Physicochemical, antioxidant and antimicrobial characteristics of two types of mumies(shilajit)

In this work the physicochemical, antioxidant and antibacterial properties of two varieties of yellow and black shilajit, obtained from Kerman mountains, were studied. The findings indicated notable distinctions between the physicochemical properties of black and yellow shilajit (P < 0.05). Yellow shilajit displayed the greatest and least quantities of iron and calcium, respectively, while black shilajit displayed the opposite pattern. The main functional groups detected in the FTIR spectra of both black and yellow shilajit comprised O-H, C = O, -COO-, C-H, and C-O-C. The results of the colorimetry test revealed a significant difference in the L* color indices between the two types of black and yellow shilajit (p < 0.05). Consequently, the most elevated and most reduced L* color indices were associated with the yellow shilajit and the black sample, respectively. Furthermore, the black and yellow shilajits exhibited the highest and lowest values for the color indexes a* and b*, respectively. Black shilajit showed superior antimicrobial activities compared to yellow shilajit in both disc diffusion method and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Overall, the outcomes of this study indicated that both black and yellow shilajit have the potential to be used in fortified food products after demonstrating their non-cytotoxicity. This is due to the high protein content and strong antioxidant and antimicrobial properties found in black shilajit, as well as the elevated levels of calcium and iron in yellow shilajit.