Survival of resistant starch during the processing of atmospheric and vacuum fried instant noodles

The objective was to develop instant noodles (IN) made by atmospheric and vacuum frying processes, with addition of 10% of three different sources of resistant starch: resistant starch type 2 (RS2), resistant starch type 3 (RS3) and green banana flour (GBF) aiming the increasing of the fibre content. The IN obtained by atmospheric frying lost water faster and absorbed more fat. However, for both frying treatments, the RS3 noodles absorbed the least amount of oil. The greatest loss of RS occurred during the cooking stage. RS2 and GBF noodles presented a loss of RS of around 30% during steam cooking, while the RS3 approximately 18%. The frying process decreased RS content of noodles, however, during both frying process, the samples with the highest RS content at all frying times were noodles containing RS3. When comparing products obtained after 90 and 120 s of atmospheric and vacuum frying, respectively, it was observed that, although the frying time in vacuum process was longer, higher RS values were obtained for the three different formulations. The vacuum frying process has advantages due to the lower fat absorption (3% less), lighter colour and a reduced conversion of RS to digestible starch, compared to atmospheric frying.