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Utilização da irradiação em alimentos: avaliação das alterações químicas e seu potencial antioxidante
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Abstract(s)
São inúmeras as técnicas de conservação de alimentos descritas atualmente na literatura, todas visando o aumento de tempo de vida útil dos alimentos, sem perdas nutricionais significativas dos mesmos. A utilização da energia ionizante para a preservação dos géneros alimentares tem vindo a ser muito estudada pela indústria alimentar. Nesse sentido, a tecnologia alimentar está a progredir de forma a aumentar a preservação alimentar e contribuir para a diminuição da incidência de doenças relacionadas com a ingestão de alimentos. A irradiação consiste na exposição do alimento a uma radiação ionizante, de forma a minimizar a flora microbiana e a diminuir a velocidade das reações químicas intrínsecas do mesmo. Inerentes a essas condições, a presença de certos compostos químicos, correntemente designados como bioativos, onde se incluem os compostos fenólicos, são reconhecidos pelos seus efeitos biológicos na promoção da saúde. Quando ingeridos em quantidades adequadas, atuam na captação de radicais livres nocivos ao organismo e evitam a oxidação de substâncias facilmente oxidáveis. No presente trabalho foram estudados dois alimentos submetidos à técnica de irradiação. As sementes de abóbora e os grãos de feijão mungo foram testados a doses crescentes, de forma a avaliar a atividade antioxidante proveniente dos compostos fenólicos e dos flavonoides totais, presentes nestas matrizes alimentares, tendo sempre em consideração um grupo controlo. Conclui-se neste trabalho, que a irradiação não afetou o teor de compostos bioativos, tendo sido favorável no acréscimo dos mesmos, até uma determinada intensidade de radiação. O mesmo foi observado para a atividade antioxidante.
There are many techniques for food preservation described in the literature, all aimed to increase the “life” of the food, without significant nutritional losses. The use of ionizing energy for preservation has been widely studied by the food industry. In this regard, food technology is making progress towards increasing food preservation and contributing to a reduction in the incidence of food-related diseases. Irradiation consists of exposing the food to an ionizing radiation in order to minimize microbial flora and slow the intrinsic chemical reactions of the microbial flora. Inherent in these conditions, the presence of certain chemical compounds, commonly referred to as bioactive, which include phenolic compounds, are recognized for their biological effects on health promotion. When ingested in adequate quantities, they act in the capture of free radicals that are harmful to the organism and avoid the oxidation of easily oxidisable substances. In the present study, two foods were submitted to the irradiation technique. Pumpkin seeds and mung bean were tested at increasing doses in order to evaluate the antioxidant activity from phenolic compounds and flavonoids total in these food matrices, always taking into account a control group. It was concluded in this work that the irradiation did not affect the content of bioactive compounds, having been favorable in the addition of the same, up to a certain intensity of radiation. The same was observed for antioxidant activity.
There are many techniques for food preservation described in the literature, all aimed to increase the “life” of the food, without significant nutritional losses. The use of ionizing energy for preservation has been widely studied by the food industry. In this regard, food technology is making progress towards increasing food preservation and contributing to a reduction in the incidence of food-related diseases. Irradiation consists of exposing the food to an ionizing radiation in order to minimize microbial flora and slow the intrinsic chemical reactions of the microbial flora. Inherent in these conditions, the presence of certain chemical compounds, commonly referred to as bioactive, which include phenolic compounds, are recognized for their biological effects on health promotion. When ingested in adequate quantities, they act in the capture of free radicals that are harmful to the organism and avoid the oxidation of easily oxidisable substances. In the present study, two foods were submitted to the irradiation technique. Pumpkin seeds and mung bean were tested at increasing doses in order to evaluate the antioxidant activity from phenolic compounds and flavonoids total in these food matrices, always taking into account a control group. It was concluded in this work that the irradiation did not affect the content of bioactive compounds, having been favorable in the addition of the same, up to a certain intensity of radiation. The same was observed for antioxidant activity.
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Keywords
Sementes edíveis Abóbora (Cucurbita pepo) Feijão mungo (Vigna radiata) Irradiação Fenólicos Flavonoides Atividade antioxidante Edible seeds Pumpkin (Cucurbita pepo) Mung beans (Vigna radiata) Irradiation Phenolic Flavonoids Antioxidant activity