Abstract
The antimicrobial activity of 25 essential oils and plant extracts against Salmonella Typhimurium and Penicillium roqueforti was tested by disc diffusion and quantified by agar dilution. Afterwards, the effect of the most promising essential oils was studied in an extruded pet food product over 21 days, with the oil mixed either into the product or as part of its coating. In vitro, the best inhibitors for Salmonella were cinnamon essential oil (EO) at 0.05% and thyme EO at 0.1%, while P. roqueforti was best inhibited by cinnamon EO at 0.01% and spearmint EO at 0.5%. When tested in the extruded product, cinnamon EO (0.05% and 0.1%) and spearmint EO (0.5%) proved ineffective against P. roqueforti, either mixed into the product or as part of its coating. Only cinnamon EO (0.1%) as part of the coating was able to reduce Salmonella significantly faster than the control (p-value=0.0408) during storage for 21 days. Based on the results, spice essential oils can act as inhibitors of Salmonella in a pet food product, when present at a sufficient concentration.
Highlights
The Centers for Disease Control and Prevention (CDC) has reported more than 19,000 laboratory-confirmed cases of foodborne infection for 2012, with Salmonella as the cause of more than 40% of the cases (Centers for Disease Control and Prevention (CDC), 2013) [1]
This study aimed to evaluate the effect of essential oils and plant extracts in controlling microbial contamination in extruded pet food products, by testing them in vitro against organisms of interest, determining their Minimum Inhibitory Concentration (MIC) and incorporating them into pet food products for challenge studies
Different plant essential oils had in vitro inhibitory activity against Salmonella Typhimurium and Penicillium roqueforti
Summary
The Centers for Disease Control and Prevention (CDC) has reported more than 19,000 laboratory-confirmed cases of foodborne infection for 2012, with Salmonella as the cause of more than 40% of the cases (Centers for Disease Control and Prevention (CDC), 2013) [1]. The CDC has associated the human infections with handling of the contaminated product [2]. Another problem faced by the pet food industry relates to economic losses due to mold spoilage. The actual economic value of this problem is difficult to quantify because the industry does not report numbers on the issue. This is certainly of interest to the pet food industry, especially with the new generation of products that have soft and hard pieces in the same bag. The higher moisture content of the product increases palatability, but makes it necessary to add humectants or organic acids to control water activity [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
