| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 1.99 MB | Adobe PDF |
Advisor(s)
Abstract(s)
O muesli, conhecido por ser um alimento saudável e nutritivo, consiste em uma mistura
de cereais, grãos (geralmente aveia em flocos), nozes, sementes e frutas secadas, como
uvas passas e tâmaras. O presente trabalho teve como objetivo principal desenvolver um
muesli inovador que incorporasse castanha (Castanea sativa Mill.). Para se atingir este
objetivo, começou-se por caracterizar três amostras de muesli comerciais para melhor
conhecer os componentes geralmente presentes neste produto, bem como as suas
proporções. Em seguida, avaliou-se a secagem de castanhas inteiras (1º ensaio) e partidas
(2º ensaio), modelando-se o processo, visando definir o método de secagem a utilizar
posteriormente para se obter a castanha a incluir no muesli. Após se ter verificado que o
método de secagem mais adequado consistiu em desidratar os frutos já partidos durante
40 minutos, prepararam-se diferentes formulações segundo um desenho experimental de
misturas, onde foram testadas várias proporções de aveia, castanha e figo, para encontrar
a combinação ideal. Os parâmetros avaliados incluíram a cor, atividade da água, teor de
humidade e análise sensorial. Após as análises feitas e tratamento dos dados, a proporção
indicada pelo otimizador de resposta, considerando que a formulação final deveria ter
uma atividade de água entre 0,4 e 0,6, uma intensidade do aroma a castanha entre 4 e 10
e uma intensidade do sabor a castanha entre 3 e 10, foi de 84,5% aveia, 10,0% castanha
e 5,5% figo (Formulação A). De seguida, caracterizou-se esta formulação em termos de
cor, atividade da água, teores de humidade, cinzas, gordura, proteína, metais (K, Ca, Mg,
Fe, Mn, Zn), perfil de ácidos gordos, análise microbiológica e análise sensorial, bem
como mais duas, designadamente: B - 84,5% aveia e 15,5% figo e C - 84,5% aveia e
15,5% castanha. Os resultados mostraram que os valores de atividade de água variaram
entre 0,61 e 0,65, a proteína entre12,0 e 12,4%, p.f., e a gordura entre 5,8 e 8,1%, p.f.,
não existindo diferenças significativas entre formulações. Os ácidos gordos maioritários
nas três formulações foram o ácido linoleico (C18:2n6c) e o ácido oleico (C18:1n9c).
Relativamente à análise sensorial, os três mueslis apresentaram valores médios de
aparência geral elevados (entre 7,9 e 8,2) e uma boa apreciação geral (entre 7,3 e 8,1),
indicando boa aceitação. Contudo, a Formulação B (só com figo e aveia) foi a preferida
por 44% dos provadores, seguindo-se a Formulação A (aveia, figo e castanha) (33%). Em
termos microbiológicos, apenas a formulação A apresentou qualidade microbiológica
satisfatória, sugerindo que na elaboração de formulações futuras deva existir um maior
controlo das matérias-primas, e o cumprimento de boas práticas de higiene e de fabrico. Em conclusão, a presente dissertação demonstrou que a incorporação da castanha no
muesli pode resultar em um produto inovador e saudável, mas também promover a
valorização da identidade cultural e das tradições alimentares locais, oferecendo uma
alternativa nutritiva e saborosa para os consumidores.
