Abstract

Solanum aethiopicum Shum fruits can be used as a source of coagulant in cheese-making

Author(s): Valentin D�������©sir�������© Guiama, Esther Ngah, Robert Germain Beka, Humphrey Mbah Mbuh, Juliette Koub�������©, Francois Krier, Didier Guillochon, Dominique Vercaigne-Marko, David Gabriel Libouga

This study was performed to develop a sustainable process for preparing coagulant fromSolanum aethiopicum Shum(SAS) fruits. Fruit powder of SAS was soaked at different conditions, and obtained extract was used to determine its properties in light to apply it in cheese-manufacturing. Results showed that milk-clotting enzyme was uniformly distributed in coat and seed SAS fruit, and wasmost active from6 to 8 weeks maturity regardless CameroonÂ’s agro-ecological zones. SAS extract had the greatest rennet strength with 4% NaCl used as extractant medium. The rennet strength of SAS extract was temperature, pH, calcium and enzyme concentration dependent. The milk-clotting enzyme of SAS extract was more thermosensitive, and lost its activity after wet-heating at 55oC for 10 min. The bovine casein hydrolysis by SAS extract increased hyperbolically with incubation time. SAS extract hydrolyzed essentially all k-casein after about 180 min, and the duration of non-enzymatic phase of coagulation was about 4 min. At low temperature (4°C), SAS extract can be stored without preservative for two months; and citric acid can be used as preservative for long termstorage. The estimated yield of curd made with SAS extract was not significantly different froma control curd made with calf rennet.