不同干燥方式对毛竹笋全粉中氨基酸含量和蛋白质结构的影响

Effects of different drying methods on amino acid content and protein structure of Phyllostachys pubescens shoot powder

为探究不同干燥方式对竹笋全粉氨基酸含量及蛋白质结构的影响,该实验采用喷雾干燥(spray drying,SD)、热风干燥(hot air drying,HAD)、微波干燥(microwave drying,MD)、低温真空干燥(low-temperature vacuum drying,LVD)4种方式制备毛竹笋全粉(Phyllostachys pubescens shoot powder,PPSP),分析了4种干燥方式的PPSP氨基酸组成及含量,并基于拉曼光谱酰胺Ⅰ带比较了4组样品蛋白质二级结构变化。结果表明,LVD制备的PPSP总氨基酸含量最高,为29.19 g/100 g,其次为SD,HAD制备的PPSP总氨基酸含量最低。LVD组的PPSP中必需氨基酸含量最高,为10.43 g/100 g,占总氨基酸含量的35.73%。LVD和SD制备的PPSP中呈味氨基酸含量分别为17.58 g/100 g、15.81 g/100 g,显著高于HAD和MD组的呈味氨基酸含量。LVD样品中氨基酸组成最接近于标准模式谱。通过主成分分析提取出2个主成分,累计方差贡献率达89.45%,综合评分结果为:LVD>SD>MD>HAD,聚类热图将4种干燥方式分为3类。干燥后的PPSP蛋白质中β-折叠结构最高,占总二级结构的74.66%~83.35%,HAD样中β-折叠、α-螺旋结构含量明显高于其他样品。该研究可为毛竹笋干燥及竹笋全粉的开发利用提供理论参考。

To explore the effects of different drying methods on the amino acid content and protein structure of bamboo shoot powder,Phyllostachys pubescens shoot powder(PPSP)were treated by spray drying(SD),hot air drying(HAD),microwave drying(MD),and low-temperature vacuum drying(LVD),the amino acid content was analyzed and the changes of protein secondary structure were compared based on Raman spectrum amideⅠband.Results showed that the content of total amino acid of PPSP obtained by LVD was the highest(29.19 g/100 g),followed by SD,and the sample prepared by HAD was the lowest.The content of essential amino acids in PPSP dried using LVD was the highest(10.43 g/100 g),accounting for 35.73%of the total amino acid content.The content of flavorful amino acids in PPSP prepared by LVD and SD was 17.58 g/100 g and 15.81 g/100 g respectively,which was significantly higher than that in HAD and MD groups.The amino acid composition of LVD samples was closest to the standard model.Two principal components were extracted by principal component analysis,and the cumulative variance contribution rate was 89.45%.The comprehensive score was LVD>SD>MD>HAD.The 4 drying methods were divided into 3 kinds by cluster heatmap.Theβ-fold structure of the dried PPSP protein was the highest,accounting for 74.66%-83.35%of the total secondary structure.The contents ofβ-fold andα-helix structures in HAD samples were significantly higher than those in other samples.This study can provide a theoretical reference for the drying of Phyllostachys pubescens shoot and the development and utilization of bamboo shoot powder.