This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Sales-Gomes, M. Articles by Lima-Costa, M.E. Search for Related Content Social Bookmarking                         What's this?

Immobilization of Endoproteases from Crude Extract of Cynara cardunculus L. Flowers

Faculdade de Engenharia de Recursos Naturais, Universidade do Algarve Campus de Gambelas. 8005-139 Faro, Portugal, mgomes{at}ualg.pt

M.E. Lima-Costa

Faculdade de Engenharia de Recursos Naturais, Universidade do Algarve Campus de Gambelas. 8005-139 Faro, Portugal

The cardoon (Cynara cardunculus L.) is a variety of thistle which grows wild and abundantly in uncultivated areas of many regions of Portugal. Its dried flowers are used as a milk coagulant in the manufacture of traditional cheeses, due to its high content in aspartic proteases, namely cardosins A and B. In general, proteases can be immobilized without significant loss of their catalytic activity and their use as milk coagulant offers several advantages over their soluble counterparts, namely simplified protocols, long term stability of the coagulant and successful reutilization. Since proteases are often expensive, especially at high degrees of purity, immobilization may increase their industrial applicability. In this work, aqueous extracts of cardoon were immobilized on celite by adsorption. The properties of free and immobilized extracts from cardoon (kinetic parameters, pH effects, activation energy, ionic effects, clotting time) were compared. Optima pH and temperature were 5.0 and 60 °C, respectively, for extracts in both forms. Upon immobilization, a 60—70% loss of enzyme activity, as well as a decrease in the specificity constants (up to 90%) were observed. Immobilized biocatalyst was evaluated for bovine and caprine caseins, at a laboratory scale, showing a higher specificity towards the latter.

Key Words: cardoon • celite • cheese • immobilization • proteases

Food Science and Technology International, Vol. 14, No. 3, 271-276 (2008)
DOI: 10.1177/1082013208095688


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?