ANALYTICAL STUDY TO DETERMINE THE USE OF ANIMAL RENNET IN THE MANUFACTURE OF ANCIENT EGYPTIAN FOSSIL CHEESE

Abstract

The recently discovered fossil cheese was carefully analyzed under the current study by using multiple analyzes such as, digital microscopy assessment, FTIR, XRD & SEM in a serious attempt to discover dairy products of Ancient Egyptians furthermore; knowing the type of rennet that was used to coagulate the milk, is it vegetable or animal? To make the results more accurate, fresh cheese samples were prepared from the pastures of the rich Saqqara region according to the old inherited recipes to make a revealing comparison with the archaeological sample then the fresh sample was subjected to accelerated heat- light ageing;the results revealed a striking similarity between the archaeological and the aged fresh cheese where the digital microscope revealed that both samples have the same structure but archeological sample was more fossilized which may be attributed to the survival of Ptahmes's cheese for thousands of years under the burning sands. It should be noted that the analysis of the infrared spectrum revealed accurate and important information about the technology of dairy products in the ancient Egyptians, especially that the authors compared the Ptahmes sample with the aged modern sample and a dried calf rennet sample, to prove or deny the Egyptian's use of calf rennet to coagulate milk, and it was a resounding surprise a presence of a band associated with N-H stretching vibration and hydrogen bands presented in collagen were detected which suggests the existence of helical arrangements of chymosin -solubilized collagen from casein furthermore a matching between the archaeological sample and the dried rennet in the region from 2000 to 4000 cm-¹ was detected which suggests using the calf rennet in curdling of milk in the ancient Egyptian civilization, the infrared spectraalso confirmed a presence of crystalline residues of fenugreek and red pepper, which are still used until now in storing cheese in upper Egypt.