Proteolysis, volatile compounds, and sensory evaluation in Hispánico cheese manufactured with the addition of a thermophilic adjunct culture, nisin, and calcium alginate-nisin microparticles.
Nisin, free or incorporated in calcium alginate microparticles, was added to pasteurized milk (80% cows' and 20% ewes' milk) used for the manufacture of Hispánico cheese with a mesophilic starter and a thermophilic adjunct culture of high aminopeptidase activity. Addition of nisin incorporated in microparticles promoted early lysis of thermophilic adjunct culture bacteria. Extracellular aminopeptidase activity in 1-d-old cheese made with both thermophilic adjunct culture and nisin incorporated in microparticles was 1.8-fold higher than in cheese made with thermophilic adjunct culture and free nisin and 2.0-fold higher than in cheese made only with thermophilic adjunct culture without any addition of nisin. Addition of nisin, free or incorporated in microparticles, did not influence cheese proteolysis measured using hydrophilic or hydrophobic peptides, o-phthaldialdehyde ripening index, or free amino acids. Moreover, a total of 37 volatile compounds were identified in the volatile fraction of Hispánico cheese, using a dynamic headspace technique with a purge and trap system followed by a gas chromatography mass spectrometry analysis. The volatile compound profile was not influenced by nisin addition, either free or incorporated in microparticles, but addition of thermophilic adjunct culture enhanced the formation of 2-butanone, diacetyl, 2,3-pentanedione and acetoin and improved the flavor quality (sensory panel) of cheese.
Garde
S
S
Departamento de Tecnología de Alimentos Instituto Nacional de Investigacíon y Tecnología Agraria y Alimentaria (INIA) Carretera de La Coruña Km 7, Madrid 28040, Spain.
Gaya
P
P
Fernández-García
E
E
Medina
M
M
Nuñez
M
M
D000464:Alginates; D000626:Aminopeptidases / Q000378:metabolism; D000818:Animals; D000900:Anti-Bacterial Agents; D002417:Cattle; D002611:Cheese / Q000032:analysis* / Q000382:microbiology; D010450:Endopeptidases / Q000378:metabolism; D005511:Food Handling / Q000379:methods*; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013294:Lactococcus lactis; D008863:Microspheres; D009561:Nisin; D012756:Sheep; D013649:Taste; D014835:Volatilization
D000464:Alginates; D000900:Anti-Bacterial Agents; D006603:Hexuronic Acids; D009561:Nisin; D020723:Glucuronic Acid; D010450:Endopeptidases; D000626:Aminopeptidases