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101.
Cavit Bircan Sheryl A. Barringer Ulku Ulken & Rahsan Pehlivan 《International Journal of Food Science & Technology》2008,43(8):1492-1498
Three hundred and thirteen of 2643 dried fig, two of eighty hazelnut, sixteen of twenty-eight pistachio, five of ten peanut and nineteen of twenty-three paprika samples for export from Turkey were contaminated with total aflatoxins in the range of 0.2–162.76, 5.46–6.55, 2.31–63.11, 0.75–26.36 and 1.79–6.55 μg kg−1 , respectively. Samples were collected from January to August 2007 and tested for aflatoxins (B1 , B2 , G1 and G2 ) by immunoaffinity column extraction using RP-HPLC. Fifty-six of the 313 dried fig, all of the contaminated hazelnut and pistachio, two of the sixteen peanut and three of the nineteen paprika samples exceeded the regulatory limits of the European Union. The ratio of the different types of aflatoxin present in each sample exhibited great variability. For example, of 313 contaminated fig samples, 159 contained only aflatoxin B1 , eighty-five contained B1 (49.7%) + G1 (50.3%), twenty-two contained only G1 , twenty contained B1 (89.4%) + B2 (10.6%), thirteen contained B1 (73.7%) + B2 (10.8%) + G1 (15.5%) and fourteen contained all four types, B1 (26%) + B2 (2.5%) + G1 (66.5%) + G2 (5%). 相似文献
102.
Power Thomas G.; McGrath Marianne P.; Hughes Sheryl O.; Manire Sarah H. 《Canadian Metallurgical Quarterly》1994,30(6):980
To provide data on the development of compliance and self-assertion toward mothers and fathers, 2-, 4-, and 6-yr-old children were observed in their homes. Compared with younger children, older children were more compliant, more likely to use logical argument, and less likely to ignore or to show defiance. Two-year-olds showed more ignoring of their fathers, whereas 4-yr-olds were more ignoring of their mothers and showed greater compliance to their fathers. Regardless of age, boys showed higher levels of compliance to their fathers, whereas girls did not respond differentially to mothers or fathers. Girls were, however, more likely to state their desires and preferences and to use logical argument. Further analyses suggested that none of the gender differences in child response were apparent artifacts of differences in parental treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
103.
Matthews Karen A.; Wing Rena R.; Kuller Lewis H.; Meilahn Elaine N.; Kelsey Sheryl F.; Costello E. Jane; Caggiula Arlene W. 《Canadian Metallurgical Quarterly》1990,58(3):345
We investigated the psychological and symptom consequences of the natural menopause in a longitudinal study of 541 initially premenopausal healthy women. All women were given an extensive evaluation at baseline. After 3 yrs of follow-up, 69 women ceased cycling for 12 months; another 32 women had ceased cycling and had taken hormone replacement therapy for a total of 12 months. These women were reevaluated in a clinic examination identical with the baseline examination, as were 101 age-matched premenopausal control women. Comparison among groups at the baseline and follow-up examination showed that natural menopause led to few changes in psychological characteristics, with only a decline in introspectiveness and an increase in reports of hot flashes being apparent. We conclude that natural menopause did not have negative mental health consequences for the majority of middle-aged healthy women. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
104.
Abstract: Volatile compounds were quantified in the headspace of Indian, Vietnamese, and Brazilian cashews, both raw and during roasting by selected ion flow tube‐mass spectrometry. The optimum roasting times based on color measurements were also determined. Raw cashews were oil roasted for 3 to 9 min at 143 °C and color and volatiles measured. An excellent correlation, following a pseudo 1st‐order reaction, was found between L* value and roasting time; darkness increases as roasting time increases. The optimum roasting time was 6, 8, and 9 min for Vietnamese, Indian, and Brazilian cashews, respectively. Raw cashews had lower concentrations of volatiles than roasted cashews. Most volatiles significantly increased in concentration during roasting of Brazilian, Indian, and Vietnamese cashews. Only a few volatiles significantly decreased during roasting. Ethanol and 1‐heptene significantly decreased during roasting in Brazilian cashews and toluene decreased in Vietnamese cashews. Brazilian cashews had significantly higher levels of most volatiles than Indian and Vietnamese cashews. Most volatile levels in Indian and Vietnamese cashews were not significantly different. Of the volatiles, Strecker aldehydes, including methylbutanal, 2‐methylpropanal, and acetaldehyde, were at the highest concentration in roasted cashews. The Maillard reaction contributed to the formation of most of the volatiles in cashews from the 3 countries. There was also degradation of sugars to form furan‐type compounds and oxidation of lipids to form alkanals such as hexanal. Practical Application: The volatile profile during roasting of cashews can be used to determine the best roasting time for each type of cashew. The rate of color development and the production of volatiles differ for the cashews from the 3 geographical locations. 相似文献
105.
