Strategies to stabilize locally grown produce for year round sales: A feasibility study


One of the barriers to enlarging the locally grown market is the seasonality of the fresh grown products. Locally grown products are available only during the months of peak ripeness and not available during winter months. This feasibility study seeks to determine if on-farm, small-scale stabilization of highly perishable foods is physically and economically possible. The objectives for the project are:

  1. Determine the willingness-to-pay for year-round availability of locally grown produce,
  2. Determine the types of food processing unit operations that would be amenable to small scale,
  3. Determine the energy costs associated with unit processing of each selected operation,
  4. Determine the placement of pathogen reduction technologies within the operation, and
  5. Develop plans and determine resources for construction of pilot unit.

The expert panel of food scientists and engineers determined that the unit operations most amenable to small-scale processing are blanching/freezing units. Additionally, consumer acceptance of frozen products is greater than that for canned products. The specific processing units that are required include a blanching unit, a spiral mechanical freezer (compressor), and accessories for cleaning and washing product. The blanching step was determined to be the pathogen reduction step most amenable to this process. Pathogens chosen for study were Listeria monocytogenes, Salmonella spp, and E. coli O157:H7. Times and temperatures for blanching of specific vegetable products to achieve best product quality were determined. These conditions were used for pathogen reduction. In all cases, at least a five-log reduction in pathogen counts on artificially inoculated vegetables was observed through the lab blanching.

Willingness to pay for locally processed foods is being determined by interviewing of shoppers at grocery stores in Ames, Fort Dodge and Des Moines. Research has shown that consumers are willing to pay a small premium for a locally grown and processed food.

Sam Beattie
Food Science and Human Nutrition, Iowa State University
515.294.3357
beatties@iastate.edu

Lester Wilson
Food Science and Human Nutrition, Iowa State University
515.294.3889
lawilson@iastate.edu

Aubrey Mendonca
Food Science and Human Nutrition, Iowa State University
515.294.2950
amendon@iastate.edu