Optimization of chestnut starch acetate synthesis by response surface methodology and its effect on dough properties.

Chestnut starch acetate (CSA) was prepared by attaching acetic anhydride groups on chestnut starch (CS) molecules. The process conditions for the preparation of CSA were optimized through single‐factor testing and response surface analysis. The optimal conditions were as follows: acetic anhydride content 7%, time of reaction 92 min, temperature 33°C, and pH 8. The actual average apparent viscosity of CSA was 480.53 ± 0.29 mPa·s, which was 109.38% higher than that of natural CS. Fourier transform infrared spectroscopy analysis showed that the hydroxyl group was replaced by the acetyl group on the acetic anhydride. The X‐ray diffraction analysis revealed that the crystal form of CSA was type C even after modification. As observed by scanning electron microscopy, the surface of some CSA granules presented different degrees of sag, breakages, and wrinkles. The water retention analysis of the dough revealed that the addition of CSA in the dough was 6%, and the dough had the strongest hydrophilicity and the best water retention. Further, a high number of freeze‐thaw cycles reduced the water retention of the dough. The texture characteristics analysis indicated the addition of CSA in the raw dough was 6%–9%, which improved the firmness and toughness of the frozen‐thawed dough. Practical applications: The chestnut processing industry is looking for a new way to develop chestnut derivatives and comprehensively utilize chestnut fruit waste. As the main component of chestnut fruit, starch can be used as a substitute for traditional starch sources such as cereals and tubers. In recent years, modified starch has been widely used in food processing fields such as bread, ice cream, and gluten‐free food due to its excellent properties such as high transparency, good stability, and strong water retention. The present study provides an investigation about optimization of chestnut starch acetate (CSA) synthesis by response surface 3D modeling methodology and its effect on dough properties. The results show that the technology of preparing CSA can be regarded as one of the excellent alternative methods to simplify the processing and improve the quality of modified starch. And the modified starch is applied to the dough, the dough shows excellent water retention, and its hardness and toughness are also improved. We believe that the chestnut industry can use the results of this research in the reprocessing of chestnut derivative products and utilization of discarded chestnuts. [ABSTRACT FROM AUTHOR]