CONICET | Buscador de Institutos y Recursos Humanos

The objective of this research was the obtention of fibre products from the left over of quince (Cydonia oblonga Miller) industrialization and their characterization. For that purpose, quince was submitted to different drying conditions without or with a previous extraction either with water or ethanol (drying with convective air at 80C during 4 h-M fraction; treatment with ethanol and drying with convective air at 30C during 24 h-ME fraction; treatment with distilled water and drying with convective air al 30C during 24 h-MA fraction). Chemical composition as well as physical and functional properties of the isolated fractions were evaluated (de Escalada Pla et al., 2010). Significantly lower yields were observed for MA or ME with respect to M product. MA and ME fibre products were richer in cell wall polymers and showed higher proportions of proteins. Fats were concentrated in the MA product The hydration properties were similar to those reported for citrus and apple pulps in bibliography, and half of the water was loosely absorbed. Pectin contents seemed to be responsible for the high velocity of spontaneous water absorption showed by all the dried fibre products. However, this initial characteristic was followed by different saturation behaviors which were mainly determined by the microstructure of the materials: high drying temperature without previous extraction of simple sugars (product M) which promoted the porous collapse, as well as high fat content remaining after water extraction and drying (product MA) which impermeabilized the polysaccharide network of powder, led to the significant decrease in the water binding capacity at equilibrium in the short time scale of the kinetic assays, and also determined a different hydration response at long times of equilibrium with water (swelling capacity, water holding capacity, water retention capacity). Conversely, oil absorption seemed to essentially depend on the microstructural characteristics of the fibre powders. Higher specific volume, which was also in part a function of structural differences, could be used as an index of the ability for oil uptake. It can be concluded that it is possible to produce fibre products from quince with adequate functional properties based on modifications of its compositional and/or microstructural characteristics, adding value to industrial residues of vegetable processing.

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