Abstract
Superheated steam impingement drying was used as an alternative technique to develop nutritious fat-free potato chips. The effect of superheated steam temperature (115, 130, and 145° C) and convective heat transfer coefficient (100 and 160 W/m² °C) on the drying rate of potato chips and on the product quality properties such as shrinkage, density, porosity, microstructure, color, texture, and nutrition loss was investigated. Furthermore, superheated steam impingement dried potato chips (130 and 145° C, h = 100 W/m² °C) were compared to air dried (same conditions), commercial, and fried potato chips. During superheated steam impingement drying, temperature and convective heat transfer coefficient had a significant effect on the drying rate. Potato chips dried at higher drying temperature and convective heat transfer coefficient showed lower shrinkage, lower bulk density, higher porosity, larger pores, and darker color when compared to chips dried at lower temperatures and convective heat transfer coefficient. They presented lower values of hardness and lower vitamin C content. A higher rate of evaporation during the falling rate period was obtained when superheated steam was used as compared to air impingement drying. Potato chips produced using superheated steam impingement drying (130, and 145° C, h = 100 W/m² °C) had higher shrinkage, higher bulk density, lower porosity, smaller pores, and lighter color than air dried chips dried under the same temperature and convective heat transfer coefficient conditions. Moreover, superheated steam dried potato chips retained more vitamin C during the drying process. Superheated steam dried potato chips presented similar texture to fried commercial samples. The vitamin C content of the superheated steam dried chips was higher (25.48 mg/100g dry matter) than the fried potato slices (11.83 mg/100g dry matter).
Caixeta, Aline Teixeira (2001). Impingement drying of potato chips. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2001 -THESIS -C35.