Effects of different drying methods on amino acid composition and nutritional evaluation of Lycopus lucidus Turcz.var.hirtus Regel
This study established a pre-column derivatization-high performance liquid chromatography(HPLC)method for determi-ning the content of 17 amino acids in Lycopus lucidus Turcz.var.hirtus Regel under different drying methods.The experiment used phenyl isothiocyanate(PITC)as the derivatization reagent,Venusil-AA(4.6 mm × 250 mm,5 µm)amino acid analysis column as the chrom-atographic column,and the mobile phase was 0.1 mol/L sodium acetate-80％acetonitrile solution(glacial acetic acid adjusted to pH 6.5),A gradient elution was used with a flow rate of 0.8 mL/min,a detection wavelength of 254 nm,and a column temperature of 35 ℃.Results showed that the 17 amino acids had good linearity within their respective mass concentration ranges(r≥ 0.999 0),with an average recovery rate of 96.79％to 103.94％and a relative standard deviation(RSD)of 0.73％to 2.97％.After being treated with 12 drying methods,there were differences in the total amount of amino acids in Lycopus lucidus Turcz.var.hirtus Regel(P＜0.05),ran-ging from 13.085 to 28.988 mg/g.Among them,with the highest content was 28.988 mg/g under vacuum freezing at-80 ℃.In addi-tion,all 17 amino acids were detected in all 12 drying methods,including 7 essential amino acids and 9 medicinal amino acids.The pro-portion of essential amino acids to total amino acids(EAA/TAA)ranged from 31.80％to 36.51％,with an average of 34.36％and the proportion of medicinal amino acids to total amino acids(MAA/TAA)ranged from 57.72％to 67.84％,with an average proportion of 63.12％.Three principal components were extracted through principal component analysis,and their cumulative variance contribution rate reached 92.83％.The comprehensive score showed that vacuum freezing at-80 ℃ had the highest quality.Cluster analysis divided the 12 drying methods into 3 categories,with vacuum freezing at-80 ℃ and shade-drying having higher content.This method is simple to op-erate,has good separation effect,and is suitable for simultaneously determining the content of 17 amino acid components in Lycopus lucid-us Turcz.var.hirtus Regel.Among the 12 drying methods,vacuum freezing at-80 ℃ had the highest content and high nutritional value,providing a theoretical and practical basis for the processing of Lycopus lucidus Turcz.var.hirtus Regel.
万方数据
维普
