Molecules to Mozzarella and Peptides to Pizza

Senior Scientist:

• Eleanor Brown, 215-233-6481, Ellie.Brown@ars.usda.gov  
• Edyth Malin, 215-233-6444, Edyth.Malin@ars.usda.gov  
• Michael Tunick, 215-233-6454, Michael.Tunick@ars.usda.gov

The Problem

Developing More Nutritious Lunches for School Children

• National Academy of Sciences recommends reducing dietary fat and cholesterol.
• USDA/HHS publish dietary guidelines for Americans, 1990.
• Ellen Haas, consumer advocate, calls for more nutritious school lunches.
• Food and Nutrition Service contacts Dairy Processing & Products Research Unit at ERRC, 1992.  "Can you help?"
• Low-fat Mozzarella cheese identified as a desirable component of school lunches.
  • Cheese is an important source of calcium and protein.
  • Pizza is a favorite with all school children.
• Commercially available low-fat Mozzarella cheeses have poor texture and flavor, poor consumer acceptability.

Meeting the Challenge

A Scientific Approach to Low-Fat Mozzarella

• Cheese is a complex material, and its manufacture depends on the interplay of natural systems.  No evidence that low-fat cheeses available in 1992 were developed with a sound conceptual basis.
• The Dairy Processing & Products Research Unit knowledge base:
  • Molecular modeling of caseins and peptide fragments.
  • Sophisticated instrumental analysis of cheese texture.
  • Electrophoretic techniques to assess casein breakdown.
  • Electron microscopy/image analysis of cheese structure.
  • Comprehensive dairy pilot plant facilities and expertise.

Three-dimensional molecular models for caseins were developed using amino acid sequences of caseins and physical-chemical data on caseins developed by scientists at ERRC and other institutions.  The validity of these models is apparent after assembling multiple copies into a structure very similar to that of casein submicelles observed by electron microscopy.

Enzymatic breakdown of as1-casein during storage is a predictor of improvement in texture and meltability of very low fat Mozzarella cheese.  Changes in electron micrographs suggest that reorganization of casein submicelles is responsible for improved qualities.

Molecular modeling of peptides resulting from proteolytic breakdown predicts that these fragments have a strong tendency to become more compact and act as fat replacers in breaking up the density of the protein matrix.  This observation was confirmed by electron microscopy.

Achieving Success

Mozzarella Cheese with <10% fat

• Innovative modifications in processing conditions enhance texture and meltability.
• Successful commercial-scale production at three cheese plants.
• Pizza made with low fat Mozzarella tested in schools.  "We like it!"
• Specifications developed with Agricultural Marketing Service.
• National School Lunch Program adopts very low fat cheese for use on pizza - first invitation for bids in January 1995.

Successful Tech Transfer

To date, totals for Lite Mozzarella supplied by several manufacturers have reached 23,000,000 pounds with an estimated value of $34,500,000.

The team involved in the development of Lite Mozzarella received the following awards:

• 1994 Philadelphia Executive Board Gold Medal Team Award
• 1995 National ARS Award for Technology Transfer
• 1996 Federal Laboratory Consortium Award of Merit for Excellence in Technology Transfer.

Results

A nutritious product for a diet conscious market and a new information base for future developments.