基于结构特性分析工艺对速食面叶复水性及品质的影响

Analysis of the influence of process on the rehydration characteristics and quality of instant noodle slice based on structural characteristics

目的探究和面、压延和干燥过程中速食面叶结构特性的变化,分析对其复水特性及品质的影响。方法利用低场核磁、傅里叶红外光谱仪、扫描电镜对速食面叶加工过程中水分分布、蛋白质二级结构、微观结构、面筋网络结构进行分析,研究不同工艺对面叶复水特性及品质的影响。结果和面、压延过程中,速食面叶水分主要以T21、T22、T23形式存在,且T22占比在80%左右。加水量的增加和压延的进行,结合水比例上升,自由水比例下降,面叶持水能力增强。加水量38%、压延5次时,面叶中的二硫键和氢键含量最高,游离巯基和疏水相互作用含量最低,此时速食面叶有较好的复水性和品质;提高干燥温度,可以显著降低速食面叶湿基含水率,加大干燥速率,对蛋白质二级结构及孔隙率分布有显著影响。与60℃干燥相比,气流热风90℃只需干燥10 min,速食面叶的水分含量就能达到10%左右,气流热风干燥由于风速的影响,远比烘箱干燥速率快;随着干燥温度的升高,面叶内部孔隙率从4.17%增加到12.04%,复水时间从362 s缩短到273 s。结论从加工过程中结构特性变化来看,适当的加工工艺有利于水分由自由水向结合水迁移,加强速食面叶的持水能力;也有助于完善面筋网络结构,增强蛋白质二级结构稳定性,提升内部孔隙率,加大面叶干燥速率,缩短复水时间,为优良品质速食面叶的开发提供理论参考。

Objective To explore the influence of the structural characteristics of instant noodle slice in the mixing,rolling and drying process on the rehydration characteristics and quality.Methods Low field nuclear magnetic resonance,Fourier transform infrared spectroscopy,and scanning electron microscopy were used to analyze the water distribution,protein secondary structure,microstructure,and gluten network structure of instant noodle leaves during processing.The effects of different processes on the rehydration characteristics and quality of noodle leaves were studied.Results In the process of mixing and rolling,the water of instant noodles mainly existed in the form of T21,T22,T23,and T22 accounted for about 80%.With the increase of water addition and rolling times,the proportion of combined water increased,the proportion of free water decreased,and the water holding capacity of instant noodle slice was increased.When adding 38%water and rolling 5 times,the disulfide bond and hydrogen bond had the highest content,free thiol content and hydrophobic interaction content were the lowest,then the instant noodle slice had good rehydration characteristics and quality;improving the drying temperature could significantly reduce the moisture content and increase the drying rate,which had a significant impact on the protein secondary structure and porosity distribution.Compared with 60℃drying,90℃of hot-air drying for 10 min,the moisture content of instant noodle slice could reach about 10%,hot-air drying was far faster than the oven drying rate because of the wind speed.With the drying temperature rising,the porosity increased from 4.17%to 12.04%,the rehydration time was shortened from 362 s to 273 s.Conclusion From the change of structural characteristics in the processing,appropriate processing technology is beneficial to migrate from free water to combined water,strengthen the water holding capacity of instant noodle slice;it also helps to improve the gluten network structure,enhance the stability of the protein secondary structure,improve the internal porosity,increase the drying rate and shorten the rehydration time,then provides theoretical reference for the development of fine quality instant noodle slice.