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1.
J Food Sci Technol ; 53(6): 2817-26, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27478238

ABSTRACT

New active films based on chitosan and polycaprolactone blends and containing α-tocopherol were designed for food packaging applications. Mechanical properties, stability against temperature and swelling degree in 50 % ethanol (v/v) were evaluated. Migration kinetics of α-tocopherol from the developed films into butter and food simulants [50 % ethanol (v/v), 95 % ethanol (v/v), and isooctane] at different temperatures were studied. α-Tocopherol was quantified in the food simulants by means of high performance liquid chromatography with diode-array detection at 292 nm. The proposed method exhibited a good sensitivity with a limit of detection of 0.1 mg/L. The kinetics release of α-tocopherol was characterized by determining the partition and the diffusion coefficients by using a mathematical modeling based on Fick's Second Law. The diffusion coefficients obtained ranged between 1.03 × 10(-13) and 2.24 × 10(-12) cm(2)/s for 95 % ethanol (v/v) at 4 and 20 °C, respectively. Developed films maintained the antioxidant activity for more than 20 days.

2.
Article in English | MEDLINE | ID: mdl-25351874

ABSTRACT

It is a well-known fact that amines are not stable in food of a fatty nature. In this study the synthesis and characterisation of the products obtained as a result of the reaction of amines in a fatty medium are reported. Based on the well-known reactions among amines and acid and esters groups, two novel compounds were synthesised using m-xylylenediamine (mXDA), a primary diamine widely used as monomer in the manufacture of food contact materials and two fatty acids, oleic acid and palmitic acid, which occur in most fats. The resulting compounds were two molecules belonging to the family of fatty acid amides, dioleamide and dipalmitamide. A complete characterisation of both products was carried out employing several techniques such as infrared spectroscopy, (1)H- and (13)C-NMR spectroscopy, electron ionisation mass spectrometry, LC-MS/MS and UV spectrometry. The results obtained by the different techniques were well correlated. In the second part of the work, the formation of these compounds in real samples was evaluated. For this purpose a certain volume of olive oil was spiked with a known amount of mXDA. Olive oil was selected as a fatty medium since it is a widely consumed food and additionally is used as a fatty food simulant in migration studies of food contact materials. A method was developed to extract the fatty acid amides from the fatty matrix, which were then identified by LC-MS/MS. The toxicity of the synthesised compounds was predicted using a toxicity estimation software tool.


Subject(s)
Amides/chemical synthesis , Oleic Acid/chemistry , Palmitic Acid/chemistry , Xylenes/chemistry , Amides/analysis , Chromatography, Liquid , Diffusion , Food Contamination , Food Packaging , Humans , Models, Chemical , Olive Oil , Plant Oils/chemistry , Tandem Mass Spectrometry
3.
Anal Bioanal Chem ; 406(17): 4251-9, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24817346

ABSTRACT

Photoinitiators (PIs) are components of UV-cured inks widely used in printing of food packaging. These substances can migrate into food and may be a hazard to human health. High-performance liquid chromatography with diode-array detection (HPLC-DAD) has been used for analysis of PIs and amine synergists in food packaging. Analysis was performed with a Kromasil C18 column (250 mm × 3.2 mm i.d., 5 µm particle size) with a binary mobile phase gradient prepared from acetonitrile and Milli-Q water. The flow rate was 0.5 mL min(-1). The method enables separation of fourteen PIs and amine synergists in a single run. The method was validated for linearity, repeatability, and limits of detection and quantification. Excellent sensitivity (LODs ≤ 1.56 µg dm(2)) and appropriate repeatability (RSD (n = 10) <0.9%) were achieved. Different types of food packaging material including plastic films, cardboard, and cans were analyzed and PIs were detected in 47% of the samples tested (n = 17). Positive samples were confirmed by use of LC-MS-MS in positive electrospray ionization (ESI) mode.


Subject(s)
Amines/analysis , Chromatography, High Pressure Liquid/methods , Food Contamination/analysis , Food Packaging/instrumentation , Photosensitizing Agents/analysis , Plastics/analysis , Spectrometry, Mass, Electrospray Ionization/methods , Tandem Mass Spectrometry/methods
4.
Article in English | MEDLINE | ID: mdl-20640959

ABSTRACT

Photo-initiators are used in printing inks hardened with UV light and one of the most commonly used photo-initiators is benzophenone (BP). Recent notifications under the Rapid Alert System for Food and Feed have shown migration of 4-methylbenzophenone (4-MBP) from packaging into cereals. A specific migration limit exists for BP of 0.6 mg kg(-1) for its use as an additive in plastics. There is no specific European legislation covering cardboard boxes and/or printing inks for food contact use. However, due to the high levels detected, the European Food Safety Authority (EFSA) published recommendations and the Standing Committee for the Food Chain and Animal Health endorsed a limit of 0.6 mg kg(-1) for the sum of BP and 4-MBP. While studies have been published on photo-initiators in the past, there is a fundamental lack of data on 4-MBP especially for its combined analysis with others. We present an HPLC method with diode array detector to simultaneously determine the levels of BP, 4-MBP as well as 7 other possible derivatives from secondary packaging for food applications. The method was tested and applied to 46 samples of paperboard for secondary packaging collected both from supermarkets and directly from a paperboard supplier. In addition, a survey was conducted on recycled paperboard (n = 19) collected from a supplier, to evaluate the background quantity of BP and other derivatives in recycled board. The most abundant photo-initiator found in the survey was BP, in 61% of samples, and 4-MBP was found in 30% of the samples. It seems that these compounds are used to replace one another. Other derivatives were found in minor quantities. Traces of BP were also found in 42% of the samples of recycled, unprinted board.


