Formation of resistant starch during processing and storage of instant noodles

Instant noodle was prepared in a commercial noodle plant using varying steaming and frying conditions. Wheat flour had very low amount of resistant starch (RS) as 0.26 g/100 g dry solids. Dough was formed by mixing wheat flour with other adjuncts for 15-20 min, cut into about 0.5 mm strands and steamed in a tunnel for 90 to 240 s. Steaming of dough increased RS content from 0.22 to 0.49 g/100 g dry solids in 90 s and to 1.4 g/100 g dry solids in 240 s. Frying of steamed noodles at temperatures ranging from 145-170°C for 60-160 s resulted in sudden decrease in moisture content from 42.9-49.6 to 0.6-1.6 g/100 g dry solids and increase in oil content up to about 20 g/100 g dry solids. Frying of steamed noodle strands resulted in only slight increase in RS content (up to 1.2 times), depending on steaming time and temperature. Storage of instant noodles showed up to 1.4 times increase in RS content but refrigerated storage did not increase the RS content.