Next, the model for the pH response was analyzed. It generated an F-value of 16.02 (p = 0.0002). Scheller eliminated the Emulsifier Type 2 runs from this analysis since the meltability model already indicated that this emulsifier produced unacceptable results. To eliminate acidic flavor notes, the ideal pH for this formulation needed to be between approximately 6.00 and 6.15. The model in Figure 3 shows that an emulsifier ratio of D provides good pH results.
Figure 4: Hunter “a” model graph for Emulsifier Type 1
Identifying a workable solution
Finally, the effect of emulsifier ratio on the browning of the cheese was analyzed as indicated by the Hunter “a” value. The model produced an F-value of 9.04 (p = 0.0021). The results indicate that an emulsifier ratio of D provides a Hunter “a” value of about -1.83, which is a significant improvement over the baseline formulation for this product. “DOE helped us show that it is possible to improve the appearance of the new product in cheese sauce application without adversely affecting other characteristics,” Scheller says.
“This was the first time that Mostafa and I applied DOE on the project,” Scheller concludes. “The application demonstrated the ability of DOE to provide a degree of rigor that imparts more confidence in the results than our previous one-factor-at-a-time experimentation. DOE explores the entire design space, which helps eliminate concerns that a better answer might be lurking somewhere in the unknown. For certain applications, DOE can reduce the number of runs required to achieve meaningful results, providing substantial savings in time and materials.
Jerry Fireman, president, Structured Information, Lexington, MA, has over 30 years experience in writing technical articles, with over 9,000 articles published to date.
Land O’Lakes is a farmer-owned cooperative that offers farmers, local cooperatives and customers across the nation an extensive line of agricultural supplies, as well as production and business services. It is also a leading marketer of dairy-based products for consumers, foodservice professionals and food manufacturers. Land O’Lakes produces a full line of quality dairy products, including: butter and butter blends, margarine and spreads, dairy case cheese, and deli cheese. For more information, email Michael Scheller at
MJScheller@landolakes.com, or log on to www.landolakesinc.com, www.landolakes.com or www.statease.com.