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- A review of analytical methodologies for the determination of bisphenol A in foodstuffs as result of its migrationPublication . Sanches-Silva, A.; Albuquerque, T.G.; Costa, H.S.Bisphenol A (BPA), 2,2-bis(4-hydroxyphenyl)propane, is a monomer made by combination of acetone and phenol and it is used in the production of polycarbonate, epoxy resins for internal food can lining and in dental sealants. In the last few years, the public interest on the migration of BPA has increased because it is a widespread endocrine disruptor and to have oestrogenic activity. Although polycarbonate plastics are considered stable, BPA can be released from these containers when they are hydrolysed at high temperature and neutral to alkaline pH. BPA can also be released from incompletely polymerized epoxy resins or it can be found in food heated at typical can processing temperatures. According to the European Union (EU) Regulation 10/2011/EU [1], related to plastic materials and articles intending to come into contact with foodstuffs, the use of BPA is permitted in food contact materials. However, the use of BPA for the manufacture of polycarbonate infant feeding bottles is prohibited according to Directive 2011/8/EU [2]. This measure was taken on the basis of the precautionary principle because infants are identified as the particular vulnerable part of the population. The aim of this study was to carry out a review on the sample preparation and analytical methods used to determine BPA in foodstuffs and food simulants as result of its migration. Moreover, special attention was devoted to the migration levels found in different groups of food matrices and food simulants. At last, the factors that most influence BPA migration into foodstuffs was discussed to identify potential risks to the consumer. [1] Commission Regulation (EU) No 10/2011 on plastic materials and articles intended to come into contact with food. OJ L12, 14.01.2011, p.1-89. [2] Commission Directive 2011/8/EU as regards the restriction of use of bisphenol A in plastic infant feeding bottles. OJ L26, 28.01.2011, p.11-14.
- Recent developments in the analytical methods for sterols separation in food matricesPublication . Albuquerque, T.G.; Sanches-Silva, A.; Costa, H.S.Phytosterols (PS) and the related phytostanols are bioactive compounds of many foodstuffs, especially in food items of plant origin, such as vegetable oils, cereal grains, nuts and seeds. PS are known to have several bioactive properties with various implications on human health, including anti-inflammatory, anti-oxidative, anti-carcinogenic activities and cholesterol lowering capacity. Analytical methods are critical elements for the correct and accurate determination of PS. A review of the last three decades, based on compilation of the available information on the different steps (extraction, saponification, derivatization and chromatographic method) of PS determination was performed. The preparation samples for PS analyses should take into account the nature of matrix, its physical sate, among others. Most of the times, ethanolic or methanolic potassium hydroxide are the selected reagents for the saponification, which can be performed at room temperature or with heating. For derivatization, N,O-Bis (trimethylsilyl) trifluoroacetamide (BSTFA) with 1% of trimethylchlorosilane (TMCS) or N-Methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA) are the most used reagents. Capillary gas-chromatography (GC), with flame ionization detector (FID) or mass spectrometry (MS), proved to be simple and accurate to perform analytical determinations on this group of compounds. However, high performance liquid chromatography (HPLC) with different detection systems has also been used. Analysis of PS are best carried out using 30 m x 0.25 mm i.d. x 0.25 µm film thickness, flexible, fused capillary columns coated with 5% phenyl and 95% methyl siloxane, because it has a high thermal stability and provides better resolution of peaks. Some of these columns are supplied under the trade designations: DB-5, HP-5, RTx-5 or CP Sil-8. This review aims to contribute for a better understanding of the analytical approaches adopted to determine PS and to follow the tendency over the last few years to enhance the knowledge towards PS content found in food products.