海苔和茶叶中铝的亚细胞分布及风险评估

以海苔和茶叶为研究对象,采用差速离心法结合微波消解—电感耦合等离子体质谱法分析茶叶和海苔中铝的亚细胞分布,结果表明,茶叶中铝在细胞壁、细胞器、细胞质中占比分别为78.4%,11.2%,9.5%,海苔中铝在细胞壁、细胞器、细胞质中占比分别为91.60%,6.95%,1.33%。结合透射电子显微镜—能谱法对茶叶和海苔中铝的分布在单细胞范围内进行面扫分析,直观地揭示了茶叶和海苔中铝主要分布在细胞壁中。人工模拟胃液提取茶叶和海苔及其亚细胞组分中的铝,直接提取茶叶中铝的提取率为9.0%左右,其亚细胞组分提取率均不足3.0%;海苔及其亚细胞组分中铝的提取率均低于1.5%,提示茶叶和海苔中铝摄入的食品安全风险较低。

Subcellular distribution and risk assessment of aluminum in seaweed and tea

The subcellular distribution of aluminium in seaweed and tea leaves was analyzed by differential centrifugation with microwave digestion and inductively coupled plasma mass spectrometer.The results showed that the proportion of aluminium in cell wall,organelle and cytoplasm of tea leaves were 78.4%,11.2%and 9.5%,respectively;the proportion of aluminium in cell wall,organelle and cytoplasm of seaweed were 91.60%,6.95%and 1.33%,respectively.Using transmission electron microscope with energy dispersive spectroscopy,surface scanning analysis was carried out on the distribution of aluminum in the single cell of tea leaves and seaweed,intuitively revealing that aluminum was mainly distributed in the cell wall of tea leaves and seaweed.The extraction of aluminium from tea leaves,seaweed and its subcellular components by simulated gastric juice was studied.The extraction rate of aluminium in tea leaves was about 9.0%,but the extraction rate of its subcellular components was less than 3.0%.The extraction rate of aluminum in seaweed and its subcellular components was less than 1.5%,suggesting that the food safety risk of ingestion of aluminum in tea and seaweed was low.