Slowly digestible state of starch: mechanism of slow digestion property of gelatinized maize starch.
Slowly digestible state of starch: mechanism of slow digestion property of gelatinized maize starch.
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DOI：
10.1021/jf072823e
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发表时间：
2008-05
影响因子：
6.1
通讯作者：
Genyi Zhang;Maghaydah Sofyan;B. Hamaker
中科院分区：
文献类型：
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作者：
Genyi Zhang;Maghaydah Sofyan;B. Hamaker
从淀粉的回生和底物对酶的敏感性的角度，研究了支链淀粉的精细结构(以线性短链的重量比[聚合度(DP/=13)]表示)与慢消化淀粉(SDS)含量之间的抛物线关系的机理。代表长链比例较高的第I组样本的玉米突变体样品，随着回生时间的延长，其SDS图谱呈钟形，而代表第II组样本中较高比例的短链淀粉的突变样本的SDS变化不显著。这与X射线粉末衍射和差示扫描量热法的结果相一致，表明HLCS在回生过程中结晶度和热焓迅速增加，而样品HSCs的结晶度和热焓变化不大。因此，对于第一组样品，回生与十二烷基硫酸钠含量有关，而对于第二组样品，回生与十二烷基硫酸钠含量无关。对支链淀粉的精细结构、十二烷基硫酸钠含量、回生热、十二烷基硫酸钠物质脱枝图谱和水解谱的分析表明，对于第I组样品，支链淀粉DP9-30的线形支链可能是支链支链部分的锚点，从而减缓了支链淀粉DP9-30支链部分的消化，而对于第II组样品，支链淀粉固有的分子结构具有较高的支链数量和较短的链，不利于快速酶消化。为了更好地描述淀粉慢消化特性的机理基础，提出了一种可以是化学或物理实体的慢消化淀粉状态(SDS态)的概念。
The mechanism underlying the previously reported parabolic relationship between amylopectin fine structure, represented by the weight ratio of linear short chains [degree of polymerization (DP /= 13], and slowly digestible starch (SDS) content was investigated from the viewpoint of starch retrogradation and substrate susceptibility to enzyme hydrolysis. A maize mutant sample, termed "highest long-chain starch" (HLCS) representing group I samples with a higher proportion of long chains, showed a bell-shaped SDS pattern with retrogradation time, whereas insignificant changes in SDS were found for the sample termed "highest short-chain starch" (HSCS) representing group II samples with a higher proportion of short chains. This corresponded to results from X-ray powder diffraction and differential scanning calorimetry that showed a rapid increase of crystallinity and enthalpy for HLCS during retrogradation, but negligible changes for sample HSCS. Therefore, retrogradation was associated with SDS content for group I samples, but not for group II samples. Analysis of amylopectin fine structure, SDS content, retrogradation enthalpy, SDS material debranching profile, and hydrolysis pattern demonstrated, for group I samples, that linear branched chains of DP 9-30 of amylopectin may act as anchor points to slow the digestion of branced-chain fractions of DP > 30, which constitute the major slowly digestible portion, whereas for group II samples, it is the inherent molecular structure of amylopectin with a higher amount of branches and shorter chains that is not favorable for rapid enzyme digestion. The concept of a slowly digestible starch state (SDS state) that could be a chemical or physical entity is proposed to better describe the mechanistic underpinning of the slow digestion property of starches.