Milk-clotting potential of fruit extracts from Solanum esculentum, Solanum macrocarpon L. and Solanum melongena

摘要

Fruit extracts from?Solanum esculentum,?Solanum macrocarpon?L. and?Solanum melongena?were tested for their milk-clotting potential. The release of substances associated with milk-clotting was highly dependent upon quantity of berries, extraction duration and sodium chloride concentration. The highest milk-clotting activity was obtained after 8 h (for?S. esculentum?and?S. melongena), and 12 h (forS. macrocarpon) of soaking 20 g of fruit in 6% NaCl 4°C. In these conditions, there was a non linear relationship between the milk-clotting time and the amount of fruit extracts from each species. The loss of milk-clotting activity was dramatic after wet-heating of extracts from?S. esculentum?and?S. macrocarpon?at 80°C for 10 min and after dry-heating of fruits at 100°C for 24 h. Heat treatment did not significantly affect the clotting activity of extract from?S. melongena. Fruit extracts from?S. esculentum?had the greatest milk-clotting activity followed by extracts from?S. macrocarpon?and?S. melongena. Extracts from?S. esculentum?and?S. macrocarponexhibited a proteolytic activity on the casein.