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Oil Quality (oil + quality)
Selected AbstractsOptimization of activated carbon-based decontamination of fish oil by response surface methodologyEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7 2007Åge Oterhals Abstract The effect of activated carbon (AC) adsorption on the reduction of persistent organic pollutants (POP) in fish oil was studied based on response surface methodology at a 5-g/kg AC inclusion level. Pretreatment of the oil by alkali refining and bleaching increased the POP levels. The tested process variables (contact time and temperature) affected the AC adsorption rate and significant first- and second-order response models could be established. Polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/F) showed a very rapid adsorption behavior and the concentration and toxic equivalent (TEQ) level could be reduced by 99%. Adsorption of dioxin-like polychlorinated biphenyls (DL-PCB) was less effective and depended on ortho substitution, i.e. non- ortho PCB were adsorbed more effectively than mono- ortho PCB with a maximum of 87 and 21% reduction, respectively, corresponding to a DL-PCB-TEQ reduction of 73%. A common optimum for both PCDD/F and DL-PCB adsorption could not be identified. AC treatment had no effect on the level of polybrominated diphenyl ether flame retardants. The differences in adsorption patterns may be explained based on molecular conformation. No change in oil quality could be observed based on oxidation parameters. Compliance with present PCDD/F and DL-PCB legislation levels in fish oil can be achieved based on AC adsorption. [source] Correlation between physicochemical analysis and radical-scavenging activity of vegetable oil blends as affected by frying of French friesEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2006Mohamed Fawzy Ramadan Abstract The main goal of the present work was to compare and correlate the results of physicochemical parameters and antiradical performance of some oil blends during deep-frying, which will be an initial indicator for applying antiradical tests for monitoring deep-frying oils. Two oil blends were prepared. The first blend was a mixture (1,:,1, wt/wt) of sunflower seed oil and palm olein (SO/PO) and the second was a mixture (1,:,1, wt/wt) of cottonseed oil and palm olein (CO/PO). The oil blends were evaluated during intermittent frying of French fries on two consecutive days for 16,h, with oil replenishing after 8,h. Changes in the fatty acid profile and some physicochemical parameters (peroxide value, color index, viscosity, total polar compounds and UV absorbance at 232 and 270,nm) were used to evaluate the alterations during frying. A quick spectrophotometric method was developed to assess deep-frying oil quality. With the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, the neutralization of the stable radical DPPH by antioxidants present in the oil during frying was measured. Radical-scavenging activity (RSA) of both oil blends was recorded during frying, wherein the results showed that the SO/PO blend had the highest RSA. It was evident from the results that a proportional correlation and positive relationship existed between the levels of fatty acids and the physicochemical characteristics of the vegetable oil blends and their RSA. The initial results obtained allow us to suggest that antiradical measurements could be used to quantify the oxidative and hydrolytic deterioration of vegetable oils upon frying. [source] Post-harvest storage effect on quantity and quality of rose-scented geranium (Pelargonium sp. cv. ,Bourbon') oil in UttaranchalFLAVOUR AND FRAGRANCE JOURNAL, Issue 6 2005P. Ram Abstract Drying and storage of herbage for 5 days prior to distillation significantly reduced the essential oil recovery as well as oil quality. The study suggested that the geranium green biomass should be distilled afresh for better oil yield and quality in the conditions of Uttaranchal. Copyright © 2005 John Wiley & Sons, Ltd. [source] Determination of essential oil quality index by using energy summation indices in an elite strain of Cymbopogon citratus (DC) Stapf [RRL(J)CCA12]FLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2005Ashok Kumar Shahi Abstract Out of the several accessions of Cymbopogon citratus (DC) Stapf introduced from Central and West India, one accession coded as RRL(J)CCA12, selected through a mass selection technique, was found to have citral (,80%) as the major constituent in its essential oil. Citral has tremendous application in the ,avour and perfume industries. Plant adaptation was judged by quantifying the regression coef,cient (b) value, which was 1.0 using essential