Submitted to: Australian Journal of Dairy Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/18/2006
Publication Date: 5/23/2007
Citation: Rynne, N.M., Beresford, T.P., Kelly, A.L., Tunick, M.H., Malin, E.L., Guinee, T.P. 2007. Effect of exopolysaccharide-producing adjunct starter cultures on the manufacture, composition and yield of half-fat cheddar cheese. Australian Journal of Dairy Technology. 62:12-18. Interpretive Summary: The Departments of Agriculture and Health & Human Services recommend that Americans consume low-fat cheese as part of a healthy diet, but reduced-fat Cheddar cheese often has poor quality. Reduced-fat Cheddar can be improved by increasing its moisture content, which is usually done by adjusting the manufacturing procedures. Another method of increasing the moisture is by adding special starter culture bacteria that produce exopolysaccharides (EPS), a sugar substance that covers the outside of the bacterial cell and enhances the ability of the cheese curd to hold water. In this study, Cheddar cheeses containing half the fat of regular Cheddar were made with EPS-producing cultures and compared with cheese made with the usual cultures. The Cheddar containing EPS-producers could be prepared in 198 minutes instead of 227 minutes, and the amount of cheese obtained per 1000 lbs of milk was 176 lbs instead of 171 lbs. These results would represent a significant savings for a company that produces many vats of reduced-fat cheese in a day.
Technical Abstract: The effect of exopolysaccharide (EPS)-producing adjunct starter cultures on the manufacture, composition and yield of half-fat Cheddar cheeses (ca. 16%, w/w, fat) was examined. Four replicate trials were undertaken, in each of which three batches of cheese were manufactured using either a control starter culture alone (CTRL), control starter plus a capsular EPS-producing (EPSCap) adjunct culture, or control starter plus a ropy EPS-producing (EPSRop) adjunct culture. Compared to the CTRL and EPSCap cultures, use of the EPSRop culture significantly improved rennet coagulation properties, reduced manufacturing time, and increased cheese moisture content (by ca. 0.18 kg/100 kg milk), percentage of milk fat recovered to cheese (by ca. 2.5% of total milk fat) and the actual cheese yield (by ca. 0.25 kg/100 kg milk). In contrast, use of the EPSCap culture had little or no effect on the above parameters.