Percorrer por autor "Rodrigues, Gisela"
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- Atributos de qualidade da carne de cordeiro de duas raças autóctones: efeitos das propriedades intrínsecas e da maturaçãoPublication . Rodrigues, Gisela; Cadavez, Vasco; Gonzales-Barron, UrsulaEm Portugal, a produção de carne ovina e caprina constitui 2,8% da produção de carne do país, com um nível de auto-suficiência de aproximadamente 82%. Consequentemente, aumentar a produção de carne de ovino e otimizar a sua qualidade, para a tornar mais atraente para os consumidores, é essencial para garantir um nível digno de rendimento aos produtores de ovinos. A qualidade da carne, tal como é julgada pelo consumidor, é ditada principalmente pela cor, pela suculência (relacionada à capacidade de retenção de água) e pela tenrura. Os objetivos deste estudo foram: (i) avaliar as propriedades intrínsecas da carcaça e da carne de cordeiro de duas raças autóctones, a Bordaleira de Entre Douro e Minho (BEDM) e a Churra Galega Bragançana (CGB), assim como os atributos da qualidade de carne de cordeiro ao longo da maturação; e (ii) avaliar os efeitos do tempo de maturação e das propriedades intrínsecas da carcaça/carne nos atributos de qualidade da carne de cordeiro. Um total de 30 cordeiros de raça BEDM e 30 de raça CGB foram criados em sistema semi-intensivo nas cidades de Ponte de Lima e de Bragança, respetivamente, e abatidos aos 4 meses de idade no matadouro municipal de Bragança. Após refrigeração das carcaças por 24 h, o peso da carcaça fria (PCF) e as categorias de engorda e de conformação foram anotados. Amostras do músculo L. dorsi foram cortadas e embaladas a vácuo e mantidas a 4ºC até 15 dias. As propriedades intrínsecas, determinadas no 1º dia pós-abate, foram o pH final (pH24), a atividade de água (aw24), a humidade, o teor de gordura, o teor de proteína e o teor de cinzas. Os atributos de qualidade da carne, quantificados nos dias 3, 9 e 15 pós-abate, foram a cor no espaço L*, a*, b*, a oxidação lipídica (TBARs), a capacidade de retenção de água (CRA) e a tenrura da carne mediante a prova Warner-Bratzler (declive, trabalho e força máxima). Uma série de modelos mistos foram ajustados aos dados para avaliar os efeitos da raça e do sexo do animal, do tempo de maturação e de cada uma das propriedades intrínsecas da carne sobre os atributos de qualidade. Nem o sexo do cordeiro nem o teor de proteína da carne tiveram qualquer influência (p>0,05) nos atributos de qualidade estudados. Todos os atributos de qualidade da carne foram afetados pelo tempo de maturação (p<0,0001), exceto L* (p=0,156). Enquanto a*, b* e os TBARs aumentaram durante a maturação, a CRA e os atributos do esforço de corte diminuíram no tempo. A raça influenciou (p>0,0001) a componente a* da cor e os três atributos de tenrura, apresentando-se a carne dos cordeiros BEDM mais avermelhadas e mais tenras. Contudo, este efeito do fator raça deve ser interpretado com cautela, uma vez que a raça esteve fortemente confundida com o pH24 (5,58 – 5,64 para a carne dos cordeiros CGB, e 5,77 – 5,83 para a carne dos cordeiros BEDM) e com o PCF (13,72 a 14,80 Kg para os cordeiros CGB e 6,45 – 7,60 para os cordeiros BEDM). A componente b* da cor, apesar de relacionada com a componente a*, não foi afetada pelas propriedades intrínsecas da carcaça/carne. Para ambas as raças, a carne com pH24 mais alto (p<0,0001), maior humidade (p<0,0001) ou maior teor de cinzas (p=0,001) tenderam a ser mais pálidas (L* elevados); enquanto as carcaças com maior PCF (p=0,003) ou maior teor de gordura (p=0,011) produziram carne mais escura. Ao contrário, a carne com pH24 mais baixo (p<0,0001), menor humidade (p<0,0001) ou menor teor de cinzas (p<0,0001) tenderam a ser mais avermelhadas (a* elevados), enquanto as carcaças com menor PCF (p<0,0001) ou menor teor de gordura (p<0,0001) produziram carnes menos avermelhadas. O grau de oxidação lipídica da carne de cordeiro não foi afetado pelo pH24 (p=0,248), mas sim pelo PCF (p=0,061), o teor de gordura (p=0,016), a aw24 (0,028), a humidade (p=0,001), e, portanto, o teor de cinzas (p=0,035). Assim, maior PCF ou maior teor de gordura estiveram associados com maiores níveis de TBARs durante a maturação, enquanto carne com maior teor de humidade, de maior aw24 ou maior teor de cinzas, apresentaram níveis de TBARs mais baixos. No final da maturação, maior PCF (p=0,049), pH24 mais alto (p=0,002) e maior teor de gordura (p=0,022) produziram maior CRA, enquanto carne com menor teor de humidade (p=0,014) ou menor teor de cinzas (p=0,001) tenderam a sofrer maiores perdas por cocção. No que diz respeito ao atributo de tenrura, o amaciamento ativo da carne, embalada ao vácuo, ocorreu até os 9 ou 10 dias de maturação em ambas as raças. No entanto, as propriedades determinantes (p<0,0001) dos três atributos de tenrura da carne de cordeiro foram o pH24 e o PCF. A carne mais tenra apresentou maior pH24 e provieram de cordeiros com maior PCF. Adicionalmente, o teor de humidade (p=0,012) e o teor de gordura (p=0,040) modularam inversamente o trabalho de cisalhamento.
- Características físico-químicas y terneza de la carne de cordero de dos razas autóctonas portuguesasPublication . Rodrigues, Gisela; Lorenzo Rodriguez, Jose Manuel; Gonzales-Barron, Ursula; Cadavez, VascoEn la Unión Europea (UE), la producción de carne de ovino se basa predominantemente en sistemas de pastoreo, sistemas de producción extensivos o semi-intensivos.
- Effect of Sage (Salvia officinalis L.) Extract on the Survival of Staphylococcus aureus in Portuguese Alheira Sausage during MaturationPublication . Coelho-Fernandes, Sara; Rodrigues, Gisela; Faria, Ana Sofia; Caleja, Cristina; Pereira, Eliana; Pinela, José; Carocho, Márcio; Barros, Lillian; Cadavez, Vasco; Gonzales-Barron, UrsulaThe objective of this study was to assess the effect of sage (Salvia officinalis L.) extract on the survival of Staphylococcus aureus in a Portuguese non-ready-to-eat meat product (alheira sausage). Alheira batter was produced, mixed with 0.0%, 0.5%, 1.0%, or 1.5% of lyophilised sage extract, and stuffed in natural casings. Sausages were then individually inoculated with S. aureus and left to ferment/mature at 10 °C/85% RH for 10 days. Sage extract was found to inactivate S. aureus (p < 0.001) with no significant differences between doses. At the 10th day of maturation, S. aureus decreased in 1.146 log CFU/g (SE = 0.065 log CFU/g) in alheiras mixed with 0.5–1.0% sage extract. Nonetheless, this extract retarded the growth of indigenous lactic acid bacteria during maturation. The higher the dose, the greater the effect (p < 0.001).
- Evolution of lamb meat quality traits under prolonged vacuum storagePublication . Rodrigues, Gisela; Lorenzo Rodriguez, Jose Manuel; Gonzales-Barron, Ursula; Cadavez, VascoMeat quality, as judged by the consumer, is mainly dictated by colour, juiciness and tenderness. Wet maturation of meat done by vacuum-packaging (VP) allows the ageing process to continue, yet in conditions that retard meat spoilage. The objective of this study was to evaluate the evolution of meat quality traits (colour, TBARs, water retention capacity [WRC] and Warner-Bratzler shear-force [SF]), and their interrelationships with physicochemical characteristics (pH, water activity [aw] and proximate composition) in VP lamb meat during refrigeration.
