Productos enriquecidos en fibra obtenidos a partir de Cydonia oblonga Miller. Efecto de los tratamientos sobre las propiedades físico-mecánicas.

DE ESCALADA PLA MF, ROJAS AM, GERSCHENSON LN

Cdad. de Cordoba, Cordoba, Argentina.

Congreso; III Congreso Internacional de Ciencia y Tecnología de los Alimentos; 2009

Abstract: Quince (Cydonia oblonga Miller) fruit is used to make jam, marmalade and jelly. During the process, quince pulp is separated, and the remaining is discarded or used as animal feed. The aim of this work was to profit this by-product, evaluating three different treatments to obtain products enriched with dietary fibre and study the properties of them. Following process were chosen: i) water washing step previous a drying at 35ºC (MA product), ii) Boiling ethanol treatment previous a drying at 35ºC (ME product) and iii) drying at 80ºC (M product). Fractions obtained were milled rendering enriched fibre products with low water activity and so stable, with adequate particle size to be used in further applications as functional food ingredients. Apparent density (ra) of ME was slight but significantly (p<0,01) lower than that of M while no differences were observed respect to MA. True density (rt) is the solid material density excluding air pores and is a function of the water content and solid characteristics. True densities of the three fractions were significant different (p<0,001), being higher values for M and lower for ME.  Particle size distribution was determined through light scattering. Mass median diameter d0,5 and Sauter parameters, showed significant highest values (p<0,001) for ME fraction. Although, same grinding process was applied on the three cases, ME fraction showed a different behavior rendering particles with higher size. It could be also observed, for three fractions, that d0,5 increased 1,28 to 1,37 times when particles were hydrated. Mechanical assays of compression and relaxation showed that ME presented the lowest compressibility (p<0,001) making evident the capacity of this fraction to be deformed with the lowest change on density respect to M and MA. This indicates a more solid behavior of ME fraction. It could be concluded that pre-treatment with boiling ethanol performs a more solid fraction (ME), that could offer mayor resistance to grinding, rendering a mayor median particle size, with lower true density matrix. Different physical and mechanical properties observed would affect the functionality of this fibre enriched products during the gut transit.   Palabras clave: subproductos de membrillo, fibra dietaria, propiedades físico-mecánicas.   Key words: quince wastes, dietary fibre, physical-mechanical properties.