Avaliação da autenticidade de Alheiras de caça por identificação específica de espécies

A produção de diferentes enchidos tradicionais é uma práti-ca enraizada em várias regiões do país, em particular no Nordeste Transmontano onde é produzido um produto mui-to apreciados por diversos consumidores, nomeadamente a alheira. A alheira é um produto cárneo tradicional, fumado e fermentado, cuja origem remonta ao final do século XV e se relaciona com a presença de comunidades Judaicas nesta região. Naquela data, sendo frequente o consumo de enchi-dos pela população Cristã e sendo o porco uma espécie não consumida pelos Judeus, para evitar serem facilmente iden-tificados pela Inquisição pelos seus diferentes hábitos ali-mentares, estes começaram a produzir um enchido com forma similar à da cozinha Cristã, mas usando carne de aves em vez de porco. A receita foi, eventualmente, passando através de gerações e tornou-se popular também entre os Cristãos, sendo atualmente produzida com base numa mis-tura de carne e gordura de porco, carne de aves, pão de trigo, azeite, alho, sal e especiarias [1]. Dado o seu sucesso, nos últimos anos, têm surgido novas versões deste tipo de enchido, entra as quais se destacam as alheiras de caça. Estas distinguem-se das suas congéneres tradicionais pelo facto de incluírem na sua composição carne de caça, a qual pode ser adicionada total ou parcialmente em relação à car-ne utilizada na sua confeção.info:eu-repo/semantics/publishedVersio

Characterization of Three Portuguese Varietal Olive Oils Based on Fatty Acids, Triacylglycerols, Phytosterols and Vitamin E Profiles: Application of Chemometrics

In Portugal, olive oil production is considered an ancient activity, where old olive groves can still be observed. In the last few years monovarietal groves seem to be increasing, though some disadvantages, such as the susceptibility to insects and diseases, can result from the growth of individual olive varieties (Aguilera et al., 2005). In some typical producer countries, the olive cultivation is being improved by renewing old trees, reducing the association with other crops, selecting the olive varieties suited to local agroclimates and planting new single variety orchards (Criado et al., 2008). This is leading to an increase in the prevalence of monovarietal olive oils

Riscos e benefícios associados ao consumo de carne de caça

A caça de animais é praticada pelo homem desde tempos ancestrais, tendo sido uma das principais fontes de nutrien-tes/alimentos na era pré-histórica. Com o progredir da civili-zação, e principalmente após o desenvolvimento da agricul-tura e a domesticação de animais, a importância da carne de caça como meio de subsistência diminuiu substancialmente em várias regiões do globo. Contudo, atualmente continua ainda a ser de grande relevância em diversos países, princi-palmente nos chamados países subdesenvolvidos e em vias de desenvolvimento, sobretudo Africanos, mas também Asiáticos, nos quais a carne de animais selvagens é frequen-temente consumida e também alvo de trocas económicas [1].info:eu-repo/semantics/publishedVersio

Polymerase chain reaction for soybean detection in heat processed meat products

Since vegetable proteins are considerably cheaper than muscle proteins, they are frequently used as meat extenders in order to reduce the cost of the final product. Due to several interesting characteristics, soybean is reported to be the most widely used vegetable protein in the meat industry. Nevertheless, soybean is included in the group of 12 ingredients potentially allergenic, which should therefore be labelled according to the Codex Alimentarius FAO/WHO and the European Commission (Directive 2003/89/EC). In fact, it has been described that amounts of soy bellow 0.1% and 1% (w/w) can lead to allergic reactions in sensitive consumers (1)

Hypericum species identification to assess the authenticity of plant food supplements

In the last years, medicinal plants and derived products have become increasingly available in the EU market as ingredients of formulations sold as food supplements. This type of products is legally considered as food under the Directive 2002/46/EC [l], thus with legal responsibility of its safety relying on business operators as they are not under the control of the European Medicines Agency (EMA).This work has been supported by FCT through grant PEst-C/EQB/LA0006/2013 and project EXPL/DTP-SAP/1438/2013 (Safety of PIant Food Supplements: searching for adulterant pharmaceutlcal drugs and plants)info:eu-repo/semantics/publishedVersio

Real time polymerase chain reaction for the quantitative detection

Soybean protein is reported to be the most widely used vegetable protein in the meat industry. Several characteristics of soybean protein such as the emulsifier properties, preventing the coalescence of fat during heating, and the increased capacity of water-holding improving the texture of the final product are reasons for its generalised use. However, as soybean is included in the group of ingredients potentially allergenic, if not declared, it can be considered a hidden allergen, representing a potential risk to sensitised individuals. Various methods have been proposed for the detection of soybean in food products, mainly based on the analysis of proteins, such as immunological assays, electrophoretic and chromatographic methods. Due to the higher stability of nucleic acids when compared to proteins and to their ubiquity in every type of cells, DNA molecules have been the target compounds for species identification in several recent works [1]. The aim of this work was to develop highly sensitive and fast DNA-based techniques as alternative to the currently used protein-based methods. For that purpose, binary mixtures of soybean protein in pork’s meat were prepared. In a previous stage of this project, qualitative PCR techniques were successfully applied in the species-specific PCR detection of soybean lectin gene in Frankfurt type sausages [2]. In the present work, we propose a novel approach for the quantitative detection of soybean in processed meat products by means of real-time PCR coupled with fluorescent TaqMan probes. The assays involved the amplification targeting an eukaryotic DNA fragment with specific primers and probe as reference gene for quantification. The amplification of soybean lectin gene was performed in parallel reactions using specific primers and probe. With the values of cycle threshold (Ct) a calibration standard curve was obtained using the Ct method, allowing the detection and quantification of soybean protein in pork’s meat in the proportions of 0.1% to 50%. The established real-time PCR technique was successfully applied in the confirmation of qualitative PCR results and in the estimation of soybean protein in commercial meat products

