A comparative study of starch granule-associated proteins/lipids on short-term and long-term retrogradation of normal...

To evaluate the contribution of starch granule-associated proteins/lipids (SGAPs/SGALs) to the short- and long-term retrogradation of starch, a comparative study was conducted using normal and waxy corn starches. Following the removal of SGAPs, peak viscosity (3504.71 cP) and breakdown viscosity (1659.20 cP) significantly increased, while pasting temperature (74.31 °C) significantly decreased, compared to SGALs-removed (3131.00 cP, 1229.80 cP, 75.46 °C) and native normal corn starches (2704.40 cP, 794.60 cP, 79.30 °C). Rheological profiles further revealed that the removal of SGAPs/SGALs effectively promoted the short-term retrogradation of amylose, as evidenced by larger hysteresis rings and higher consistency indices (K) in the SGAPs/SGALs-removed starch gel. While SGAPs removal also greatly facilitated amylopectin recrystallization and double helix structure aggregation than removal of SGALs, thereby significantly increased the retrogradation enthalpy (from 6.48 to 7.37 J g^-1) and gel hardness (from 461.26 gf to 518.31 gf) in normal corn starch after 14 days of storage, while no notable differences were observed in their corresponding waxy counterparts after both treatments. In conclusion, SGAPs showed significant superiority over SGALs in accelerating both short- and long-term retrogradation of normal corn starch, while both had minimal impact on waxy corn starch.