Attributes of quality of pumpkin(Cucurbita moschata cv. Milk) obtained by different cooking methods

Pumpkin is a vegetable that has a remarkable nutritional importance, especially because it is a rich source of carotenoids, the essential compounds to human nutrition. Although the cooking methods may influence the retention of nutrients and phytochemicals in foods, there is a need to know the best...

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Bibliographic Details
Main Author: Maria de FÃtima Gomes da Silva
Other Authors: Paulo Henrique Machado de Sousa
Format: Others
Language:Portuguese
Published: Universidade Federal do Cearà 2012
Subjects:
Online Access:http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8043
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Summary:Pumpkin is a vegetable that has a remarkable nutritional importance, especially because it is a rich source of carotenoids, the essential compounds to human nutrition. Although the cooking methods may influence the retention of nutrients and phytochemicals in foods, there is a need to know the best way to promote cooking in pumpkin, minimizing the significant nutritional and sensory loss. This study aimed to determine and compare the quality attributes of fresh pumpkin, achieved by different cooking methods: boiling, steam, vacuum (sous-vide) and microwave. It was made chemical and physico-chemical determinations, staining, functional constituents and microbiological and sensory analysis of the products. At the end of the study, it was found that the parameters of soluble solids, non-reducing sugars, total sugars, soluble dark pigments, hue angle, total anthocyanins, yellow flavonoids, carotenoids and phenolic compounds, and the sensory attributes of flavor, texture, overall impression and purchase intention presented significant variations for the effect of the performed cooking methods. The color of cooked samples was less bright (L*), red (a*) and yellow (b*) than the color of the fresh sample. The loss of vivid colors (reduction of chroma) over the fresh pumpkin was observed for all cooked samples. All cooking methods reduced the content of ascorbic acid, anthocyanins and total polyphenols. Total carotenoids ranged from 8,933.92 to 24,772.72 mg 100 g-1 of fresh sample, and 24.58% higher in cooking in microwave and 2.26% cooking in boiling, while the cooks in the steam and in vacuum (sous-vide) caused a reduction. The yellow flavonoids were more preserved for cooking in microwave and ranged from 9.31 to 13.73 mg 100 g-1 between the brews made. The sous-vide cooking caused the greatest loss of functional components, being attributed to increased cooking time and degradation by light. The products showed no microbiological contamination. The cooking in microwave showed the highest scores for all sensory attributes evaluated. The other three cooking were also well accepted by panelists, representing different market niches. Pumpkin has many quality attributes, with high levels of functional components, and cooking in microwave oven is the preferred method to promote their cooking. === A abÃbora à um legume que apresenta uma notÃvel importÃncia nutricional, destacando-se pelo fato de ser uma rica fonte de carotenÃides, compostos imprescindÃveis na nutriÃÃo humana. Todavia, os mÃtodos de cocÃÃo podem influenciar a retenÃÃo de nutrientes e fitoquÃmicos em alimentos, havendo a necessidade de se conhecer a melhor forma de promover a cocÃÃo em abÃbora, minimizando as significativas perdas nutricionais e sensoriais. Este trabalho objetivou determinar e comparar os atributos de qualidade de abÃbora in natura e obtida por diferentes mÃtodos de cocÃÃo: ebuliÃÃo, vapor, vÃcuo (sous-vide) e micro-ondas. Foram realizadas determinaÃÃes quÃmicas e fÃsico-quÃmicas, coloraÃÃo, constituintes funcionais e anÃlises microbiolÃgicas e sensoriais dos produtos. Ao final do estudo, constatou-se que os parÃmetros de sÃlidos solÃveis, aÃÃcares nÃo redutores, aÃÃcares totais, pigmentos escuros solÃveis, Ãngulo hue, antocianinas totais, flavonÃides amarelos, carotenÃides totais e polifenÃis totais, e os atributos sensoriais de sabor, textura, impressÃo global e intenÃÃo de compra apresentaram variaÃÃes significativas pelo efeito dos mÃtodos de cocÃÃo realizados. A cor das amostras cozidas foi menos brilhante (L*), vermelho (a*) e amarelo (b*) do que a cor da amostra in natura. A perda de cores vivas (diminuiÃÃo de croma) em relaÃÃo à abÃbora in natura foi observada para todas as amostras cozidas. Todos os mÃtodos de cocÃÃo reduziram os conteÃdos de Ãcido ascÃrbico, antocianinas totais e polifenÃis totais. Os carotenÃides totais variaram de 8.933,92 a 24.772,72 Âg 100 g-1 de amostra fresca, sendo elevados em 24,58% na cocÃÃo em micro-ondas e em 2,26% na cocÃÃo em ebuliÃÃo, enquando as cocÃÃes no vapor e no vÃcuo (sous-vide) provocaram reduÃÃo. Os flavonÃides amarelos foram mais preservados na cocÃÃo em micro-ondas e variaram de 9,31 a 13,73 mg 100 g-1 entre as cocÃÃes realizadas. A cocÃÃo sous-vide ocasionou as maiores perdas de componentes funcionais, sendo atribuÃdas ao maior tempo de cocÃÃo e a degradaÃÃo pela luz. Os produtos nÃo apresentaram contaminaÃÃes microbiolÃgicas. A cocÃÃo em micro-ondas foi a que apresentou maiores mÃdias para os atributos sensoriais avaliados. As outras trÃs cocÃÃes tambÃm foram bem aceitas pelos provadores, representando nichos diferenciados de mercado. A abÃbora possui muitos atributos de qualidade, apresentando elevados nÃveis de componentes funcionais, sendo a cocÃÃo em micro-ondas o mÃtodo preferido para promover a sua cocÃÃo.