Muesli, known for being a healthy and nutritious food, consists of a mixture of cereals, grains (usually rolled oats), nuts, seeds and dried fruits, such as raisins and dates. The main objective of this work was to develop an innovative muesli that incorporated chestnuts (Castanea sativa Mill.). To achieve this objective, we began by characterizing three samples of commercial muesli to better understand the components generally present in this product, as well as their proportions. Next, the drying of whole (1st test) and broken (2nd test) chestnuts was evaluated, modeling the process, aiming to define the drying method to be used later to obtain the chestnut to be included in the muesli. After verifying that the most appropriate drying method consisted of dehydrating the already broken fruits for 40 minutes, different formulations were prepared according to an experimental design of mixtures, where various proportions of oat, chestnut and figs were tested, to find the ideal combination. The parameters evaluated included colour, water activity, moisture content and sensory analysis. After the analyzes carried out and data processing, the proportion indicated by the response optimizer, considering that the final formulation should have a water activity between 0.4 and 0.6, a chestnut aroma intensity between 4 and 10 and an intensity of chestnut flavor between 3 and 10, it was 84.5% oat, 10.0% chestnut and 5.5% fig (Formulation A). This formulation was then characterized in terms of colour, water activity, moisture content, ash, fat, protein, metals (K, Ca, Mg, Fe, Mn, Zn), fatty acid profile, microbiological analysis and sensory analysis, as well as two more formulations, namely: B - 84.5% oat and 15.5% figs and C - 84.5% oat and 15.5% chestnut. The results showed that water activity values varied between 0.61 and 0.65, protein between 12.0 and 12.4%, f.w., and fat between 5.8 and 8.1%, f.w., with no significant differences between the formulations. The major fatty acids in the three formulations were linoleic acid (C18:2n6c) and oleic acid (C18:1n9c). Regarding sensory analysis, the three mueslis presented high average values for general appearance (between 7.9 and 8.2) and good general appreciation (between 7.3 and 8.1), indicating good acceptance. However, Formulation B (only with figs and oat) was preferred by 44% of tasters, followed by Formulation A (oat, figs and chestnuts) (33%). In microbiological terms, only formulation A presented satisfactory microbiological quality, suggesting that when preparing future formulations there must be greater control of raw materials, and compliance with good hygiene and manufacturing practices. In conclusion, this dissertation demonstrated that the incorporation of chestnuts in muesli can result in an innovative and healthy product, but also promote the appreciation of cultural identity and local food traditions, offering a nutritious and tasty alternative for consumers.
Muesli, known for being a healthy and nutritious food, consists of a mixture of cereals, grains (usually rolled oats), nuts, seeds and dried fruits, such as raisins and dates. The main objective of this work was to develop an innovative muesli that incorporated chestnuts (Castanea sativa Mill.). To achieve this objective, we began by characterizing three samples of commercial muesli to better understand the components generally present in this product, as well as their proportions. Next, the drying of whole (1st test) and broken (2nd test) chestnuts was evaluated, modeling the process, aiming to define the drying method to be used later to obtain the chestnut to be included in the muesli. After verifying that the most appropriate drying method consisted of dehydrating the already broken fruits for 40 minutes, different formulations were prepared according to an experimental design of mixtures, where various proportions of oat, chestnut and figs were tested, to find the ideal combination. The parameters evaluated included colour, water activity, moisture content and sensory analysis. After the analyzes carried out and data processing, the proportion indicated by the response optimizer, considering that the final formulation should have a water activity between 0.4 and 0.6, a chestnut aroma intensity between 4 and 10 and an intensity of chestnut flavor between 3 and 10, it was 84.5% oat, 10.0% chestnut and 5.5% fig (Formulation A). This formulation was then characterized in terms of colour, water activity, moisture content, ash, fat, protein, metals (K, Ca, Mg, Fe, Mn, Zn), fatty acid profile, microbiological analysis and sensory analysis, as well as two more formulations, namely: B - 84.5% oat and 15.5% figs and C - 84.5% oat and 15.5% chestnut. The results showed that water activity values varied between 0.61 and 0.65, protein between 12.0 and 12.4%, f.w., and fat between 5.8 and 8.1%, f.w., with no significant differences between the formulations. The major fatty acids in the three formulations were linoleic acid (C18:2n6c) and oleic acid (C18:1n9c). Regarding sensory analysis, the three mueslis presented high average values for general appearance (between 7.9 and 8.2) and good general appreciation (between 7.3 and 8.1), indicating good acceptance. However, Formulation B (only with figs and oat) was preferred by 44% of tasters, followed by Formulation A (oat, figs and chestnuts) (33%). In microbiological terms, only formulation A presented satisfactory microbiological quality, suggesting that when preparing future formulations there must be greater control of raw materials, and compliance with good hygiene and manufacturing practices. In conclusion, this dissertation demonstrated that the incorporation of chestnuts in muesli can result in an innovative and healthy product, but also promote the appreciation of cultural identity and local food traditions, offering a nutritious and tasty alternative for consumers.
Description
Keywords
Muesli Castanha Secagem Desenho experimental de misturas Propriedades nutricionais Análise sensorial.