Partial characterization of a plant coagulant obtained from the berries of Solanum elaeagnifolium

The berries of Solanum elaeagnifolium (trompillo) have been used since ancient time in Chihuahua, Mexico, as a milk coagulant in cheese making. This article describes an approach to the characterization of the plant coagulant from trompillo. From the main results, it was noticed that only the yellow berries of trompillo have proteolytic and milk-clotting activity. These activities were observed in the crude extracts (CEs) obtained from both seeds and fruit peels of yellow berries. The proteolytic activities of these CEs ranged from 6.0 to 8.5 U-Gly/mg, although the absence of NaCl in the CEs decreased their activities significantly. The milk-clotting activities of CEs from the berries of trompillo (4347–2564 MCA) were similar to those reported for other plant coagulants. Some CEs had a similar ratio of milk-clotting activity/proteolysis as rennin and chymosin. This plant coagulant produced an unspecific hydrolysis on caseins, increasing the yield in fresh-type miniature cheese.