The effect of liposome-encapsulated Bacillus subtilis neutral proteinase on Manchego cheese ripening
1995
Picon, A. | Gaya, P. | Medina, M. | Nunez, M.
Neutral proteinase from Bacillus subtilis was entrapped in dehydration-rehydration liposomes, which were added to pasteurized ewe milk to accelerate Manchego cheese ripening; proteinase level was .040 Anson units/kg in fresh curd. Encapsulated proteinase had no apparent effect on whey composition or on dry cheese yield, but experimental cheese showed a higher DM from d 15 and a higher protein content from d 30. Proteolysis was enhanced by encapsulated proteinase by 24 h after manufacture; 26.5% of alpha s1-casein and 53.4% of beta-casein that was initially present in milk had been degraded in 1-d-old control cheese and 51.3 and 83.5%, respectively, in experimental cheese. After 90 d of ripening, amounts of N that were soluble at pH 4.6, in TCA, and in phosphotungstic acid were 34.09, 17.50, and 11.88% in experimental cheese and 20.09, 13.67, and 8.58% in control cheese, respectively. Hydrophobic and hydrophilic peptides measured at 214 and 280 nm were higher in experimental cheese than in control cheese from d 15. Higher fracturability, elasticity, and hardness values were recorded for experimental cheese despite its more extensive proteolysis; the firmer texture was ascribed to its higher DM content. No bitter flavor defect was detected in experimental cheese, although development of flavor intensity was accelerated by encapsulated proteinase.
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