ABSTRACT
Squalene is a cancer chemo-preventive and skin protective agent with high commercial demand. Here, we report for the first time that the green tea (Camellia sinensis) leaves is a surprisingly rich plant-based source of squalene. Young and tender leaves and old and turf leaves were collected at four different collecting seasons (April-August). Lipophilic compounds in the leaves and commercial green teas were extracted with hexane. The squalene contents in the hexane extracts varied greatly with the types of the leaves and collecting seasons. The hexane extract of turf leaves contained significantly higher contents of squalene than the extract of tender leaves. The hexane extract of the turf leaves collected in August contained the highest content of squalene (29.2 g/kg extract). This represents the first report on the qualitative and quantitative information on squalene in green tea leaves.
ABSTRACT
Rice and rice products have been reported to contain high contents of toxic inorganic arsenic (iAs). The inorganic arsenic contents in microwavable ready-to-eat rice products (n=30) and different types of Korean rice (n=102) were determined by a gas chromatography-tandem mass spectrometry (GC-MS/MS). The method showed low limit of detection (0.015pg), high intra- and inter-day repeatability (<7.3%, RSD), and recovery rates (90-117%). The mean iAs content in the ready-to-eat rice products was 59µgkg-1 (dry weight basis). The mean iAs contents in polished white, brown, black, and waxy rice were 65, 109, 91, and 66µgkg-1, respectively. The percentages of ready-to-eat rice products, white, brown, black, and waxy rice containing iAs over the maximum level (100µgkg-1) set by EU for the infant foods were 17, 4, 70, 36 and 0%, respectively.
