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A simple and rapid method was developed for the determination of erucic acid in rapeseed oil by single bounce attenuated total reflectance (SB-ATR) Fourier transform infrared (FTIR) spectroscopy. The various ratios prepared from the three different types of oils (rapeseed, canola, and sunflower) were run on gas chromatograph to identify amount of erucic acid. Therefore, a wide range of erucic acid (0.5‐ 53.0%) was obtained for the calibration. The partial least squares (PLS) calibration was used for predicting erucic acid using spectral region at 2983‐657/cm. The root mean square error of prediction (RMSEP), root mean square error of calibration (RMSEC), and root mean square error of cross-validation (RMSECV) were also determined to assess the accuracy of the method. The regression coefficient (R 2 ) was obtained 0.999 with least errors of RMSEC (0.12%), RMSECV (1.96%), and RMSEP (1.38%). The accuracy of the FTIR method was evaluated by analyzing canola and rapeseed oil samples by GC-MS and the results of both the techniques were found to be comparable. Practical applications: Generally, GC is used for determination of erucic acid in vegetable oils. But it needs the very laborious process of derivatization of fatty acids into their respective volatile methyl esters. Furthermore, lot of health hazardous chemicals and reagents are involved in the process of derivatization which are potential source for environmental pollution. Generally, FTIR spectroscopy has been recognized as a very simple, rapid, and cost effective technique. During the last decade, several researchers have used multivariate regression to build up calibration models based on FTIR data. The use of multivariate calibration methods is able to provide, estimates of the precision of the analysis, and yields important qualitative, quantitative, and analytical information. The objective of the present study was to develop a simple methodology for the quantitative analysis of low and high levels of erucic acid in canola and rapeseed oil, respectively by SB-ATR FTIR spectroscopy with PLSs regression.

Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of EnvironmentalElectrochemistry, Hlavova 2030, 12843 Prague 2, Czech Republic*e-mail: barek@natur.cuni.czReceived: January 20, 2010Accepted: February 15, 2010AbstractA new simple, fast and sensitive differential pulse voltammetric method was developed for the determination ofdifferent aliphatic phthalates. Dibutyl phthalate, diethyl phthalate, didecyl phthalate, and diallyl phthalate can bedetermined in 0.1 M tetramethylammonium bromide in methanol using a hanging mercury drop minielectrode and ameniscus modified silver solid amalgam electrode. Optimum conditions were found including concentration andcomposition of supporting electrolyte and solvent, scan rate, pulse amplitude, pulse width, etc. Linear calibrationcurves were obtained for 10

A differential pulse voltammetric (DPV) method was developed for the determination of 4-nitrophenol (4-NP) at a newly developed silver amalgam paste electrode (AgA-PE) in Britton–Robinson buffer pH 3.0. The electrode is based on a disposable plastic pipette tip filled with paste amalgam based on a mixture of mercury and fine silver powder (9 : 1, w/w). The experimental parameters, such as pH of Britton–Robinson buffer and activation and regeneration potential of the electrode surface were optimized. The reduction peak current dependences were linear for the concentration of 4-NP from 0.2 to 100 μM. The method showed reproducible results with RSD (n=45) of 1.7%. The limit of determination (LOD) was 0.3 μM. The method was successfully applied for the direct determination of 4-NP in drinking water.

An efficient voltammetric method was developed for the determination of maleic acid at a silver amalgam paste electrode (AgA-PE) in Britton–Robinson buffer pH 2.0. The experimental parameters, such as pH of Britton–Robinson buffer, type of the supporting electrolyte and activation of the electrode surface were optimized. Under the optimal conditions, a linear response was observed over the 2×10−6–1×10−4 mol L−1 maleic acid concentration range, determination limit being 5×10−7 mol L−1. A highly stable response, with a relative standard deviation (RSD) of 1.6% for 45 repetitive measurements of 1×10−4 mol L−1 maleic acid showed that there was no apparent surface passivation indicating the suitability of the method. The method was successfully applied for direct determination of maleic acid in drinking and river water.

The fat contents of 12 brands of biscuits were extracted and evaluated for free fatty acids (FFA) and their fatty acid composition (FAC). The oil content and FFA varied from 13.7 to 27.6% and 0.2 to 1.0%, respectively. The FAC was analyzed by gas chromatography–mass spectroscopy with particular emphasis on trans fatty acids (TFA). Total saturated, unsaturated, cis-monounsaturated and polyunsaturated fatty acids were determined in the range of 37.9–46.9, 53.0–62.0, 12.3–43.7 and 0.1–9.2%, respectively. The high amount of TFA was observed in all biscuit samples and varied from 9.3 to 34.9%. The quantity and quality of the lipid fraction of the biscuits indicated that the all analyzed biscuits are a rich source of fat, saturated fatty acids and trans fatty acids, consequently not suitable for the health of consumers. The high content of trans fatty acids and palmitic acid also indicated that blends of RBD palm oil and partially hydrogenated oil had been used in the biscuit manufacturing.

