Application of probiotics to improve the microbial safety of tomatoes.

Commodities

• Vegetables: tomatoes

Practices

• Crop Production: food product quality/safety

In the last two decades, tomatoes have been implicated in over
170 foodborne outbreaks in the US. Among the different foodborne
pathogens, Salmonella enterica has been associated with
over 37% of tomato-related outbreaks. Fresh tomatoes can get
contaminated from via multiple routes including irrigation water,
soil, and manure. In addition, since fresh tomatoes are consumed
raw, they pose an increased risk for food safety and public
health. Thus, improving the microbial safety of tomatoes
continues to be a pressing need for the produce industry.
However, while chemical methods do not appeal to consumer
preference for natural foods, physical methods tend to be
expensive and cannot provide the sustainable antimicrobial
effect. Hence, it is critical to develop effective, safe,
consumer and environmentally friendly antimicrobial strategies to
control foodborne pathogens in tomatoes. Toward this, probiotics
including lactic acid bacteria can be ideal candidates for
application in produce safety.  Probiotics exert their
antimicrobial ability by producing lactic acid, antimicrobial
peptides, and via bacterial antagonism. Further, they occupy the
same niche as pathogens and hence can provide a sustained
antimicrobial effect against pathogens including
Salmonella. Thus, this study will investigate the
efficacy of probiotic spray application in controlling S.
enterica contamination on tomatoes. Overall, the successful
completion of the study is anticipated to develop an effective,
natural, user and environmentally friendly antimicrobial strategy
to improve the microbial safety of tomatoes.

The overall objective of this proposed study is to improve food
safety and public health while also benefiting the produce
industry. Specifically, this study aims to develop an effective,
environmentally friendly, natural and sustainable antimicrobial
intervention to reduce foodborne pathogen contamination of
tomatoes. The hypothesis of this research is that spray
application of probiotics can reduce S. enterica
contamination in tomatoes following harvest and during subsequent
storage thereby improving the microbial safety of tomatoes.

The specific objectives for this study are:

To determine the efficacy of probiotics to reduce S.
enterica on tomatoes

1. when applied as a post-harvest spray, and
2. during refrigerated storage