Acúmulo de matéria seca e óleo nas sementes de pinhão-manso e qualidade do óleo extraído

Abstract

R ESU M OObjetivou-se, com o presente trabalho, avaliar o efeito do estádio de maturação dos frutos sobre o rendimento em massa de matéria seca e óleo das sementes de pinhão-manso (Jatropha curcas L.), e sobre a qualidade do óleo extraído. Frutos de pinhão-manso foram classificados em quatro diferentes estádios de maturação, de acordo com sua coloração: verde, amarela, marrom-amarela e marrom. Amostras dos frutos de cada estádio foram retiradas para a determinação do teor de água, dimensões principais, volume e contagem de sementes por fruto. As sementes foram extraídas para determinação do teor de água, dimensões principais, volume, massa seca de mil sementes, percentual em massa de óleo e percentual de ácidos graxos livres do óleo extraído. A colheita de frutos de pinhão-manso com coloração marrom-amarelo e marrom, proporcionou maior rendimento em massa seca das sementes e em conteúdo de óleo. A colheita dos frutos com coloração marrom-amarelo além de possibilitar bons rendimentos em óleo e em matéria seca, permite a obtenção de óleo com índice de acidez menor, sendo o estádio de maturação mais indicado para a realização da colheita dos frutos e sementes de pinhão-manso para fins industriais. Palavras-chave: Jatropha curcas L., época de colheita, maturidade de massaDry matter and oil accumulation in the jatropha seeds and quality of extracted oil A B ST R A C T The aim of this study was to evaluate the effect of ripening stage of the fruits on the increase in dry matter and oil content of physic nut (Jatropha curcas L.) seeds. The quality of the oil was also investigated and related to the ripening stage. The fruits were classified in four classes of colors: green, yellow, brownyellow and brown (dry fruits). Samples of fruits were collected for each ripening stage and the analysis of water content, size, volume and numbers of seeds were performed. For the seeds, water content, size, volume, mass of thousand seeds, oil content and acid value were evaluated. The harvest of brownyellow and brown fruits provided higher yields in dry matter and oil of seeds. The brown-yellow fruits presented higher oil yield and dry matter, lower acid value, so it represent the more suitable ripening stage for harvesting fruits and seeds for industrial uses.

Morphophysiological profile of Jatropha curcas L. fruits and seeds maturation

“…curcas fruits were also visually classified according to six maturation stages using the Munsell colour chart: green, beginning of yellow pigmentation, predominantly yellow, beginning of brown pigmentation, ripe, and dry beginning dehiscence (DRANSKI et al, 2010). Other authors found only four stages (PESSOA et al, 2012;SANTOS et al, 2012), including green, yellow, yellow with brown and dry. Silva et al (2012) The seeds were classified according to 13 different maturation stages: green (divided into A, B, C, The seeds were classified according to 13 different maturation stages: green (divided into A, B, C, D, E, F, G, H), yellow-green, yellow, yellow-brownish, brown-yellowish, and brown-dry.…”

“…in earlier stages than described by those authors. Several authors who studied the maturation of J. Curcas seeds made no distinction between the seeds from green fruits (KAUSHIK, 2003;DRANSKI et al, 2010;PESSOA et al, 2012;SANTOS et al, 2012;SILVA et al, 2012). Rubio et al (2013), on the other hand, classified these seeds according to only two stages, light and dark green.…”

“…The high moisture content found in early seed maturation is essential for the transport of photosynthesised products that are used as an energy source for metabolism by the developing seeds, and subsequently are stored as reserves to be used at the time of germination (CORVELLO et al, 1999;SANTOS et al, 2012). Xu et al (2011) also verified an exponential increase in fresh weight during the early stages of J. curcas seed development and a stop in growth during the last stages, thereby initiating the process of desiccation with increased accumulation of lipids and other nutrients as a reserve.…”

“…Jatropha curcas L. occurs naturally in the semiarid northeastern part of Brazil and countries of the equatorial Americas. However, although the species has not been fully domesticated yet, it already stands out for the potential of its oleaginous seeds, as well as for its apparent hardiness and tolerance to conditions of abiotic stress, and maybe even to conditions of biotic stress (SATURNINO et al, 2005). At present, this culture is considered to be yet another option for agriculture in the Brazilian northeast, as it constitutes a viable crop for obtaining oil as raw material for the manufacture of biodiesel, with a minimum yield of two tons of seeds per hectare (DRUMMOND et al, 2008).…”

Acúmulo de matéria seca e óleo em sementes de pinhão-manso irrigado e de sequeiro

“…O teor de óleo das sementes extraídas de frutos verdes foi 1,59 vez inferior ao das sementes extraídas de frutos secos, que estatisticamente, foi considerado igual ao teor de óleo extraído de sementes extraídas de frutos colhidos nos estádios maduro e na proporção de 20% de frutos verdes e o restante amarelos, marrons e secos, indicando que, a partir da coloração do fruto marrom-amarelo, o teor de óleo nas sementes pode ser considerado máximo. SANTOS et al (2012) verificaram que sementes de pinhão-manso continham teor de óleo máximo quando os frutos passaram a apresentar sinais de maturação pela coloração amarela, mas observaram que tanto o acúmulo como a composição do óleo dependem também de fatores genéticos e condições de campo durante a maturação. GANGAL et al (2009) Em relação ao manejo de água, houve diferenças entre os dois tratamentos quanto ao teor de óleo das sementes (Tabela 4).…”