Fluidized Bed Drying Process of Thinly Sliced Potato (Solanum tuberosum)

Potatoes play the role of a vegetable or a complementary dish in the Mexican diet. They are mainly consumed fresh. Dried vegetables of the particular interest in preparation of dry mixtures are used for soups. The rapid expansion of the fast food industry could result in an increase in the use of dehydrated potatoes, as a component for vegetable mixture and soups. However, Pre-drying treatments such as addition of antioxidants are needed for vegetable drying as the potato in order to avoid changes of color. In this work, the influence of different pre-treatments and drying conditions on physical characteristics (moisture content, water activity and color difference) of thinly sliced potato during drying by fluidized bed was investigated. The thinly sliced samples of fresh potato were dipped into solutions containing citric acid (0, 0.5 and 1% w/w) before drying. Potato sample were dehydrated at air temperatures of 40, 50 and 60 degrees C. The second degree polynomial model was used to describe the response variables. The analysis of variance (ANOVA) for all coded models indicated that the models were statistically significant (p <= 0.05). The temperature and citric acid increment increases color difference, and decreases the moisture content and water activity of the dehydrated samples of potato. Color closest to the original color of fresh potato was obtained in some treatments. In general, it was observed that the drying of thinly sliced potato was influenced by pretreatment.