复合改良剂对后发酵馒头冷冻面团冻藏品质的影响

冷冻面团加工技术作为一种面食生产新工艺,是目前较先进的面制品保鲜技术。冷冻处理会对酵母活力、面团品质、面团面筋结构等产生不良影响。为了提高冷冻面团品质,明确不同食品改良剂对后发酵冷冻面团馒头品质的影响,该研究优化了复配增稠剂(卡拉胶、瓜尔豆胶、海藻酸钠)、复配乳化剂(双乙酰酒石酸单双甘油酯、羧甲基纤维素)、复配酶制剂(谷氨酰胺转氨酶、葡萄糖氧化酶)和海藻糖对后发酵冷冻面团馒头品质的作用,通过单因素和响应面试验设计,考察了不同复合改良剂对冷冻面团馒头比容、质构和感官品质的影响。研究表明:海藻糖、酶制剂对冷冻面团馒头比容的影响极其显著(p0.01)。在添加量为0.4%乳化剂、0.8%增稠剂、45 mg/kg酶制剂、2%海藻糖的复配工艺下,冷冻面团馒头的比容达到最佳水3.15 mL/g,其硬度和弹性也达到较优值,分别为926.832 g、0.912 8。同时对未添加和添加复合改良剂冻藏0～2.5个月的冷冻面团进行扫描电镜观察,发现未添加复配改良剂的冷冻面团中大多数小淀粉颗粒裸露在外,颗粒分明,内部组织结构不均匀,而添加复合改良剂的冷冻面团淀粉颗粒镶嵌在面筋网络之间,蛋白网络结构清晰完整,冷冻面团内部组织结构均匀紧密,面团的抗冻性较强。

Effect of compound quality improver on the frozen quality of frozen dough for steamed bread

Abstract: Steamed bread is a traditional fermented pasta product in China, which plays an important role in the dietary structure. With the improvement of people''s living standards and the acceleration of life pace in recent years, steamed bread has become a popular fast food product for consumer. However, the shelf life of steamed bread is short and easy to be aged, which greatly affects the industrialized production of steamed bread. Frozen dough technology can provide an economic and effective technical way. However, the relevant research reports pointed out that the water in the dough formed ice crystals in the process of frozen storage. Because of the temperature fluctuation, recrystallization will occur, which will destroy the network structure of the dough, make the dough appear cracks after freezing, reduce the gas holding capacity, as well as affect the quality of frozen dough and its cooked products. At the same time, ice crystal will also lead to the damage and rupture of yeast cells, such as the damage of its respiratory system, the reduction of yeast vitality and the lack of gas production, which will cause the decline of dough specific volume, texture and sensory quality. The use of dough quality improver can enhance the structure of gluten network, protect yeast activity, improve the quality of dough, and prolong the storage period of frozen dough. To study the effect of different improvers on the quality of frozen dough and its cooked products, and to select the compound improvers which can improve the quality of the products better, it has a certain practical significance in the actual production. In order to improve the quality of frozen dough and to clarify the effect of different food improvers on the quality of unwrapped frozen dough, this paper studied compound thickeners (carrageenan, guar gum, sodium alginate) and compound emulsifier (diacetyl tartrate monoglyceride, carboxymethyl cellulose), complex enzyme preparations (glutamine transaminase, glucose oxidase) and trehalose on the quality of unwrapped frozen dough steamed bread, through single factor and response surface experimental design, the effect of different compound quality improver on the specific volume, texture and sensory quality of frozen dough. Studies have shown that the effect of trehalose and enzyme preparation on the specific volume of frozen dough is extremely significant (P<0.01). Under the compounding process of adding 0.4 % emulsifier, 0.8 % thickener, 45 mg/kg enzyme preparation and 2 % trehalose, the specific volume of the frozen dough steamed bread reached the level of 3.15 mL/g, and its hardness and the springiness also reached a superior value of 926.832 g and 0.912 8, respectively. At the same time, the frozen dough which was not added and added with the compound quality improver for 0-2.5 month was observed by scanning electron microscopy. It was found that most of the small starch granules in the frozen dough without the addition of the modifier were exposed outside, the particles were distinct, and the internal structure was uneven. The frozen dough starch granules with the compound quality improver added in the gluten network, the protein network structure is clear and complete, the internal structure of the frozen dough is even and tight.