轉麩醯胺酸酶對強化纖維饅頭品質之影響

Effect of transglutaminase on the quality of fiber-enriched steamed bread

現代飲食日趨精製，易因膳食纖維量攝取不足而產生慢性疾病。饅頭是我國的主食。食用高纖饅頭是增加國人纖維攝取量之方法。然而添加纖維往往造成饅頭之品質降低。本研究使用小麥麩皮作為纖維之來源，探討添加轉麩醯胺酸酶對含20%小麥麩皮饅頭品質之影響。結果顯示添加轉麩醯胺酸酶增加麵糰之抗展性而減低延展性。在饅頭之應力鬆弛試驗，其數據符合Peleg-Normand模式。添加1.0-1.5%轉麩醯胺酸酶所製得高纖饅頭之k1或k2值顯著性地比對照組高，而SR%有相反之趨勢。因此添加轉麩醯胺酸酶可增加高纖饅頭之彈性。添加0.5-1.0%轉麩醯胺酶高纖饅頭之比體積皆比對照組高。在質地剖面分析方面，僅添加2.0%轉麩醯胺酶高纖饅頭之硬度顯著性比對照組高，而添加1.0-2.0%轉麩醯胺酶高纖饅頭之內聚性顯著高於對照組。因此本研究建議添加1.0-1.5%轉麩醯胺酸酶可製得較佳品質之高纖饅頭。

Dietary fiber (DF) is indigestible polysaccharides and lignin in food. In human, DFbenefits health in these ways: to help prevent constipation and colon cancer, to lower serumcholesterol, and to improve body’s handling of blood glucose. Steamed bread is one ofstaple foods in Taiwan. DF intake will be increasing when fiber-enriched steamed bread isconsumed. The objective of this study is to investigate that the effects of transglutaminase(TGase) on the quality of fiber-enriched steamed bread. Results showed that TGaseincreased the resistance in extension (R) of dough and decreased the extensibility (E).Stress relaxation data of the steamed bread fitted well by Peleg-Normand model. Either k1or k2 parameter of the steamed bread with 1.0-1.5% TGase were significantly higher thanthat of control bread. However, lower %SR was found in 1.5% TGase-treated steamedbread. Therefore, the addition of TGase leads to the increase in elasticity of thefiber-enriched steamed bread. The steamed breads with 0.5-1.0% TGase had higher specificvolume than control bread. The hardness of 2.0% TGase-treated steamed bread was higherthan that of control. Moreover the cohesiveness of 1.0-2.0% TGase-treated steamed breadswas higher than that of control. The study suggests that fiber-enriched steamed bread withbetter quality can be produced by using 1.0-1.5% TGase.