Antioxidant potential of four Desi chickpeas (Cicer arietinum L.) varieties indigenous to Pakistan, namely Balksar 2000, CM98, Dasht and Winhar 2000, was evaluated. All studied varieties exhibited appreciable total phenolic content (0.92–1.12 mg gallic acid equivalents/g), total flavonoid content (0.79–0.99 mg catechin equivalent [CAE]/g) and condensed tannin content (0.58–0.69 mg CAE/g). In addition, antioxidant activities were tested using 2,2-diphenyl-1-picrylhydrazyl radical (1.05–1.24 µmol trolox/g), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (37.24–45.32 µmol trolox/g), ferric-reducing antioxidant power (0.73–0.90 mmol Fe2+equivalents/100 g) and oxygen radical-absorbing capacity (8.58–11.4 µmol trolox/g). All varieties exhibited appreciable antioxidant potential and significant differences (P

Summary Methanolic extracts of rice bran (MRB) were found to be the richest in phenolics than all the other extraction media, i.e. water, 80% methanol, 70% ethanol, diethyl ether. Thermal stability of MRB was determined by evaluating antioxidant activity of heated extracts in linoleic acid system. Cookies were prepared in sunflower oil premixed with MRB at different concentrations, i.e. 500, 1000 and 2000 ppm, and with butylated hydroxytoluene and α-tocopherol at 200 ppm. Oxidative stability of cookies was measured by storing under ambient conditions for an year with periodical analysis after every 2 months. Fatty acid composition was determined by gas–liquid chromatography. A regular decrease in unsaturated fatty acids (USFA) and increase in saturated fatty acids was observed with the increase in storage period; all the stabilised samples showed appreciably less decrease in USFA than that of control sample. Induction period ranged from 14.73 to 31.22 h while control exhibited 7.5 h. Peroxide value, iodine value and free fatty acids were chosen as the parameters for quality evaluation of cookies. Results suggest rice bran to be a potential source of antioxidants for stabilisation of cookies.

The physico-chemical characteristics of the seeds and seed oils of four citrus species, Mitha (Citrus limetta), Grapefruit (Citrus paradisi), Mussami (Citrus sinensis), and Kinnow (Citrus reticulata) were investigated. The hexane-extracted oil content of citrus seeds ranged from 27.0 to 36.5%. The protein, fiber and ash contents were found to be 3.9–9.6%, 5.0–8.5%, and 4.6–5.6%, respectively. The extracted oils exhibited an iodine value of 99.9–110.0; refractive index (40 °C), 1.4639–1.4670; density (24 °C), 0.920–0.941 mg/mL; saponification value, 180.9–198.9; unsaponifiable matter, 0.3–0.5%; acid value (mg KOH/g of oil), 0.5–2.2 and color (1-in. cell) 1.4–3.0R + 15.0–30.0Y. The oils revealed a good oxidative stability as indicated by the determinations of specific extinctions at 232 and 270 nm (2.3–4.4 and 0.6–0.9, respectively), p-anisidine value (2.2–3.2) and peroxide value (1.6–2.4 mequiv/kg of oil). The citrus seed oils mainly consisted of linoleic acid (36.1–39.8%). Other prominent fatty acids were palmitic acid (25.8–32.2%), oleic acid (21.9–24.1%), linolenic acid (3.4–4.4%), and stearic acid (2.8–4.4%). The contents of tocopherols (α, γ, and δ) in the oil were 26.4–557.8, 27.7–84.1, and 9.1–20.0 mg/kg, respectively. The results of the present study demonstrated that the seeds of citrus species investigated are a potential source of valuable oil which might be utilized for edible and other industrial applications.

Summary Owing to increased concern in a number of diseases associated with low-selenium (Se) foods, the estimation of total Se content (TSC) is the focus of research these days. TSC was determined in fruits, vegetables, meat, milk, poultry, fish and cereals. Hydride generation atomic absorption spectrometric method was employed using the wet digestion method. Different certified reference materials were used for the validation of the method. The lowest Se content was found in plant-based foods, whereas the highest was in fish and appreciable in other animal-based foods. The data was compared with TSC data from other countries. TSC in Pakistani foods was comparable with other countries, with few exceptions. This report may serve as a database for TSC in Pakistani foods.

The present study was accomplished to evaluate the intramuscular fatty acid (FA) composition of different muscles taken from Kundi steers (n = 15), which were approximately 24 months old, fed on a cottonseed cake supplement, and were made to graze on alfalfa pasture for 95 days prior to slaughter. The samples were taken from longissimus dorsi region (loin and ribeye portion) and distal region of semitendinosus muscle for intramuscular FA analysis. Saturated FA, comprising 49.48-52.09% of total FA composition, in all the muscles were studied. Ribeye portion of longissimus dorsi muscle contain relatively higher (P > 0.05) amount of trans FA (3.37%) as compared with loin portion of longissimus dorsi muscle (3.1%) and distal region of semitendinosus muscle (2.84%). The sum of monounsaturated FA in all the muscles studied was estimated in the range of 32.21-34.64%, while polyunsaturated FA contribute 11.39-12.39% of total FA. The mean conjugated linoleic acid was found to be 0.28, 0.35 and 0.41 in ribeye and loin portion of longissimus dorsi muscle and distal region of semitendinosus muscle, respectively.

