A carregar...
Publicação
Valorização de farelo de arroz em contexto de biorrefinaria
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 3.04 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
O aumento populacional tem originado uma crescente pressão no sistema alimentar e energético. A valorização dos resíduos produzidos nas diferentes atividades humanas torna-se essencial para a preservação de recursos e para o desenvolvimento de uma economia circular.
O farelo de arroz é um subproduto do processamento do arroz. A sua valorização numa abordagem de biorefinaria permite produzir diversos produtos transacionáveis.
Nesta dissertação estudou-se a extração de óleo vegetal e a produção de extratos antioxidantes e hidrolisados ricos em açúcar a partir de farelo de arroz. O resíduo da extração foi caracterizado com vista à sua valorização como componente de reções animais.
A extração de óleo de farelo de arroz foi avaliada por três métodos: Soxhlet, aquecimento a refluxo e maceração, utilizando cinco solventes: éter de petróleo, acetona, etanol, isopropanol e butanol. Os rendimentos mais elevados de óleo vegetal foram obtidos na extração Soxhlet com os solventes acetona (21,9%), isopropanol (18,7%) e butanol (22,5%). Extratos com teores de fenólicos de 3,02% a 3,29% foram obtidos a partir do farelo desengordurado por maceração em acetona e etanol a 70%.
O farelo desengordurado foi extraído com água subcrítica às temperaturas de 120°C, 140°C, 160°C e 190°C. Concluiu-se que o rendimento de extração de açúcares aumenta com a temperatura de extração, obtendo-se o valor máximo de 53% a 190°C. Após a hidrólise com água subcrítica obteve-se um resíduo rico em proteínas. Aproximadamente 70% das proteínas do farelo desengordurado mantêm-se no resíduo de hidrólise.
Population growth has caused increasing pressure on the food and energy system. The valori-sation of waste produced in different human activities becomes essential for the preservation of resources and the development of a circular economy. Rice bran is a by-product of rice processing. Its valorisation in a biorefinery approach allows the production of several tradable products. This dissertation studied the extraction of vegetable oil and the production of antioxidant ex-tracts and hydrolysates rich in sugar from rice bran. The extraction residue was characterized with a view to its valorisation as a component of animal feed. The extraction of rice bran oil was evaluated by three methods: Soxhlet, reflux heating and maceration, using five solvents: petro-leum ether, acetone, ethanol, isopropanol, and butanol. The highest yields of vegetable oil were obtained in Soxhlet extraction with acetone (21.9%), isopropanol (18.7%) and butanol (22.5%). Extracts with phenolic contents of 3.02% to 3.29% were obtained from defatted bran by mac-eration in 70% acetone and 70% ethanol. The defatted bran was extracted with subcritical water at temperatures of 120°C, 140°C, 160°C and 190°C. It was concluded that sugar extraction yield increases with the extraction tempera-ture, obtaining a maximum value of 53% at 190°C. After hydrolysis with subcritical water, a res-idue rich in proteins was obtained. Approximately 70% of the proteins in the defatted bran remain in the hydrolysis residue.
Population growth has caused increasing pressure on the food and energy system. The valori-sation of waste produced in different human activities becomes essential for the preservation of resources and the development of a circular economy. Rice bran is a by-product of rice processing. Its valorisation in a biorefinery approach allows the production of several tradable products. This dissertation studied the extraction of vegetable oil and the production of antioxidant ex-tracts and hydrolysates rich in sugar from rice bran. The extraction residue was characterized with a view to its valorisation as a component of animal feed. The extraction of rice bran oil was evaluated by three methods: Soxhlet, reflux heating and maceration, using five solvents: petro-leum ether, acetone, ethanol, isopropanol, and butanol. The highest yields of vegetable oil were obtained in Soxhlet extraction with acetone (21.9%), isopropanol (18.7%) and butanol (22.5%). Extracts with phenolic contents of 3.02% to 3.29% were obtained from defatted bran by mac-eration in 70% acetone and 70% ethanol. The defatted bran was extracted with subcritical water at temperatures of 120°C, 140°C, 160°C and 190°C. It was concluded that sugar extraction yield increases with the extraction tempera-ture, obtaining a maximum value of 53% at 190°C. After hydrolysis with subcritical water, a res-idue rich in proteins was obtained. Approximately 70% of the proteins in the defatted bran remain in the hydrolysis residue.
Descrição
Palavras-chave
Biorefinaria Farelo de arroz Solventes hidrofílicos Óleo de farelo de arroz Água subcrítica Açúcares