Journal article

The effect of pH at renneting on the microstructure, composition and texture of Cheddar cheese

Lydia Ong, Raymond R Dagastine, Sandra E Kentish, Sally L Gras



The effect of milk pH at renneting on the microstructure, composition and texture of Cheddar cheese was investigated. Four different Cheddar cheeses were made by the addition of rennet to milk pre-acidified to pH 6.7, pH 6.5, pH 6.3 or pH 6.1. The gel renneted at pH 6.1 showed a dense protein network when observed using confocal laser scanning microscopy and cryo scanning electron microscopy. This structure became more compact after cooking, forming an irregular and coarse matrix with lower porosity than in other treatments. There was less fat lost to the whey during the draining of curd after cooking and higher fat lost to the whey during pressing in samples made from milk renneted at a low..

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Awarded by Australia Research Council

Awarded by Australian Research Council

Funding Acknowledgements

This work was funded by Dairy Innovation Australia Limited and the Australia Research Council (LP0883300). The authors would like to thank the Bio21 Molecular Science & Biotechnology Institute and the Particulate Fluids Processing Centre, which is a special research centre of the Australian Research Council at The University of Melbourne, for access to equipment. We would also like to thank Murray Goulburn, Warrnambool Cheese and Butter Factory, National Foods and Burra Foods for their involvement. We appreciate the technical input from Mr. Roger Curtain (Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne) and his help operating the scanning electron microscope in ay mode.