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測量應用案例-20210302

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Amylose crystal seeds: Preparation and their effect on starch retrogradation
Bihua Zhu a,b
, Jinling Zhan a,c
, Long Chen a,b
, Yaoqi Tian a,b,*
a State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China b School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China c National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China
ARTICLE INFO
Keywords:
Amylose crystal seeds
Long-term retrogradation
X-ray diffraction
Fourier transform infrared spectroscopy
Differential scanning calorimetry
ABSTRACT
The relationship between the short-term retrogradation dominated by amylose and the long-term retrogradation
dominated by amylopectin still lacks specific experimental confirmation. In order to explore this relationship,
four types of amylose crystal seeds (ACS) were prepared and added to native rice starch to intervene the longterm retrogradation. The average particle size of ACS was 200–450 nm. The maximum relative crystallinity of
retrograded starch increased from 13.64% to 17.88% under the intervention of ACS. The ratio of absorbance at
1047 to 1022 cm? 1 of retrograded starch increased from 0.670 to the maximum 0.887. The retrogradation rate
constant increased significantly from 0.024 up to 0.051 d 1
. The long-range order, short-range order, and
retrogradation rate of retrograded starch all increased significantly, which indicated that the intervention of ACS
promoted the long-term retrogradation of starch. These findings provided data support for the analysis of correlation between different stages of starch retrogradation.
1. Introduction
Starch retrogradation is a process, which occurs when the molecular
motion of starch paste slows down due to a decrease in temperature.
During the process of retrogradation, amylose and amylopectin rearrange into microcrystalline forms through the formation of hydrogen
bonds to yield a more ordered or crystalline state (Fu, Wang, Li, Zhou, &
Adhikari, 2013; Karim, Norziah, & Seow, 2000). Starch retrogradation
includes two stages: short-term retrogradation and long-term retrogradation (Funami et al., 2009; Ronda & Roos, 2008). In the short-term
retrogradation stage, it is mainly the formation and accumulation of
double helix structure of amylose, and in the long-term retrogradation
stage, it is mainly the formation of double helix structure between
amylopectin outer branches and the ordered accumulation between
double helixes (Chen, Ren, Zhang, Tong, & Rashed, 2015). The retrogradation rate in short-term retrogradation dominated by amylose is
fast, and the retrogradation rate in long-term retrogradation dominated
by amylopectin is slow (Imberty, Bulecon, Tran, & P?eerze, 1991;
Swinkels, 1985). Besides, Tukomane et al. (2008) found that the content
of amylose in rice starch was closely related to its retrogradation degree,
and the higher amylose content was, the more easily starch retrograded.
Consequently, it is generally recognized in theory that short-term
retrogradation provides the crystal seed for long-term retrogradation.
But due to the complexity of retrogradation and limited research
methods of further analyzing the structure of crystal cells, there are no
specific data to support this hypothesis up to now. Furthermore, the
relationship between short-term retrogradation and long-term retrogradation provides the basis for the preparation of starch-based products
with slow digestion times and the development of anti-retrogradation
technology for rice noodle products. According to the classical kinetics
model of polymer crystallization, crystallization includes nucleation,
growth, and the formation of a perfect crystal (Marentette & Brown,
1993). This also holds true in the case of starch recrystallization (Bulkin,
Kwak, & Dea, 1987). In the starch retrogradation system, the essence of
retrogradation is also nucleation and crystal growth, with the crystal
nucleus promoting growth and perfection. However, in practice, the
processes of nucleation and growth during retrogradation are difficult to
separate in the starch retrogradation system.
Based on this, an innovative research idea was put forward. As
mentioned before, the gel structure observed during short-term retrogradation is mainly formed via amylose rearrangement into an ordered
structure. Therefore, in this study, short-term retrograded rice amylose
was selected as a crystal seed to simulate the short-term retrogradation
of starch and it was added to the starch recrystallization to study its
impact on the long-term retrogradation. Amylose crystal seeds (ACS)
were prepared by acid hydrolysis of short-term retrograded rice amylose 

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