Chemical Composition Profile of Canned and Frozen Sweet Corn (Zea mays L.) in Iran

Maize is one of the oldest and most productive popular grains and can be consumed as food at various developmental stages from baby corn to mature grain. The maize can be processed in different products at traditional level as well as industrial scale. Due to vast corn consumption by people in this research the concentration of histamine ,some trace and essential mineral and also heavy metals has been determined in 120 samples of popular brands of canned and frozen sweet corn in 2014. These samples (60 of them were canned corn and the rest were frozen) were collected from different local markets of Tehran, Iran. For reliable, accurate and precise measurements, all canned and frozen samples had the same date of producing. Samples were randomly purchased for analysis and analyzed according to standardized international protocols by wet digestion method. Histamine content was determined by Capillary Electrophoresis while metals were determined by Atomic absorption spectrometer. The results obtained revealed that, the mean ranges of the elements analyzed in (μg.g-1) between the frozen and canned food are as follows: Ni (0.31 – 17.44), Zn (204.14 – 266.76), Cu (6.22 – 8.03), Ca (1611 –8557), Mg (1063 – 1208), Fe (1.98-87.23), Sn (19.01350.8) respectively. Some of the measured values found, not only relatively high in canned compared to frozen food samples, but also exceeds the international tolerance levels. Histamine content in 95% of samples was lower than maximum level set by WHO. According to variance analyses of data, there was a positive correlation between the storage time and heavy metal contents especially tin, zinc and iron and they were varied significantly (p -< 0.001) after 3 months of storage .The monitoring of mineral and heavy metals in frozen and canned food samples is vital important challenge to control and improve the food industry strategies.