| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 1.32 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
Em Portugal, há uma longa tradição do cultivo da oliveira, utilizando os seus frutos para a produção de azeitona de mesa, mas sobretudo para extrair azeite. Trás-os-Montes é uma das principais regiões produtoras de azeitona a nível nacional. Também a nível nacional existe uma grande diversidade de cultivares de oliveira. Contudo, a maioria da produção assenta num conjunto reduzido de cultivares que se distribuem praticamente de norte a sul e dominam as plantações mais recentes, enquanto a maioria delas é relegada para um segundo plano, e que se não forem caraterizadas e valorizadas tenderão a desaparecer. As cultivares minoritárias estão, na maioria das vezes, melhor adaptadas a uma região, podendo a sua valorização, pela diferenciação ocorrer a nível regional e proporcionar um maior rendimento aos agricultores. É neste sentido que se insere o presente trabalho, que tem por objetivo contribuir para o conhecimento dos azeites da cv. Santulhana, uma cultivar minoritária do nordeste de Portugal, contribuindo para a sua valorização. Assim, recolheram-se 30 azeites nos concelhos de Bragança, Vimioso e Macedo de Cavaleiros onde foram estudados parâmetros de qualidade (acidez, índice de peróxidos, coeficientes de extinção específica no U.V. e análise organolética), perfil sensorial, caraterização química (composição em ácidos gordos e tocoferóis), atividade antioxidante (DPPH) e de resistência à oxidação (rancimat). Em termos de parâmetros de qualidade a maioria dos azeites apresenta valores dentro dos limites legais para a categoria de azeite virgem extra, com um perfil sensorial com caraterísticas únicas. Na composição em ácidos gordos, o teor médio dos ácidos gordos maioritários foi de 67,60% para o ácido oleico, 13,36% para o ácido palmítico, e 3,06% para o esteárico. No que toca a vitamina E, os teores médios foram de 257,71%, variando entre 224,54 e 272,48%. A resistência à oxidação rondou em média as 8,5 horas, e nos fenóis totais verificou-se uma variação entre 99,24 e 200,40 mg em equivalentes de ácido cafeico/kg de azeite, e um valor de DPPH de 50% de inibição.
In Portugal, there is a long tradition of the cultivation of the olive tree, using its fruit for olive production table, but especially for extracting oil. Trás-os-Montes is one of the main olive producing regions nationwide. Also, at national level there is a great diversity of olive cultivars. However, the majority of production is based on a reduced set of cultivars that are distributed practically from north to south and dominate the most recent plantations, while most of them are relegated to a second plan, and that if they are not characterized and valued they may tend to disappear . These minority cultivars are often better adapted to a given region, so their appreciation, through differentiation, may occur at the regional level providing greater income to farmers. It is in this sense that the present work is inserted, which aims to contribute to the knowledge of olive oils from cv. Santulhana, a minority cultivar from northeast of Portugal, contributing to its recovery. Thus, 30 olive oils were collected in the municipalities of Bragança, Vimioso and Macedo de Cavaleiros where quality parameters (acidity, peroxide index, specific extinction coefficients in UV and organoleptic analysis), sensory profile, chemical characterization (fatty acids composition and tocopherols), antioxidant activity (DPPH) and oxidation resistance (rancimat). In terms of quality parameters, most oils present values within the legal limits for the category of extra virgin olive oil, with a sensory profile with unique characteristics. In the fatty acid composition, the average content of major fatty acids was 67,60% for the oleic acid, 13,36% for the palmitic acid, and 3,06% for stearic acid. For the Vitamin E, the average levels were 257,71%, varying between 224,54 and 272,48%. Regarding oxidation resistance, it averaged around 8,5 hours, in terms of total phenols, there was a variation between 99,24 and 200,40 mg in equivalents of caffeic acid / kg of olive oil, and a DPPH value of 50% inhibition
In Portugal, there is a long tradition of the cultivation of the olive tree, using its fruit for olive production table, but especially for extracting oil. Trás-os-Montes is one of the main olive producing regions nationwide. Also, at national level there is a great diversity of olive cultivars. However, the majority of production is based on a reduced set of cultivars that are distributed practically from north to south and dominate the most recent plantations, while most of them are relegated to a second plan, and that if they are not characterized and valued they may tend to disappear . These minority cultivars are often better adapted to a given region, so their appreciation, through differentiation, may occur at the regional level providing greater income to farmers. It is in this sense that the present work is inserted, which aims to contribute to the knowledge of olive oils from cv. Santulhana, a minority cultivar from northeast of Portugal, contributing to its recovery. Thus, 30 olive oils were collected in the municipalities of Bragança, Vimioso and Macedo de Cavaleiros where quality parameters (acidity, peroxide index, specific extinction coefficients in UV and organoleptic analysis), sensory profile, chemical characterization (fatty acids composition and tocopherols), antioxidant activity (DPPH) and oxidation resistance (rancimat). In terms of quality parameters, most oils present values within the legal limits for the category of extra virgin olive oil, with a sensory profile with unique characteristics. In the fatty acid composition, the average content of major fatty acids was 67,60% for the oleic acid, 13,36% for the palmitic acid, and 3,06% for stearic acid. For the Vitamin E, the average levels were 257,71%, varying between 224,54 and 272,48%. Regarding oxidation resistance, it averaged around 8,5 hours, in terms of total phenols, there was a variation between 99,24 and 200,40 mg in equivalents of caffeic acid / kg of olive oil, and a DPPH value of 50% inhibition
Description
Keywords
Azeite monovarietal Qualidade Caraterização Perfil químico e sensorial Valorização