直链和支链淀粉，谁更易被人体消化吸收并更快速引起血糖波动?

支链淀粉。

人的消化系统从支链淀粉中分解出葡萄糖·麦芽糖并吸收的速度较快。这是因为淀粉酶从淀粉分子末端将其拆散为葡萄糖单体或麦芽糖分子。直链淀粉只有首尾两个末端，水解速度比拥有更多末端的支链淀粉慢。

支链淀粉比直链淀粉更快引起血糖波动。含支链淀粉较多的糯米比大米不易咀嚼且密度更大（通过填满胃部带来饱腹感的能力差），给人们「支链淀粉不易消化」的错误印象，其实 糯米饭的血糖生成指数约 87 （不同研究测得 76 ^[1] ~92 ^[2] ） ，我国常见的短粒精白米饭 ^[3] 的血糖生成指数约 83 （不同品种的大米、不同研究测得 50 ^[4] ~92 ^[5] ，某些大米的直链淀粉含量很高，血糖生成指数相应较低。糙米比同品种大米加工出的精米的血糖生成指数低）。

研磨与加热可以打断食物中的淀粉分子。温度下降后，食物中业已断裂的一些淀粉可以 重新结晶 ，叫做 淀粉回生 ，回生的淀粉不易消化，隔夜饭的血糖生成指数低于同一份米饭刚煮好的时候 ^[6] 。直链淀粉比支链淀粉更容易结晶 ^[7] ，工业淀粉经常需要对此进行改性处理。

参考

1. ^ 以葡萄糖溶液为100 Kim, D., Kim, Y., & Lim, H. (2019). Glycaemic indices and glycaemic loads of common Korean carbohydrate-rich foods. British Journal of Nutrition, 121(4), 416-425. doi:10.1017/S0007114518003446
2. ^ 以葡萄糖溶液为100 Ranawana DV, Henry CJ, Lightowler HJ, Wang D. Glycaemic index of some commercially available rice and rice products in Great Britain. Int J Food Sci Nutr. 2009;60 Suppl 4:99-110. doi: 10.1080/09637480802516191. PMID: 19169946.
3. ^ 磨去了糠层，仅保留胚乳
4. ^ 以葡萄糖溶液为100 Ranawana, V., Henry, C., Lightowler, H., & Wang, D. (2009). Glycaemic index of some commercially available rice and rice products in Great Britain. International Journal of Food Sciences and Nutrition, 60(Supp 4), 99–110.
5. ^ Chiao-Hsin Yang, Chia-Wei Chang, Jenshinn Lin, White Rice Glycemic Index Measured in Venous and Capillary Blood Samples, Food Science and Technology Research, 2017, Volume 23, Issue 2, Pages 297-304, Released May 27, 2017, Online ISSN 1881-3984, Print ISSN 1344-6606, https://doi.org/10.3136/fstr.23.297, https://www.jstage.jst.go.jp/article/fstr/23/2/23_297/_article/-char/en
6. ^ Chiao-Hsin Yang, Chia-Wei Chang, Jenshinn Lin, White Rice Glycemic Index Measured in Venous and Capillary Blood Samples, Food Science and Technology Research, 2017, Volume 23, Issue 2, Pages 297-304, Released May 27, 2017, Online ISSN 1881-3984, Print ISSN 1344-6606, https://doi.org/10.3136/fstr.23.297, https://www.jstage.jst.go.jp/article/fstr/23/2/23_297/_article/-char/en
7. ^ https://doi.org/10.3945/an.113.004325
8. ^ https://pubs.acs.org/doi/abs/10.1021/ed052p729
9. ^ https://doi.org/10.3945/jn.111.152975
10. ^ https://doi.org/10.1017/S0007114509992534
11. ^ NDP-葡萄糖-淀粉-葡糖基转移酶