Test show promising shelf life for new salsa

- Fall - 1998 "Update" Newsletter Article -

Tests show promising shelf life for new salsa

From CATI Publication
Copyright © 1998. All rights reserved.

helf-life studies of a new food using a new processing method have shown that you can get closer to "fresh" in a canned product using microwave vacuum (MIVAC) drying technology pioneered at California State University, Fresno.

Details of the study are contained in a report published by the California Agricultural Technology Institute (CATI). It is titled "A New Tomato-based Salsa: Shelf Life Studies." The study was conducted this past year on a salsa developed by a faculty/student research team with funding support from CATI. A key ingredient of the salsa is cilantro, an herb used to flavor many popular fresh salsas.

The problem in producing canned salsa is the loss of fresh cilantro flavor during processing, explained project director Dennis Ferris, a professor in the Department of Enology, Food Science and Nutrition.

"Heat processing affects cilantro flavor and causes a change in the taste of a salsa," Ferris said. "Cilantro aroma and taste is also affected and completely destroyed by most drying processes" used prior to processing. The MIVAC drying process is different in that it uses low temperatures in a vacuum, allowing foods to retain most of their volatile compounds, he explained.

In preparing the new Fresno State Salsa, Ferris and his research team used a common "hot-fill-hold" processing method, but waited to add the microwave-vacuum-dried cilantro until the last moments prior to filling and sealing the jars. The goal was to preserve as much of the fresh cilantro flavor as possible.

The question was whether the small amounts of yeast, mold and other microbes on the cilantro would survive and contaminate the canned salsa. Shelf-life studies provided good news, however.

"There was a concern that adding 'MIVACed' cilantro to a salsa batch near the end of processing might lead to microbial growth," Ferris said. "This concern was alleviated as all batch-size samples analyzed showed no microbial growth. The hot-fill-hold method applied to produce the salsa was an effective method to eliminate viable microbial loads."

Ferris said that if the new processing method proves effective in larger salsa batch processing, it could be used to produce other products using other MIVAC-dried herbs and spices.

"The work performed for this project can have significant impact on the California agricultural industry, especially the cilantro, tomato, pepper and onion producers," he said.

The project is continuing this year with production of larger lots of salsa in the university's new food processing laboratory. This will be followed by additional sensory evaluations using both consumer surveys and trained sensory panels, and additional microbial analysis. To view a copy of the research report just published, see the Research Publications section of this web site.

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