oil growth indices. For prediction of essential oil quality index (EOQI), a multiple regression equation was developed for the ,rst time by using essential oil yield/plant and energy summation indices as EOQI (citral %) = 61.6 + 1.09 × essential oil yield/plant (g) - 0.005 × heat use ef,ciency + 0.675 × phenothermal index. For obtaining a better quality of essential oil (citral ,78%), the optimal value of independent variable would be: X1 = 2.49; X2 = 0.018 and X3 = 20.47, where X1, X2 and X3 denote essential oil yield/plant, heat use ef,ciency and phenothermal index, respectively. The validation of the EOQI model is done by correlating the predicted and calculated values of citral (%) which exhibited signi,cant r value = 0.955 at 5% probability level. The thermal requirement of the selectant was ,5500 degree days to exhibit plant maturity in terms of qualitative and quantitative characteristics of its essential oil at 6.0 vegetative lea,ng stage, with attainment of plant height ,1.0 m from previous date of harvest (December 2001). Prediction of essential oil quality by using the mathematical model is helpful for integrating the growth processes and evaluating crop management strategies. Copyright © 2004 John Wiley & Sons, Ltd. [source] Effect of deep-fat frying of potato chips and chicken on the quality of soybean oilINTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 4 2000Daya Goburdhun Abstract The type of products may affect the quality of oil during deep-fat frying. The quality changes in pure soybean oil during frying of potato chips and chicken drumsticks were evaluated and compared. The oil was subjected to continuous frying at 180°C for a period of 315 min. The parameters used to assess the oil quality were peroxide value (PV), iodine value (IV), free fatty acids (FFA), refractive index (RI) and colour. The percentage of oil absorbed by the two products was determined. The oil was also assessed visually for any change in colour, viscosity, turbidity, flavour and deposit. Results showed that, for both products, PV, IV, FFA, RI and colour changed significantly with time (P < 0.05). Potato absorbed oil during frying (6.9%), whereas chicken released fat into the frying medium (2.4%). When the rates of change of the various parameters in the oils were compared for the two products, significant differences (P < 0.05) were noted for PV and colour only. The oil used during the frying of chicken appeared visually to be at a more advanced stage of deterioration. [source] The Dielectric Property of Soybean Oil in Deep-Fat Frying and the Effect of FrequencyJOURNAL OF FOOD SCIENCE, Issue 3 2002C. Inoue ABSTRACT: : Suitability of the dielectric constant for real time and continuous evaluation of frying oil was investigated. Measurements of the dielectric capacitance, in the frequency range 1 kHz to 100 kHz, were made on soybean oil heated at several temperatures (180, 200, 220, and 240 °C) for a few d. Frequency dependence was also measured between 50 Hz and 30 MHz. The dielectric constant of the soybean oil increased with increase in the heating time, and was well correlated with acid value, density, and relative viscosity. Our equipment for measuring capacitance would be available for real time and continuous evaluation of frying oil quality in the food industry. [source] Erratum: The effects of a seaweed extract in addition to nitrogen and boron fertilization on productivity, fruit maturation, leaf nutritional status and oil quality of the olive (Olea europaea L.) cultivar Koroneiki.JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2009Christos Chatzissavvidis, Eleftheria Tsabolatidou., Ioannis Therios, Maria Tasioula, Vassilios Chouliaras The original article to which this Erratum refers was published in Journal of the Science of Food and Agriculture 2009: 89: 984,988 [source] A chromametric method for the rapid assessment of deep frying oil qualityJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2003Xin-Qing Xu Abstract A rapid chromametric method was developed for the assessment of deep frying oil quality based on the strong correlation between colour index and total polar compounds in deep frying oil. Colour indices of frying oil samples, measured by chromameter, decreased significantly during frying and were strongly correlated with frying time (r , 0.95, p < 0.001). Colour indices of a set of oil samples taken from 0 to 80 h of deep frying were also significantly correlated with total polar compounds of the same samples determined using the official method of the American Oil Chemists' Society (r = 0.96, p < 0.001). The equation for conversion of the colour index (x) to the content of total polar compounds (y) in an oil