Quantitation of volatile compounds in heated triolein by static headspace capillary gas chromatography/infrared spectroscopy-mass spectrometry

Static headspace and capillary gas chromatography/infrared spectroscopy-mass spectrometry were used to collect, separate, identify and quantitate the oxidative and thermal decomposition products in heated triolein. Approximately 4 L of triolein was heated in a deep-fat fryer at 190°C for 12 h each day for a total of 60 h, until it contained>-20% polymeric material. The concentration of heptane and octane increased after 12 h heating, then decreased upon further heating, while the concentration of volatile aldehydes decreased gradually during heating. After 12 h of heating, the concentrations of the major volatiles changed as follows: heptane (16.36 to 30.17 ppm), octane (24.48 to 40.77 ppm), heptanal (21.68 ppm to 9.11 ppm), octanal (35.53 to 36.64 ppm), nonanal (68.95 to 43.16 ppm), (E)-2-decenal (135.00 to 89.00 ppm) and (E)-2-undecenal (88.50 to 61.00 ppm). After 60 h of heating, when the oil contained over 20% polymeric material, the concentrations of heptane, octane, heptanal, octanol, nonanal, (E)-2-decenal and (E)-2-undecenal were 5.16, 4.39, 5.45, 7.02, 18.07, 12.50 and 6.00 ppm, respectively.     

An Overview of Potential Factors for Effective Telemedicine Transfer to Sub-Saharan Africa

This paper gives an overview of core factors mitigating effective transfer of TeleMedicine to Sub-Saharan Africa (SSA) as a capability for improving the extremely poor state of healthcare delivery systems in that region of the world. Using specific examples of TeleMedicine applications, such as in TeleRadiology and health education, the paper highlights the importance of TeleMedicine in SSA. It then presents the salient factors that influence TeleMedicine technology transfer in the form of a conceptual framework. In explaining the framework, the paper offers opinions and supportive arguments on the importance and significance of the identified factors in effective TeleMedicine ldquouptakerdquo within the SSA. We believe the framework provides a grounded theoretical basis that information and communications technologies (ICT) or technology transfer researchers can use for empirical investigation in order to understand the efficacy of TeleMedicine adoption within developing countries at large.     

Determination of the depletion of furazolidone residues in chicken tissues using a Bacillus stearothermophilus test

This study assessed the applicability of a Bacillus stearothermophilus test for detection of the depletion of furazolidone anticoccidial drug residues in chicken tissues. Thirty-three Ross breed chicken were dosed orally with furazolidone (2 mg/kg body weight) daily for 5 days. After the last treatment the birds were sacrificed in groups of three at intervals of 1, 3, 6, 10, 24, 48, 144, 240, 360 and 480 h. Liver, kidney and breast muscle samples were collected and immediately analysed at each interval for furazolidone residues. Serum was separated from the blood collected from jugular veins into bottles containing glass beads and analysed. Supernatant from the homogenates was analysed for the presence or absence of furazolidone residues using the B. stearothermophilus test. Semi quantification of furazolidone residues was done by comparing the obtained zones of inhibition on a Bacillus subtilis test plates and the zones from calibrated standard curves. Qualitatively the B. stearothermophilus test was positive for furazolidone residues up to 480 h post treatment in serum samples, 360 h in liver samples, 480 h in kidney samples and 360 h in muscle samples. Semi quantitatively from the B. subtilis test plates, serum samples were observed to have the highest furazolidone concentration of 3.2 μg/ml. The lowest furazolidone concentration was recorded in kidney tissues at 0.21 μg/ml. Kidney and serum tissues appear to be good tissues for testing of furazolidone tissues. The Kidney samples would appear best for post-mortem screening of furazolidone residues while serum could be used antemortem screening of depletion in chicken.     

Bitter taste in cassava roots correlates with cyanogenic glucoside levels

Cassava roots contain cyanogenic glucosides. Malawian farmers classify cultivars into two groups based on the perceived danger of eating raw roots that they associate with bitterness. In the vernacular, cultivars that produce roots with bitter taste are called vyakubaba (bitter), whereas those yielding non‐bitter roots are called vyakuzizra (cool). In the scientific literature they are distinguished as ‘bitter’ or ‘sweet’. Roots from ‘bitter’ cultivars are processed prior to consumption. We studied the ability of farmers to predict the cyanogenic glucoside levels of 492 roots from the 10 most commonly grown cultivars. Twenty‐eight farmers predicted the taste of each of the cultivars that they grew, and scored bitterness on a five‐point scale by tasting the root tip. Thereafter cyanogenic glucosides were determined on half of the root, while a taste panel scored the taste of the other half. The mean cyanogenic glucoside level in 132 roots from ‘cool’ cultivars was 29 mg HCN eq kg^?1 fresh weight (CI 25–33, range 1–123) and in 360 roots from ‘bitter’ cultivars was 153 mg HCN eq kg^?1 fresh weight (CI 143–163, range 22–661). Farmers' distinction of ‘cool’ and ‘bitter’ cultivars predicts glucoside levels. The tasting of the tip of the root improved the farmers' prediction of toxicity. Scoring of bitterness by a trained taste panel showed a stronger correlation with glucoside levels (r² = 0.67). This suggests that cyanogenic glucosides confer the bitter taste, notwithstanding the probability of additional modifying intrinsic factors. Copyright © 2004 Society of Chemical Industry     

Stability of native starch quality parameters,starch extraction and root dry matter of cassava genotypes in different environments