- Microbial deterioration of lamb meat from European local breeds as affected by its intrinsic propertiesPublication . Gonzales-Barron, Ursula; Coelho-Fernandes, Sara; Rodrigues, Gisela; Choupina, Altino; Bermúdez Piedra, Roberto; Osoro, Koldo; Celaya, Rafael; García, Rocío R.; Peric, Tanja; Bianco, Silvia del; Piasentier, Edi; Chiesa, Francesco; Brugiapaglia, Alberto; Battaglini, Luca; Baratta, Mario; Bodas, Raúl; Lorenzo Rodriguez, Jose Manuel; Cadavez, VascoAlthough sheep meat has a small share of 1.5 % of the total meat production in the EU, sheep farming is of great importance to rural development and the environment. Enhancing the quality of lamb meat of local breeds is essential to ensure both profitability for sheep producers and the conservation of endangered breeds. This study aimed to (i) characterise the evolution of spoilage microorganisms in refrigerated vacuum-packed lamb meat from a total of 10 farms housing 8 local breeds of Portuguese, Spanish, Italian and Slovenian origin raised in intensive, extensive or semi-extensive regime; and (ii) elucidate how intrinsic properties of meat can affect its microbial spoilage. Cold carcass weight (CCW), ultimate pH (pH24) and proximate analysis were quantified on carcass/meat from each of the 285 animals raised and slaughtered for this purpose; while mesophiles, lactic acid bacteria, Pseudomonas spp. and psychrotrophic bacteria were enumerated during 15-day storage at 4 °C. Substantial variability in all attributes were found between the ten farms. CCW of intensively-raised lambs (21.4 kg; 95 % CI: 20.6–22.1 kg) were higher (p lt 0.05) than the ones in semi-extensive regime (14.9 kg; 95 % CI: 14.4–15.4 kg), and in turn these were heavier (p lt 0.05) than the extensively raised lambs (12.4 kg; 95 % CI: 12.0–12.7). Mean contents of protein (76.5–87.4% db), fat (3.78–13.1% db) and ashes (4.62–5.65% db) in lamb meat were highly dependent on the farm. Although meat from some farms was associated to higher microbial levels, in general, microbial growth was found to be modulated by intrinsic properties of meat. Higher pH24 (p lt 0.05), moisture (p lt 0.05), protein content (p lt 0.05) and ashes content (p lt 0.01) accelerated spoilage rate; whereas meat from heavier carcasses (p lt 0.001) and of higher fat content (p lt 0.01) presented slower growth of spoilage bacteria. In order to improve the microbial quality of lamb meat, animal handling must be enhanced to minimise pre-slaughter stress; slaughtering practices and hygiene must be improved; and a carcass classification system could be adopted towards the selection of fatter animals and chilled carcasses of optimal pH24.
- Microbial deterioration of lamb meat of portuguese origin as affected by its intrinsic propertiesPublication . Cadavez, Vasco; Gonzales-Barron, Ursula; Félix-Oliveira, Diogo; Coelho-Fernandes, Sara; Rodrigues, GiselaIn Portugal, sheep and goat meat production constitutes 2.8% of the total meat production, with a self-sufficiency of ~82%. The main autochthonous sheep breeds exploited for meat production are Churra-Galega-Bragançana (CGB) and Bordaleira-de-Entre-Douro-e-Minho (BEDM), whose quality must be optimised in order to ensure adequate income levels for sheep producers. The study aimed to characterise the evolution of spoilage microorganisms in refrigerated vacuum-packed (VP) lamb meat from BEDM and CGB breeds; and elucidate how intrinsic properties of meat can affect its microbial spoilage. Meat from BEDM breed presented higher (p<.0001) populations of mesophiles, lactic acid bacteria, Pseudomonas spp. and psychrotrophic bacteria, since its higher ultimate pH (means: 5.77 for BEDM vs. 5.58 for CGB) accelerated spoilage rate (p<.0001). While water activity and protein content were not found to modulate microbial deterioration (p>0.05), the growth of spoilage bacteria was found to be exacerbated by higher moisture (p<.0001) and higher ash content (p<0.001). By contrast, a higher fat content retarded (p<.0001) the growth of spoilage bacteria in VP lamb meat. In order to extend the shelf-life of Portuguese-origin lamb meat, animal handling must be enhanced to minimise pre-slaughter stress, and a carcass classification system should be adopted towards the selection of fatter animals and chilled carcasses of optimal ultimate pH.
