Effect of spontaneous fermentation on the physical properties of corn starch and rheological characteristics of corn starch noodle

Starch was isolated from spontaneously fermented corn to study the effect of fermentation on the physical properties of corn starch and the suitability of fermented corn for starch noodle. Considering the security of fermentation, aflatoxin B, content in fermented samples was also tested. Results showed that above 75 degrees C, fermented samples had significantly lower swelling power and solubility than control samples (p < 0.05). The peak viscosity and breakdown initially increased and then decreased, while final viscosity and setback decreased gradually with fermentation time. Fermented samples had significantly higher gel strength (p < 0.05) and noodles from them had higher maximum tensile stress, maximum tensile strain and work to break the noodle. Results of sensory evaluation indicated that fermentation significantly improved quality of corn starch noodle, and quality of starch noodle from corn fermented for 19 days was comparable to mung bean starch noodle. The spontaneous fermentation was safe based on the results of toxin test. (C) 2007 Elsevier Ltd. All rights reserved.