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Macauba (Acrocomia aculeata) is a promising tropical palm for the production of vegetable oil for both the food and non-food sectors. In this work, a multi-target response surface optimization of the aqueous extraction of Macauba kernel oil aimed to maximize the oil yield and minimize the free acidy and peroxide value. High yield was achieved at a high pH, long extraction periods and moderate temperatures, but these conditions contributed to elevating the peroxide value of the oil. On the other hand, pH presented the only significant effect on the oil’s acidity, which decreased with the increase in pH in the aqueous medium. Therefore, the multi-target response surface optimization based on a desirability approach showed that pH 11, room temperature (25 °C) and a 60 min agitation time was preferred to obtain high yield and low free acidity and peroxide values. These conditions resulted in 30% yield (63.1% of the yield obtained by solvent extraction), 0.3% free acidity, and a peroxide value of 2.9 meqO2/kg. The oil from the optimized aqueous extraction had a higher saturated fatty acid content compared to that from solvent extraction, especially fatty acids with < 14 carbon atoms, which can make the oil harder and more useful for producing special fats for specific food applications.

Objetivou-se avaliar o uso de descritores morfológicos na caracterização e seleção de genótipos de capim-elefante (Pennisetum sp.) de porte baixo e determinar a herdabilidade dos caracteres avaliados. Foram utilizados nove clones de capim-elefante de porte baixo (Taiwan A.146 - 2.14, Taiwan A.146 - 2.27, Taiwan A.146 - 2.37, Taiwan A.146 - 2.114, Merker México - 6.2, Merker México - 6.5, Merker México - 6.31, cv. Mott e CNPGL92F198.7) em delineamento experimental de blocos ao acaso com três repetições. Os descritores morfológicos foram aplicados a cada 60 dias, após os cinco cortes de uniformização, realizados em intervalos de 60 dias, a 10 cm do nível do solo. Os clones de capim-elefante de porte baixo com maior altura foram os que apresentaram maior desejabilidade agronômica, portanto, esta característica deve ser considerada no momento da seleção. A estimativa da herdabilidade foi alta para todos os caracteres avaliados em capim-elefante de porte baixo, com valores que variaram entre 100% para cor da nervura central e 66% para cerosidade da bainha. O clone Taiwan A.146 - 2.37 foi semelhante ao cultivar Mott. Os valores de herdabilidade indicaram variabilidade genética entre os clones, detectada aos 60 dias de idade. Alguns descritores morfológicos aplicados permitem caracterizar os genótipos avaliados. Os clones Taiwan A. 146-2.27, Taiwan A. 146-2.37, Taiwan A. 146-2.114 e Merker México 6.31 apresentam maior altura e maior intensidade de perfilhamento total, além de maior desejabilidade, portanto maior potencial para utilização sob corte.The experiment was carried out with the objectives to evaluate the use of morphologic descriptor in the characterization and selection of dwarf elephant grass genotypes, and to evaluate the heritability of the evaluated traits. Nine dwarf elephant grass clones were used (Taiwan A.146 - 2.14, Taiwan A.146 - 2.27, Taiwan A.146 - 2.37, Taiwan A.146 - 2.114, Merker México - 6.2, Merker México - 6.5, Merker México - 6.31, cv. Mott, and CNPGL92F198.7) was allotted to a randomized complete block design was used with three replications. The morphologic descriptors were applied every 60 days after the staging cut. A total of five cuts were performed at 60-day intervals using a height of 10 cm from ground level. Among the evaluated dwarf elephant grass clones the tallest ones were more desirable, and this trait should be considered at the moment of selection. Heritability estimate was high for all evaluated traits of dwarf elephant grass, varying from 66% for sheath wax to 100% for mid-rib color. The Taiwan A.146 - 2.37 clone was similar to the Mott cultivar. Heritability values showed genetic variability among clones, detected at 60 days regrowth. Some of the used morphologic descriptors allowed characterization of the evaluated genotypes. The clones Taiwan A. 146-2.27, Taiwan A. 146-2.37, Taiwan A. 146-2.114, and Merker México 6.31 were the tallest and showed greater total tillering intensity, and were more desirable, presenting greater potential for use under cutting.