EFFECT OF PRETREATMENT ON COLOR OF DEHYDRATED PRODUCTS
Titel:
EFFECT OF PRETREATMENT ON COLOR OF DEHYDRATED PRODUCTS
Auteur:
Krokida, M. K. Kiranoudis, C.T. Maroulis, Z. B. Marinos-Kouris, D.
Verschenen in:
Drying technology
Paginering:
Jaargang 18 (2000) nr. 6 pagina's 1239-1250
Jaar:
2000-07-01
Inhoud:
The effect of pretreatment on color of convective dried products (namely apple, banana, potato and carrot) was investigated. Five different types of pretreatment were taken into consideration; microwave, osmotic, sulfite, water blanching and steam blanching. Color characteristics were identified by measuring the color parameters (namely, Lightness (L), Redness (a) and Yellowness (b)) using a Hunter Lab chromatometer. The type of pretreatment was found to significantly affect the three color parameters. In addition, Redness (a) and Yellowness (b) were found to follow a first order kinetic model. Untreated dried materials showed an extensive browning, indicated by a significant drop of the L parameter and a corresponding increase of a, b parameters. Osmotically and microwave pretreated samples supressed browning compared to the untreated samples. In this case, lightness decreased slightly, while a, b increased slightly. Sulfite pretreatment prevented significantly color deterioration, while water and steam blanching also prevented enzymatic browning during convective drying.