In the confectionery coating industry, hard butters are frequently used as cocoa butter replacers. An electrohydrodynamic (EHD) system, which forms fine droplets with a relatively narrow size distribution, may be beneficial in confectionery coating to produce more even coverage. The objective of this study was to determine the effect of lecithin content and fat type on electrical resistivity and apparent viscosity, and the effect of these variables under EHD (25kV) and non-EHD coating on droplet size, width of coating area, thickness, and minimum flow rate to produce complete coverage. Total of 3 different types of fat were used: cocoa butter, cocoa butter equivalent, and lauric butter. As lecithin content increased, resistivity and apparent viscosity decreased, except all samples showed a local apparent viscosity minimum at 0.5% lecithin. EHD coating was more efficient than non-EHD as a smaller droplet size and thinner coating was formed. Due to repulsive forces between the like-charges on the droplets during EHD, it spread over wider areas which lead to a higher minimum flow rate to get complete coverage. Under EHD, increasing resistivity significantly increased the droplet size, but only at the highest resistivities. There was no correlation between resistivity and droplet size or width of coating under non-EHD. The width of coating under EHD decreased significantly as resistivity increased. Thickness and minimum flow rate to produce complete coverage, significantly correlated to resistivity, for EHD coating, and to apparent viscosity, for 2 of the 3 fat types during both EHD and non-EHD. PRACTICAL APPLICATION: Electrohydrodynamic (EHD) spraying offers great potential improvement to the food industry especially in the confectionery area. From the quality point of view, EHD offers greater and more complete coverage than non-EHD coating. From the economic point of view, lower cost can be achieved for coated food because during EHD, smaller droplet size and thinner coating is produced. 相似文献
106.
Sheryl A. Tittlemier Robert Trelka Mike Roscoe Michael Tran Don Gaba Veronique Barthet 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2016,33(6):1003-1009
A method using QuEChERS sample preparation with liquid chromatography polarity-switching tandem mass spectrometry was developed and validated for the analysis of quinclorac and its degradation product quinclorac methyl ester in canola seed. The method was used to analyse canola treated with quinclorac, harvest sample composites and samples of canola shipments. Quinclorac residues were present in all samples of canola treated with a quinclorac-containing herbicide that were analysed. Quinclorac was found in 93% of samples, with an average of 0.018 mg kg–1. All samples contained quinclorac methyl ester, with an average of 0.061 mg kg–1. The average concentration of total residues (as quinclorac equivalents) on treated canola was 0.075 mg kg–1, with a range of 0.016–0.124 mg kg–1. The observed residues were all at least 10 times lower than the Canadian maximum residue limit of 1.5 mg kg–1. Quinclorac and quinclorac methyl ester were not found in any harvest and export composite samples, which represented the majority of canola grown in western Canada in 2015 and canola exported in late 2015. Even though usage of quinclorac-containing herbicide on canola can result in the presence of low concentrations of residues, the absence of quinclorac residues in harvest and shipment samples suggests that use of quinclorac-containing herbicide was not widespread, and that any residues present were diluted as canola was combined along the grain-handling chain into shipment lots, or segregated and prevented from entering shipment lots. 相似文献
107.
