Guilan Science and Technology Park

Rasht, Iran

Guilan Science and Technology Park

Rasht, Iran
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Yavari A.,University of Tehran | Hamedi M.,University of Tehran | Heshmati A.,Hamadan University of Medical Sciences | Haghbin S.,Guilan Science and Technology Park
Lipid Technology | Year: 2010

Even though trans fatty acids (TFAs) are present in natural sources such as foods from ruminant origins, the development of partially hydrogenated vegetable oil contributed to a significant increase in total TFAs consumption in humans. Currently, TFA consumption is considered to be a risk factor for coronary heart diseases. Researchers are now starting to discover that not all TFAs behave in a similar manner, that is, isomer specificity may be found. Among non-conjugated TFAs, plant originated TFAs (mainly elaidic and linolelaidic acids) are particularly linked to increased risk for coronary heart diseases, while animal originated TFAs (mainly vaccenic acid) are not. Among conjugated TFAs, two major isomers of conjugated linoleic acid (CLA), cis-9, trans-11 and trans-10, cis-12, show distinctive biological activities. A number of clinical trials of CLA with effects on body composition have been reported, but effects on coronary heart disease risk factors have been inconsistent. Meanwhile, safety concerns regarding CLA, in particular isomer specificity, have also been raised. Thus, it is critical to identify isomer specific effects of TFAs on particular risk factors, to determine their health impact. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gheibi S.,Guilan Science and Technology Park | Karimi-Maleh H.,Kerman Graduate University of Technology | Khalilzadeh M.A.,Islamic Azad University | Bagheri H.,Islamic Azad University at Takestan
Journal of Food Science and Technology | Year: 2013

The electrocatalytic oxidation of ascorbic acid (AA) has been studied by p-aminophenol modified carbon nanotubes paste electrode (APMCNTPE). Cyclic voltammetry (CV) and chronoamperometry were used to investigate the suitability of AP as a mediator for the electrocatalytic oxidation of AA in aqueous solution. The oxidation of AA occurs at a potential about 320 mV less positive than with the unmodified carbon paste electrode at pH 7.0. The catalytic reaction rate constant, kh was calculated (2.257 × 103 M−1s−1) using chronoamperometry. The differential pulsevoltammetric (DPV) peak currents of the electrode increased linearly with the corresponding AA concentration in the range of 2.0 × 10−7 M – 1.2 × 10−4 M with a detection limit of 8.0 × 10−8 M. The influence of pH and potential interfering substances on the determination of AA were studied. Finally, the proposed method was also examined as a selective, simple and precise electrochemical sensor for the determination of AA in real samples such as fruit juices and fresh vegetable juice. © 2013, Association of Food Scientists & Technologists (India).

Yavari A.,University of Tehran | Heshmati A.,Hamadan University of Medical Sciences | Hamedi M.,University of Tehran | Haghbin S.,Guilan Science and Technology Park
Food Chemistry | Year: 2011

Moisture and fat contents are two important parameters in quality evaluation of fried chicken nuggets. This study was undertaken to evaluate moisture and fat contents of fried breaded chicken nuggets using VIS/NIR hyper-spectroscopic technique. Breaded nugget samples were fried for different times in hydrogenated soybean oil in order to obtain various levels of moisture and fat contents. Reflectance spectra of samples were collected within the range of 400-1750 nm using a spectro-radiometer. Partial least squares (PLS) calibration models were developed for quantitative evaluation of the two parameters. The R2 and root mean square error (RMSE) for each prediction were calculated to assess the prediction capability of the model. R2 values of 0.92 were obtained from cross validation of calibration for total moisture and fat contents. Validation of the calibration resulted in RMSE of 0.105 for moisture content and 0.017 for fat content predictions. VIS/NIR spectral analysis was proved to be a straightforward and fast method for prediction of the two important parameters of fried breaded chicken nuggets (moisture and fat) and once the calibration model was developed, the VIS/NIR instrument was capable of doing the analysis in few min. © 2010 Elsevier Ltd. All rights reserved.

Abdolmohammadi S.,University of Tehran | Pirelahi H.,University of Tehran | Balalaie F.,Guilan Science and Technology Park | Balalaie S.,K. N. Toosi University of Technology
Heterocyclic Communications | Year: 2010

Dihydrochromeno[4,3-b]chromenone derivatives were synthesized successfully via a pseudo three-component reaction of salicylaldehyde derivatives with 4-hydroxycoumarin in a ratio of 1:2 respectively in aqueous media catalyzed by diammonium hydrogen phosphate (DAHP) or S-proline at room temperature. This later modified by a solvent-free approach without catalyst at 80°C. These are the first reports on the synthesis of dihydrochromeno[4,3-b]chromenones by these procedures. The application of these methods to corresponding products are highlighted that can be adopted for simple operation, easy work-up, high yields, high-speed (specially under solvent-free approach) and environmentally benign procedure.

Yavari A.,University of Tehran | Heshmati A.,Hamadan University of Medical Sciences | Haghbin S.,Guilan Science and Technology Park
JAOCS, Journal of the American Oil Chemists' Society | Year: 2010

The oxidative oil stability index (OSI) of seven frying oils studied decreased exponentially during the frying process. The slope of the linear equation obtained from the plotting of the logarithms of OSIs versus frying times, which was considered to be a measure of the rate of OSI decrease during the frying process, was significantly different for the oils. The results of the present study confirmed that the OSI determined via the Rancimat test on the original oil cannot guarantee or predict the actual frying performance of the oil but it is considered that this method can be useful to act as a "screening" test and eliminate the possibility of introducing lower stability oils into the production area with all the attendant consequences. There was a strong correlation (r2 = 0.9949) between the OSI and total polar compounds (TPC) of the frying oils (y = 52.00 x-0.9766). Assuming that 25% of TPC is the maximum level permitted in frying oils, the OSI of used frying oils should be ≥2.31 h. There was a power relationship (y = 121.2 x-1.0423) between the OSI and carbonyl value (CV) with a high determination coefficient (r2 = 0.9856). Assuming that 50 μmol/g of CV is the maximum level permitted in frying oils, the OSI of used frying oils should be ≥2.11 h. © 2010 AOCS.

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