Yazar "Sherazi, S. T. H." seçeneğine göre listele

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    Application of multivariate chemometric techniques for simultaneous determination of five parameters of cottonseed oil by single bounce attenuated total reflectance Fourier transform infrared spectroscopy
    (Elsevier, 2014) Talpur, M. Younis; Kara, Huseyin; Sherazi, S. T. H.; Ayyildiz, H. Filiz; Topkafa, Mustafa; Arslan, Fatma Nur; Naz, Saba
    Single bounce attenuated total reflectance (SB-ATR) Fourier transform infrared (FTIR) spectroscopy in conjunction with chemometrics was used for accurate determination of free fatty acid (FFA), peroxide value (PV), iodine value (IV), conjugated diene (CD) and conjugated triene (CT) of cottonseed oil (CSO) during potato chips frying. Partial least square (PLS), stepwise multiple linear regression (SMLR), principal component regression (PCR) and simple Beer's law (SBL) were applied to develop the calibrations for simultaneous evaluation of five stated parameters of cottonseed oil (CSO) during frying of French frozen potato chips at 170 degrees C. Good regression coefficients (R-2) were achieved for FFA, PV, IV, CD and CT with value of > 0.992 by PLS, SMLR, PCR, and SBL. Root mean square error of prediction (RMSEP) was found to be less than 1.95% for all determinations. Result of the study indicated that SB-ATR FTIR in combination with multivariate chemometrics could be used for accurate and simultaneous determination of different parameters during the frying process without using any toxic organic solvent. (C) 2014 Elsevier B.V. All rights reserved.
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    Occurrence of ochratoxin A in poultry feeds and feed ingredients from Pakistan
    (Springer Heidelberg, 2015) Sherazi, S. T. H.; Shar, Z. H.; Sumbal, G. A.; Tan, Eddie T.; Bhanger, M. I.; Kara, Huseyin; Nizamani, S. M.
    A study was conducted to evaluate the occurrence of ochratoxin A (OTA) in complete poultry feeds (n=80) and poultry feed ingredients (n=286) from Pakistan. All samples were first analyzed by indirect enzyme linked immunosorbent assay (ELISA), samples with OTA concentrations above the European Union maximum regulatory limit (MRL, 100 mu g/kg) were further confirmed by HPLC-FLD. Contamination frequency and mean OTA levels were 31 % and 51 mu g/kg in feed ingredients, and the corresponding values for complete feeds were 38 % and 75 mu g/kg. Ten samples of complete poultry feed and 19 samples of feed ingredients contained OTA at levels higher than the MRL. The results of the present study indicate that there is a strong need for a more intense monitoring programs for OTA in poultry feed.
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    A simplified FIR chemometric method for simultaneous determination of four oxidation parameters of frying canola oil
    (Pergamon-Elsevier Science Ltd, 2015) Talpur, M. Younis; Hassan, S. Sara; Sherazi, S. T. H.; Mahesar, S. A.; Kara, Huseyin; Kandhro, Aftab A.; Sirajuddin
    Transmission Fourier transform infrared (FTIR) spectroscopic method using 100 mu m KCl cell was applied for the determination of total polar compounds (TPC), carbonyl value (CV), conjugated diene (CD) and conjugated triene (CT) in canola oil (CLO) during potato chips frying at 180 degrees C. The calibration models were developed for TPC, CV, CD and CT using partial least square (PLS) chemometric technique. Excellent regression coefficients (R-2) and root mean square error of prediction values for TPC, CV, CD and CT were found to be 0.999, 0.992, 0.998 and 0.999 and 0.809, 0.690, 1.26 and 0.735, respectively. The developed calibration models were applied on samples of canola oil drawn during potato chips frying process. A linear relationship was obtained between CD and TPC with a good correlation of coefficient (R-2 = 0.9816). Results of the study clearly indicated that transmission FTIR-PLS method could be used for quick and precise evaluation of oxidative changes during the frying process without using any organic solvent. (C) 2015 Elsevier B.V. All rights reserved.