To date, monosodium glutamate is the most used flavour enhancing food additive. Because high levels of glutamate are toxic to brain concerns appeared regarding the safe use of glutamate and there is a 10 g kg
concentration limit in foodstuff. A simple HPLC-UV method, based on a derivatization procedure with
-phthaldialdehyde, was developed for determination of glutamate in meat products, soup bases and vegetable concentrates. Even if our method is less sensitive than the HPLC-fluorescence ones widely available, it is able to measure amounts at least 200 times smaller than the maximum allowed one, has good reproducibility (CV under 2% for intraday and under 3% for interday determinations), linearity and accuracy. Less expensive HPLC systems are required and the formed derivative is very stable (at least 1 week), good separation is obtained with the less expensive 5 μm particle C
columns and methanol as organic phase. Concentration of free glutamate ranged between 0.14 g kg
in sausage without added glutamate to as high as 2.16 g kg
in a pork sausage. Concentration in vegetable mixes and soup bases were between 80–120 g kg
This study examines the occurrence of aflatoxins (AFS) and ochratoxin A (OTA) in bread and durum wheat samples. A total of 141 samples were collected from eleven different regions of Turkey. An analytical method based on liquid extraction, immunoaffinity column (IAC) clean-up followed by high performance liquid chromatography (HPLC) was used for the determination of AFs and OTA levels. As a result, AFs and OTA were detected in 2% and 9.2% of wheat samples at concentrations varying from 0.21 to 0.44 µg kg−1 and from 0.1 to 3.2 µg kg−1, respectively. Aflatoxin B1 (AFB1) and aflatoxin B2 (AFB2) were found positive in samples ranging between 0.21–0.35 µg kg−1 and 0.094 µg kg−1, respectively. However, none of the samples contained aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2). The study also recommended that contamination levels in wheat and wheat-based products should be routinely monitored in greater sample numbers to insure food safety.
Artificial sweeteners were introduced in therapy as sugar substitutes for diabetic patients. Nowadays these substances are widely used for sugar substitution in low calorie drinks and sweets. Most commonly used products to date are saccharine, cyclamate, aspartame, and acesulfam; maximum accepted daily intakes are stated for each one.A simple reverse phase (RP18) HPLC-UV method with direct detection (196 nm) was developed by us in order to measure the concentrations of the three sweeteners. No sample preparation is required, other than dilution. Limits of detection are 12 mg l−1, 0.5 mg l−1 and lower than 0.25 mg l−1 for cyclamate, aspartame and saccharine, respectively. Concentrations ranged between 113.14–280.07 mg l−1 in the case of cyclamate, 17.96–50.94 mg l-1 for saccharine, and 9.94–296.82 mg l−1 for aspartame.
://www.journals.istanbul.edu.tr/iuvfd/article/viewFile/1019000921/1019000721 (last accessed 7 December 2014).
O MURTAG , G.Z.
( 2001 ): Determination of Fumonisins B 1 and B 2 in corn and corn-based products in Turkey by HPLC
Ochratoxin A, is a well-known nephrotoxic, hepatotoxic and carcinogenic mycotoxin, produced by some species of mould genera such as Aspergillus spp. and Penicillium spp. under various environmental conditions, such as moisture and temperature. The main sources of Ochratoxin A intake for humans are cereals and cereal derived products, when they are consumed in large quantities, as in the case of breakfast cereals and cereal based baby foods principally consumed by babies. In this study, a total of 150 samples (50 infant formulas, 50 follow-on formulas, and 50 cereal based supplementary foods for infants and children) were obtained randomly from various supermarkets and pharmacies in Istanbul, and 52 out of 150 (34.7%) analysed samples were contaminated with Ochratoxin A. None of the examined baby food samples were above the Turkish Food Codex maximum limit of Ochratoxin A in baby, infant, and young children foods (0.5 μg kg−1). These results reinforce the idea of strict and routine quality controls and good hygiene practices have to be performed in every step of production to minimize the potential risk of Ochratoxin A contamination.
The chemical analysis and antibacterial activity of propolis collected from some parts of Western Algeria were investigated. The ethanolic extracts of propolis (EEP) were evaluated for further investigation. The major constituents in EEP were identified by high-performance liquid chromatography (HPLC) analysis. All EEP samples were active against Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus), but no activity was found against Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli). The mean diameters of growth inhibition of the EEP ranged between 8.05 and 21.4 mm. The propolis extract obtained from Sidi bel Abbés (SFS-SBA) was more active than other samples as well as showed unique HPLC profile. These results support the idea that propolis can be a promising natural food preservative in food industry and alternative candidate for management of bacterial infections caused by drug-resistant microorganisms.
The lycopene content in pulp and peel of five fresh tomato cultivars, most common on Croatian market, was determined by spectrophotometry and the high-performance liquid chromatography (HPLC). Peels from the raw tomatoes contained more lycopene (expressed on a fresh basis) than the pulps: the ratio was 3.75±1.08 for spectrophotometric and 3.50±0.95 for HPLC measurements. Comparison of the results of lycopene content expressed on a dry weight basis revealed that the peel from raw tomato contains 1.74±0.36 times (spectrophotometry) more lycopene than the pulp as compared to a factor of 1.61±0.24 obtained by HPLC analysis. Fraction of the pulp in a whole tomato was found to vary between 89.9 and 95.2%, while that of tomato peel was between 4.9 and 10.1%. Nutritional habits in Croatia often include tomato-based food, all year around, prepared partlyof whole fresh tomatoes (including peel), partly of industrial tomato products (from which peel is often excluded). This study provides evidence that the peel of one of the most common varieties of tomatoes on Croatian market is richer in lycopene than the pulp and, moreover, that a diet including 100 g of raw tomatoes provides 1.35±0.29 mg lycopene from pulp as compared to 0.35±0.18 mg lycopene from tomato peel. In addition, results of this study will be useful in further attempts to quantify lycopene content of intact, whole tomatoes by means of the nondestructive, photoacoustic method.
Oilseeds are very popular edibles that are often used to enhance the fibre content of baked goods, and specific types are used for preserving and seasoning. Polyphenol-related researches have been receiving growing attention in the last 20 years, especially the ones concentrating on stilbenoids. In previous studies, resveratrol concentrations have been determined from oilseeds such as peanut.The aim of our research was to define the composition of oilseeds with a focus on the bioactive compounds, more specifically the resveratrol.Research took place in 2010–2011 at the University of Pécs, Medical School, using non-random, convenience sampling. Oilseeds studied in the research were: sunflower seed, roasted peanut, un-roasted peanut, sesame seed, pumpkin seed, almond, linseed, bio white mustard seed, bio black mustard seed, mustard seed of foreign provenance, and wild black mustard seed. All of these oilseeds can be purchased from trade. Samples used in the research were obtained from the producers and collectors. High Performance Liquid Chromatography (HPLC) was used for the measurements.Summarising our results, it can be stated that each type of oilseed analysed in our research can be regarded as good sources of resveratrol. The highest level of resveratrol was detected in the sunflower seeds (0.00398±0.0001 mg g−1), almonds (0.00176±0.00021 mg g−1), roasted peanut (0.00206±0.00013 mg g−1), and wild black mustard seeds (0.0023±0.0007 mg g−1).
final volume was adjusted to 1 ml using methanol. Finally, the solution was filtered using a 0.45 μm filter for subsequent HPLC-UV analysis. The experiment was carried out in the dark to minimise HN degradation. Samples were immediately analysed after