- Microbiological and physicochemical assessment of artisanally produced “Alheira” fermented sausages in Northern PortugalPublication . Coelho-Fernandes, Sara; Zefanias, Odete; Rodrigues, Gisela; Faria, Ana Sofia; Fernandes, Ângela; Barros, Lillian; Cadavez, Vasco; Gonzales-Barron, UrsulaAlheira is a traditional non-ready-to-eat sausage produced mainly in northern Portugal. The objective of this study was to evaluate the associations between some relevant physicochemical and microbiological attributes of alheiras produced by different regional producers. Finished products from 8 regional factories amounting to 40 samples were analyzed. Counts of mesophiles, lactic acid bacteria, Staphylococcus aureus, presumptive Clostridium perfringens, and Salmonella spp., as well as pH, water activity (aW), and proximate analysis were determined. Principal component analysis (PCA) of these variables was conducted to construct quality maps. Three meaningful components were extracted, accounting for 63% of data variability. PC1 (26% data variability) was positively associated with LAB, mesophiles, and S. aureus, characterizing therefore longer fer- mentation. PC2 (22% data variability) correlated negatively with moisture, aW and positively with C. perfringens, and thus has been linked to greater dehydration of sausages. PC3 (15% data varia- bility) correlated positively with pH and protein content, implying the use of more meat in the formulation. This preliminary work has identified three quality factors underpinning the variabil- ity in artisanal alheiras; and has also highlighted the need to implement better microbiological control and process standardization during the production of artisanal alheiras.
- Modelação da sobrevivência do Staphylococcus aureus em bifes revestidos com extrato de Urucum (Bixa orellana L.) em óleo de cocoPublication . Novaes, Karinne; Coelho-Fernandes, Sara; Rodrigues, Gisela; Cadavez, Vasco; Gonzales-Barron, UrsulaO presente estudo teve por objetivo avaliar a cinética do Staphylococcus aureus, durante o período de refrigeração, em bifes de carne bovina revestidos com extrato de sementes de Bixa orellana L. (urucum) ao 0%, 10%, 20% e 30% em óleo de coco, embalados em atmosfera normal e a vácuo. A caracterização da sobrevivência do S. aureus nos bifes foi realizada mediante o ajuste do modelo Weibull (σ, β) a cada uma das curvas experimentais obtidas após inoculação superficial do patogénico nos bifes (~5.2 log CFU/cm2). Quanto maior foi a concentração de urucum extraído, maior foi seu poder bactericida. Exceto para o extrato de urucum a 30%, todas as curvas do S. aureus inoculado nos bifes mantidos em atmosfera normal apresentaram uma fase inicial de resistência à inativação. Comprovou-se uma maior inativação quando os bifes foram embalados a vácuo, mediante o decréscimo imediato do S. aureus em todas as curvas de sobrevivência, agora côncavas (β<1,0). Uma transformação dos parâmetros Weibull σ e β permitiu estimar o tempo necessário para atingir a primeira redução decimal do S. aureus em bifes revestidos com óleo de urucum extraído ao 0%, 10%, 20% e 30%, o qual foi ∞, 14,4 dias (IC 95%: 8,1-20,8 dias), 8,3 dias (IC 95%: 6,6-10,1 dias) e 2,5 dias (IC 95%: 0,24-4,8 dias), respectivamente, quando embalados em atmosfera normal; e significativamente menores quando embalados a vácuo: 10,6 dias (IC 95%: 0,80-22 dias), 7,2 dias (IC 95%: 0,11-14,3 dias), 2,9 dias (IC 95%: 2,2-3,7 dias) e 0,43 dias (IC 95%: 0,05-0,81 dias), respetivamente. Este trabalho de investigação permitiu concluir que o extrato de sementes de urucum em óleo de coco apresenta-se como um antimicrobiano promissor que pode ser aplicado como cobertura de carnes de bovino frescas para o controle do S. aureus.
