酒精发酵处理对小麦非淀粉多糖的影响及酒糟在馒头中的应用

Effect of ethanol fermentation on non-starch polysaccharides of wheat and application of DDGS in making steamed bread

在实验室条件下对4种不同产地、皮色的小麦样品进行酒精发酵处理,研究酒精发酵对籽粒中膳食纤维、阿拉伯木聚糖等非淀粉多糖的影响,并将副产物酒糟(DDGS)应用于高纤维(膳食纤维含量6%以上)馒头的开发。小麦籽粒及麸皮中水溶性膳食纤维的含量很低,仅占膳食纤维总量的5%左右。酒精发酵处理后,膳食纤维总量不变,水不溶性膳食纤维转化为水溶性膳食纤维,DDGS中水溶性膳食纤维占总膳食纤维的比例提高至10.59%~16.02%。发酵后DDGS中可溶性阿拉伯木聚糖、多酚的总量分别是发酵前籽粒全粉中相应总量的6~7倍、8~10倍。在发酵醪液中检测到一定活性的木聚糖酶,该酶可能帮助水解阿拉伯木聚糖,释放阿魏酸,使DDGS中可溶性阿拉伯木聚糖和总酚的含量显著增加。采用含DDGS的混合粉制作的馒头与小麦粉馒头的比容没有显著性差异,最大达到2.78 m L/g;与麸皮混合粉馒头相比,DDGS混合粉馒头的比容显著增大,硬度降低,弹性和回复性提高。

Four wheat samples with different habitats and colors were provided by Guangdong Xinliang Industrial Co.Ltd.In order to study the effect of fermentation treatment on non-starch polysaccharides in wheat,stimulating the dry mill process in laboratory was used to ferment wheat with alcohol.Distillers Dried Grains with Solubles(DDGS),a by-product of alcohol fermentation,has the potential to be applied in the development of high fiber food.In this study,DDGS was used to develop high fiber steamed bread(more than 6% of dietary fiber content,dry basis).The content of water-soluble dietary fiber in wheat seeds and bran is very low,accounting for 5% of the total dietary fiber.The results showed that after alcohol fermentation treatment,the total dietary fiber content remained unchanged.However,water-insoluble dietary fiber was converted into water-soluble dietary fiber,and the ratio of water-soluble dietary fiber to total dietary fiber in DDGS increased to 10.59%-16.02%.The content of water-soluble arabinoxylans and total phenols in DDGS after fermentation was 6-7 and 8-10 times of its counterparts in the whole wheat flour.It is reported that xylanase could facilitate the hydrolysis of arabinoxylan by cutting off the β-1,4-glycosidic bond on the side chain of arabinoxylan,promote the conversion of insoluble arabinoxylan to arabinoxylan,and further release ferulic acid.Xylanase with certain activity was detected in mash,which might help to hydrolyze arabinoxylans,release ferulic acid,and increase the content of water-soluble arabinoxylans and total phenols in DDGS significantly.In order to achieve balanced nutrition,more and more studies focus on the application of dietary fiber in staple food.As the main source of dietary fiber,bran can be added to produce whole wheat flour.Unsoluble dietary fiber in whole wheat flour usually produces unpleasant taste and lowers consumers’ acceptance.Biological fermentation can increase the solubility of dietary fiber and improve the texture of flour products.There was no significant difference between the specific volume of steamed breads made with premixes containing DDGS and its counterpart made with flour.The maximum specific volume for steamed breads with DDGS was 2.78 mL/g.In comparison with steamed breads made from premixes containing bran,DDGS breads had larger specific volumes,lower hardness,and improved elasticity and resilience.This study has shown that the incorporation of DDGS in steamed breads can be a way for the reutilisation of this by product.In addition,it can also increase consumers’ acceptance of whole wheat food.