Storage stability of Jatropha curcas L. oil naturally rich in gamma-tocopherol

• Autor(a) principal: Rodrigues, Joana
• Data de Publicação: 2015
• Outros Autores: Miranda, Isabel, Furquim, Leonnardo, Gominho, Jorge, Vasconcelos, Manuel, Barradas, Gonçalo, Pereira, Helena, Bianchi-de-Aguiar, Fernando, Ferreira-Dias, Suzana
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.5/14035
• topic: gamma-tocopherol; Jatropha curcas; oil; seeds; stability

tJatropha curcas L. is an interesting tropical oil crop for biodiesel production. However, seed conservationuntil oil extraction may be a problem under high temperature and humidity. In this study, Jatropha curcasL. seeds grown in Mozambique and presenting 160 mg/kg of gamma-tocopherol in their oil were storedfor 42 days, in dark, at 35◦C and 75% or 92% relative humidity (RH). Along storage, the oil was extractedand analysed in terms of fatty acid composition, tocopherol content, acidity, initial and final oxidationproducts (monitored by K232 and K270 values, respectively).Jatropha seeds presented an initial water content of 8.4% and an oil content of 45.7% (dry basis). Theoil was rich in oleic (41.2%) and linoleic (38.8%) acids.Along 42 days of storage, the acidity increased from 0.8% to 7.4% and 25.3% and K270 increased from0.07 to 0.25 and 0.46 in oils from seeds stored at 75% and 92% RH, respectively. Simultaneously, a decreasein gamma-tocopherol content was observed, which was more pronounced at 92% RH than at 75% RH (96%decrease versus 57% decrease). Gamma-tocopherol showed to protect the oil against oxidation principallyduring the second stage of oxidation. During the storage at 35◦C, the fatty acid composition of the oilsfrom seeds kept either at 75% or 92% of humidity, did not significantly vary throughout the test