A cost-effective method for wet potato starch preservation based on hurdle technology

A new cost-effective method based on hurdle technology was developed for preserving wet potato starch (WPS; moisture content 44.5 +/- 0.5%). Firstly, lactic acid, NaCl, and NaSO3 were used as hurdles to preserve WPS. Consequently, WPS treated with 2.0 g/kg lactic acid, 8.0 g/kg NaCl, and 300 mg/kg NaSO3 achieved superior preservation results during 30 d storage at 37 degrees C. Specifically, significantly reduced water activity (a(w)) (p < 0.05) was observed and total plate count (TPC) was far below the threshold limit of acceptability (4.0 log(10) CFU/g). Meanwhile, high scores reflecting desirable sensory properties of WPS were sustained throughout storage, with no significant changes observed in WPS processing properties (starch granule swelling power, solubility, thermal and pasting, and morphological characteristics) during 180 d storage at 25 degrees C (p < 0.05). Only Bacillus subtilis was detected in optimally treated WPS, while 4 dominant spoilage microorganisms (Acinetobacter baumannii, Acinetobacter calcoaceticus, Bacillus amyloliquefaciens, and B. subtilis) were detected in the control group, indicating that the treatment effectively inhibited microbial metabolism by increasing deoxygenation and reducing pH and a w values. Thus, this method prolongs WPS shelf life and shows great promise for use in industrial-scale production.