Oil in noodle processing

In noodle processing, the frying is an important step which is conducted to dehydrate the gelatinized noodle strips in a short time such that dried noodles having quick reconstitutability are obtained.

Vegetable oil such as palm oil, sesame oil or rapeseed oil; an animal oil/fat such as lard; or a hydrogenated oil/fat thereof is used in general.

The frying process not only enables high productivity but also provides easy-to-eat property and favorable roast and savory flavor.

Oil uptake during the frying process in instant noodles is important in view that it imparts a distinct flavor, mouth-feel and improves product acceptability. However, higher oil uptake accounts for raising health concerns.

During frying process, the surface temperature of the instant noodles increases rapidly after being placed in the hot oil. The water on the instant noodles surface immediately goes into a boiling state, which causes instant noodles to dry out, and thus heat and mass exchange takes place.

The process leads to shrinkage and raises the level of porosity and roughness. The moisture contained in the gelatinized starch granules evaporates due to the high temperature. The empty spaces previously occupied by the moisture are next partially filled with oil.

When whole grain flour was used, the oil content of the fried noodles decreased by up to 30% compared with those made from white flour.

The wheat cultivar also affected the oil content of the fried noodle and the dough development time during noodle making was negatively correlated with oil uptake. Conversely, oil content has been found to increase as the dough mixing time increased.

Krokida in 2000 have reported an increase in oil content with longer frying times, especially for thinnerproducts, which has been related to the microstructure developed during frying. (J. Food Eng. 44, 39–46)

Pinthus and Sam Saguy (1994) have also stated that crust porosity increases with frying time thus contributing to increased oil uptake. (J. Food Sci.59, 804–807)
Oil in noodle processing