sample is y = 0.0174x2 , 2.9506x + 124.34. In addition, colour indices of 10 different types of frying oils were strongly correlated with the corresponding contents of total polar compounds in the oils with samples taken from 0 to 80 h of deep frying in duplicate (r = 0.95, p < 0.001, n = 220). The results of colour index analyses agreed well with the results of chemical and sensory analyses of the frying oils tested. This chromametric method is rapid, convenient and reliable. Copyright © 2003 Society of Chemical Industry [source] Effect of harvest time and storage conditions on almond kernel oil and sugar compositionJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 4 2003Ioannis Kazantzis Abstract The effect of storage for 6 months at 5,°C (80% RH) versus 20,°C (60% RH) of shelled versus in-shell almonds was studied on early versus late harvested nuts from ,Ferragnes' and ,Texas' trees. Kernel quality characteristics, oil composition and sugar composition were determined initially and after 6 months of storage. Early harvested almonds had similar kernel weight to but higher moisture content than late harvested almonds after 6 months of storage. Early harvested almonds also had similar oil quality (based on ultraviolet absorption coefficient measurements) and oil composition but lower sugar content and modified sugar composition compared with late harvested almonds. Storage of shelled almonds resulted in kernels with higher oil content, better oil quality, similar oil composition, similar sugar content and some modifications in sugar composition compared with in-shell stored almonds. Finally, storage for 6 months at either 5 or 20,°C resulted in lower moisture content, higher oil content, similar oil quality and composition, similar sugar content and some modifications in sugar composition compared with freshly harvested almonds. Almonds stored at 5,°C retained higher kernel weight and moisture content than almonds stored at 20,°C. © 2003 Society of Chemical Industry [source] Intraspecific olive diversity assessed with AFLPPLANT BREEDING, Issue 2 2003F. Sanz-Cortés Abstract Amplified fragment length polymorphism (AFLP) was used to study diversity within and among Spanish olive varieties. A high degree of diversity was found among the varieties present in each growing region. Olive oil production and quality relies on appropriate cultivar selection as well as good orchard management. Production based only on a few superior cultivars would result in improved yield, oil quality, and production management. Amplified fragment length polymorphism were evaluated as a tool to identify the intraspecific and intravarietal diversity of olive. Amplified fragment length polymorphism analysis of 38 accessions belonging to 10 cultivars using six primer combinations produced 106 polymorphic bands. Results were analyzed for similarity among accessions via unweighted pair-group means cluster analysis, resulting in 10 clusters corresponding to named variety designations. Similarity among varieties ranged from 0.60 to 0.72. Diversity within varieties was identified. Similarity within named varieties (accessions with the same varietal name) ranged from 0.75 to 0.96. Differences in several markers were found among 34 accessions. Intravarietal diversity was shown to exist within the Spanish olive varieties grown in the region surrounding Valencia. [source] Modification of sunflower oil quality by seed-specific expression of a heterologous ,9-stearoyl-(acyl carrier protein) desaturase genePLANT BREEDING, Issue 2 2002P. Rousselin Abstract The coding sequence of ,9-stearoyl-(acyl carrier protein) desaturase from Ricinus communis was introduced into sunflower, under the control of seed-specific promoter and terminator sequences of the late embryogenesis abundant gene from sunflower, Hads10. Two independent primary transformants contained three and six copies of the T-DNA, as demonstrated by hybridization using nptII as a probe. The transgene proved genetically stable and was transmitted as a Mendelian trait. Transcript analysis of the heterologous ,9-stearoyl-(acyl carrier protein) desaturase under control of the Hads10 promoter verified tissue-specific expression in the developing embryos and not in the leaves. Fatty acid composition of the seed oil was followed over five generations under greenhouse and open field conditions. Some of the transgenic lines produced oil with a significantly reduced stearic acid content compared with non-transformed plants under greenhouse and field conditions. However, additional studies need to be performed to assess whether or not physiologically stable lines can be developed from these transgenic lines. [source] | |||||||||||||