- Quality attributes of lamb meat from European breeds: Effects of intrinsic properties and storagePublication . Gonzales-Barron, Ursula; Rodrigues, Gisela; Piedra, Roberto Bermúdez; Coelho-Fernandes, Sara; Osoro, Koldo; Celaya, Rafael; Maurício, Raimundo Serrão; Pires, Jaime; Tolsdorf, Anna; Geß, Andreas; Chiesa, Francesco; Pateiro, Mirian; Brugiapaglia, Alberto; Bodas, Raúl; Baratta, Mario; Lorenzo Rodriguez, Jose Manuel; Cadavez, VascoThe sustainability of the European sheep farming sector can be ensured through the high and consistent quality of products, although the concept of meat quality, being multifaceted, is challenging to keep up by farmers and producers. The objectives of this study were (i) to evaluate quality attributes (CIE L*, a*, b*, lipid oxidation, cooking loss and Warner-Bratzler texture test) of lamb meat during cold storage originating from eight European breeds raised under their normal production systems (n = 292 lambs); and (ii) to elucidate the influence of storage and intrinsic properties (cold carcass weight [CCW], ultimate pH [pH24], water activity [aw], and proximate composition) on the aforementioned quality attributes measured on the 3rd, 9th and 15th day post slaughter. All meat quality properties displayed a high variability due to the breed × production systems, although, as a whole, L*, a*, b*, TBARs and cooking loss increased during storage (P lt 0.001), whereas the tenderisation process was of non-linear decay nature (P = 0.001). While production system – taken across breeds – was not found to affect meat cooking losses, it heavily influenced CCW, producing intensive systems heavier (P lt 0.001) carcasses (21.4 kg) than those raised in semi-extensive (14.9 kg) and extensive systems (13.8 kg). On the 15th day of storage, TBARs from intensive systems was significantly (P lt 0.001) higher than those of extensively raised lambs (0.839 mg MDA/kg vs. 0.299 mg MDA/kg, respectively). Although the extensive and semi-extensive systems initially produced less tender meat (P lt 0.05) than intensive systems, on the 15th day of storage, meat from extensive (23.4 N/cm2) and semi-extensive systems (24.4 N/cm2) presented as good tenderness quality (P lt 0.10) as that of the intensive systems (22.1 N/cm2). Within breed × production systems, higher CCW or intramuscular fat was associated to darker meat (P lt 0.001 and P = 0.014), higher redness (P lt 0.001 for both), greater lipid oxidation (P = 0.016 and P lt 0.001), and lower slope (P = 0.014 and P = 0.004) and force (P = 0.027 and P = 0.001). The only intrinsic property that heavily affected most of the quality attributes was ash content, since meat of higher ash content presented higher luminosity (P = 0.008), and lower redness (P lt 0.001), yellowness (P lt 0.001), TBARS (P lt 0.001), cooking loss (P = 0.002) and tenderness (P lt 0.001). The elucidation of the impact of intrinsic properties on the lamb meat quality attributes during storage can help breeders and producers modify current flock management, feeding strategies and pre-slaughter and slaughter practices towards quality improvement or meeting particular consumers’ demands.
- Staphylococcus aureus inactivation in a non-ready-to-eat sausage during maturation: a dynamic modelPublication . Coelho-Fernandes, Sara; Rodrigues, Gisela; Faria, Ana Sofia; Cadavez, Vasco; Gonzales-Barron, UrsulaThe aim of this study was to model the effect of annatto (Bixa orellana) extract against S. aureus (SA) in a Portuguese non-ready-to-eat meat product (alheira sausage) during maturation. Alheira batter was prepared with 0.0%, 0.5%, 1.0%, or 1.5% of lyophilised annatto extract and stuffed in pre-washed natural casings following inoculation with SA, then hung in a climatic-controlled chamber at 10 °C for 13 days. For every treatment, a dynamic model was adjusted and adequately fitted to all survival curves with residuals and root mean square errors between 0.0008–0.0016 and 0.029–0.040, respectively, producing significant parameter estimates. Therefore, the addition of annatto extracts significantly shortened the shoulder phase and decreased the time to achieve one log reduction, which, in practical terms, corresponded to up to 1.35 [SE = 0.08] log CFU/g reduction by the end of the 13-day maturation.