SYBR green I real-time polymerase chain reaction as a tool to detect poultry’s meat adulteration with pork’s meat

Nowadays, meat species adulteration in ground and comminuted products is being considered as a widespread problem in retail markets [1]. This problem encompasses many issues, such as adulteration by substitution with lower value meats, the presence of undeclared species and the fraudulent substitution of meat by lower price vegetable proteins. Another issue to be considered is related to religious practices since pork’s meat consumption is sometimes forbidden. Several techniques are currently used for meat species identification in complex mixtures, including different protein-based methods such as HPLC, ELISA and electrophoretic techniques. Nevertheless, these methods can be significantly less sensitive and difficulties can arise in the case of thermally processed foods. Due to the higher stability of DNA molecules compared to proteins, and to its ubiquity in every type of cell, they are currently preferred as target compounds for meat species identification. Moreover, the analysis of DNA coupled with polymerase chain reaction (PCR) presents a fast, sensitive and highly specific alternative to protein-based methods [2]. In the present work, the development of a real-time PCR technique for pork’s meat detection in complex matrices is reported. To achieve this objective, DNA was extracted from reference binary meat mixtures containing known percentages of pork’s meat. The real-time PCR approach was based on the specific amplification targeting the 18S rRNA mitochondrial gene for pork species detection and targeting a eukaryotic DNA fragment as a reference gene for quantification. The amplification products were monitored by using the fluorescent dye SYBR Green I associated with melting curve analysis to verify the specificity of obtained fragments. Under our experimental conditions, pork and eukaryotic detection systems produced fragments with 149 bp and 140 bp, and with melting temperatures of 83.5ºC and 87.5º, respectively. Calibration curves were obtained with the cycle threshold (Ct) values by using the Ct method. The detection and quantification of pork’s meat was achieved in the range of 0.1% to 25%, with a high correlation coefficient (R2=0.9943) and a PCR efficiency of 88.7%. The developed methodology was successfully validated using blind samples and applied to the quantitative evaluation of pork’s meat in different poultry processed meat products, including sausages, hamburgers and nuggets

Assessing the variability of the fatty acid profile and cholesterol content of meat sausages

Eighteen different brands of meat sausages including pork, poultry and the mixture of both meats (pork and poultry) in sausages, were analysed for their nutritional composition (total fat, moisture, crude protein and ash), cholesterol content and fatty acid composition. As expected, the pork Frankfurter sausages presented a higher fat content compared to sausages that include poultry meat in their composition. A multivariate statistical analysis was applied to the data showing the existence of significant differences among samples. Regarding fatty acid composition, significant differences were verified in canonical variate plots when the samples were grouped by sausage type, suggesting that the fatty acid profile is strongly influenced by the type of meats, as well as other ingredients such as vegetable oil and lard, used in its formulation. The group of poultry Frankfurter sausages presented lower levels of SFA and higher levels of PUFA, which can point to a healthier profile compared to the pork and meat mixture sausages. Nevertheless, some poultry sausages showed a higher cholesterol content compared to the pork Frankfurters. The lowest mean cholesterol content was obtained for the group of pork Frankfurters, which somehow contradicts the consumers' idea that pork meat products should be avoided due to its high cholesterol levels.The authors acknowledge the grant no. PEst-C/EQB/LA0006/2011 to FCT - Fundação para a Ciência e a Tecnologia. Sónia Soares is grateful to FCT PhD grant (SFRH/BD/75091/2010).info:eu-repo/semantics/publishedVersio

A SYBR green real-time PCR assay to detect and quantify pork meat in processed poultry meat products

Species identification in meat products has grown in interest in recent years since these foodstuffs are susceptible targets for fraudulent labelling. In this work, a real-time PCR approach based on SYBR Green dye was proposed for the quantitative detection of pork meat in processed meat products. For the development of the method, binary meat mixtures containing known amounts of pork meat in poultry meat were used to obtain a normalised calibration model from 0.1 to 25% with high linear correlation and PCR efficiency. The method revealed high specificity by melting curve analysis, being successfully validated through its application to blind meat mixtures, which confirmed its adequacy for pork meat determination. The fully applicability of the method was further demonstrated in commercial meat products, allowing verification of labelling compliance and identification of meat species in processed foods