ABSTRACT

Mung bean starches are widely used for producing transparent, good-quality noodles in the food industry. This study isolated starches from eight mung bean varieties and investigated how the amylose contents (19.1–32.9%) of the beans affected the structures, physicochemical properties, and resistant starch (RS) fractions of these starches. The starches were classified into three groups according to their amylose content: low-amylose starches with <25% amylose content (TN182, DXVN7, and DX208 varieties), intermediate-amylose starches with 25%-30% amylose contents (DX14, KPS1, and V123 varieties), and high-amylose starches with >30% amylose contents (T135 and DX044 varieties). The amylose content of mung bean starches negatively correlated with the average degree of polymerization ($\overline{D{P}_n}$) of the starch, whereas the mung bean variety dictated the average chain length ($\overline{C{L}_n})$, degree of order, and short-range molecular order of the starch. All mung bean starches were found to have an A-type crystalline structure with a relative crystallinity of 25.8–34.7%. The starches with higher amylose contents exhibited higher peaks, final viscosities, and setbacks than the other starches. The contents of the RS fraction were in the range of 3.6–13.0%; the starches of the DX14, T135, and DX044 varieties had higher contents of the RS fractions (9.0%, 9.9%, and 13.0%, respectively) than the starches from the other mung bean varieties.

Abbreviations: MB1, starch isolated from TN182 variety; MB2, starch isolated from DXVN7 variety; MB3, starch isolated from DX208 variety; MB4, starch isolated from DX14 variety; MB5, starch isolated from KPS1 variety; MB6, starch isolated from V123 variety; MB7, starch isolated from T135 variety; MB8, starch isolated from DX044 variety.

摘要

绿豆淀粉被广泛用于食品工业中生产透明，优质的面条。这项研究从8个绿豆品种中分离了淀粉，并研究了豆中直链淀粉含量（19.1–32.9％）如何影响这些淀粉的结构，理化性质和抗性淀粉（RS）组分。淀粉按直链淀粉含量分为三类：直链淀粉含量<25％的低直链淀粉（TN182，DXVN7和DX208品种），直链淀粉含量25％-30％的中直链淀粉（DX14，KPS1，和V123品种）和直链淀粉含量大于30％的高直链淀粉（T135和DX044品种）。绿豆淀粉的直链淀粉含量与平均聚合度呈负相关（$\stackrel{〜}{d{P}_{ñ}}$），而绿豆品种决定了平均链长（$\stackrel{〜}{C{\mathrm{大号}}_{ñ}}）$，淀粉的有序度和短程分子有序。发现所有绿豆淀粉均具有A型晶体结构，相对结晶度为25.8–34.7％。直链淀粉含量较高的淀粉比其他淀粉具有更高的峰，最终粘度和缩水。RS级分的含量在3.6-13.0％的范围内。DX14，T135和DX044品种的淀粉的RS馏分含量分别高于其他绿豆品种的淀粉（分别为9.0％，9.9％和13.0％）。

缩写： MB1，从TN182品种中分离出的淀粉；MB2，从DXVN7品种中分离出的淀粉；MB3，从DX208品种中分离出的淀粉；MB4，从DX14品种中分离出的淀粉；MB5，从KPS1品种中分离出的淀粉；MB6，从V123品种中分离出的淀粉；MB7，从T135品种中分离出的淀粉；MB8，从DX044品种中分离出的淀粉。