Milk-clotting activity of berries extracts from nine <i>Solanum</i> plants

Abstract

Nine Solanum species (Solanum aculeastrum, Solanum aethiopicum, Solanum anomalum, Solanum cerasiferum, Solanum dasyphyllum, Solanum indicum, Solanum nigrum, Solanum nodiflorum and Solanum terminale) berries were studied in order to find a new source of milk-clotting enzymes for artisanal use by Cameroonian farmers. The results showed that milk-clotting activity was obtained by soaking fresh and dried berries in either distilled water or 5% NaCl solution. Maximum milk-clotting activity was obtained by soaking dried berries in 5% NaCl solution at optimum time of extraction for each species. Dried berries released active enzymes more easily than fresh ones, and addition of salt facilitated the extraction process. Extract from S. aethiopicum berries had the highest milk-clotting activity. All extracts had proteolytic activity. High milk-clotting and proteolytic activities were found in extract from S. cerasiferum obtained after 24 h of soaking dried berries in 5% NaCl solution. High milkclotting and low proteolytic activities were found in extract from S. aethiopicum obtained under same conditions