Heavy Metal Concentrations in Canned Fruits of Litchi chinensis, Prunus persica, and Ananas comosus Marketed in the Philippines

Monitoring of heavy metals in consumer products is essential in order to aid in the production of safer food commodities for the Filipino public. Ten canned fruits commercially available in Metro Manila, Philippines were randomly selected for the study. Five brands of canned fruits of Prunus persica (peaches), three of Litchi chinensis (lychees) , and two of Ananas comosus (pineapple) were tested for lead, cadmium and chromium levels. The fruit and syrup portions were separately tested quantitatively for the said heavy metals through Flameless Atomic Absorption Spectroscopy. Chromium was found to be present in nine out of the ten syrup samples from the canned fruits while cadmium is present in one syrup sample of canned peaches. All the amounts of the heavy metals were in acceptable chromium and cadmium levels for consumption. Lead was observed to be present in acceptable values in the solid fruits of all samples analyzed. Four syrup samples showed lead levels with the syrup from peaches exceeding the allowed safe limit. The rest of the syrup samples went below the detection limit of the instrument. Higher number of canned fruits and other canned products in the market must be analyzed with regard to lead, cadmium and chromium to complete the baseline data related to contaminants in these products for consumer safety.

Determination and evaluation of principal minerals in Negella sativa by atomic absorption technical methods

Determination and evaluation of principal minerals in Negella sativa by atomic absorption technical methods were showed, using wet ashing method. This work was done on Negella sativa because of wide using of this plant in many formulations ( in food or medicine ).two types of atomic absorptions were used : first, flame atomic absorption spectroscopy, for minerals of high concentrations such as, Na, Mg, K, Fe, Ca, Li, Ni, Zn, Mn, Cu. Second, flameless atomic absorption spectroscopy, for minerals of low concentrations such as, Al, Si, V, B, Pb, Co, Cd, Cr ,Si, Hg, Sn .The results showed the existence of many minerals in Negella sativa useful to human sanity with acceptable dietary allowance. On other side, the presence of harmful minerals to human sanity(Pb, Cd, Hg ) were negligible.

Effect of Zn(II) on the Structure and Biological Activity of Natural β-NGF

Only β-NGF, the subunit of the 7S NGF complex, exhibits NGF activity, but the function of the zinc ion in native β-NGF has received little attention. Flameless atomic absorption spectroscopy (FAAS) measurements reveal that native β-NGF contains Zn(II) with a Zn(II)/β-NGF stoichiometry of 1:14.6. The presence of Zn(II) in the native molecule results in significant changes of the secondary structure and local tertiary structure around Trp(s) with respect to those of apo β-NGF, as suggested by spectra of fluorescence and circular dichrosim. Stopped-flow studies show that there are at least two steps during the interaction of Zn(II) with the apo form. In comparison with its apo form, the native β-NGF shows a higher ability to trigger the proliferation of TF1 cells and mediate the survival of PC12. Thus it is most likely that the structural changes caused by the presence of Zn(II) directly lead to the increase in the biological activity of β-NGF. All results indicate that Zn(II) in native β-NGF plays an important role in the structure and the biological activity of the protein.