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Abstract(s)
O presente estudo foi realizado em pareceria com o Super Bock Group e teve como principal objetivo desenvolver uma bebida pronta a granizar, que preserve o aroma, o sabor, a naturalidade e o teor de gás da Pedras Limão (uma bebida gasocarbónica, à base de Água das Pedras, presente atualmente no mercado). Os granizados são bebidas semicongeladas constituídas por cristais de gelo, pequenos e arredondados, dispersos uniformemente numa matriz aquosa. Os granizados podem ser produzidos em máquinas específicas para a sua produção, com temperatura e agitação constantes, ou a partir de bebidas prontas a granizar. As bebidas prontas a granizar são transportadas e armazenadas à temperatura ambiente e no estado líquido, mas, quando são colocadas num congelador doméstico adquirem a textura de granizado. A Pedras Limão, tal como a maioria das bebidas, quando é colocada num congelador doméstico sem agitação, não tem tempos de congelação reprodutíveis, devido ao fenómeno do sobrearrefecimento, e adquire cristais de gelo grandes e angulares, que posteriormente se aglomeram e formam um bloco de gelo. Neste trabalho avaliou-se: o potencial da Pedras Limão como bebida base para um granizado; o efeito do CO2 na taxa de arrefecimento da Água das Pedras; e o efeito da adição de agentes de nucleação (carbonato de cálcio e estigmasterol) e de modeladores da morfologia de cristais de gelo (pectina, goma de guar e de goma xantana) à Pedras Limão, na reprodutibilidade dos tempos de congelação, na quantidade e na morfologia dos cristais de gelo, e nas características sensoriais da bebida. Os resultados obtidos demonstraram que: a Pedras Limão tem potencial para ser a bebida base de um granizado; o teor de CO2 não influencia a taxa de arrefecimento da Água das Pedras; o estigmasterol, ao contrário do carbonato de cálcio, garante a reprodutibilidade dos tempos de congelação, aumenta o número de cristais de gelo e diminui o seu tamanho; e a adição de pectina conjugada com goma de guar e goma xantana numa proporção de 5:1 ou de 10:1, diminui o tamanho dos cristais de gelo, torna-os mais arredondados e contribui para que estes se mantenham distribuídos uniformemente na matriz aquosa. Neste trabalho desenvolveu-se a formulação de uma bebida pronta a granizar que preserva as principais características da Pedras Limão e adquire a textura de bebida granizada, 120 – 150 minutos, após ser colocada num congelador doméstico sem agitação.
The present study was carried out in partnership with the Super Bock Group and its main purpose was to develop a ready-to-slush beverage that preserves the aroma, taste, naturalness and gas content of “Pedras Limão” (a “flavored water” currently present on the market). A slush, also known as slushie, is a semi-frozen beverage containing ice crystals dispersed in aqueous matrix. Slushes can be produced in specific machines for their production, with constant temperature and agitation, or from ready-to-slush beverages. Ready-to-slush beverages are transported and stored at room temperature and in the liquid state, but when placed in a domestic freezer, they acquire a slush texture. Pedras Limão, like most beverages, when places in a domestic freezer without constant agitation, does not have reproducible freezing times, due to the supercooling phenomenon, and acquires large and angular ice crystals, which then agglomerate and form a block of ice. This study evaluated: the potential of “Pedras Limão” as a base for a slush; the effect of CO2 on the cooling rate of “Água das Pedras”; and the effect of adding ice nucleation agents (calcium carbonate and stigmasterol) and modelers of ice crystal morphology (pectin, guar gum and xanthan gum) to “Pedras Limão”, on the reproducibility of freezing times, the ice crystals’ quantity and morphology, and on the sensory characteristics of the beverage. The results demonstrated that: “Pedras Limão” as the potential to be the base beverage of a slush; the CO2 does not influence the cooling rate of “Águas das Pedras”; stigmasterol, unlike calcium carbonate, ensures reproducibility of freezing times, increases the number of ice crystals and decreases its size; and the addition of pectin conjugated with guar gum and xanthan gum in a ratio of 5: 1 or 10: 1, decreases the size of ice crystals, renders them more rounded and contributes to them being uniformly distributed in the aqueous matrix. This study developed a formulation for a beverage that preserves the main characteristics of “Pedras Limão” and acquires a slush texture when placed in a domestic freezer, for 120 – 150 minutes, without agitation.
The present study was carried out in partnership with the Super Bock Group and its main purpose was to develop a ready-to-slush beverage that preserves the aroma, taste, naturalness and gas content of “Pedras Limão” (a “flavored water” currently present on the market). A slush, also known as slushie, is a semi-frozen beverage containing ice crystals dispersed in aqueous matrix. Slushes can be produced in specific machines for their production, with constant temperature and agitation, or from ready-to-slush beverages. Ready-to-slush beverages are transported and stored at room temperature and in the liquid state, but when placed in a domestic freezer, they acquire a slush texture. Pedras Limão, like most beverages, when places in a domestic freezer without constant agitation, does not have reproducible freezing times, due to the supercooling phenomenon, and acquires large and angular ice crystals, which then agglomerate and form a block of ice. This study evaluated: the potential of “Pedras Limão” as a base for a slush; the effect of CO2 on the cooling rate of “Água das Pedras”; and the effect of adding ice nucleation agents (calcium carbonate and stigmasterol) and modelers of ice crystal morphology (pectin, guar gum and xanthan gum) to “Pedras Limão”, on the reproducibility of freezing times, the ice crystals’ quantity and morphology, and on the sensory characteristics of the beverage. The results demonstrated that: “Pedras Limão” as the potential to be the base beverage of a slush; the CO2 does not influence the cooling rate of “Águas das Pedras”; stigmasterol, unlike calcium carbonate, ensures reproducibility of freezing times, increases the number of ice crystals and decreases its size; and the addition of pectin conjugated with guar gum and xanthan gum in a ratio of 5: 1 or 10: 1, decreases the size of ice crystals, renders them more rounded and contributes to them being uniformly distributed in the aqueous matrix. This study developed a formulation for a beverage that preserves the main characteristics of “Pedras Limão” and acquires a slush texture when placed in a domestic freezer, for 120 – 150 minutes, without agitation.
Description
Keywords
Bebida pronta a granizar Modeladores da morfologia dos cristais de gelo Agentes de nucleação de cristais de gelo Congelação Ready-to-slush beverage Freezing Ice crystal morphology modelers Ice nucleation agents