Daniel Pioch

Acylation over cation-exchanged montmorillonite

The Friedel-Crafts acylation of aromatic compounds (benzene, toluene, xylene) with carboxylic acids (CH3(CH2)n COOH, n = 0–14) was performed over cation-exchanged montmorillonites (H+, Al3+, Ni2+, Zr4+, Ce3+, Cu2+, La3+). Yields in ketones were found to be dependent upon the nature of the interlayer cation and on the acid chain length.

Towards an efficient membrane based vegetable oils refining

Abstract The diversification of the non food uses of vegetable oils and the need for softer processing demands new oil refining processes. Taking advantage of the membrane technology for vegetable oil refining, the preliminary results reported here concern a single dead-end or crossflow microfiltration step. The influence of experimental parameters (temperature, pore size, pressure …) on the flow rate of permeate and on the free fatty acids (FFA) (as soap) and phosphorus retention ratios is discussed. After addition of sodium hydroxide followed by dead-end filtration the quality of the oil meets the quality standard but the main drawback is the very poor flow rate as a consequence of the rapid fouling of membranes. Cross-flow filtration allows a higher flow rate of permeate which shows a slow decrease after operating for several hours, with only a slight loss of quality of the processed oil compared to dead-end filtration. From this preliminary study, the cross-flow microfiltration gives promising results for vegetable oils refining. This is the first report of simultaneous reduction of phosphorus, free fatty acids and water concentrations after a solvent free single microfiltration step.

Detailed study of Brazil nut (Bertholletia excelsa) oil micro-compounds: phospholipids, tocopherols and sterols

O oleo da castanha-do-para (Bertholletia excelsa) foi estudado por causa da sua composicao em acidos graxos, tocoferois, esterois e fosfolipidios. A composicao de acidos graxos nos fosfolipideos tambem foi estudada. Os resultados foram comparados com os do girassol, da castanha, amendoa, noz, soja e azeites. O seu alto teor em acidos graxos insaturados, em β-tocoferol e em β-sitosterol confere a castanha-do-para interessantes propriedades antioxidantes e de prevencao do colesterol. A composicao de acidos graxos em fosfolipidio e muito diferente da composicao do oleo. O acido linolenico, que nao se encontra no oleo, encontra-se em grande quantidade na fosfatidiletanolamina.

First lipase-catalysed synthesis of fatty carbonate esters

SummaryEthyl carbonate reacts with fatty acids and alcohols in the presence of an immobilized lipase. The biocatalyst converts oleic acid into ethyl oleate almost quantitatively. From octadecenol, the main product is ethyl octadecenyl carbonate. These experiments show that lipase is capable of catalytic activity in carbonic series.

Characterisation of Blighia sapida (Sapindaceae) seed oil and defatted cake from Benin

A sample of Blighia sapida seeds collected in Benin has been analysed and the results are compared to the scarcely available literature data. The chemical analysis of seed oil shows a saponification value of 145 and an iodine value of 66, consistent with the high mono-unsaturated fatty acids (FAs) content (63.8 wt%). The most interesting feature is the prominent concentration of eicosenoic acid (48.4 wt%). Arachidic acid being the main component within the saturated group, the C20 FAs fraction accounts for 68.4 wt%, thus making the peculiar composition of this oil. Among the unsaponifiable fraction (2.4 wt%), the major sterol is stigmasterol (54.6 wt%), surprisingly over passing β-sitosterol. Tocols (338 ppm) contains mainly α- and γ-tocopherol. Regarding the defatted cake, results show the prominent position of starch and a noticeable amount of proteins and fibers (44.2, 22.4, 15.6 wt%, respectively). Seventeen amino acids were identified together with valuable minerals (total ashes 3.5 wt%). Possible uses of oil and defatted cake are discussed.

Rapid analysis of jojoba wax fatty acids and alcohols after derivatization using Grignard reagents

This method, based on the action of Grignard reagents, is an original approach to wax derivatization and differs from the methods previously described, which were essentially based on wax alcoholysis. Grignard reagents, especially magnesium ethyl bromide, react on ester functions to turn the wax constituents into primary and tertiary alcohols, the latter being the fatty acid derivatives. The mixture of these alcohols is analyzed by a single gas chromatographic injection. The overall time, about 1.5 hr, makes this method suitable for routine analysis. It could be also considered for analyzing low carbon condensation organic acid esters.