Interprovenance variation was examined in the composition of Moringa oleifera oilseeds from Pakistan. The hexane-extracted oil content of M. oleifera seeds harvested in the vicinity of the University of Agriculture, Faisalabad (Punjab, Pakistan), Bahauddin Zakariya University (Multan, Pakistan), and the University of Sindh, Jamshoro (Sindh, Pakistan), ranged from 33.23 to 40.90%. Protein, fiber, moisture, and ash contents were found to be 28.52–34.00, 6.52–7.50, 5.90–7.00, and 6.52–7.50%, respectively. The physical and chemical parameters of the extracted M. oleifera oils were as follows: iodine value, 67.20–71.00; refractive index (40°C), 1.4570–1.4637; density (24°C), 0.9012–0.9052 mg/mL; saponification value, 177.29–184.10; unsaponifiable matter, 0.60–0.83%; color (1-in. cell), 1.00–1.50 R+20.00–30.00Y; smoke point, 198–202°C; and acidity (% as oleic acid), 0.50–0.74. Tocopherols (α, γ, and δ) accounted for 114.50–140.42, 58.05–86.70, and 54.20–75.16 mg/kg, respectively, of the oils. The induction periods (Rancimat, 20 L/h, 120°C) of the crude oils were 9.64–10.66 h and were reduced to 8.29–9.10 h after degumming. Specific extinctions at 232 and 270 nm were 1.80–2.50 and 0.54–1.00, respectively. The major sterol fractions of the oils were campesterol (14.13–17.00%), stigmasterol (15.88–19.00%), β-sitosterol (45.30–53.20%), and 5-avenasterol (8.84, 11.05%). The Moringa oils were found to contain high levels of oleic acid (up to 76.00%), followed by palmitic, stearic, behenic, and arachidic acids up to levels of 6.54, 6.00, 7.00, and 4.00%, respectively. Most of the parameters of M. oleifera oils indigenous to different agroclimatic regions of Pakistan were comparable to those of typical Moringa seed oils reported in the literature. The results of the present analytical study, compared with those for different vegetable oils, showed M. oleifera to be a potentially valuable oilseed crop.

This study presents the FA composition and trans FA (TFA) contents of different hydrogenated vegetable oils and blended fats marketed in Pakistan. Thirty-four vanaspati (vegetable ghee), 11 shortenings, and 11 margarines were analyzed. The contents of saturated FA, cis monounsaturated FA, and cis PUFA were in the following ranges: vanaspati 27.8–49.5, 22.2–27.5, 9.3–13.1%; vegetable shortenings 37.1–55.5, 15.8–36.0, 2.7–7.0%; and margarines 44.2–55.8, 21.7–39.9, 2.9–20.5%, respectively. Results showed significantly higher amounts of TFA in vanaspati samples, from 14.2 to 34.3%. Shortenings contained TFA proportions of 7.3–31.7%. The contents of TFA in hard-type margarines were in the range of 1.6–23.1%, whereas soft margarines contained less than 4.1% TFA.

Determination of oxidative stability of different edible oils, fats, and typical fat products was made using the Rancimat method and the active oxygen method. Induction periods (IP) were recorded under controlled conditions at 110, 120, and 130 ± 0.1°C for all products and over a range of 100–160°C for selected fats. A general oil stability evaluation industrial shortenings and vanaspati to be the most stable fats, with IP ranging from 10.00 to 15.47 h. Margarine and butter samples (IP, 4.98–6.04 h) were also found to show fair oxidative stability. Among the extracted and open-market salad-grade cooking oils, rapeseed oil (IP, 4.10 h) and soybean oil (IP, 4.00 h) showed the highest oxidative stability, whereas Salicornia bigelovii oil (IP, 1.40 h) was the least stable. The induction periods of typical fat products ranged from 2.59 to 9.20 h. CV for four determinations were

Cellulose acetate (CA) is well known glassy polymer used in the fabrication of gas-separation membranes. In this study, 5,11,17,23-tetrakis(N-morpholinomethyl)-25,26,27,28-tetrahydroxycalix[4]arene (CL) was blended with CA to study the gas-permeation behavior for CO2, N2, and CH4 gases. We prepared the pure CA and CA/CL blended membranes by following a diffusion-induced phase-separation method. Three different concentrations of CL (3, 10, and 30 wt %) were selected for membrane preparation. The CA/CL blended membranes were then characterized via Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction analysis. The homogeneous blending of CL and CA was confirmed in the CA/CL blended membranes by both SEM and AFM analysis. In addition to this, the surface roughness of the CA/CL blended membranes also increased with increasing CL concentration. FTIR analysis described the structural modification in the CA polymer after it was blended with CL too. Furthermore, CL improved the tensile strength of the CA membrane appreciably from 0.160 to 1.28 MPa, but this trend was not linear with the increase in the CL concentration. CO2, CH4, and N2 gases were used for gas-permeation experiments at 4 bars. With the permeation experiments, we concluded that permeability of N2 was higher in comparison to those of CO2 and CH4 through the CA/CL blended membranes. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39985.