Measurement and Analysis of Calcium Content in Wild Chinese Dwarf Cherry (<em>Prunus humilis</em>) Fruits by Inductively Coupled Plasma-optical Emission Spectrometer

摘要： Different forms of calcium in wild Chinese dwarf cherry (Prunus humilis) fruits (two genotypes, small-fruit-type and big-fruit-type) were sequential extracted and measured by Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES). The calcium content variation after postharvest storage was also studied, to provide the theory basis for the active nutritional ingredient evaluation of Chinese dwarf cherry (Prunus humilis). The results showed that, wild Chinese dwarf cherry (Prunus humilis) fruits in mature stage were rich in calcium nutrition element and mainly composed by water soluble calcium and calcium phosphate which absorbable to human. Absorbable calcium (including water soluble calcium and calcium phosphate) content in small-fruit-type (63.79%) was significantly higher than that of big-fruit-type (54.97%). After postharvest storage, the water soluble calcium content was increased while the calcium pectate and calcium oxalate content dropped. Especially to the big-fruit-type, the absorbable calcium content increased to 75.49% compared with just picking 54.97% (small-fruit-type increased from 63.79% to 68.86%). The study suggested that Chinese dwarf cherry (Prunus humilis) was a natural and biological calcium supplement to people; meanwhile, small-fruit-type was more suitable, especially after postharvest storage.