest amount of linolenic acid accumulating in yeast cells grown at 15°C. The amount of linolenic acid synthesized in yeast cells by tung FAD3 is ca. 10‐fold higher than that observed by expression of a rapeseed (Brassica napus) FAD3 in yeast, suggesting that tung FAD3 might be useful for biotechnological production of omega‐3 FA in transgenic organisms.

Characterization of bile acids and fatty acids from ox bile in oil paintings by gas chromatography–mass spectrometry

Characterization of ox bile, traditionally used in painting, is of interest in the fields of archaeometry and conservation and restoration of works of art. Bile acids, fatty acids (F), and cholesterol found in ox bile have been identified using a derivatization method that combines the formation of ethyl esters from the carboxylic groups and the trimethylsilyl ethers from hydroxyl groups. This method of analysis is consistent with these others proposed by the authors to analyze drying oils, proteins, and diterpenic resins usually used as binders and varnishes by the painters. Bile acids from binary samples such as animal glue/ox bile, casein/ox bile and Arabic gum/ox bile have been successfully analyzed using the proposed method. Finally, a method of analysis of mixtures of drying oil and ox bile has been also proposed attempting to quantitatively characterize samples in which ox bile was added to the drying oil for increasing the surfactant properties.

Evaluation and characterization of the seed oils of Trichosanthes cucumerina (snake gourd) and Ricinodendron heudelotii (honey plum)

The estimation of the chemical composition and physical properties of the seed oils of Trichosanthes cucumerina and Ricinodendron heudelotii using standard methods of analysis showed that the seed of T. cucumerina and R. heudelotii have high oil content (46.3±4% and 42.5±5% respectively). Assessment of the physical constants revealed that Ricinodendron heudelotii had a low heat of combustion (12.9 ± 3kcal/g) when compared to that of Trichosanthes cucumerina (32.8 ± 4kcal/g). The refractive indices at 400C, boiling point, smoke point and flash points were high in the two oils. Their relative densities were high and their melting points were low. From the chemical parameters, the high ester value and saponification values of T. cucumerina and R. heudelotii qualifies them to be used in industries for soap making, while the high iodine value for R. heudelotii (158.8 ± 8gI/100g oil) qualifies it as a drying oil and suggest possible usefulness in the paint industry. Their percentage free fatty acid and acid values were low suggesting increased stability and usefulness in nutritional and industrial applications. Key Words: seed oil, chemical composition, Trichosanthes cucumerina, Ricinodendron heudelotii. (Global Journal of Pure and Applied Sciences: 2003 9(2): 217-220)

Characterization of Natural Resin Films and Identification of Ancient Coating

Typical Japanese natural resin films, i.e., oriental lacquer films, cashew resin films, and drying oil polymers were characterized, and also an ancient coating was identified using two-stage pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Urushiol, laccol, and thitsiol components, which are the main constituents of the respective oriental lacquers, were detected by the pyrolysis at 400°C. Additionally, the pyrolysis products, which reflect the structure of the urushiol, laccol, and thitsiol polymers, were detected by pyrolysis at 500°C after pyrolysis at 400°C. All the results have shown a significant progress occurring in the side chain-side chain C-C coupling and aromatic nucleus-side chain C-O coupling of urushiol, laccol, and thitsiol concurrently with the formation of the respective lacquer films. The cashew resin film was found to be terminated with saturated cardols and cardanols by the pyrolysis at 400°C. Furthermore, pyrolysis at 500°C revealed that the autoxidative side chain-side chain C-C coupling accelerated the cross-linking of trienyl- and dienylcardanols during the polymerization. The C4-C18 free fatty acids were detected by the pyrolysis of the drying oil polymers. These pyrolysis products are significant markers for a drying oil polymer. The drying oil polymer is terminated with saturated fatty acids, especially with hexadecanoic acid and octadecanoic acid. Based on these results, the ancient coating sample obtained from the surface of a wooden dish excavated at Tobarikyu, Kyoto prefecture, Japan was identified as Rhus vernicifera lacquer combined with an drying oil, presumably added as the solvent. Py-GC/MS was proved to be effective for the characterization of natural resin films and identification of organic coatings of historic artifacts.

