不同冻结方式对非发酵面团的水分状态及品质特性的影响

Effects of Different Freezing Methods on Water State and Quality Characteristics of Non-fermented Dough

本实验从冻结方式的应用场合出发,对比研究了家庭常用的低温冰箱冻结(cryogenic refrigerator freezing,RF)、传统企业化生产采用的螺旋隧道冻结(spiral tunnel freezing,SF)、新兴待开发的液氮喷淋冻结(liquid nitrogen spray freezing,LF)处理对非发酵面团的水分状态、质构特性、流变学特性以及微观结构产生的影响。结果表明,3种冻结方式的冻结速率存在明显差异,其中LF(1.33℃/min)>SF(0.31℃/min)>RF(0.08℃/min),且随着冻结速率减慢,面团的冻结失水率呈上升趋势,强结合水T_(21)与弱结合水T_(22)的峰面积比例呈下降趋势,面团的质构品质和流变学特性变差,尤其是硬度变大。由面团的微观结构分析发现,冷冻速度越慢,造成面团中的孔隙较大,面团的组织结构致密程度较差。综上,经LF处理后解冻的面团与新鲜面团的品质最相近,其次是SF和RF处理,表明新兴的LF处理比传统企业化的SF处理更有优势,而家庭常用的RF处理不利于保持面制食品的品质。

Considering the different applications of freezing methods(commonly used in households,traditional industrial production,and research laboratories),three freezing methods were selected to freeze non-fermented dough,namely cryogenic refrigerator freezing(RF),spiral tunnel freezing(SF)and liquid nitrogen spray freezing(LF).This study compared the effects of the freezing methods on the various characteristics of non-fermented dough,including water state,texture characteristics,rheological characteristics and microstructure.The results showed that there were significant differences in the freezing rates of the three different freezing methods,showing a decreasing order of LF(1.33℃/min)>SF(0.31℃/min)>RF(0.08℃/min).Furthermore,with the decrease in freezing rate,the water loss rate after dough freezing showed an upward trend,the proportion of A_(21)(peak area of strongly bound water)and A_(22)(peak area of weakly bound water)showed a downward trend,and the texture quality and rheological properties of the thawed dough deteriorated.In particular,we observed an increase in hardness.The microstructural observation showed that as the freezing rate slowed down,the pores in dough became larger and the structural compactness became poorer.In conclusion,the quality of the thawed dough treated by LF was the closest to that of fresh dough,followed by SF and RF.Therefore,LF,an emerging technology to be developed,is superior to SF,while RF is not conducive to maintaining the quality of flour-based foods.