Effect of drying on the physical properties of quince

• Main Author: Guiné, Raquel
• Publication Date: 2012
• Other Authors: Barroca, M J
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://hdl.handle.net/10400.19/1101
• topic: quince; drying; texture; hardness; colour

This study aimed at evaluating the textural properties of quince in fresh and after drying at different conditions. In parallel, colour was also measured to evaluate how the visual aspect of the product changed with drying. The experiments were done in a tunnel drier, at different temperatures, from 30 to 60ºC, and different air velocities, varying in the range 0.7 to 1.2 m/s. The colour coordinates of the fresh quince were: L* = 78.02±0.86, a* = - 1.27±0.32 and b* = 31.75±1.68. These values indicate that the samples were bright, because L* was closer to 100 than to 0. Furthermore, it can be seen that quince was greenish, although very slightly and strongly yellowish. With drying, the samples became darker and redness was intensified, as a result of browning. In relation to the textural properties in fresh, the values were: hardness = 48.46±6.47 (N), springiness = 74.86±5.17 (%), cohesiveness = 0.75±0.06, resilience = 0.47±0.08 and chewiness = 27.23±4.06 (N). Furthermore, it was observed that drying, regardless of the conditions, induced an important hardening, increasing hardness and diminishing springiness.