Influência da aplicação do ultrassom de alta intensidade na desidratação osmótica do gengibre
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Data
2019-02-25
Autores
Martins, Maria Júlia Neves
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Universidade Estadual Paulista (Unesp)
Resumo
Alguns alimentos como frutas, legumes e hortaliças apresentam nível de perecibilidade elevado, o que gera insatisfação do consumidor ao adquirir o alimento após alguns dias da colheita. Por isso as indústrias alimentícias estão à procura de processos que aumentem a vida útil dos alimentos. O gengibre é um desses alimentos e está cada vez mais presente na alimentação da população. Pesquisadores têm estudado a aplicação do ultrassom na desidratação osmótica desses alimentos, combinando essas técnicas, com o propósito de aumentar a eficiência da desidratação osmótica, reduzir gastos e aumentar a vida útil dos alimentos. O objetivo deste trabalho foi verificar a influência da aplicação do ultrassom de alta intensidade na desidratação osmótica do gengibre em uma solução osmótica de sacarose. Para o desenvolvimento do trabalho foi determinada a densidade e o calor específico das soluções de sacarose nas concentrações de 10% a 60% (m∙m-1) na faixa de temperatura entre 0˚C e 90˚C, que variaram entre 970,77 a 1191,08 kg.m-3 e 2,89 a 4,11 kJ∙kg-1∙°C-1. Cinco modelos matemáticos foram elaborados, entre eles modelo linear, quadrático e exponenciais, posteriormente foram ajustados aos dados de densidade e calor específico, porém, o modelo que variou linearmente em função da concentração e quadraticamente em função da temperatura apresentou melhor ajuste em ambas as propriedades. As potências reais aplicadas ao meio foram determinadas por meio do método calorimétrico, obtendo-se um fator de conversão de 30%. Por meio dos experimentos de desidratação osmótica do gengibre, com e sem a aplicação do ultrassom de alta intensidade, foi possível verificar que aplicação do ultrassom auxilia na perda de umidade, perda de água e no ganho de sólidos.
Fresh food, such as fruit and vegetables, are highly perishable and often leave customers unhappy for they have to buy the product days after it was harvested. Therefore, the food industry is always searching for processes that enhance products' shelf life. Ginger is one of these products and its presence in our regular diet is increasing. Researchers have been studying the application of ultrasound to osmotic dehydration - called combined techniques - with the objective of increasing the efficiency of osmotic dehydration, cutting costs and enhancing the product's shelf life. This study aimed at checking the influence of applying high intensity ultrasound to the osmotic dehydration of ginger in a sucrose osmotic solution. Thus, the density and the specific heat of the sucrose osmotic solutions were determined, at concentrations of 10% to 60% (m∙m-1), in a temperature range of 0˚C and 90˚C; the values varied from 970.77 to 1191.08 kg.m-3 and from 2.89 to 4.11 kJ∙kg-1∙°C-1. Five mathematical models were elaborated, among them linear, quadratic and exponential models, later they were adjusted to the data of density and specific heat; the best adjusted one for both properties was the model that varies linearly in function of concentration and quadratically in function of the temperature. The real potencies applied to the medium were determined through a calorimetric method resulting in a conversion rate of 30%. Through the osmotic dehydration experiments with ginger both applying the high intensity ultrasound and without applying the ultrasound, it was possible to verify that ultrasound application helps in the loss of moisture, loss of water and in the gain of solids.
Fresh food, such as fruit and vegetables, are highly perishable and often leave customers unhappy for they have to buy the product days after it was harvested. Therefore, the food industry is always searching for processes that enhance products' shelf life. Ginger is one of these products and its presence in our regular diet is increasing. Researchers have been studying the application of ultrasound to osmotic dehydration - called combined techniques - with the objective of increasing the efficiency of osmotic dehydration, cutting costs and enhancing the product's shelf life. This study aimed at checking the influence of applying high intensity ultrasound to the osmotic dehydration of ginger in a sucrose osmotic solution. Thus, the density and the specific heat of the sucrose osmotic solutions were determined, at concentrations of 10% to 60% (m∙m-1), in a temperature range of 0˚C and 90˚C; the values varied from 970.77 to 1191.08 kg.m-3 and from 2.89 to 4.11 kJ∙kg-1∙°C-1. Five mathematical models were elaborated, among them linear, quadratic and exponential models, later they were adjusted to the data of density and specific heat; the best adjusted one for both properties was the model that varies linearly in function of concentration and quadratically in function of the temperature. The real potencies applied to the medium were determined through a calorimetric method resulting in a conversion rate of 30%. Through the osmotic dehydration experiments with ginger both applying the high intensity ultrasound and without applying the ultrasound, it was possible to verify that ultrasound application helps in the loss of moisture, loss of water and in the gain of solids.
Descrição
Palavras-chave
Desidratação osmótica, Gengibre, Sacarose, Técnicas combinadas, Ultrassom de alta intensidade, Osmotic dehydration, Ginger, Sucrose, Combined techniques, High intensity ultrasound