| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 7.83 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
Este trabalho teve como objetivo global efetuar um estudo sobre características físicoquímicas
de méis monoflorais Portugueses de forma a contribuir para o estudo experimental
de caraterização dos méis de alfarroba (Ceratonia siliqua), medronheiro (Arbutus unedo),
poejo (Mentha pulegium) e tomilho (Thymus vulgaris) (méis que ainda não foram objeto de
estudos). Os outros méis monoflorais incluídos neste estudo foram: Castanheiro (Castanea
sativa), Echium (Echium vulgare), Eucalipto (Eucalyptus melliodora), Laranjeira (Citrus
sinensis), Rosmaninho (Rosmarinus officinalis) e Urze (Ericaceae). Os parâmetros físicoquímicos
avaliados em cada amostra de mel foram: cor, pH, acidez total, humidade,
condutividade elétrica, teor em cinzas, HMF, diástase, açúcares redutores, teores em fenóis
e flavonoides.
Das 25 amostras de mel estudadas, somente 21 das amostras foram confirmadas como
sendo de méis monoflorais, através da análise polínica. Também se verificou uma grande
variação no perfil polínico, o que justificou a elevada variação experimental encontrada nas
caraterísticas físico-químicos dos méis analisados. As cores dos méis foram usadas para
estabelecer a ordem de apresentação dos méis e proceder à avaliação dos parâmetros físicoquímicos
analisados. Em geral, os méis apresentaram qualidade físico-química com
exceções, em valores de pH em 5 méis e valor de HMF, num mel. De salientar que para os
méis de alfarroba, medronheiro, poejo e tomilho não existem parâmetros mínimos e
máximos legais, pelo que a avaliação global dos resultados obtidos para estes méis não foi
possível.
Para o estudo global dos resultados físico-químicos usou-se a análise de agrupamentos
estatísticos (MDS, “multidimensional scaling”) onde se verificou que as variações na cor do
mel podem ser maioritariamente atribuídas à elevada percentagem associada ao seu pólen
mais predominante. Por outro lado, as diferenças dos méis no perfil polínico, representado
pelo segundo pólen mais predominante, permitem justificar as variações encontradas nas
propriedades físico-químicas dos méis. Os resultados mostraram que os méis de alfarroba,
poejo e tomilho são semelhantes nas variáveis físico-químicas analisadas, enquanto que as
dos méis de medronheiro se aproximaram principalmente dos méis com o pólen
predominante de Erica.As análises microbiológicas mostraram que as amostras não apresentaram qualquer
contaminação patogénica (ausência de contaminações com Staphylococcus aureus,
Coliformes totais, Escherichia coli, Clostridium sp e Salmonella sp.) e tiveram níveis baixos
de presença dos microrganismos Aérobios Mesófilos e Bolores/Leveduras, ou seja, os méis
estudados demonstraram qualidade ao nível microbiológico.
The objective of this work was to study the physicochemical characteristics of Portuguese monofloral honeys in order to contribute to the experimental characterization of the honeys of carob (Ceratonia siliqua), Arborutus (Arbutus unedo), squaw mint (Mentha pulegium) and thyme (Thymus vulgaris) (honeys that have not yet been studied). The other monofloral honeys included in this study were chestnut (Castanea sativa), echium (Echium vulgare), eucalyptus (Eucalyptus melliodora), laranjeira (Citrus sinensis), rosmaninho (Rosmarinus officinalis) and erica (Ericaceae). The physical-chemical parameters evaluated in each sample of honey were: color, pH, total acidity, humidity, electrical conductivity, ash content, HMF, diastase, reducing sugars, phenol and flavonoid contents. From the 25 samples of honey studied, only 21 of the samples were confirmed as monofloral honey, through pollen analysis. There was also a great variation in the pollen profile, which justified the high experimental variation found in the physicochemical characteristics of the honeys analyzed. The colors of the honeys were used to establish the order of honeys presentation and to proceed to the evaluation of the physicochemical parameters analyzed. In general, the honeys presented physical-chemical quality with exceptions, in pH values in 5 honeys and HMF value, in one honey. It should be noted that for the honeys of carob, arbutus, squaw mint and thyme there are no legal physicochemical minimum and maximum limits, so the overall evaluation of the results obtained for these honeys was not possible. A multidimensional scaling (MDS) was used for the global study of physicochemical results, where it was found that variations in honey color may be attributed mainly to the high percentage associated with its most predominant pollen. On the other hand, the differences of the honeys in the pollen profile, represented by the second most predominant pollen, allow to justify the variations found in the physicochemical properties of the honeys. The results showed that carob, squaw mint and thyme honeys are similar in the analyzed physicochemical variables, while those of the arbutus honeys were mainly close to the honeys with the predominant pollen of Erica. Microbiological analyzes showed that the samples did not present any pathogenic contamination (absence of contaminations with Staphylococcus aureus, Total Coliforms, Escherichia coli, Clostridium sp and Salmonella sp) and had low levels of presence of the Aerial Mesophilic and Mold/Yeast microorganisms, meaning that the honeys studied showed microbiological quality.
The objective of this work was to study the physicochemical characteristics of Portuguese monofloral honeys in order to contribute to the experimental characterization of the honeys of carob (Ceratonia siliqua), Arborutus (Arbutus unedo), squaw mint (Mentha pulegium) and thyme (Thymus vulgaris) (honeys that have not yet been studied). The other monofloral honeys included in this study were chestnut (Castanea sativa), echium (Echium vulgare), eucalyptus (Eucalyptus melliodora), laranjeira (Citrus sinensis), rosmaninho (Rosmarinus officinalis) and erica (Ericaceae). The physical-chemical parameters evaluated in each sample of honey were: color, pH, total acidity, humidity, electrical conductivity, ash content, HMF, diastase, reducing sugars, phenol and flavonoid contents. From the 25 samples of honey studied, only 21 of the samples were confirmed as monofloral honey, through pollen analysis. There was also a great variation in the pollen profile, which justified the high experimental variation found in the physicochemical characteristics of the honeys analyzed. The colors of the honeys were used to establish the order of honeys presentation and to proceed to the evaluation of the physicochemical parameters analyzed. In general, the honeys presented physical-chemical quality with exceptions, in pH values in 5 honeys and HMF value, in one honey. It should be noted that for the honeys of carob, arbutus, squaw mint and thyme there are no legal physicochemical minimum and maximum limits, so the overall evaluation of the results obtained for these honeys was not possible. A multidimensional scaling (MDS) was used for the global study of physicochemical results, where it was found that variations in honey color may be attributed mainly to the high percentage associated with its most predominant pollen. On the other hand, the differences of the honeys in the pollen profile, represented by the second most predominant pollen, allow to justify the variations found in the physicochemical properties of the honeys. The results showed that carob, squaw mint and thyme honeys are similar in the analyzed physicochemical variables, while those of the arbutus honeys were mainly close to the honeys with the predominant pollen of Erica. Microbiological analyzes showed that the samples did not present any pathogenic contamination (absence of contaminations with Staphylococcus aureus, Total Coliforms, Escherichia coli, Clostridium sp and Salmonella sp) and had low levels of presence of the Aerial Mesophilic and Mold/Yeast microorganisms, meaning that the honeys studied showed microbiological quality.
Description
Keywords
Mel Alfarroba Medronheiro Poejo Tomilho Cor