- 期刊
Influence of Rice Flours and Substitution Levels on the Physicochemical Property and Glycemic Response of Breads
米穀粉與其取代度對麵包物化性質及升糖反應之影響
摘要
In the present study the comparison of physicochemical properties and digestibility between wheat bread (WB) and rice substituted bread (RSB) were investigated. Three commercial rice flours (indica, japonica and glutinous) along with two substitution levels (15% and 30%) were applied to prepare the RSB. Substitution of rice flour in WB resulted in a slight decrease in height and specific volume of breads, however, the color performance of breads was not influenced. In texture profile, hardness and chewiness of RSB were significant higher than those of WB, especially for the indica sample and at higher substitution level; while, resilience and springiness of RSB were similar to WB. After 24-hr storage, RSB performed quite different texture properties from the fresh ones due to the rice flours accelerating the retrogradation and staling of RSB. In the digestion study, not only the GI values based on the body tests but also the eGI (estimated glycemic index) resulted from the in vitro hydrolysis were discussed. Three regression equations in literature were applied to predict the eGI of RSB according to HI. Both the body test and in vitro experiment concluded the high glycemic response of all breads. Distributions of the rapidly digested starch to resistant starch in RSB were about 70/30, which the slowly digested starch in breads was very small. The in vitro test indicated a reduction of eGI of RSB in comparison with that of WB, however, the body test did not.
並列摘要
本文探討小麥麵包（WB）及其以米穀粉部分取代之麵包（RSB）之物化性質及消化性之比較，RSB分別以稉，秈，糯三種米穀粉及15和30％兩種取代度製備，結果得知，米穀粉的取代會造成麵包膨發高度與比體積略微下降，但是色澤則不受影響。在質地表現上，RSB的硬度和咀嚼度會高於WB，尤其是秈米及高取代度的產品；但是，回覆性與彈性則無差異。由於米穀粉會加速麵包的老化，RSB經24小時儲存後之質地性質與新鮮製品差異甚大。在消化性質上，本文同時進行體內及體外的試驗並做比較。在體外試驗中，藉由模擬人體酵素作用獲得水解指數（HI），再分別帶入三條回歸方程式獲得估算升糖指數（eGI），不論體內試驗或是體外試驗均獲知RSB皆具高升糖性質，且快速消化澱粉（RDS），抗性澱粉（RS）的比值約為7/3，幾乎沒有慢速消化澱粉（SDS）。體外試驗發現RSB比WB具有較低的eGI，但是體內試驗則相反，這部分需要更多體內試驗數據做驗證。