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Enhanced deactivation of bacterial lipases by a modified UHT treatment
Author(s) -
BUCKY A. R.,
ROBINSON D. S.,
HAYES P. R.
Publication year - 1987
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.1987.tb00453.x
Subject(s) - thermostability , lipase , chemistry , enzyme , triacylglycerol lipase , food science , chromatography , biochemistry
Summary Lipase was produced by three non‐fluorescent pseudomonads during culturing in resterilized UHT whole milk at 10°C. The enzymes exhibited pronounced thermostability in milk with 85–88 and 82–89% of the original activities retained after heat treatments at 140°C for 5 sec and 80°C for 10 min, respectively. Also, after a single treatment at 60°C for 10 min approximately 95% of the untreated activities remained. Double heat treatments consisting of either 130 or 140°C for 5 sec followed by 60–80°C for 3 min enhanced lipase deactivation by as much as 40% compared with the combined effect of both higher and lower temperature treatments performed on separate enzyme samples. No significant enhancement of deactivation was noted when samples were heated at 60°C for 3 min followed by 140°C for 5 sec compared with the latter treatment alone. Lipase deactivation was non‐linear at 60°C following treatment at 140°C for 5 sec; no substantial additional loss of activity occurred at the lower temperature between 5 and 10 min.