Subject(s)
Benzophenones/analysis , Food Contamination/analysis , Food Packaging/instrumentation , Paper , Photosensitizing Agents/analysis , Chromatography, High Pressure Liquid/methods , Edible Grain/chemistry , Reproducibility of Results , Solvents
5.
Talanta ; 77(1): 98-102, 2008 Oct 19.
Article in English | MEDLINE | ID: mdl-18804605

ABSTRACT

In this study, a conventional TEKNOKROMA, Tr-015605 TRACER EXTRASIL ODS2 (25 cm x 0.4 cm, i.d. 5 microm) column and a new stationary phase TEKNOKROMA, Tr-010065 Mediterranea sea(18) (15 cm x 0.4 cm, i.d. 3 microm) were compared for the separation of five phenolic compounds. Sensitivity, performance characteristics, analysis time and method validation were reported for both columns. A better sensitivity and performance were achieved with the novel chromatographic support. In addition the total analysis time was significantly reduced. The method was applied to the determination of the selected polyphenols in commercial available white wines. LC-MS was used as a confirmatory technique.


Subject(s)
Chromatography, High Pressure Liquid/instrumentation , Chromatography, High Pressure Liquid/methods , Flavonoids/isolation & purification , Phenols/isolation & purification , Flavonoids/chemistry , Molecular Structure , Phenol , Phenols/chemistry , Polyphenols , Spectrometry, Mass, Electrospray Ionization
6.
Int J Food Sci Nutr ; 55(4): 259-63, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15369980

ABSTRACT

Thiamin and riboflavin were determined in the sea urchin, Paracentrotus lividus, by reversed-phase liquid chromatography with fluorescence detection and a mobile phase consisting of 72% 0.005 M NH(4)OAc and 28% MeOH at a flow rate of 1.450 ml/min. The total analysis time never exceeded 20 min. After acid hydrolysis and enzymatic digestion, thiamin was oxidized to thiochrome and the oxidized fraction was purified and concentrated by solid-phase extraction. Limits of detection were 9 pg/ml and 80 pg/ml for thiamin and riboflavin, respectively. Good results were obtained with respect to repeatability (RSD%<2.4) and recovery (>91.3%).


Subject(s)
Riboflavin/analysis , Sea Urchins/chemistry , Thiamine/analysis , Animals , Chromatography, High Pressure Liquid/methods
7.
J Chromatogr A ; 1032(1-2): 7-15, 2004 Apr 02.
Article in English | MEDLINE | ID: mdl-15065770

ABSTRACT

A reversed-phase high performance liquid chromatographic (RP-HLPC) method was compared with a gas chromatography-flame ionization detection (GC-FID) method for determining fatty acids in potato crisps. Different extraction procedures were used. Fatty acids were quantified by linear regression. Both methods presented good precision (R.S.D. < or = 5.88%) and recovery (> or = 82.31%). The precision using HPLC method was slightly better than for GC-FID method. There was good agreement between the fatty acid composition of potato crisps analysed by both methods. For most purposes the HPLC method would be better. However, when more fatty acids need to be analysed, GC is a more suitable method.


Subject(s)
Chromatography, Gas/methods , Chromatography, High Pressure Liquid/methods , Fatty Acids/chemistry , Solanum tuberosum/chemistry , Reproducibility of Results
8.
J Chromatogr A ; 1032(1-2): 135-9, 2004 Apr 02.
Article in English | MEDLINE | ID: mdl-15065789

ABSTRACT

A reversed-phase high-performance liquid chromatography (HPLC) method, with a combination of fluorescence and ultraviolet detectors, to determine the folate forms present in commercial macroalgae products form northwest Spain as part of nutritional studies in dehydrated and canned seaweeds is reported. The method includes extraction of folates from seaweed by heat treatment, deconjugation of folate polyglutamates by incubation with hog kidney conjugase and purification by solid-phase extraction (SPE) with strong anion-exchange (SAX) cartridges. Separation was achieved with a Tracer Extrasil ODS 5 microm 25 cm x 0.4 cm column using acetonitrile and potassium phosphate buffer (pH 2.21 as mobile phase. Good results were obtained with respect to repeatability (relative standard deviation (R.S.D.) < or = 4.12%) and recovery (> or = 90.80%). The amount of folate (as folic acid) in the six species ranged from 61.4 to 161.6 microg per 100 g dry mass. In all the seaweeds studied (Himanthalia elongata, Laminaria ochroleuca, Palmaria spp., Undaria pinnatifida and Porphyra spp. and Saccorhiza polychides) the single most abundant form is 5-CH3-H4-folate, except Porphyra and Himanthalia.


Subject(s)
Chromatography, High Pressure Liquid/methods , Folic Acid/analysis , Seaweed/chemistry , Reproducibility of Results , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet
9.
Article in English | MEDLINE | ID: mdl-12013246

ABSTRACT

A simple high-performance liquid chromatography (HPLC) method for determination of major phospholipid classes in sea urchin Paracentrotus lividus is described. The separation was performed on a Tracer Extrasil SI 5 microm 25 x 0.4 cm column and an isocratic mobile phase of acetonitrile-methanol 85%-phosphoric acid (50:50:1.8, v/v). The HPLC method utilizes UV detection at 205 nm. Five phospholipids were identified and quantified: phosphatidylinositol (PI), phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM). Fresh and canned samples were analyzed. Student's t-test showed no significant difference (P < or = 0.05) between the mean phospholipid contents of raw and canned sea urchin.


Subject(s)
Chromatography, High Pressure Liquid/methods , Phospholipids/isolation & purification , Animals , Reproducibility of Results , Sea Urchins , Sensitivity and Specificity , Spectrophotometry, Ultraviolet
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