Interactions of chitin, chitosan, N-lauryl chitosan and N-dimethylaminopropyl chitosan with olive oil

Chitin, chitosan and the newly synthesized and fully characterized N-lauryl chitosan and N-dimethylaminopropyl chitosan, endowed with higher hydrophob icity and cationicity, respectively, were tested for their capacity to alte r the composition of olive oil upon percolation of the latter through a bed of their respective powders. The oil samples were extracted, saponified an d submitted to gas-chromatography. Results indicated that the percentages o f 12 fatty acids were not modified, but the diacylglycerol and steroid conc entrations were greatly altered. The percolated oil was depleted of C34 and C36 diacylglycerols (lowered to 42% of the control) when the oil was conta cted with chitosan and N-lauryl chitosan, whilst the oil fraction percolate d through chitin became 30% enriched. N-Dimethylaminopropyl chitosan was al so effective in retaining diacylglycerols. The direct analysis of the unsap onifiable fraction revealed that campesterol, stigmasterol and avenasterol were enriched in the oil fraction retained by chitin and N-lauryl chitosan, while beta-sitosterol increased slightly in the fraction retained by chito san and N-lauryl chitosan. Triterpene alcohols were higher in the oil fract ion retained by chitin. This work indicates that chitin might be more suita ble than chitosan for sequestering steroids, and that, in general, the chit in derivatives discriminate among the various lipids. (C) 2000 Elsevier Sci ence Ltd. All rights reserved.