Effect of galactose metabolising and non-metabolising strains of Streptococcus thermophilus as a starter culture adjunct on the properties of Cheddar cheese made with low or high pH at whey drainage

Hou, Jia; Hannon, John A.; McSweeney, Paul L. H.; Beresford, Thomas P.; Guinee, Timothy P.

Effect of galactose metabolising and non-metabolising strains of Streptococcus thermophilus as a starter culture adjunct on the properties of Cheddar cheese made with low or high pH at whey drainage

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Accepted Version

Date

2016-10-20

Authors

Hou, Jia

Hannon, John A.

McSweeney, Paul L. H.

Beresford, Thomas P.

Guinee, Timothy P.

Publisher

Elsevier

Published Version

10.1016/j.idairyj.2016.10.003

Abstract

Cheddar cheese was made using control culture (Lactococcus lactis subsp. lactis), or with control culture plus a galactose-metabolising (Gal+) or galactose-non-metabolising (Gal-) Streptococcus thermophilus adjunct; for each culture type, the pH at whey drainage was either low (pH 6.15) or high (pH 6.45). Sc. thermophilus affected the levels of residual lactose and galactose, and the volatile compound profile and sensory properties of the mature cheese (270 d) to an extent dependent on the drain pH and phenotype (Gal+ or Gal-). For all culture systems, reducing drain pH resulted in lower levels of moisture and lactic acid, a higher concentration of free amino acids, and higher firmness. The results indicate that Sc. thermophilus may be used to diversify the sensory properties of Cheddar cheese, for example from a fruity buttery odour and creamy flavour to a more acid taste, rancid odour, and a sweaty cheese flavour at high drain pH.

Keywords

Cheddar cheese , Streptococcus thermophilus , Food science , Dairy science , Galactose metabolising strain , Drain pH

Citation

Hou, J., Hannon, J. A., McSweeney, P. L. H., Beresford, T. P. & Guinee, T. P. ‘Effect of galactose metabolising and non-metabolising strains of Streptococcus thermophilus as a starter culture adjunct on the properties of Cheddar cheese made with low or high pH at whey drainage’, International Dairy Journal. doi: 10.1016/j.idairyj.2016.10.003. Article In Press.