Abstract:In order to optimize the processing technology of alum-free fresh potato/cassava starch noodles, the effects of addition ratio of sodium alginate, shaping time, refrigerated and frozen time, etc, on the texture properties, moisture content, and overall acceptability of alum-free fresh potato/cassava starch noodles were evaluated. In addition, effects of different retrogradation treatments on the breaking time, apparent and microstructure (scanning electron microscopy, Fourier infrared spectrum, small angle X-ray scattering) of alum-free fresh potato/cassava starch noodles were investigated, the mixture starches of potato and cassava (potato starch: cassava starch=1:1, W/W) was used as raw material, the fresh starch noodles without alum and with 0.30% alum were used as control. The results showed that the tensile strength (2.86 g/mm2), tensile deformation (63.88%), shear stress (39.89 g/mm2), shear deformation (37.76%), moisture content (60.40%), and overall acceptability of fresh potato/cassava starch noodles were the closest to those of fresh starch noodles with 0.30% alum after adding 1% sodium alginate, indicating 1% sodium alginate could be used as alum substitute for the production of fresh starch noodles. Furthermore, the optimal conditions for processing fresh potato/cassava starch noodles without alum were as follows: shaping time 1 min, cold storage at 4 ℃ for 24 h. The fresh potato/cassava starch noodles without alum obtained under this condition exhibited better elasticity and chew ability, longer breaking time and more uniform apparent structure. Therefore, the study can provide new basic data and theoretical support for the industry application of alum-free fresh wet potato starch noodles.
