Analysis of Rancidity Mechanism of Armeniacae Semen Amarum During Storage / 中国实验方剂学杂志

ABSTRACT

Objective:To explore the mechanism of rancidity during storage by researching the changes of water content， relative permeability of cell membrane and rancidity levels of Armeniacae Semen Amarum in deterioration process. Method:Armeniacae Semen Amarum samples under different storage conditions were evaluated and classified by sensory assessors， and samples with different levels of rancidity were obtained. Water content was measured by toluene method， and water activity was obtained by water activity meter. Malondialdehyde （MDA） and relative conductivity were measured using thiobarbituric acid colorimetry and conductivity meter， respectively. The content of fatty oil was obtained by Soxhlet extraction. The acid value and peroxide value were measured in accordance with the general rules 0713 and 2303 of the 2020 edition of <italic>Chinese Pharmacopoeia</italic> （part Ⅳ）， respectively. Based on the above experimental data， chemometric methods （cluster analysis， principal component analysis） were selected to establish classification and discriminant models of Armeniacae Semen Amarum with different rancidity levels， in order to verify the accuracy of the classification results. Result:According to the results of sensory evaluation， Armeniacae Semen Amarum samples were divided into three classes， including no rancidity， slight rancidity and rancidity. Compared with the no rancid samples， the color of surface and cotyledon were deepened in rancid samples， and the oil was appeared on surface with rancid taste. The values of water content， water activity， MDA content and relative conductivity were all significantly increased in deterioration process （<italic>P</italic><0.01）. The content of fatty oil was significantly decreased with the occurrence of rancidness （<italic>P</italic><0.01）， while the acid value and peroxide value increased significantly （<italic>P</italic><0.01）. The results of cluster analysis and principal component analysis showed that the rancid samples could be distinguished from the no rancid and slightly rancid samples. Conclusion:The storage conditions under high temperature and high humidity can accelerate the rancidness of Armeniacae Semen Amarum， which is accompanied by the increase of internal water content， the increase of cell membrane permeability and the occurrence of fatty acid rancidity. It is suggested that Armeniacae Semen Amarum should be stored in low temperature， dry environment， as well as short storage time.