Abstract:
Jalapeño peppers are usually consumed raw and fresh with minimal processing. They
contain antioxidants and bioactive compounds which are of human health benefits.
There have been an increasing number of reports of foodborne outbreaks attributed to
inaccessibility of sanitizers to Salmonella , E.coli and Listeria monocytogenes when
embedded in fruit and vegetable surfaces. Furthermore, increasing sanitizer strength to
compensate has been reported to impair the food quality attributes of the pepper fruit.
The objectives of the first part of this project were 1) to investigate the efficacy of
combining electrolyzed oxidizing(EO) water and ultraviolet (UV) light on the
microbiological quality (both the surface and internalized) of fresh Jalapeño peppers,
and 2) to examine the effect this combination on the shelf life and appearance of the
treated Jalapeno pepper. The effects of varying contact times (10, 20 and 30 minutes) all
through 10 days of storage study were documented. Serratia marcesens was used as the
marker organism and as a surrogate for Salmonella . S. marcesens and yeasts showed a
significant reduction (p=0.0044 and 0.0134 respectively) among all the treatments and
control while the aerobic plate count (APC) and coliforms counts showed no significant
response to treatments (p = 0.2568 and 0.3996 respectively). In addition, there was no
significant difference in responses of the pepper to various contact times with EO water
and storage times, though evident effects which varied among treatments were
observed. Compared to control, all EO and UV treatments reduced contamination and
had no negative impact on the color, texture and the final mass of pepper. Overall,
peppers treated with and UV and EO water for 30 minutes gave the best microbial
inhibition.
The second part of the project focused on investigating the effect of gas exchange of
Jalapeño pepper with nitrogen, oxygen and air on the uptake of EO water. The efficacy
of EO water uptake in reducing surface and internalized S. marcesens and other native
microflora was documented. In addition the post treatment effect of these treatment on
the color, mass and texture of peppers was studied during 10 days of storage. Uptake of
treatment solution was highest in oxygen exchanged peppers. Oxygen exchanged
peppers gave the highest reduction in microbial count, yet maintaining their firmness
and color.
Overall, the results of this project suggest that EO water and UV reduced microbial
contamination as well as preserved the quality of Jalapeño peppers. Also, gas
exchanged enhanced uptake of treatment solution and significant reduction of both
internalized and surface microbial contaminants without imparting the freshness of the
pepper. The findings from this project provide important groundwork for exploring the
potentials of combining UV light's antimicrobial effect with EO water for sanitization
purposes. Moreover, enhancement of the uptake of treatment solution into fruits by gas
exchange can be applied to reduce microorganisms lodged within the tissues of fruits
and vegetable without risk of altering its physical attributes.
