A lacticin 481-producing adjunct culture increases starter lysis while inhibiting nonstarter lactic acid bacteria proliferation during Cheddar cheese ripening.
OBJECTIVE
The main aim of this study was to exploit a lacticin 481 producing strain, Lactococcus lactis CNRZ481, as an adjunct for Cheddar cheese manufacture, to increase starter cell lysis and control nonstarter lactic acid bacteria (NSLAB) proliferation in cheese.


RESULTS
Lactococcus lactis CNRZ481 was exploited as an adjunct to L. lactis HP for the manufacture of Cheddar cheese at pilot scale (450 l). In these trials, inclusion of the adjunct strain did not compromise acid production by L. lactis HP and cheese was successfully manufactured within 5 h. Experimental cheese exhibited levels of lactate dehydrogenase (LDH) up to five-fold higher than control cheese and a significant reduction in NSLAB growth was also observed throughout the ripening period.


CONCLUSIONS
The aims of the study were accomplished as (i) greater enzyme release was achieved through lacticin 481-induced lysis which was associated with an improved flavoured cheese as assessed by a commercial grader and (ii) NSLAB growth was controlled, thus reducing the risk of off-flavour development.


CONCLUSIONS
The use of lacticin 481-producing adjuncts for cheese manufacture may prove beneficial for manufacturers who aim to achieve faster ripening through premature and elevated intracellular enzyme release while minimizing inconsistencies in cheese quality because of NSLAB activity.
O'Sullivan
L
L
Dairy Products Research Centre, Teagasc, Moorepark, Fermoy, County Cork, Ireland.
Ross
R P
RP
Hill
C
C
D001426:Bacterial Proteins / Q000096:biosynthesis*; D001430:Bacteriocins; D002611:Cheese / Q000032:analysis / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D005516:Food Microbiology; D005524:Food Technology / Q000379:methods; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D013294:Lactococcus lactis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D019105:Random Amplified Polymorphic DNA Technique / Q000379:methods
D001426:Bacterial Proteins; D001430:Bacteriocins; D004269:DNA, Bacterial; C082508:lacticin 481; D007770:L-Lactate Dehydrogenase