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New food safety indicators – Audio

Sundaram Gunasekaran, Professor
Department of Biological Systems Engineering
UW-Madison College of Agricultural and Life Sciences
guna@wisc.edu
Phone (608) 262-1019, (608) 262-7794

3:00 – Total Time

0:17 – Research into food safety indicator
0:39 – Food thermal history
1:11 – A sticker to show quality & freshness
1:40 – Temperature history through the cycle
2:19 – Nanotechnology key
2:49 – Three to five years away
2:51 – Lead out

Sevie Kenyon: Research on a new food safety indicator. We’re visiting today with Sundaram Gunasekaran Department of Biological Systems Engineering University of Wisconsin Madison in the College of Agricultural and Life Sciences, and I’m Sevie Kenyon. Sundaram, please describe the research project you’re working on.

Sundaram Gunasekaran: We’re developing a tag, or a label if you will, that will indicate the safety and quality of foods used by date indications are not necessarily accurate because the food service is subject to different thermal history, that may help compromise its quality and safety.

Sevie Kenyon: Explain what thermal history means.

Sundaram Gunasekaran: Let’s say you have milk in your refrigerator, you take it out and leave it on the counter and stick it back in the refrigerator, but when you took it out and left it outside on the counter, you’re subjecting the milk to conditions are not supposed to be. All these temperature changes during the storage and handling can adversely effect and support microbial growth, if the time temperature exceeds certain critical conditions.

Sevie Kenyon: Can you tell us what this may look like on a food?

Sundaram Gunasekaran: You can think of this as a little stick on labels that will indicate a color. If the food has gone through an expected temperature history, storage history, then the colors will match. If the colors are different that means the food has been subject to conditions that are not safe for long-term consumption.                                                                              

Sevie Kenyon: Could you walk us through the cycle?

Sundaram Gunasekaran: There is a number of different temperatures involved, manufacturing conditions, transportation, storage, handling, display counters, so on and so forth. And also for the exacerbated, how the consumers may use it at their homes because they not follow the same conditions that the foods are supposed to be stored and handled and all these temperature histories have an affect on the safety and quality of the foods. What we want to do is to provide a tag that would continually monitor the overall thermal history.

Sevie Kenyon: Can you describe how this works?

Sundaram Gunasekaran: We use gold nanoparticles, of all things, and the gold nanoparticles change its color so that tags we’re talking about are what we call nano reactors and with time and temperature the particles size and shape change and with that the color of these tags continue to change, so the color of the nanoparticles system is then comparable to the time and temperature history of the foods.

Sevie Kenyon: Sundaram, when might this appear in stores?

Sundaram Gunasekaran: I’m thinking maybe three to five years.

Sevie Kenyon: We’ve been visiting today with Sundaram Gunasekaran University of Wisconsin Madison in the College of Agricultural and Life Sciences, and I’m Sevie Kenyon.