Rice bran oil extraction using alcoholic solvents: Physicochemical characterization of oil and protein fraction functionality

Autor(es)

Capellini, Maria C. ; Giacomini, Vanessa ; Cuevas, Maite S. ; Rodrigues, Christianne E. C.

• Tipo de documento: Artigo Científico
• Fonte: INDUSTRIAL CROPS AND PRODUCTS; v. 104, p. 133-143, OCT 1 2017.
• Citações Web of Science: 18

Resumo

Rice bran, an underutilized rice processing by-product, is a promising source for food and biodiesel oil production and can also be used to produce protein for use in human food products. The main objective of this study was to assess the feasibility of replacing hexane, which is traditionally used to extract vegetable oils, with safer solvents, i.e., ethanol and isopropanol, in rice bran oil (RBO) extraction. Thus, the effects of the solvent type on the physicochemical characteristics of the oil and defatted bran products were studied. The results showed that the presence of water in the alcoholic solvents negatively affected the oil extraction; however, using absolute solvents in single-stage batch extractions at 80 degrees C resulted in oil yields of up to approximately 80%. The solvent water content and process temperature strongly impacted the properties of the protein fraction; the nitrogen solubility index (NSI) decreased from approximately 40% for the absolute solvents to 17 and 15% for the aqueous ethanol and isopropanol, respectively, when the extraction was performed at 80 degrees C. More of the minor nutraceutical compounds were transferred from the oleaginous matrix to the oil by aqueous ethanol than by hexane, yielding RBO with 1.53% gamma-oryzanol and 769 mg/kg tocotrienols. On the other hand, absolute isopropanol exhibited a higher tocopherol extraction capacity; RBO with a tocopherol content of 98.1 mg/kg was obtained with this solvent. Based on these results, short-chain alcohols are promising alternatives to the conventional extraction solvent, because they enable high-quality protein fractions and oils to be obtained and add value to the rice production chain. (AU)

• Processo FAPESP: 14/09446-4 - Desenvolvimento de processo de extração de óleos vegetais utilizando solventes alcoólicos: avaliação da composição do óleo e de alterações na fração protéica
• Beneficiário: Christianne Elisabete da Costa Rodrigues
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/13339-6 - Viabilidade Técnica do Emprego de Solventes Alcoólicos na Extração de Óleos Vegetais: Caracterização Físico-Química do Óleo, Funcionalidades da Fração Proteica e Recuperação do Solvente
• Beneficiário: Maria Carolina Capellini
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 14/21252-0 - Equilíbrio e processos de produção de biocombustíveis e bioprodutos
• Beneficiário: Antonio José de Almeida Meirelles
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 10/13285-5 - Extração de Óleo de Farelo de Arroz utilizando Solventes Alcoólicos: Avaliação de Alterações na Fração Proteica e na Composição do Óleo
• Beneficiário: Maria Carolina Capellini
• Modalidade de apoio: Bolsas no Brasil - Mestrado