Tomy GT Pleskach K Arsenault G Potter D McCrindle R Marvin CH Sverko E Tittlemier S 《Environmental science & technology》2008,42(2):543-549
1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) is used primarily as an additive flame retardant. Technical grade TBECH consists of near equimolar amounts of two (of a possible four) diastereoisomers: rac-(1R,2R)-1,2-dibromo-(4S)-4-((1S)-1,2-dibromoethyl)cyclohexane ((alpha-TBECH) and rac-(1R,2R)-1,2-dibromo-(4S)-4-((1R)-1,2-dibromoethyl)cyclohexane (beta-TBECH). The two other possible isomers, gamma- and delta-TBECH, appear in the technical mixture when heated at temperatures above 120 degrees C. Careful selection of GC-capillary column length was critical in resolution of the two main diastereoisomers. Column lengths of 60 or 30 m (0.25 microm film thickness) resulted in incomplete separation of the alpha- and beta-isomers, while on a 10 m column, the isomers were baseline separated. The gamma- and delta-isomers could not be resolved on any column length in this study. Increased injector port temperature induced thermal conversion of the alpha- and beta-isomers to gamma- and delta-TBECH. Electron impact ionization (EI) was used to provide specificity because no characteristic ions in the electron capture negative ionization (ECNI) mass spectrum of TBECH were evident. In EI, the dominant ions in the mass spectrum corresponded to a concomitant loss of HBr and Br from the molecular ion; the biggest peak in this ion cluster (m/z 266.9208) was used for quantitation and the second biggest peak (m/z 264.9227) was used for confirmation. Beluga (Delphinapterus leucas) blubber extracts of animals from the Canadian Arctic (n=29) were analyzed using low resolution (LR) MS and high resolution (HR) MS run at a resolving power of 10,000. beta-TBECH was the only isomer observed in the samples and was detected in 17 samples. The LRMS technique appeared to overestimate beta-TBECH concentrations compared to HRMS, suggesting a small interference arose at the nominal mass monitored. This potential interference also led to some false positive and negative values (n=7) based on the expected ion ratio of the quantitation and confirmation ions. Observed concentrations of the beta-isomer as measured by HRMS ranged from 1.1 to 9.3 ng/g (lipid weight). 相似文献
108.
Tomatoes and cardiovascular health 总被引:6,自引:0,他引:6
Diet is believed to play a complex role in the development of cardiovascular disease, the leading cause of death in the Western world. Tomatoes, the second most produced and consumed vegetable nationwide, are a rich source of lycopene, beta-carotene, folate, potassium, vitamin C, flavonoids, and vitamin E. The processing of tomatoes may significantly affect the bioavailability of these nutrients. Homogenization, heat treatment, and the incorporation of oil in processed tomato products leads to increased lycopene bioavailability, while some of the same processes cause significant loss of other nutrients. Nutrient content is also affected by variety and maturity. Many of these nutrients may function individually, or in concert, to protect lipoproteins and vascular cells from oxidation, the most widely accepted theory for the genesis of atherosclerosis. This hypothesis has been supported by in vitro, limited in vivo, and many epidemiological studies that associate reduced cardiovascular risk with consumption of antioxidant-rich foods. Other cardioprotective functions provided by the nutrients in tomatoes may include the reduction of low-density lipoprotein (LDL) cholesterol, homocysteine, platelet aggregation, and blood pressure. Because tomatoes include several nutrients associated with theoretical or proven effects and are widely consumed year round, they may be considered a valuable component of a cardioprotective diet. 相似文献
109.
110.
Haigwood Nancy L.; Mullenbach Guy T.; Moore Gregory K.; DesJardin Lucy E.; Tabrizi Azita; Brown-Shimer Sheryl L.; Stauss H.; Stohr H.A.; Paques Eric-Paul 《Protein engineering, design & selection : PEDS》1989,2(8):611-620
Mutations were directed to specific regions of the human tissue-typeplasminogen activator (t-PA) gene in an effort to better definestructurefunction relationships of the enzyme. Threetypes of modifications were effected by in vitro mutagenesis:elimination of glycosylation sites; substitutions of amino acidsat the cleavage site for conversion of single-chain t-PA totwo-chain t-PA; and truncations of the N- and C-termini. Thirteenvariants were purified from permanent CHO cell lines and analyzedfor specific activity, fibrin stimulation, fibrin binding, inhibitionby plasminogen activator inhibitor-2 (PAI-2) and half-life.The results of these analyses are: (i) variants with carbohydratedepletedkringle domains possessed higher specific activities than wild-typet-PA; (ii) a cleavage site variant substituted at Arg275 withGly had greatly reduced specific activity; (iii) two variantssubstituted at Lys277 exhibited altered interactions with PAI-2;(iv) the variant with a truncated C-terminus had reduced activityin the absence of fibrin; and (v) no variants had significantlyaltered halflives. In order to test the effects of combiningmutations, four additional variants were produced. Each combinationvariant retained at least one of the altered properties observedin the original variants, and in three of the variants the diverseproperties were additive. 相似文献