Factors affecting oil extraction/water adsorption in sequential extraction processing of corn

AbstractThe sequential extraction process (SEP) uses ethanol to extract oil and protein from cracked, flaked, and dried corn, and the dried corn simultaneously dehydrates the ethanol. Value‐added co‐products are possible, potentially making production of fuel ethanol more economical. The effects of solvent‐to‐corn (S/C) ratio, corn moisture content (MC), and number of extraction stages on ethanol drying, oil recovery, and protein loss during the simultaneous oil extraction/water adsorption step of SEP were evaluated. Extractions were carried out by using both aqueous ethanol and ethanol/hexane blends at 56°C. The S/C ratios tested were 3∶1, 2∶1 (control), 1.5∶1, and 1∶1 (w/w). More anhydrous ethanol, greater oil yields, and less co‐extracted protein were obtained with higher S/C ratios. Less anhydrous ethanol and lower moisture adsorption capacities were obtained when the corn MC was ≥1.12%. Oil yields gradually decreased with drier corn, whereas protein loss increased when corn MC was <1.12%. Reducing the number of extraction stages from seven (original SEP) to five did not affect ethanol drying capability, oil yields, and protein co‐extracted with oil. Using ethanol/hexane blends resulted in more anhydrous ethanol, higher oil yields, and less protein co‐extracted with oil.

Effects of lamination and coating with drying oils on tensile and barrier properties of zein films.

Zein films plasticized with oleic acid have been considered potentially useful for biodegradable packaging applications. However, moisture was found to affect their tensile and gas barrier properties. We investigated the effects of two converting processes, fusion lamination and coating with drying oils, on tensile properties and gas permeability of zein films. Zein films were laminated to 4-ply sheets in a Carver press and coated with tung oil, linseed oil, or a mixture of tung and soybean oils. Tensile properties and permeability to water vapor, oxygen, and carbon dioxide were measured according to ASTM methods. Laminated films were clearer, tougher, and more flexible, and had a smoother finish than nontreated sheets. Lamination decreased O(2) and CO(2) permeability by filling in voids and pinholes in the film structure. Coating increased tensile strength and elongation and decreased water vapor permeability. Coatings acted as a composite layer preventing crack propagation and increasing film strength. They also formed a highly hydrophobic surface that prevented film wetting.

Acceleration of the drying rates of paprika fruit with drying oil and cutting

Summary Paprika fruit (Capsicum annuum L.) were dipped in water (control), cold oil (10% plus 2.5% K2CO3) for 3 min, or hot oil at 65 °C, and left whole or were cut in halves or small pieces. The fruit were dried at 45 °C and ground. The quality of the powder was assessed before and after 8 weeks of storage at 37 °C. Both oil dips and cutting accelerated the drying. Hot oil dipping of whole fruit halved the drying period compared to the control, but cutting the fruit into small sections accelerated the drying most, reducing the drying times by 81%. Combining the oil with fine cutting did not further accelerate drying. The oil dips changed the structure of the surface wax, increasing the water permeability; the cutting opened alternative routes to the cuticle for water movement. Colour intensity and stability increased slightly for cut fruit, but was unaffected by oil. The aroma of water‐dipped samples was ‘hay‐like’, while that of the oil dipped samples was ‘nutty’.

AN UNUSUAL PASTIGLIA-LIKE TECHNIQUE IN THE EIGHTEENTH CENTURY

AN UNUSUAL PASTIGLIA-LIKE TECHNIQUE IN THE EIGHTEENTH CENTURY

Studies on some seeds and seed oils

The chemical compositions of seeds and the physicochemical characteristics of the oils extracted from them have been investigated for six varieties of mango ( Mangifera indica) seeds and for five other tropical seeds. The oil contents of Mangifera indica seeds were in the range 12·2–25·8%, while those of the other seeds were as high as 54·7% in Bridelia ferruginea. Characterization of the oils of Mangifera indica varieties showed that they were non-drying, except for Petters-Ibadan which was semi-drying. Of the other tropical seeds, Monodora myristica gave a drying oil, Crysophilum abidum and Bridelia ferruginea gave semi-drying oils, while Canarium schweinfurthii and Khaya senegalensis gave non-drying oils. The chemical compositions of the seeds suggest they may be suitable as animal feeds.