Cassava is an important food and cash crop in Malawi. It is also becoming increasingly important for industrial use. The aim of this study was to investigate the native starch quality of different Malawi cassava genotypes. Trials were conducted at Chitedze and Makoka in Malawi in the 2000/01 season. Apart from root dry matter and starch extraction, starch quality parameters considered included protein, moisture and ash contents, pH and whiteness. Various stability measures were used to deal with the problem of genotype × environment interaction. The results showed that all the cassava genotypes produced starch with no protein and with colour as white as required by the industry. Moisture and ash contents and pH fell within the industry‐recommended ranges. This suggests that native cassava starch is suitable for use in various industries. Additive main effects and multiplicative interaction (AMMI) was strongly correlated with other measured stability parameters and is therefore recommended for stability analysis of starch quality parameters. Genotype had a larger influence than environment on root dry matter. This agrees with the hypothesis that one or a few major genes control root dry matter in cassava. Copyright © 2004 Society of Chemical Industry     

Information infrastructure,governance, and socio-economic development in developing countries

There is growing interest in the role and contribution of national information infrastructure (NII) to the quality of governance and the socio-economic development of nation states. In this paper, we use publicly available archival data to explore the relationships among NII, governance, and socio-economic development in developing countries. Results substantiate a significant relationship between NII and governance, and NII and socio-economic development. The findings suggest that NII have the capacity to contribute to country development, both directly (via impacts on socio-economic development) and indirectly (via its impacts on governance, which in turn influences socio-economic development).     

Quantitation of volatile compounds in heated trilinolein by static headspace-capillary gas chromatography/infrared spectroscopy-mass spectrometry

Static headspace and capillary gas chromatography/infrared spectroscopy-mass spectrometry were used to collect, separate, detect and quantitate the oxidative and thermal decomposition products in heated trilinolein. Trilinolein without added antioxidants was heated in a deep-fat fryer at 190°C for 12 h each day for a total of 24 h until the amount of polymeric material in the oil exceeded 20%. The concentration of the volatile compounds in trilinolein, as well as thep-anisidine values and polymer content, increased with an increase in heating time. After 24 h of heating, the concentrations of the major volatile compounds (>10 ppm) had increased as follows: pentane (33.4–398.7 ppm), pentanal (11.7–73.5 ppm), 1-pentanol (5.2–46.7 ppm), hexanal (67.6–346.1 ppm), (E)-2-hexenal (12.9–87.6 ppm), (E)-2-heptenal (309.6–894.1 ppm), 1-octen-3-ol (35.2–150.2 ppm), formic acid (0–18.7 ppm), hexanoic acid (0–83.8 ppm), heptanal (2.5–29.5 ppm), 2-pentylfuran (29.2–146.9 ppm), (E)-2-octenal (26.4–347.2 ppm), (E)-2-octenal (26.4–347.2 ppm), (E)-2-nonenal (31.6–163.2 ppm), (E,Z)-2,4-decadienal (15.0–320 ppm) and (E,E)-2,4-decadienal (43.1–1137.5 ppm).     

Orientation gradient detection exhibits variable coupling between first- and second-stage filtering mechanisms

We investigated sensitivity to orientation modulation using visual stimuli with bandpass filtered noise carriers. We characterized the relationship between the spatial parameters of the modulator and the carrier using a 2-AFC detection task. The relationship between these two parameters is potentially informative of the underlying coupling between first- and second-stage filtering mechanisms, which, in turn, may bear on the interrelationship between striate and extrastriate cortical processing. Our previous experiments on analogous motion stimuli found an optimum sensitivity when the ratio of the carrier and modulator spatial frequency parameters (r) was approximately ten. The current results do not exhibit an optimum sensitivity at a given value of the ratio r. Previous experiments involving second-order modulation sensitivity show an inconsistent range of estimates of optimum sensitivity at values of r between 5 and 50. Our results, using a complementary approach, confirm these discrepancies, demonstrating that the coupling between carrier and modulator frequency parameters depends on a number of stimulus-specific factors, such as contrast sensitivity, stimulus eccentricity, and absolute values of the carrier and modulator spatial frequency parameters. We show that these observations are true for a stimulus limited in eccentricity and that this orientation-modulated stimulus does not exhibit scale invariance. Such processing can not be modeled by a generic filter-rectify-filter model.     

Volatile compounds in heated oleic acid-esterified propoxylated glycerol

Static headspace and capillary gas chromatography, in combination with infrared and mass spectrometry, were used to collect, separate, identify, and quantitate the oxidative and thermal decomposition products in two heated model compound triacylglycerols, oleic acid-esterified propoxylated glycerol (EPG-08 oleate) and triolein. The EPG-08 oleate and triolein were each heated in a deep-fat fryer at 192±8°C for 12 h each day until the oil contained ≥20% polymeric material. Most of the volatile compounds identified in heated triolein and EPG-08 oleate were associated with the oxidative and thermal decomposition of oleates, such as short-chain alkanes, aldehydes, and alcohols. The major volatile compounds (concentration >20 ppm) in heated EPG-08 oleate and triolein were heptane, octane, heptanal, octanal, trans-2-decenal, nonanal, and trans-2-undecenal. However, a few minor volatile compounds, not previously found in heated fats and oils, were identified in the heated EPG-08 oleate samples. These compounds included 1,2-propanediol, 1-hydroxy-2-propanone (hydroxyacetone), 1-acetoxy-2-propanone (acetoxyacetone), 2-ethyl-4-methyl-1,3-dioxolane, 2,2,4-trimethyl-1,3-dioxolane, 2-heptyl-4-methyl-1,3-dioxolane, and 4-methyl-2-octyl-1,3-dioxolane. Alkyl-substituted dioxolanes have been found in heated methyl linoleate.