小麥種子穗上發芽對製粉品質之影響

Effect of Pre-harvest Sprouting on Flour Quality of Wheat Seeds

楊金英(Jin-Ying Yang) ； 林訓仕(Hsun-Shih Lin)

《臺中區農業改良場研究彙報》 140期 (2018/09) Pp. 55-65

摘要

本試驗探討不同穗上發芽程度與比率對小麥發芽率、沉降係數、全麥麵粉品質及烘焙之影響，以瞭解影響小麥品種台中選2號商品價值之穗上發芽率容許值。試驗結果顯示，已萌發、種皮開裂及未萌發之小麥種子發芽率分別為0%、62%及98.7%；隨著種子種皮開裂比率提高，沉降係數隨之下降，低於5%對麵粉品質影響尚低，但若高於10%沉降係數僅餘227 sec，即未符合加工標準。然而已萌發之種子對小麥沉降係數影響較種皮開裂種子顯著，1%即導致沉降係數降至210 sec，乾麵筋與濕麵筋含量則隨其比率提高而降低，已萌發種子比率由0%增加至1%，乾麵筋含量即由23.2%降至16.4%；尖峰黏度、破裂黏度、回升黏度亦隨其比率提高而下降。烘焙試驗顯示，含1%已萌發之小麥種子磨製之全麥粉，烘焙後吐司體高度下降16.6%，已萌發之小麥種子含量提高至10%，吐司體高度則下降45.5%。綜合上述試驗結果得知，已萌發之小麥種子對麵粉品質影響較種皮開裂種子顯著，高於1%即影響小麥品種台中選2號烘焙用途。

關鍵字

穗上發芽 ； 小麥 ； 沉降係數 ； 麵粉品質

並列摘要

The present study investigated the effect of various preharvest sprouting (PHS) levels on the percentage germination, falling number, flour quality, and baking quality of whole wheat flour and the effects of field PHS allowance rates on the commercial value of wheat 'Taichung Sel. 2'. The results showed that the germination rates of wheat grains at root and shoot emergence, seed-coat splitting, and ungerminated stages were 0%, 62%, and 98.7%, respectively. If the seed-coat splitting grain content was less than 5%, the falling number was low, not affecting flour quality; however, if the content increased to higher than 10%, the falling number reduced to 227 s, affecting the flour quality. Nevertheless, the falling number of root and shoot emergence grains had a more significant effect than that of seed-coat splitting grains; with 1% root and shoot emergence grain content, the falling number was reduced to 210 s. The dry and wet gluten contents decreased as the root and shoot emergence grain content increased. The increase of root and shoot emergence grain content from 0% to 1% reduced the dry gluten content, from 23.2% to 16.4%. The maximum, breakdown, and setback viscosities decreased as root and shoot emergence grain content increased. The baking tests demonstrated that the height of bread decreased by 16.6% and 45.5% when the flour contained 1% and 10% of root and shoot emergence seeds, respectively. Therefore, the root and shoot emergence grain content affects flour quality more significantly than does the seed-coat splitting grains; moreover, at more than 1% root and shoot emergence grain content, the baking quality of 'Taichung Sel. 2' wheat flour is significantly affected.

並列關鍵字

pre-harvest sprouting ； wheat ； falling number ； flour quality