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Azeites co-processados em agricultura biológica
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Abstract(s)
O método de co-processamento (ou co-extração) baseia-se na adição de ingredientes, normalmente frutos ou plantas aromáticas, no moinho ou antes da batedura das pastas de azeitona no processo de extração de azeite. Trata-se de um método que tem a vantagem relativamente à infusão de aromas de não necessitar de filtração. De forma a contribuir para o aumento da competitividade em meio rural, nomeadamente para os azeites provenientes de olivais em agricultura biológica, a produção de azeites co-processados pode ser mais uma oportunidade de diferenciação, sobretudo no mercado consumidor não tradicional.
Neste trabalho, apresenta-se um estudo sobre o efeito do co-processamento de azeitona com diferentes ingredientes, no rendimento e na qualidade do produto final. Os ingredientes utilizados foram: amêndoa, erva-do-caril (Helichrysum Miller), gengibre (Zingiber officinale Roscoe), pimento (Capsicum annuum L.), tomilho limão (Thymus x citriodora,) e tomilho bela-luz (Thymus mastichina L.). Os ensaios foram efetuados com a cv. ‘Galega Vulgar’ e no caso da erva-do-caril foram repetidos com a cv. ‘Cobrançosa’, utilizando azeitonas de índice de maturação superior a 6. Foram avaliados diversos parâmetros no azeite nomeadamente: a acidez, o índice de peróxido, as absorvâncias no UV, os ácidos gordos maioritários, a análise sensorial, a cor (CIELAB), os fenóis totais, a atividade antioxidante e a estabilidade oxidativa. Além do efeito da co-extração, estudou-se ainda a ação do armazenamento, durante 6 e 12 meses, nas características dos azeites.
Os resultados mostram que todos os ingredientes melhoram a composição dos azeites em fenóis totais, provocando consequentemente um incremento na sua atividade antioxidante e estabilidade oxidativa. Por sua vez, os ensaios com erva-do-caril são os que conduzem a valores mais elevados de estabilidade oxidativa. Relativamente às características sensoriais dos azeites verifica-se que são os ensaios com tomilho bela-luz e tomilho limão que provocam uma maior intensidade de aromas orto e retronasais.
Abstract: The co-processing (or co-milling) method is based on the addition of ingredients, usually fruits or aromatic plants, to the crushed olive paste before the malaxation step or during milling. This is a method that has the advantage over infusion that it does not require filtration. In order to contribute to increasing competitiveness in rural areas, namely for olive oils from olive groves in organic farming, the production of co-processed oils can be another opportunity for innovation, especially in the non-traditional consumer market. In this work, a study is presented on the effect of olive co-processing with different ingredients, on the yield and quality of the final product. The ingredients used were: almond, curry plant (Helichrysum Miller), ginger (Zingiber officinale Roscoe), peppers (Capsicum annuum L), lemon thyme (Thymus x citriodora) and Thymus mastichina (Thymus mastichina L). The trials were performed with cv. ‘Galega Vulgar’ and in the case of Helichrysum Miller were repeated with cv. 'Cobrançosa', using olives with a ripening index higher than6. Several parameters were studied in olive oil, namely: acidity, peroxide value, UV absorbances, major fatty acids composition, sensory analysis, color (CIELAB), total phenols, antioxidant activity and oxidative stability. In addition to the effect of co-processing, the action of storage, during 6 and 12 months, on the characteristics of olive oils was also studied. The results show that all the ingredients improve the composition of the oils in total phenols, consequently causing an improvement in their antioxidant activity and oxidative stability. In turn, trials with Helichrysum Miller are those that lead to higher values of oxidative stability. Regarding the sensory characteristics of olive oils, the trials with Thymus x citriodora and Thymus mastichina L. were the ones that caused a greater intensity of ortho and retronasal aromas.
Abstract: The co-processing (or co-milling) method is based on the addition of ingredients, usually fruits or aromatic plants, to the crushed olive paste before the malaxation step or during milling. This is a method that has the advantage over infusion that it does not require filtration. In order to contribute to increasing competitiveness in rural areas, namely for olive oils from olive groves in organic farming, the production of co-processed oils can be another opportunity for innovation, especially in the non-traditional consumer market. In this work, a study is presented on the effect of olive co-processing with different ingredients, on the yield and quality of the final product. The ingredients used were: almond, curry plant (Helichrysum Miller), ginger (Zingiber officinale Roscoe), peppers (Capsicum annuum L), lemon thyme (Thymus x citriodora) and Thymus mastichina (Thymus mastichina L). The trials were performed with cv. ‘Galega Vulgar’ and in the case of Helichrysum Miller were repeated with cv. 'Cobrançosa', using olives with a ripening index higher than6. Several parameters were studied in olive oil, namely: acidity, peroxide value, UV absorbances, major fatty acids composition, sensory analysis, color (CIELAB), total phenols, antioxidant activity and oxidative stability. In addition to the effect of co-processing, the action of storage, during 6 and 12 months, on the characteristics of olive oils was also studied. The results show that all the ingredients improve the composition of the oils in total phenols, consequently causing an improvement in their antioxidant activity and oxidative stability. In turn, trials with Helichrysum Miller are those that lead to higher values of oxidative stability. Regarding the sensory characteristics of olive oils, the trials with Thymus x citriodora and Thymus mastichina L. were the ones that caused a greater intensity of ortho and retronasal aromas.
Description
Projeto Final apresentado à Escola Superior Agrária do Instituto Politécnico de Castelo Branco, para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Inovação e Qualidade na Produção Alimentar.
Keywords
Análise sensorial Co-extração de azeite Estabilidade oxidativa Fenóis Rendimento Sensory analysis Co-processing of olives Oxidative stability Phenols Yield