Evaluation of the mechanism of oil uptake and water loss during deep-fat frying of tortilla chips

Simple equation Mt/M∞ = Ktn is evaluated to describe the Fickian mechanism of oil absorption and water release during the frying of tortilla chips in nixtamalized samples with lime and without lime where Mt/M∞ is the fractional solute absorption or release, and n is the diffusional exponent characteristic of the Fickian mechanism that changes with food physical and chemical properties. For the Fickian mechanism, the exponent (n) is ≤0.50, and non-Fickian is 0.5<n<1 for slabs. Moisture releases showed a Fickian mechanism form tortilla chips with lime (n = 0.5) due to water interaction with matrix components and non-Fickian for tortilla chips without lime (n = 0.6). Oil absorption showed a Fickian mechanism for nixtamalization with lime n = 0.4 and for nixtamalization without lime, one of n = 0.3. The larger water diffusion coefficient in the tortilla chip compared to that of oil diffusion indicates that water release and oil absorption during frying is not a simultaneous event. The behavior of the water and oil diffusion is an interesting topic that, in this study, was investigated using a practical equation with potential application in food processing.

Keywords: antioxidant, pitaya juice, sensory quality, refrigerated storage.