INVESTIGADORES
PEROTTI Maria Cristina
congresos y reuniones científicas
Título:
Enhanced Lipolysis and Proteolysis in Hard Cooked Cheese by Changes in Cheesemaking
Autor/es:
VÉLEZ, M. A.; BERGAMINI, C.; MEINARDI, C.; CANDIOTI, M.C.; PEROTTI M.C.; REBECHI, S.; HYNES, E.R.
Lugar:
Wisconsin
Reunión:
Congreso; Cheese Science; 2012
Institución organizadora:
FIL
Resumen:
Proteolysis
and lipolysis during hard cooked cheeses are main biochemical changes that lead
to the appreciated characteristics of the product. The aim of this work was to increase
the activity of native milk enzymes (plasmin and lipoprotein lipase) and
coagulant enzyme by modifications in hard cooked cheese technology, in order to
enhance lipolysis and proteolysis and accelerate ripening.
Changes
in cheesemaking were first assayed in preliminary experiments in minicurds and
miniature cheeses. The effect of pH at whey drainage (4.6, 5.4 and 6.4),
cooking temperature (50 and 56ºC),
curd washing and type of coagulant enzyme (bovine and camel quimosin) on
activities of plasmin and coagulant on specific substrates was assessed, as
well as its influence on proteolysis, described by peptide profiles,
electrophoresis and nitrogen fractions. As for lipolysis, different
pre-treatments of cheesemilk were tested: mechanical treatments (homogeneization
and agitation) and sanitation methods (natural creaming and thermal treatment).
Miniature cheeses were made with pretreated milk and lipolysis was analyzed by
GC.
Changes
in pH were discarded as high pH values increased plasmin activity and b
casein hydrolysis but diminished coagulant activity and production of peptides
derived from as1 casein. A similar trend was observed for cooking temperature: at 56 °C coagulant activity
decreased, and even if it reactivated later, proteolysis was slowed down. On
the contrary, including a step of curd washing was favorable because it
increased plasmin activity and did not affected coagulant enzyme, with
resultant increased global proteolysis. Total lipolysis was significantly higher
only for homogeneized, non-thermally treated milk.
Most
favorable treatments were combined and applied in cheese making trials at pilot
plant. Experimental cheeses were made with homogenized milk; curd was washed and
cooked at 50 ºC.
Standard cheesemaking was applied for control cheeses. Experimental cheeses had
increased levels of enzyme activities, proteolysis and lipolysis, and their genuine
aroma and piquant taste was intensified.