Journal de la transformation et de la technologie des aliments

Abstrait

Effect of Osmo-dehydration Conditions on the Quality Attributes of Pears

Djendoubi Mrad Nadia, Boudhrioua Mihoubi Nourhène, Kechaou Nabil, Courtois Francis and Bonazzi Catherine

The aim of this work is to study the effect of osmotic dehydration on mass transfer (solid gain (SG) and water loss (WL)) and on some quality attributes kinetics degradation of pears (ascorbic acid and total phenolic contents, color). Pears samples (1×0.8×0.8 cm3) were osmotically dehydrated for different time, following a 53 central composite experimental design (osmosis time: 30, 120, 210, 300, and 390 min, sucrose concentration: 25, 35, 45, 55 and 65 °Brix and temperature 20, 30, 40, 50, and 60°C). The interactive term of osmosis time, sucrose concentration and temperature have a significant effect on WL and SG. As expected, water loss and solids gain increased with the increase of temperature and solution concentration. Sucrose concentration, osmosis time and temperature induce significant increase of a* and b* colormetric parameters but did not affect the lightness (L*) of pear slices. This seems to be a result of matrix concentration and solids uptake. Osmosis time is the most important factor affecting total phenolic content. Volume change is linearly correlated with temperature and osmosis time. These results suggest that shrinkage is essentially due to water loss and solid gain.