Naslov
Separation and identification of cuticular fractions of dried tomato by-products

Autori
Ninčević Grassino, Antonela ; Grabarić, Zorana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
European Biotechnology Congress 2011 ; Current Opinion in Biotechnology, Vol 22 (S1) / Dundar, Munis ; Gahan Peter B ; Magni, Maria Pia - : Elsevier, 2011, 152-152

Skup
European Biotechnology Congress 2011

Mjesto i datum
Istanbul, Turska, 28.09.2011. - 01.10.2011

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
cutin; cuticular fractions; extraction; FTIR spectroscopy; tomato byproducts

Sažetak
Tomato (Lycopersicon esculentum Mill) is one of the most widely cultivated vegetable crops in Mediterranean countries. Significant amounts are consumed in the form of processed products, i.e. tomato juice, paste, purée, ketchup, sauce and salsa. The commercial processing of tomato results in the accumulation of large amounts of waste, composed by mixture of tomato skin, pulp and seeds. The cuticle of these by-products is chemically heterogeneous in nature consisting mainly of a wax fraction, soluble in organic solvents, and an insoluble lipophilic matrix, namely cutin. This high-molecular weight polyester has a very low water sorption and permeability, high specific heat and as such could be a potential substrate for biofilm production. The present work reports methodology of cuticular fractions (bulk, dewaxed and nonhydrolyzable cuticles) extraction and purification from dried tomato skin. For that purpose, the tomato skin is firstly treated with acid/ammonium oxalate solution at 90 °C for 24 h to remove the pertinacious glue that attaches the cuticle to the epidermal layer. After that dewaxed fraction is obtained after exhaustive Soxlet extraction with various organic solvents (chloroform, dichloromethane, petroleum ether and methanol), to obtain the best extraction yield. Subsequently, the dewaxed tomato skin was hydrolysed with 6 M HCl under reflux, to obtain the pure cutin biopolymer. The obtained fractions were characterised using FTIR spectroscopy. The FTIR spectra of dewaxed cuticular fractions indicate the presence of two strong absorption bands located at 2916 and 2848 cm-1, associated with the asymmetric and symmetric stretching vibrations of the methylene groups and relatively strong bands at 1745 and 1162 cm-1, assigned to the carbonyl stretching of the carboxyl group and C-O-C stretching vibrations in the ester group. The hydrolysis of dewaxed cuticular fraction with 6 M HCl caused the ester bonds in cutin polymer to break, corresponding to removal of hydroxy fatty acids. The results of FTIR spectroscopy confirm that all cuticular fractions were successfully isolated from dried tomato skin and that this spectroscopic technique can be used as excellent tool for characterisation and validation of tomato by-products. Further investigations should be focused on modification of extractions procedure to avoid large volumes of organic solvents, which may cause environmental problems.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA