In this work, the effects of refrigerator freezing method (RF), spiral tunnel

freezing method (SF), and liquid nitrogen spray freezing method (LF) on water

distribution, microstructure, retrogradation, and digestion properties of

Liangpi are investigated. Results from SEM and water distribution show the

starch gel structure of Liangpi after LF treatment is more continuous, and its

A21 content is higher, which are closer to fresh Liangpi, followed by SF and RF.

XRD and FT-IR data indicate that as the freezing rate increases, the relative

crystallinity and R1047/1022 value of the samples decrease. This is consistent

with the data obtained from texture properties. Texture properties of samples

treat by LF and SF are closer to fresh Liangpi, especially the hardness index.

The in vitro digestibility of Liangpi also shows the same trend. Therefore, the

freezing method with a faster rate could inhibit the starch gel retrogradation,

improve the texture properties of Liangpi, and guarantee the quality of

Liangpi. However, considering the economics of enterprise production, the

spiral tunnel freezing method is more suitable for the actual production of

frozen Liangpi. The data obtained provide a theoretical guidance for the actual

production of frozen Liangpi.