Charlie O'Connor and Ephraim Bekele have been experimenting with Calotropis procerac extracts at ILCA's DebreBirhan experiment station in Ethiopia. They have recently carried out a preliminary study of the milk-coagulating properties of juice pressed from various parts of the plant. They also measured the cheese yields obtained and the fat content of the resulting whey. About 7.5kg of the plant were gathered near the station. The material was separated into leaves, young stems and old stems, and juice from each part was measured, and the juices were stored at 12 degrees Celsious. One-leter portions of milk were treated with varying quantities of each juice extract. The time taken for the milk to coagultae was recorded. They cut the curd, drained of the whey, weighed the curd produced, and measured the fat content of the whey.
Coagulation time tended to decrease as the amount of juice added increased. (See Table) Juice from the leaves gave better results than juice from stems. Cheese yields ranged from 180 to 194 g per litre of milk. Yields gernerally decreased with increased coagulation time. "the results are promising," said O' Connor, "but more extensive trials are needed on a number of cheese varieties, together with chemical, organoleptic and shelf-life tests on the cheese."